Moenkhausia cosmops - Aqualog

Aqualognews NUMBER 96 2 

T 

he genus Moenkhausia contains 

characins that have traditionally been 

among the most popular of aquarium 

fishes. There can be hardly a pet shop in 

the world that doesn’t stock at the very 

least the Red-Eye Tetra (M. sanctaefilomenae) 

as a representative of its genus. 

A first import! 

Aquarium Glaser have now imported small 

numbers of a very unusual tetra, 

Moenkhausia cosmops, from Brazil for the 

first time.This species was first scientifically 

described in 2007. To date it is known only 

from the upper reaches of the Rio 

Paraguay and Rio Tapajos basins in the 

state of Mato Grosso: Rio Juba, Rio Juruena, 

Rio Papagaio,and their tributaries. 

The closest relations of the new species 

Its nearest relatives are thought to be the 

Glass Tetra, Moenkhausia oligolepis,and the 

Red-Eye Tetra, M. sanctaefilomenae, both 

TETRAS 

A new star in the characin sky - 

Moenkhausia cosmops 

by Wolfgang Löll 

Characins are an immensely varied 

group of fishes. They include the 

tiny,prettily-colored fellows such as 

the neon tetras, much-dreaded 

predators such as the piranhas,and 

every imaginable form in between. 

The “moustache”of the species is very striking. 

Moenkhausia cosmops All Photos: Frank Schäfer 

well-known in the aquarium hobby. The 

other similar species - M. cotinho, M. 

diktyota, M. forestii,and M. pyrophthalma – 

have to date been unimportant in the 

hobby. All these species share the 

common features of a red iris and a caudalpeduncle 

spot. M. cosmops can be 

distinguished at first glance from the 

species named above by virtue of its bluegreen 

eyes and the red stripe above the 

mouth. 

No other species looks the same 

The unique coloration of this species is 

slightly reminiscent on the one hand of 

the gorgeous emperor tetras 

(Nematobrycon), and on the other of the 

Lipstick Barb (Barbus erythromycter) from 

Asia. But there is no phylogenetic 

relationship with the species named. 

Uncomplicated maintenance 

A readily recognizable characteristic:the blue eyes. 

The maximum length of Moenkhausia 

cosmops is around 6 cm. These fishes are 

somewhat timid initially.To date they have 

proved fairly hardy and peaceful. Like the 

majority of tetras they are 

unproblematical when it comes to 

feeding. Investigation of stomach contents 

in the wild revealed insects (mainly ants),

Aqualognews NUMBER 96 3

Aqualognews NUMBER 96 

Glossary for the article on Moenkhausia cosmops 

4 

plus plant remains and algae. The water 

temperature should be between 24 and 26 

°C; soft, slightly acid water will 

approximate to the conditions in the wild; 

the biotope is described as a whitewater 

The founder of the firm, Norbert Zajac, 

welcomed around 500 guests to participate 

in the festivities. 

35 years of Zoo Zajac – 

from 65 m2 to 10,065 m2 sales area 

On 3.12.2010 Zoo Zajac celebrated 35 

years of the company’s existence. 

Founded by Norbert Zajac as a two-man 

concern with a sales area of 65 m2, in the 

course of 35 years the business has 

expanded to 10,065 m2 of sales area, as 

well as import/export and organization 

of exhibitions. Zoo Zajac has been so 

successful that it now employs around 

200 staff, and there is no end to its 

success story in sight. 

Moenkhausia: name in honor of W. J. Moenkhaus, a friend of Eigenmann. 

oligolepis: ancient Greek meaning "with few scales". sanctaefilomenae: 

after the type locality of the species (a lagoon near Sa. Filomena on the 

Parnahyba). cosmops: ancient Greek meaning "with a decorated face". 

cotinho: name in honor of the collector, Major Cotinho, Brazilian attaché 

to the Thayer Expedition. diktyota: ancient Greek meaning "with a 

reticulated pattern "; forestii: name in honor of Fausto Foresti, a 

geneticist. pyrophthalma: ancient Greek, meaning "with fiery eyes". 

Nematobrycon: ancient Greek meaning "Brycon with threads", referring 

to the form of the caudal fin. Brycon is another tetra genus. Barbus:Latin, 

meaning "beard". erythromycter: ancient Greek meaning "with a red 

snout". 

Suggested common name for Moenkhausia cosmops: Lipstick 

Moenkhausia 

Moenkhausia cosmops,female 

Aquaristik 

Streng 

Spezialmischungen - Einzelsaaten - Zubehör 

91735 Muhr am See - Bahnhofstraße 48 

Telefon 09831 / 99 54 - Telefax 09831 / 88 835 

zoostreng@gmx.de - www.zoostreng.de 

biotope with a sandy bottom. The species 

forms shoals of more than 50 individuals 

that generally live among dead branches 

close to the bank vegetation in still-water 

zones of the rivers. 

All in all, Moenkhausia cosmops is a very 

attractive, uncomplicated species, and it is 

to be hoped it will become widespread in 

the hobby.


REPORT 

Etroplus canarensis - 

maintenance and breeding 

by Peter Langeland, Denmark 

This cichlid differs from the majority of other cichlids of similar size in 

that it is a shoaling fish. This behavior is very typical for Etroplus 

canarensis and it only rarely that an individual is seen more than about 

30 cm away from a conspecific. When I bred E. canarensis it became 

apparent that this behavior is present from the first day of free- 

swimming onward. 

T 

hese fishes are very peaceful right 

from the start; while in the majority 

of other cichlids juvenile males will seek 

squabbles with conspecifics, and occupy 

and defend small territories, such 

behavior can be completely ruled out in 

Etroplus canarensis. 

With the arrival of sexual maturity this 

changes to some degree. Minor battles 

and skirmishes are now to be seen more 

frequently. Because I keep one male and 

five females, I cannot say how two males 

would behave towards one another. Males 

grow to around 12 cm and are somewhat 

larger than females (10 cm) and more 

heavily built. 

Group of adult Etroplus canarensis. Photo:Oliver Lucanus 

A very typical feature of Etroplus 

canarensis is that it unconditionally 

requires vegetable food. Unfortunately 

that also means that it will eat the 

majority of aquarium plants. In my 

aquarium only Microsorium and 

Echinodorus are left unmolested. There 

used to be a good population of Giant 

Vallisneria, about a meter long, in my 

1000-liter aquarium around but they were 

all eaten in the space of a week. Unlike 

other cichlids, E. canarensis do not dig up 

plants, but they will eat them down to 

stumps. 

The history of my fishes 

I purchased six Etroplus canarensis in 

autumn 2006. At the time they measured 

around 5 cm long and on that basis were 

probably hatched in the spring of that 

year. The first spawning in my aquarium 

took place in January 2008. On that basis 

wild-caught fishes must be around two 

years old before they spawn. However my 

youngsters spawned for the first time at


This around 2 cm long juvenile exhibits a “Tilapia spot” in the dorsal fin. Photo: Erwin Schraml 

the age of only a year. 

Aquarium maintenance 

For rearing my wild-caught youngsters I 

used a 300-liter aquarium that forms part 

of my aquarium system of around 1200 

liters. All the water circulates through this 

system and as a result I achieve very stable 

water conditions, even in smaller tanks. 

The 300-liter tank proved to be 

adequately large as the fishes also 

spawned for the first time there, but later 

on I transferred them into the 

aforementioned 1000-liter tank. I regard 

good water quality as very important. In 

my aquarium system the filter volume 

corresponds to around 10% of the volume 

of the aquaria. The filter turnover is set to 

20 liters/min. A water change of around 

25% is undertaken weekly. I use our mains 

water which has a pH of 7 and a 

conductivity of 350 µS (corresponding to 

around 12 °dGH). Thanks to the extensive 

water changes nitrite and nitrate levels 

are always very low.The temperature is set 

at 25-26 °C. 

Feeding 

I regard this aspect as very important!


INFO-BOX: Indian cichlids 

Cichlids (Cichlidae) live mainly in Africa and South 

America. Only three species, all members of the 

genus Etroplus, are found in India. Their closest 

relatives live in Madagascar. In addition, it has 

recently been suggested that they are closely 

related to the damselfishes (Pomacentridae). 

Etroplus maculatus grows to 6 - 10 cm long and is a 

popular aquarium fish,while the up to 40 cm long E. 

suratensis is more for specialists. 

Here is the menu: 

- live glassworms; daily and year-round 

except in May; 

- frozen bloodworms; twice per week; 

- frozen (in summer live as well) Mysis; 

twice per week; 

- live earthworms around 20 mm long; 

twice per week; 

- deep-frozen peas (defrosted for 2 

minutes in the microwave before 

feeding); three times per week; 

- live mosquito larvae (in April); twice per 

week. 

My young fishes are fed at least twice 

daily. In my opinion the key to successful 

breeding and rearing of this fish lies in the 

very varied diet. Anyone who feeds just 

cichlid pellets won’t stand a chance. 

Unfortunately this diet is not only 

relatively expensive but it also requires 

regular – summer and winter – visits to 

ponds, no matter what the weather. The 

peas must, by the way, be chopped into 

mouth-sized pieces before feeding. I do 

this with a kitchen knife. 

Breeding 

When it comes to reproductive behavior, 

Etroplus canarensis is similar to other 

open-brooding cichlids, for example 

Cleithracara maronii. But there are also a 

The blue marks on the head and pectoral-fin base are striking. Photo: Frank Schäfer 

number of important differences: 

- the fishes are not monogamous; the 

male spawns with several females, as is 

also known from the checkerboard 

cichlids (Dicrossus). 

- the eggs have little “stalks”. When the 

parents fan fresh water across the rock, etc 

to which the spawn is attached, the eggs 

can be clearly seen to move. 

- the growth of the young is strikingly 

uniform.While variable growth rates often 

lead to problems during the rearing of 

other cichlid youngsters (stronger 

juveniles out-compete weaker siblings), 

such difficulties do not occur in Etroplus 

canarensis. 

Spawning, which typically follows a water 

change, is presaged by a striking change 

of color in both sexes. The vertical stripes 

are replaced by a dark horizontal zone. In 

addition vertical stripes appear on the 

forehead. This change of color is very 

significant. Immediately before spawning 

the fishes frequently indulge in quivering 

of the body, as is also known from discus 

(Symphysodon), for example. Like so many 

wild-caught fishes, E. canarensis spawn 

only during the rainy season, ie January, 

February, and March. 

When a pair have decided to spawn and 

found a suitable spawning site (a 

sheltered spot with a rock), the spawning 

territory is defended after spawning, 

although the parents aren’t particularly 

aggressive in this respect. Brood care is 

similar to that of other open-brooding 

cichlids, that is the free-swimming brood


The young of Etroplus canarensis grow on very uniformly. 

are placed in small pits dug in the bottom. 

Unfortunately a repeated problem has 

occurred with my fishes at this stage: the 

parents start to eat the free-swimming fry. 

Unfortunately I have been unable to stop 

this and I don’t know what is going wrong. 

Hence I can’t say whether Etroplus 

canarensis, like other Etroplus species, feed 

their fry with skin mucus. 

However, E. canarensis can easily be reared 

artificially and I have done so as well. 

Rearing is easy: initially the fry receive 

Artemia nauplii for a few days, then live 

Cyclops. As they increase in size they can 

be given increasingly larger foods. From a 

length of 10 mm I give the youngsters 

chopped peas as well. 

One brood that I reared in this way 

numbered 108 individuals. I didn’t suffer a 

single loss during the rearing process – 

very unusual! 

All in all Etroplus canarensis is easy to 

maintain in the aquarium. The only thing 

is to bring them into breeding mood. In 

my opinion optimal water maintenance 

and a very varied diet are the key to 

success. 

TIERÄRZTE IN IHRER NÄHE 

Jan Wolter 

Praktischer Tierarzt, 

Zierfischpraxis 

Tegeler Weg 24 

D-10589 Berlin 

Tel. 030 34502210 

K. Alexandra Dörnath prakt. 

Tierärztin 

MSc Wild Animal Health, MRCVS 

Tierarztpraxis Klein Mexiko 

Bennigsenstraße 1b 

D-28205 Bremen 

Tel. 0421 4915000 

www.exotenpraxis-bremen.de 

Not least the 2.2 million aquaria in 

German households have induced the 

TMS to organize the traditional congress 

in Friedrichshafen for the third year in 

succession. The AQUA-FISCH will be 

celebrating 20 years in existence in 2011. 

The event will be celebrated with 

numerous highlights and guests and by 

thousands of visitors from the three 

countries of Germany, Austria, and 

Switzerland. 

Save money at www.aqua-fischmesse.de! 

Reduced-cost entry with the money-off 

coupon applies to the whole weekend. 

More than just the aquarium hobby, for 

large and small 

I wish everyone who cares to have a go 

the best of luck! 

Tierärztliche Praxis für Kleintiere 

Scharnhorst GmbH 

Leitender Tierarzt: 

Volker Borchers 

Bücherstr. 1 

44328 Dortmund 

Tel. 0231 239051 

Fax 0231 239052 

I www.petdoc.de 

E info@petdoc.de 

Praxis für Kleintiere und Exoten 

Dr. med.vet.Jürgen Seybold 

Kleintierzentrum Mitteltal 

Max-Eyth-Str. 36 

72270 Baiersbronn-Mitteltal 

Tel. 0 74 49 - 91 32 45 

Fax 0 74 49 - 91 32 51 

praxis@kleintierzentrum-mitteltal.de


The goodeids – 

undervalued beauties from 

the land of the Aztecs 

by Günther Schleussner 

LIVEBEARERS 

The Mexican goodeids (Goodeidae) have been well-known in the aquarium 

hobby for several decades. During the period between 1980 and 1995 in 

particular,many species reached Europe and the USA via traveling aquarists. 

But unfortunately they have never become properly established and 

achieved a wider distribution in the aquarium hobby. A real shame..... 

O 

ne of the darkest chapters in the 

history of the discovery of the New 

World was the brutal destruction of the 

culture of the Aztecs by the Spanish 

conquistadores under the leadership of 

Hernando Cortez in the early 16th 

century. The members of a small fish 

family belonging to the toothcarp order, 

the goodeids (Goodeidae), were dumb 

witnesses to this blood tragedy in the 

highlands of what is now Mexico. In the 

course of their at least nine million years 

of evolutionary history they have always 

managed successfully to overcome the 

hostile living conditions in their native 

habitat. But now, at the beginning of the 

21st century, it appears that they have 

suddenly and irrevocably lost their battle 

for survival. 

The true livebearers 

The goodeids, known in Mexico as 

Characodon audax `Guadalupe Aguilera'. Photo: Susanne Schleussner


pintitos or mexcalpiques, are highly 

interesting fishes biologically speaking. 

With somewhat more than 40 species, 

the family is fairly insignificant in 

numerical terms, but its members are 

found in all possible ecotypes, from 

goby-like bottom-dwellers through 

laterally compressed, high-bodied forms 

adapted for life in vegetated standing 

waters, to elongate rheophiles. 

Some species are Aufwuchs-feeders 

living primarily on algae, the majority are 

omnivores, and a very few are predatory. 

They all share a unique reproductive 

strategy. Goodeids bring well-developed 

living young into the world. The anal fin 

of the male is modified into an 

inseminatory organ (andropodium) that 

permits internal fertilization. Unlike the 

poeciliids, ie Guppy, Platy & Co., the 

embryos developing in the ovary of the 

female are nourished via a so-called 

trophotaenia (= feeding cord), which is 

discarded shortly after birth. The 

Zoogoneticus tequila Photo: Frank Krönke 

goodeids thus practice a “higher” form of 

livebearing than all other bony fishes. 

Adios pintitos? 

As already hinted in the introduction to 

this article, they have another sad feature 

in common: almost all goodeids are 

threatened with extinction in the wild! 

Climatic changes, the constantly 

increasing demand for water for 

agriculture and industry, the discharge of 

insufficiently treated (if at all) waste


water into streams, rivers, and lakes, the 

increasing annexation of the few still 

intact waters for spare-time activities, 

and the uncontrolled introduction of 

alien (allochthonous) fish species are just 

some of the reasons why practically the 

entire family with its unique biological 

adaptations stands on the threshhold of 

extinction. For this reason in May 1998 

the `Fish Ark Mexico´ project was 

brought into being at the University of 

Michoacán in Morelia on the initiative of 

the Englishman Ivan Dibble, 

unfortunately recently deceased. The 

objective is to build up and retain stable 

aquarium populations of as many 

goodeid species as possible. In spring 

2009 the first open-air pond was created 

goodeids are generally marked down as 

drab-colored, wicked rough-housers, and 

notorious fin-nippers. For this reputation 

they have to “thank” the species that at 

least now and then finds its way into 

dealers’ tanks, the Red-Tailed Goodeid, 

Xenotoca eiseni. 

Xenotoca eiseni `San Marcos' Photo: Susanne Schleussner 

in order to in future be able to maintain 

and breed these fishes under the most 

natural conditions possible. There are 

also plans to establish conservation 

zones in the natural distribution regions. 

The `Fish Ark´ project is largely financed 

by donations from zoos and public 

aquaria, but also by enthusiast 

organizations from all over the world. 

Goodeids – no thanks! 

When the conversation among aquarists 

turns to goodeids, the majority 

immediately give a thumbs down. Even 

among dedicated livebearer fans the 

Skiffia francesae Photo: Susanne Schleussner 

It is true that mixing goodeids with other 

types of fishes requires careful 

consideration, a “feel” for the aquarium 

hobby, and regular observation. But 

Angelfishes may eat Cardinal Tetras if you 

aren’t careful, yet nobody ever decided 

on that basis that they were generally 

unsuitable for community tanks! 

Fresh air outside in summer 

The equally frequently bemoaned lack of 

color in the goodeids is attributable to 

serious errors in maintenance. These 

fishes impose no special demands as 

regards water chemistry: moderately


hard, neutral to slightly alkaline water, 

such as comes out of the tap in many 

places, is quite OK. But they are greedy 

feeders that need significantly more food 

for healthy development than do fishes 

of similar size from other families. And 

then, of course, there is the most 

important point: goodeids are not 

tropical fishes that can be kept yearround 

at the same high temperature! 

Their habitats lie in subtropical zones at 

an altitude of up to 2000 meters above 

sea level and are characterized by 

marked daily and seasonal temperature 

fluctuations as well as intense UV 

radiation. They thus unequivocally 

Outdoor facility of the Fish Ark project at the University of Michoacán in Morelia. 

Photo: Gunter Teichmann 

belong in an unheated tank sited in a 

room that isn’t heated too strongly. In the 

warm part of the year, say from around 

the beginning of May to the end of 

Girardinichthys viviparus 

Moribund residual water at Los Pinos on the upper Rio Canatlán, until a few years ago the habitat of a 

Characodon population Photo: Gunter Teichmann 

September, the method of choice is 

outdoor maintenance in planted 

containers or even the garden pond. 

After a four to five month stay in the 

open air, even during an average central 

European summer, the fishes will of their 

own accord exhibit a brilliance and 

intensity of color such as can never be 

Ameca splendens Photos: Susanne Schleussner 

achieved in the aquarium. The photos of 

various goodeid males accompanying 

this article are proof that under such 

conditions these purportedly drab fishes 

Aquarium facility in the Fish Ark. 

Photo: Gunter Teichmann 

can hold their own with the most colorful 

species in the standard aquarium-hobby 

repertoire. 

Birnbaumskamp 4b 

31139 Hildesheim 

Tel (05121) 47671 Fax 45750 

www.michalski-aquaristik.de 

At irregular intervals Aquarium Glaser is 

able to offer small quantities of various 

species of goodeids captive-bred by the 

few people keeping and breeding them 

in Germany – a rare opportunity to leave 

the well-trodden paths of the aquarium 

hobby and get to know this fascinating, 

often undervalued group of livebearers 

more closely.


B 

esides not looking like a typical 

aquarium characin, this species is also 

unusual – along with the other 15 members of 

its family,the Erythrinidae,known widely as the 

trahiras – in lacking the characteristic adipose 

fin borne by the vast majority of its cousins. 

But,to me,perhaps the most striking feature is 

not morphological. Rather, it’s the extreme 

slipperiness of these medium-sized predators. 

I remember vividly collecting a close relative of 

E.erythrinus – the aimara or jejú (Hoplerythrinus 

unitaeniatus) – in a backwater or the Rio Negro, 

and not being able to hold on to it for any 

length of time. This was not only because of 

the impressive power packed into the muscles 

of the creature, but because of the extremely 

slippery nature of its thick covering of body 

mucus. Indeed, I immediately nicknamed the 

specimen,the ‘soap fish’! 

CRITTERS 

Erythrinus erythrinus - 

the Red Wolf Fish 

by John Dawes 

It looks nothing like a cardinal tetra or any of its numerous colourful, 

small, shoaling relatives, but Erythrinus erythrinus is, nonetheless, a 

characiform, i.e. member of the order characiformes, just like them. 

This small family of trahiras is divided,at least,at 

the moment, into just three genera: Erythrinus 

(two species), Hoplerythrinus (three species) 

and Hoplias (11 species). Of these, perhaps the 

Erythrinus sp. “Peru” is very attractively colored. Photos: Frank Schäfer


best-known within the aquarium hobby is 

Hoplias malabaricus,the tiger characin, trahira 

or tigerfish, despite the fact that E. erythrinus 

has been around since 1910. 

A little confusingly, E. erythrinus is, like 

Hoplerythrinus,often referred in Portuguese as 

jejú, an indication of their biological proximity. 

However, within the aquarium hobby, 

Erythrinus is generally known as the red or 

rainbow wolf fish…and with good reason. 

Like its canine counterpart, E. erythrinus has a 

large mouth and the fearsome dentition 

typical of a predator that feeds on other 

animals. In the wild, the diet consists largely of 

insects, crustaceans and other fish, which it 

hunts in the tributaries, swamps, backwaters, 

pools, forest lakes and other, generally slowflowing 

habitats of its native waters in Central 

and South America (Amazon and Orinoco 

River basins and coastal regions of the 

Guianas). The red wolf fish is often found (as 

was the case with the H.unitaeniatus I referred 

to above) in very shallow water,either lying on 

the bottom or hiding among surface 

vegetation, from where it can launch 

lightning-fast attacks on unsuspecting prey. 

The maximum length for the species given by 

FishBase is 20cm SL (i.e. Standard Length, 

which extends from the snout to the base of 

the tail…not the tip). Most specimens 

imported are, however, smaller than this and 

are, presumably, juveniles or recently-matured 

adults. 

The sexes can be easily told apart, since males 

have considerably larger pelvic (ventral) fins 

than females. They also tend to have a larger 

dorsal fin, but this may vary, making this 

feature a more unreliable one. 

As the common names imply, the red or 

rainbow wolf fish can be quite colourful. In 

Erythrinus sp.‘Peru’, the dorsal and caudal fins 

bear quite a bit of orange-red coloration. The 

body may also carry bold similarly-coloured 

splashes arranged in two roughly parallel 

bands running lengthwise above and below 

(and overlapping) the characteristic dark 

brownish band that extends from behind the 

eye to the caudal peduncle. 

This fish is currently thought to be Erythrinus erythrinus. Photo: Migge /Aqualog-Archiv 

It is this colourful appearance that has made 

this fish so attractive to aquarists who can 

provide for its needs.Now,such aquarists have 

a new wolf fish to consider. Little is known 

about this newcomer, which carries a broad 

orange stripe covering the whole of the 

posterior part of the belly. Some of this 

coloration extends into the pelvics and the 

anal fin, as well as the posterior base of the 

pectorals. However, there are none of the 

‘roughly parallel splashes’ mentioned above. 

Neither does it bear the bright caudal and 

dorsal fin edges characteristic of E.sp.’Peru’. 

It is possible (but not certain) that the new wolf 

fish is the adult form of the previously 

imported, but unspectacular, Erythrinus sp. 

‘Madre de Diós’ (Madre de Diós is a region of 

south eastern Peru bordering Brazil and 

Bolivia).It is also possible,of course,that we are 

dealing with a new species of wolf fish.Could it 

be that the new wolf fish is the real E.erythrinus, 

with the one we’ve traditionally regarded as 

such,being another species? After all,we know 

that wolf fish are widely distributed (see 

above) and, as often happens with such 

species, there are gaps in our knowledge 

regarding the variation that exists in the wild. 

This lack is not helped by the fact that imports 

of Erythrinus erythrinus are almost exclusively 

from Peru,so it could be that we currently have 

an inaccurate overall picture of the species.

Aqualognews NUMBER 96 15


In fact, studies carried out by Bertollo et al in 

2004 (see reference below), demonstrated that 

there are chromosomal differences between E. 

erythrinus specimens from different localities. 

They found, for example, that females from 

some localities had 54 chromosomes and males 

53, while, in fish from other localities, females 

had 52 chromosomes and males 51.There were 

also differences in the types of chromosomes 

possessed by fish from different populations, 

leading the researchers to conclude that “this 

species may represent a species complex.” 

In terms of aquarium care, wolf fish require 

spacious accommodation, preferably 

containing at least 100 litres. There should be 

abundant floating vegetation and some 

clumps of robust submerged plants, plus a 

number of shelters and open spaces.The tank 

should have a well-fitting cover.With regard to 

water chemistry, wolf fish are quite hardy and 

can easily cope with a pH range between 5.5 

and 7.5 (the range reported from the wild is 

5.6-7.8). Water hardness can go up to 30 dH 

and the temperature between 22-26oC. The 

diet must consist of meat-based items such as 

earthworms, shrimps, etc., or one or other of 

Erythrinus sp.“Orange Belly” 

the excellent animal-based commercial 

formulations (as long as the individual 

components are not too small). 

Owing to the predatory instincts of all 

erythrinids, they should only be kept with 

robust equally-sized tankmates, including 

catfish…but not other wolf fish.This is likely to 

result in battles for dominance…usually with 

serious consequences for one party or the 

other, or both. As yet, there are no reports of 

successful aquarium spawnings…so this 

challenge is still open. 

Reference 

L.A.C. Bertollo, C. Oliveira, W.F. Molina, V.P. Margarido, 

M.S. Fontes, M.C. Pastori, J. das N. Falcão and A.S. 

Fenocchio, Chromosome evolution in the erythrinid 

fish, Erythrinus erythrinus (Teleostei: Characifomres). 

Heredity (2004) 93,228-233. 

Erythrinus sp.“Madre de Dios”


STINGRAYS 

A new freshwater ray from Peru 

Potamotrygon sp. Mozaico 

by Frank Schäfer 

Aquarium Glaser received a wonderful surprise from Peru in the first 

week of the new year: two rays such as had never been seen there 

before! The two males exhibit a unique coloration that clearly 

distinguishes them from all other freshwater stingray species known 

to date. 

T 

Potamotrygon sp.“Mozaico” All Photos: Frank Schäfer 

he two rays imported by Aquarium 

Glaser were caught in the Rio Ucayali. 

The Ucayali is a large southern tributary of 

the Amazon (known there are the Marañón) 

around 2700 km long (including parts in its 

upper course that sometimes go under 

different names); the Ucayali is thus not only 

the largest Peruvian Amazon tributary, but is 

today regarded as the most important 

headwater of the Amazon itself, comparable 

to the Marañón. The Ucayali is 

correspondingly significant and well 

explored. Over the course of the centuries it 

has borne various names - San Miguel, 

Cocama, and Rio de Cuzco are the best 

known. 

But despite the fact that numerous 

expeditions have explored the Ucayali, it is 

not only possible, but even relatively 

probable, that many species as yet unknown 

to science live in the Ucayali. Moreover the 

freshwater rays are among the fish species 

that have been exceptionally poorly studied 

by science. And they also present scientists 

with particularly difficult problems. 

Pacific origins 

The consensus is that the freshwater 

stingrays in all probability originate from the 

Pacific. At any rate their closest relatives, the 

stingrays of the family Urolophidae,live there 

today, as demonstrated by DNA studies and 

morphological comparisons. Unfortunately 

there are hardly any usable fossils as rays are 

well-known to be cartilaginous fishes, and 

thus possess no bones. The only structures 

that survive as fossils are the teeth.These are 

in fact species-specific in form, but vary


depending on age and sex, in some species 

at least. 

The course of the Amazon reversed only 10- 

15 million years ago. This happened as a 

result of the uplifting of the Andes, the chain 

of mountains along the west coast of South 

America, which originated because after the 

fragmentation of the primeval continent of 

Gondwana (consisting of South America, 

Africa, India, Australia,and Antarctica) the 

South American continental plate was 

subducted by the Pacific plate. The result of 

this uplifting was that for a long time the 

Amazon was dammed up in the central part 

of South America,creating a huge freshwater 

inland sea that was home to the ancestors of 

the Potamotrygon species that exist today. It 

is only since around five million years ago 

that the Amazon has drained into the 

Atlantic as it does today. 

Hybridization as a driving force for 

speciation 

Potamotrygon sp.“Mozaico”,the second specimen imported to date. 

Evolutionary biologists are becoming 

increasingly of the view that new species of 

animals evolve less frequently than 

previously thought through spontaneous 

random alterations in the genome (the 

technical term is mutation), and instead arise 

through the crossing of different species. It is 

true that the results of such crosses,so-called 

hybrids, are usually limited in their fertility, 

but it appears that some specimens are 

sufficiently fertile to back-cross with the 

parent species and introduce new genetic 

material into their gene pool.This method is 

also well known from animal breeding in 

captivity. A very large number of our 

cultivated forms of platies and swordtails, for 

example, came into being in this way, with 

characteristics seen in only one of the parent 

species being introduced into the other via 

hybridization and subsequent backcrossing. 

There have not been very many genetic 

studies of freshwater stingrays (as there have 

been only very few scientific studies of them 

at all),but the genetic information that we do 

have on these fishes indicates very clearly 

that natural hybridization between them 

occurs very frequently. 

When the ancestors of the current species 

found themselves trapped in the vast 

“Amazon Sea”, this undoubtedly resulted in 

an enormous amount of such hybridization. 

Difficult to tell apart 

Unfortunately the majority of freshwater 

stingray species differ only slightly from one 

another, except in their coloration. If only 

morphological characters were to be taken 

into account then the number of species 

would be fairly small. But that very obviously 

doesn’t accord with the situation in the wild, 

as the stingray species differ considerably in 

their coloration. However, here too the 

Potamotrygon species again present 

Ein 

einzigartiges 

Futter von 

Tropical 

CARNIVORE was developed to meet the 

high nutritional needs of carnivorous 

bottom-dwelling fishes such as 

Potamotrygonidae, riverine eels, 

carnivorous Loricariidae, true catfishes, 

snakeheads, and other predatory fishes. 

The “HI-PRO/HI-ENERGY/LOW-CARB” 

(high protein/high energy/low fat) formula 

developed by Tropical protects fishes 

against fatty degeneration of the internal 

organs and improves their condition. A 

high component of Omega-3 and Omega- 

6 unsaturated fatty acids, as well as 

BetaGlucan 1.3/1.6, supports the immune 

system and encourages vitality. 

CARNIVORE improves growth, increases 

willingness to spawn, and encourages 

digestion. 

problems, as their coloration is not only 

species-specific, but also varies enormously 

from individual to individual. You thus need 

to have seen a whole lot of wild-caught 

individuals in order to be able to judge fairly 

accurately the difference between species-


specific coloration and individual variation. 

Rays grow large! 

Almost all Potamotrygon species grow large, attaining a body 

diameter of 40 cm or more,and our two P.sp.“Mozaico”males are still 

“children” at 15-20 cm in diameter, as confirmed by their still very 

small copulatory organs. 

Their size results in numerous problems when it comes to research. 

The facilities are not usually available to preserve a statistically 

significant number of adult specimens in the field. As a result the 

descriptions of many species are based on just one specimen! In 

addition these are often more than 150 years old and time has left its 

mark on them. In many cases it is not only difficult, but at present 

even impossible, to determine the species correctly, as important 

specific characters are no longer recognizable in the type specimens. 

Unfortunately the size of these fishes also means that only a few 

aquarists have sufficiently spacious facilities to maintain and breed 

them and thus answer many of the open questions they pose as 

aquarists have done with numerous other fish groups that are 

difficult for scientists to study. 

In the case of rays these questions are: 

- To what extent are the sometimes clear differences in coloration 

seen in widespread species (such as P. motoro) genetically fixed such 

that they can be used for the description of new species? 

- What do juveniles look like and how does the patterning alter in the 

course of the individual’s life? 

- Which of the observed differences in dentition are species-specific, 

which depend on diet, and which are sex-specific? 

-Unfortunately the scientific study of freshwater rays cannot advance 

further in the absence of satisfactory answers to these questions.It is 

thus to be hoped that as many aquarists as possible will devote 

themselves to these splendid fishes, assuming they have the 

necessary facilities. At the same time it is important to work with 

wild-caught individuals of the same provenance,as large numbers of 

rays are being bred in South-East Asia (primarily for the Asian 

market). Such fishes may make nice pets, but are useless for 

answering the questions posed above. 

Potamotrygon motoro, “Variante”from Peru.


The Koran Angelfish - 

Pomacanthus semicirculatus Cuvier, 1831 

by Joachim Frische 

This species owes its name to the pattern on the caudal fin during the 

transition from juvenile to adult. At this time the pattern of blue lines 

resembles Arabic script from the Koran. 

T 

Half-grown specimen with the typical caudalfin 

pattern. Photos: Frank Schäfer 

his robust species, which is 

widespread and common in the 

western Indo-Pacific, has become a 

mainstay of the marine hobby and is 

regularly imported as juveniles. 

As in all Pomacanthus species from the 

Indo-Pacific, the juvenile coloration 

consists of a blue body color with white 

stripes. While the juvenile coloration of P. 

imperator is unique, young specimens of P. 

semicirculatus are easily confused with 

other species of the genus. Hence it is 

advisable to take along a suitable 

identification guide when making a 

purchase. 

At a size of around 12 cm the attractive 

MARINES 

juvenile coloration changes to a rather 

plain adult coloration. With an ultimate 

length of more than 30 cm the species 

requires a large aquarium. 

This large angelfish feeds exceptionally 

readily in the aquarium and will take any 

artificial food. It will also often regard the 

resident corals as snacks, so maintenance 

with corals should be the subject of 

careful consideration. The species is 

regarded as not very susceptible to 

disease and hence is listed in the hobby 

literature as one of the angelfishes that 

are recommended for beginners. 

The Koran Angelfish should be kept with 

robust fishes, as the peaceful 

temperament of the juvenile stage can


change to rather “assertive” behavior with 

age. On the basis of numerous underwater 

observations, the species lives solitary by 

preference. Pairs are occasionally seen. It is 

unclear whether this has led to the 

suggestion that the social behavior of this 

species involves a sort of harem where the 

male harbors several females in his 

territory,with each occupying her own subterritory 

that is defended vehemently 

against other females. 

There is no sexual dichromatism, and only 

the length of the opercular spine offers an 

indication of sex. Although this has not yet 

been specifically documented for 

Pomacanthus semicirculatus, it is known 

from other members of the genus that the 

opercular spines in males are noticeably 

longer than those of females – a character 

that can also be seen in juveniles. This 

criterion should be utilized by anyone 

who has the pick of several juveniles of 

this species at the dealer’s and wishes to 

select a pair. 

Another method of obtaining a pair is to 

Adult Pomacanthus semicircularis. 

Maintenance in pairs is possible, but the fishes 

don’t much like one another. 

maintain a juvenile and an adult together. 

Nature has given the two life stages such 

different body coloration so that juveniles 

can live without problem in the territory 

of adults. A feature that can usefully be 

exploited in the aquarium. 

It isn’t, however, possible to predict what 

will happen to the harmony between the 

two color stages when the transition to 

adult coloration begins. It has been 

speculated that sex is determined 

permanently only at the beginning of the 

change to adult coloration and that 

juveniles can in fact undergo a change of 

sex. An interesting hypothesis that it may 

be possible to validate via observations by 

aquarists. 

Info box 

According to Klausewitz a specimen of the 

Koran Angel was once seen in a fish market in 

Zanzibar, on one side of whose caudal fin the 

words “Laillaha Illatah” (there is no God but 

Allah) appeared to be visible, and on the other 

“Skani Allah” (a warning from Allah). The value 

of the fish immediately rocketed from the 

equivalent of a few cents to 5000 Rupees... and 

ever since the species has been known as the 

Koran Angelfish! 

Juvenile Koran Angelfish


I 

n this respect Nature is our template, as 

dead wood is of considerable practical 

importance for fishes in the wild. Thus 

aggregations of wood are often actively 

introduced into rivers as part of the 

process of restoring these waters to their 

natural state. These areas of dead wood 

act rather like an artificial reef on an area 

of open sand in the sea and are 

extensively frequented by fishes. The 

twigs and branches form a retreat for 

numerous species, and above all 

protection from predators such as birds 

and piscivorous fishes. This demonstrably 

leads to more rapid re-colonization of 

formerly barren rivers as well as an 

increased number of species. 

What wood is suitable? 

The only suitable wood for the aquarium 

is that which is well-weathered, as well as 

being very hard and/or preserved 

through years of immersion in water or 

lying buried in acid bogs. But the 

provenance and type of wood also play a 

role in its suitability for the aquarium, and 

it is essential not to experiment when 

creating a habitat for fishes and 

invertebrates. Depending on the type 

and condition of wood collected in the 

wild, there may be problems with 

undesirable and oxygen-consuming 

DECORATION 

Dead wood brings life into the aquarium! 

by Henrik Weitkamp 

The addition of wood adds a very special charm to an aquarium. But in 

addition to its purely decorative aspect, wood also supplies numerous 

fishes with a dietary supplement, creates natural hiding-places, 

provides a large surface area for water-purifying micro-organisms to 

colonize, and sometimes releases the humic substances valuable to 

many freshwater fish species into the water. Moreover it gives structure 

to the habitat, offers retreats for subordinate individuals, creates 

territorial boundaries, and provides spawning sites. In short, it makes an 

important contribution to the stabilization of the entire biological 

system in the aquarium. 

processes of decay. Even if these 

processes are detected at an early stage, 

it is annoying if the recently created 

aquarium landscape has to be disturbed 

by the removal of pieces of wood or the 

entire aquarium has to be set up again 

from scratch. 

Preparation of the wood 

For this reason it is best to resort to safe, 

problem-free wood suitable for the 

aquarium hobby and available in the 

trade. Prior to use it should be scrubbed 

and soaked in warm water in order to 

remove any dirt accumulated during 

Mopani, a very durable, bicolored wood 

Aquarium decorated with mangrove roots. Photo: Frank Schäfer 

transportation and storage. But the use of 

boiling water should be avoided, as in the 

case of softer woods this may lead to the 

disintegration of the outer layers when it 

is first placed in the aquarium and can 

also encourage fungal attack. One reason 

for soaking wood is so that it becomes 

waterlogged and doesn’t float in the 

aquarium. In the case of very heavy 

woods such as savanna or mopani wood 

it is sufficient to soak in a bucket for a day, 

while so-called mangrove roots, for 

example, require a week or longer before 

they will sink. But the process can be cut 

short after around a week if the decor


combines wood and rocks in the 

aquarium and the latter are used to 

weigh down the wood. 

Why soak? 

Another reason for soaking is to reduce 

the leaching of natural pigments into the 

water, as the tannins they contain can 

lower the pH. On the other hand, the 

leaching of these substances is precisely 

the reason why wood is so valuable for 

many softwater fishes, as the humic 

substances it contains represent an 

element in their natural environment. 

When the wood is removed from soaking 

the various sorts can be graded by virtue 

of the degree of staining. While mangrove 

roots are one of the types that color the 

water, savanna wood not only sinks 

immediately but stains the water very 

little and doesn’t acidify it at all. On the 

other hand, the latter is no use as a food 

supplement – a welcome side-benefit of 

many other types of wood. The L-number 

catfishes, for example, include numerous 

wood-eaters, and they should be provided 

with softer wood such as mangrove or jati. 

Wood as a decor item 

All wood has the common feature of 

being a natural decor element. Thus, for 

example, you can create a particularly 

attractive effect by allowing slender roots 

to descent into the aquarium from above 

instead of siting them on the bottom. This 

can create a natural effect simulating 

bank vegetation characterized by tree 

roots, such as forms the habitat of Angels 

and Discus in Amazonia, for example. The 

addition of epiphytic plants such as Java 

Fern or Anubias is also attractive, plus 

these plant species don’t require much 

light and are regarded as easy to grow. 

Small specimens can be attached using 

transparent nylon thread, larger ones with 

thin black cable ties. After the plants have 

rooted it is very quick and easy to remove 

the latter using forceps, but note that 

cable ties need to be applied carefully to 

avoid squashing the roots of the plants. 

Reddish mangrove wood – a classic. 

The same applies to wood as to the 

number of plants in the aquarium: less is 

often more. Using just one type will create 

a particularly harmonious and natural 

scene. 

(to be continued)


In search of new 

aquarium plants (3) 

T 

he search for new plants for the 

aquarium often leads us to remote 

corners of the world. Getting to know a 

country and its people are among the 

side benefits of such expeditions. 

Near to the coast, in shallow gravelly 

stretches of the river, we again found 

flowering Cryptocoryne albida, plus 

Cryptocoryne crispatula and a largeleaved 

variant of Hygrophila polysperma. 

Plants are survival specialists! 

Thousands of Cryptocoryne albida were 

growing in a small river a little further 

south, both in the water and among the 

rocks of small islands. And once again we 

learnt something unexpected about our 

aquarium plants. On the bank of a small, 

PLANTS 

by Claus Christensen – www.AquaDiscover.com - Denmark 

In the first part of this series (AQUALOG News 94, like all issues of the News 

downloadable free of charge as a PDF file at www.aqualog.de) we described 

the habitat of Cyperus helferi, and additional biotopes in the second part 

(TERRALOG News 95). And now the journey draws to a close. 

The author collecting Cryptocoryne albida. Photo:Claus Christensen 

shallow lake near to the river we found 

Cryptocoryne albida growing in the 

blazing hot sun. The water in which the 

plants were rooted was so hot that I 

couldn’t stand in it in order to take 

photos. I measured the temperature of 

the water and the indicator went off the 

top of the scale – which was 50 °C! 

A short rest 

We stopped again further south, in a 

small dusty village. There was a so-called 

restaurant in a garage, as well as a shop – 

both businesses were run by the wife of 

the local rubber dealer. The rubber lay


Cryptocoryne albida 

Cryptocoryne albida occurs in two color 

variants: light green and red brown with 

dark speckling on its leaves. It requires 

somewhat more light than other 

Cryptocoryne species and a very long 

acclimatization phase before it begins to 

grow. Thereafter it is unproblematical, 

however, although it requires a nutrientrich 

substrate for growth. 

Known as Cryptocoryne costata for many 

years. 

Family Araceae 

Origin Thailand 

Height 10–30 cm 

Breadth 12–20 cm 

Lighting moderate – very high 

Temperature 20–28 °C 

Water hardness soft – hard 

pH value 5.5–8 

Growth rate slow 

Degree of difficulty difficult 

round about in large bales resembling 

heaps of bath mats. The local cuisine in 

this remote village was a wonderful 

experience. Tom gar kai is a chicken soup 

with coconut milk, coriander, lemon grass, 

small chillies, and lots of additional 

ingredients that I can no longer 

remember. Thai cuisine involves the rare 

and difficult art of combining a large 

number of herbs and spices without 

losing the individual flavors of the 

ingredients. Every flavor plays its own 

role, like the instruments of an orchestra. 

Coconut milk, for example, makes a rather 

sharp soup very tasty and acceptable to 

western palates. 

Further south we found Cryptocoryne 

cordata (Blasii variant) and large-leaved 

Barclaya longifolia. 

Relaxing while diving 

Surfing tip: 

In TERRALOG News 93 Claus Christensen described a 

new foreground plant with a multitude of uses: 

Staurogyne repens. 

Surf your way to www.aqualog.de and read all about 

it! All issues of the AQUALOG/TERRALOG News are 

available there free of charge as PDF files. 

We ended our trip in great style with a 

short diving holiday aboard the vessel 

Similan II.We sailed for six hours from Ban 

Lam Ru to the Similan Archipelago, one of 

the 10 finest 

diving areas in 

the world, which 

lies away from the 

mainland in the 

Andaman Sea 

b e t w e e n 

Thailand, Burma, 

and India. The water there is crystal clear. 

Corals that grow to only 50 cm high near 

the coast achieve a height of several 

meters there. The fauna is spectacular, 

ranging from the fascinating life of the 

coral reef to large fishes and whales 

disporting themselves in the open sea.


DISCUS 

The fabulous Nhamunda Discus 

by Harald Jahn 

The Rio Nhamunda is a comparatively small river – at least in 

Amazonian terms. Nevertheless it is around 300 km long and forms the 

boundary between the Brazilian federal states of Amazonas and Pará in 

north-western Brazil for that entire distance. 

L 

egend has it that in 1541 Orellana,one 

of Pizarro’s generals who is regarded 

as the (European) discoverer of the Amazon, 

encountered the Amazons, legendary 

female warriors, at Nhamunda, and hence 

the Amazon bears their name today. 

Nowadays, of course, we aquarists have little 

interest in the dazzling history of the bloodstained 

conquistador general, who 

disappeared without trace in 1545 during 

the attempt to conquer what is now Manaus. 

We are interested in the fishes of the Rio 

Nhamunda, which continue to go about 

their business with no regard for the fate of 

humans, just as they did back then. And this 

applies first and foremost to Discus! 

Discus species in the Rio Nhamunda 

The Rio Nhamunda is a left-bank Amazon 

tributary,where Brown/ Blue Discus are to be 

expected, while Green Discus are found in 

right-bank Amazon tributaries.There are also 

Heckel Discus in the Rio Nhamunda. The 

correct scientific names for Discus remain a 

matter for much debate; the three described 

species are nevertheless readily 

distinguishable and undoubtedly valid. On 

this basis the Brown/ Blue Discus is called 

Symphysodon haraldi, the Green S. 

aequifasciatus,and the Heckel S. discus. 

What is special about Nhamunda Discus? 

The Brown/ Blue Discus of the Rio 

Nhamunda first rose to fame because 

specimens with a high component of red in 

their body coloration are particularly 

frequent there. These fishes have been (and 

still are) marketed as “Nhamunda Rose”.But 

these Discus also exhibit other unusual 

features. Normally Brown/ Blue Discus are 

not sexually dichromatic, ie male and female 

do not differ from one another in coloration. 

It is different with the Nhamunda Rose: it 

appears that all the males are Royal Blue and 

Heckel Nhamunda Maracanha Nhamunda Maracanha Royal Blue, male Nhamunda Maracanha Blue, female 

semi Royal Blue, while the females 

correspond to Brown Discus in their external 

appearance. 

Brand new - the “Nhamunda Maracanha” 

It should be made clear right from the start 

that we don’t know precisely what is meant


by “Maracanha”. Maybe a small settlement? 

Or given that Brazil is football-mad, does the 

name refer to the legendary circular football 

stadium of the same name in Rio de Janeiro? 

When it comes to the aquarium hobby the 

precise provenance of Discus variants has 

been in doubt ever since the time that they 

first appeared in the hobby (around 1930) 

and especially since the Discus boom in the 

1980s. Who wants to let his competitors 

know where there is a collecting locality with 

attractive variants, especially when he has 

T 

Nhamunda Maracanha Semiroyal Blue, male Nhamunda Maracanha Rosé, female 

At last – 

aquaria with no leakage problems 

by aQuaDRAEN 

aQuaDRAEN has developed an aquarium that avoids water leaks or 

aquarium breakage from turning into a domestic catastrophe. Worries 

during holidays away, damage in the home, tedious insurance claims ... not 

longer a problem with aQuaDRAEN! 

he drainage cabinet provides an 

innovative method of catching water 

and hence actively protects against 

escaping aquarium water in the event of 

joint failure or glass breakage.The escaping 

water runs safely into a collecting tank 

which is capable of accepting the entire 

content of an aquarium. 

The attractive and ideal planting of the 

aquarium surround (supplied) will 

guarantee that on the one hand even water 

escaping under pressure will be channeled 

aQuaDRAEN 

searched for years to find such a site? 

The Brown/ Blue Nhamunda Marancanha 

are in any case very similar to the Nhamunda 

Rose, only brighter and larger; here too the 

Royals and semi Royals appear invariably to 

be males. 

Heckel Discus from the Nhamunda 

The Heckel Discus that originate from the 

Rio Nhamunda are again marketed under 

the name “Heckel Nhamunda Maracanha”. 

into the collecting tank, and on the other 

that the aquarium will be a visual highlight 

in your home. 

The aQuaDRAEN Sicherheit und Design is 

available as a cabinet to suit every standard 

size of aquarium, or with an aquarium 

supplied. In addition the prize-winning 

company (first place at the Technologieund 

Gründerfördergesellschaft (TGF) 2010) 

will also supply a customized version to suit 

individual requirements. 

aQuaDRAEN has not only managed to set 

new standards of safety, but has also 

Compared to other Heckel variants they 

have a very typical solid blue “scarf” 

extending from the nape to the fifth or sixth 

spine of the dorsal fin and downwards to the 

pectoral-fin insertion. They are splendid 

fishes! 

Let us hope that these lovely wild-caught 

Discus will produce lots of young so that 

even aquarists with a small budget can enjoy 

Nhamunda Discus. 

www.aquadraen.com 

combined the latter with a timeless, 

modern design. 

The product has been designed to be 

customer-friendly down to the last detail, 

with on-site installation guaranteed and 

everything down to the plants included. 

You can find more Information at 

www.aquadraen.com


HERMIT CRABS 

Terrestrial hermit crabs 

Part 2 

by Wolfgang Löll 

T 

Coenobita pseudorugosus, ,red morp. All Photos: Frank Schäfer 

here are two species of hermit crab in 

Australia: Coenobita variabilis and C. 

perlatus.Of these two species, however, only 

C. variabilis (the specific name means 

"variable") is endemic to Australia. But this 

species is not available in the international 

pet trade, as since the 1980s no commercial 

exports of living wild animals or plants have 

1. Aquarium-hobby days a complete 

success 

The organizers have expressed satisfaction with 

the results of the first Ulmer Aquaristik-Tage 

(Ulmer aquarium-hobby days). “The interest 

shown by visitors has exceeded our 

expectations and those of the exhibitors”,say the 

organizers. 

The Ulmer Aquaristik-Tage offered passionate 

aquarium enthusiasts lots of information and a 

comprehensive range of products spread over 

around 2,800 m2. The dates for the next Ulmer 

Aquaristik-Tage have already been set: from 

29th October to 1st November 2011. 

been permitted from Australia.That is a pity, 

as to date C. variabilis is the only Coenobita 

species that has been shown to have an 

abbreviated larval development,making the 

breeding of the species under vivarium 

conditions at least a possibility. According to 

Harvey (1992), following two non-feeding 

zoeal stages, the feeding megalopa larvae 

develop in only six days at 30 °C; these 

metamorphose only on land, similar to what 

was described for C. compressus in News 95. 

The second species mentioned above, C. 

perlatus, occurs in Australia only on coral 

islands and is regarded as rare there. It is 

unclear what the species name signifies. It 

probably represents a Latinized form of the 

word “pearl” and hence means "pearly", 

referring to the striking white granulae (ie 

the little “pimples”) on the surface of the 

armor in this species. The Latin for pearl is 

margarita, but the Italian is perla. 

The rare occurrence of the species in 

Australia has been blamed on excessive 

collecting for the pet trade,but it is difficult to 

determine whether that is in fact the case or 

merely propaganda from those who oppose 

the keeping of pet animals, who have a 

powerful lobby in Australia. There are 

confirmed locations for C. perlatus in 

Polynesia (the Gambier Archipelago, the


The huge smooth claw is typical for Coenobita brevimanus. 

Marquesas,the Society Islands and Tuamotu) and other South-Sea 

islands.The species supposedly also occurs from the Seychelles to 

Madagascar, on isolated islands, and on the East African coast 

opposite.Its easternmost occurrence is given as Japan.The species 

has purportedly been introduced elsewhere by Man, who uses it 

for culinary purposes, and hence there are nowadays even selfsustaining 

colonies reported from the U.S.A. (eg Cape Cod, 

Massachusetts).In many cases,however,it appears that the species 

may have been incorrectly identified. 

C. perlatus is a very attractive species, known in English-speaking 

countries as the Strawberry Hermit, which describes its coloration 

Coenobita perlatus is very attractively colored.


Lizards and fishes... 

by hanseTier 

Hamburg – 11. January 2011 

...will be the focus of the new special terrarium- and aquarium- 

hobby exhibition at the HanseTier 2011. The Hamburger Heimtier 

Messe (Hamburg pet convention) will be held from 25th-27th March 

in the MesseHalle Hamburg-Schnelsen,a day longer than previously 

(Friday 16.00-21.00 hours and Sat/Sun 10.00-18.00 hours). 

E 

verything to do with animals will be 

presented by around 70 exhibitors in an 

area of 4,000 m2.The visitors and their animal 

companions will find everything their hearts 

desire, from food, equipment, and decor to 

livestock. 

The lecture program reflects the special 

terrarium- and aquarium-hobby exhibition 

and offers interesting presentations on topics 

such as “Shrimp maintenance made easy” by 

the Garnelenfreunden Hamburg (Hamburg 

very aptly. Full-grown specimens are bright 

red and the numerous granulae on the claws 

and legs are whitish. Juveniles are white 

initially and later become beige with brown 

stripes. At all stages the antennae are red, 

and this is regarded as a diagnostic 

characteristic for distinguishing this crab 

from other, similar species. 

The other species are likewise distributed in 

the western Indo-Pacific. Coenobita 

H A N S E T I E R 

shrimp enthusiasts), “Invertebrates in the 

terrarium“ by Dr. Oliver Zompro, and “The 

beginner’s terrarium” by Norbert Grammel. 

Michael Schäfer will lecture on the subject of 

“Livestock for novices in the terrarium hobby” 

and Matthias Hajnal will provide valuable tips 

on “Snakes for beginners”. 

The lecture program also features “Bearded 

agamas” and “Native amphibians and reptiles 

in the terrarium“ by Michael Millert. And 

anyone interested in “Monitor lizards” will 

Coenobita cavipes is only rarely imported. 

brevimanus (the species name means ”with 

a short hand”) and C. rugosus (the species 

name means ”wrinkly”) are imported quite 

frequently, and occasionally C. cavipes (the 

species name means ”hollow foot”), C. 

pseudorugosus (the species name means 

"false rugosus"), C. purpureus (the species 

name means ”purple”), and C. violascens (the 

species name means ”with a violet sheen”) 

are seen for sale. The last two species listed 

originate from Japan. In view of the 

considerable variability in coloration in all 

these species, however, it is highly debatable 

whether they are always actually correctly 

identified in the pet trade. 

(to be continued) 

receive appropriate information from Michael 

Lohse. 

The HanseTier will be open on 25th March 

from 16.00 to 21.00 hours, and on 26th – 27th 

March from 10.00 to 18.00 hours.The entrance 

fee on the day will be 7 Euro (children up to 12 

years accompanied by an adult free). The 

lecture program and 1,600 parking places are 

available free of charge.Further information on 

the event can be found at www. hansetier.de 

or by phoning +49 040/550 60 61.


In this issue you will find: 

Moenkhausia cosmops . . . . . . . . . . . . .2 

Etroplus canarensis . . . . . . . . . . . . . . . .5 

The Mexican goodeids . . . . . . . . . . . .9 

Erythrinus erythrinus . . . . . . . . . . . . .13 

Potamotrygon sp.“Mozaico” . . . . . .17 

The Koran Angelfish . . . . . . . . . . . . .20 

Dead wood into the aquarium . . . .22 

The New Aquarium Plants (3) . . . . .24 

The fabulous Nhamunda Discus . .26 

Jeder Zoofachhändler, jede Tierarztpraxis und jeder 

Zoologische Garten kann beim Verlag 

Aqualognews/Terralognews kostenfrei anfordern und 

als Kundenzeitschrift auslegen. 

Versandkosten werden vom Verlag übernommen! 

Zusätzlich zum traditionellen Einzelhandel wird die 

Aqualognews/Terralognews in vielen Filialen der 

nebenstehend aufgeführten Ketten verteilt. 

Darüber hinaus liegt die Aqualognews/ Terralog news 

auf vielen Fachmessen aus und kann auch von 

Vereinen anlässlich von Veranstaltungen zum 

Verteilen angefordert werden. 

Alle AQUALOG-Produkte erhalten Sie 

weltweit im Zoofachhandel, im Buchhandel 

oder direkt beim Verlag. 

Aqualog animalbook GmbH, Liebigstraße 1, 

D-63110 Rodgau 

Tel. +49 (0) 6106 697977 

Fax +49 (0) 6106 697983 

www.aqualog.de 

info@aqualog.de 

aquaria with no leakage problems .27 

Terrestrial hermit crabs (2) . . . . . . . .28 

HanseTier 2011 . . . . . . . . . . . . . . . . . .30 

Preview: 

AQUALOG News No 97 

will appear in April 2011 

Don’t miss it! 

WIE UND WO ERHALTEN SIE DIE news? 

Filialen mit Zoofachabteilung 









impressum 

Herausgeber: Wolfgang Glaser 

Chefredakteur: Dipl.-Biol. Frank Schäfer 

Redaktionsbeirat: Thorsten Holtmann 

Volker Ennenbach 

Dr. med. vet. Markus Biffar 

Thorsten Reuter 

Manuela Sauer 

Dipl.-Biol. Klaus Diehl 

Layout: Bärbel Waldeyer 

Übersetzungen: Mary Bailey 

Gestaltung: Aqualog animalbook GmbH 

Titelgestaltung: Petra Appel, Steffen Kabisch 

Druck: Möller Druck, Ahrensfelde 

Gedruckt am: 25.1.2011 

Anzeigendisposition: Aqualog animalbook GmbH 

Liebigstraße 1, D-63110 Rodgau 

Tel: +49 (0) 61 06 - 697977 

Fax: +49 (0) 61 06 - 697983 

Verlag: Aqualog animalbook GmbH 

Liebigstraße 1 

D-63110 Rodgau 

Fax: +49 (0) 61 06 - 697983 

e-mail: info@aqualog.de 

http://www.aqualog.de 

All rights reserved. The publishers do not accept liability for unsolicited 

manuscripts or photographs. Articles written by named authors do not 

necessarily represent the editors’ opinion. 

ISSN 1430-9610 

Alle Ausgaben der news stehen 

unter www.aqualog.de als 

PDF-Dateien zur Verfügung! 

Zoofachhändler aufgepasst! 

Ihr flexibler und schneller 

Buchgroßhändler nicht nur 

für AQUALOG. 

Über 3.000 Titel rund um´s Thema Tier! 

animalbook.de 

Liebigstr.1 D-63110 Rodgau 

tel: +49 (0) 6106 697977 

e-mail: info@animalbook.de 


w 

D 

r

Moenkhausia cosmops - Aqualog

Create successful ePaper yourself

Delete template?

Save as template?