guentheri: Latinised adjective, dedication name in honour of Dr. Günther, Germany.

Pfeffer, G. (1893): "Ostafrikanische Fische gesammelt von Herrn Dr. Franz Stuhlmann im Jahre 1888 und 1889"; Jahrb. Hamburg Wiss. Anst., 10:130-183.

Pfeffer first described the species in 1893 based on many specimens caught by F. Stuhlmann in Zanzibar on the 6-Aug-1888 and 26-Oct-1888.

Zanzibar Island without much more details

In 1893, Pfeffer described N.guentheri based on a large number of specimens collected by Dr. Franz Stuhlmann some years earlier, on 6-Aug and 26-Oct-1888, in Zanzibar. These specimens were preserved at the Zoologischen Institut und Museum der Universität Hamburg under the codes H 440, H 441 and H 442. Specimen H 440 got designated as Lectotype by the Museum, specimens H 441 and H 442 as paralectotypes (Wildekamp, 1981).

In 1896, Pfeffer re-described this species in an improved format, but also added specimens from additional localities: colleted by Playfair in Zanzibar and then designated as "N.orthonotus", as well as fish colected by Emin Pascha and Dr. F. Stuhlmann from Longo Bay, which had been described by Hilgendorf as "N.guentheri (Hilgendorf, 1891)". The present city of Tanga was formerly known as Longo.

Based on this re-description by Pfeffer (Pfeffer, 1986), Boulenger (1915:36) assigned to the specimens which had been collected by Playfair in Zanzibar and which were preserved in the British Museum (Nat. Hist) under reference number 1857-3-7 and 1864-2-10-9 the status of Type for the species (Wildekamp, 1981).

According to Bergerhoff (1973), in the past N.guentheri was considered as N.orthonotus. In addition, it is closely related to N.palmqvisti. The males are however, looking at the caudal fin, clearly distinguishable. In N.palmqvisti, the caudal is uniform red; in N.guentheri, it carries in addition a clearly marked black terminal border band. The N.guentheri male is also markedly larger. N.guentheri distinguishes itself from N.orthonotus by a different number of scales. Also, the head is in N.orthonotus ending more in a point.

According to Simoens (1983), the status of this species, after having been quite stable for many years, suddenly got questioned again as some specialists of the Nothobranchius-group doubted the original description. Because of this, the species got assigned the names N.melanospilus and N. sp. Zanzibar (Wildekamp). Finally, we returned to the original description of the species.

During the early eighties, several different colour strains developed and were distributed in the hobby. They were assigned following names: N.guentheri "blue", N.guentheri "gold", N.guentheri "pink tail" and N.guentheri "gasenbergi". All these mutant colour strains, which probably lack one or both alleles for red colour in their gene pool, are characterised by a faint red colour in the body and fins, giving the fish a light faint pinkish tone to the tail and a light bluish tone to the body. All these colour strains are inter-fertile and can easily crossbred with wild and original aquarium strains.

According to Watters et al. (1998) the N.guentheri species group comprises small species such as N.guentheri (Pfeffer, 1893), N.korthausae Meinken, 1973, N.palmqvisti Lönnberg, 1907, and N albimarginatus.

According to Watters et al. (1998), in their colour pattern, male N.albimarginatus appear to be closely related to N.korthausae from Mafia Island. Both species have a white marginal band in dorsal and anal fins and irregular red stripes over a yellowish background, which can be considered as synapomorphic characters. This is also valid in N.eggersi. Red worm-like stripes over the unpaired fins are also a synapomorphic character chaired by N.lourensi [however, in N.lourensi the white marginal band is missing in these fins]. However, Krysanov who carried out karyotype studies informed Watters et al. (1998) that there appeared to be no close relationship between N.korthausae and N.lourensi. These findings where confirmed by crossbreeding experiments carried out by Peterson (1996).

An additional synapomorphy that N.korthausae and N. eggersi have in common is their polymorphy. Both species occur in two different colour forms: red and banded. The red caudal fin in male N.albimarginatus can be explained by this synapomorphy. On this basis, Watters et al. (1998) considered the species N.albimarginatus, N.eggersi, N.korthausae and N.lourensi to form a sub-group of sister-species within the N.guentheri-species group. Another, yet undescribed, species originating from the Kilombero drainage system is possibly also to be included in this sister-group.

Watters et al. (1998) consider the second sister-group with the N.guentheri-species group to be consisting of N.annectens, N.guentheri proper and N.rubripinnis. This sister-group shares the synapomorphies of a red spot on the gill cover [operculum] and the pattern of red chevron-like circular stripes over the posterior part of the body. The synapomorphies of a red tail [caudal] fin without any dark marginal band and the arch-like pattern in dorsal and anal fins are also shared with N.palmqvisti and N.patrizii, which can possibly also be included in this second sister-group. Females of all these species also share the grey circular stripes over their body (Watters et al., 1998).

As with many other Nothobranchius species, this species got its regular share of expected denomination changes over the years. Very old denomination can be found such as: Fundulus orthonotus and later even Aphyosemion guentheri. Especially the former can give rise to confusion with the Nothobranchius species of the same name, with which it shares a certain degree of resemblance.

Over time, Wildekamp has unravelled in several papers and after extensive literature serach the complex history of the correct identification of N.guentheri, N.palmqvisti and N.melanospilus. The story of N.guentheri versus N.melanospilus versus N.palmqvisti is presented herewith [after Wildekamp 1977, 1981]:

As the type material of N.melanospilus is no longer to be found, Wildekamp had to go back to the original description of the first Nothobranchius species. Dr. W. Peters discovered this first Nothobranchius near Quelimane in the northern part of the Zambezi delta, Mozambique. He described these specimens as Cyprinodon orthonotus (Peters, 1844:35). Twenty-four years later, he created for this species the new genus Nothobranchius (Peters, 1868:60-63, Pl. 12, fig.1).

Meanwhile, two years earlier, in 1866, "N.orthonotus" was reported from locations on Zanzibar as well as from the mainland, from the Pangani River, opposite Zanzibar, and from rivulets on the Seychelles (Günther, 1866:326; Playfair & Günther, 1866:118-119, Pl. 17, fig. 2-3). The female drawn in Playfair & Günther's "Fishes of Zanzibar" clearly presents dark spots over the posterior body part and on the unpaired fins. This indicated locality of the Seychelles most probably corresponds to a labeling error, as it is most unlikely to find Nothobranchius representatives on these ocean islands although the island group is of continental origin. Prof. J.L.B. Smith also did not re-discover them when he thoroughly investigated the islands fish fauna in 1954 (Smith, 1963). Most probably, these specimens must have originated from Tanga [Longo] or from an area within the lower Pangani River, where Playfair also made some collections. In 1935, on the ground of a lower number of dorsal finrays and a shorter, more compact caudal peduncle, Ahl (1935) went even a little further in considering the Playfair collection which supposedly originated from the Seychelles, and described N.seychellensis Ahl, 1935 (Wildekamp, 1977:35).

In 1891, Hilgendorf mentioned a "N.orthonotus" from Longo Bay in Usagara [present mainland Tanzania] (Hilgendorf, 1891:19-20). Emin Pascha and Dr. Franz Stuhlmann had collected these specimens on May 27, 1890. Their colour description was given as: "Males have a carmine red net-like pattern along the scale border, females present on the posterior body part and over the fins black spots" (Hilgendorf, 1891). Four of these females - Hilgendorf had five of them - were used by Pfeffer in 1896 as Type material to describe N.melanospilus. Pfeffer determined the males of the Emin Pascha and Dr. F. Stuhlmann collection as N.guentheri (Pfeffer, 1896:47-48) (Wildekamp, 1981:27). These males were sheltered in the "Zoologisches Museum der Humboldt Universität, Berlin" under reference number 21482, but their present whereabouts are however unknown.

Before the region became German East-African Territory, the island of Zanzibar comprised in addition to the actual island itself also some territories on the mainland, between Mombassa and Lindi. The present city of Tanga was formerly known as Longo (Wildekamp, 1977:34). The exact location of Longo bay or longo bach is however unknown. Scheel (1968:298, citing Klee, 1965:11-16) gives "a small rivulet near the present town of Frehami, Tanganyika". On maps of the present Tanzania, this locality if however untraceable. Wildekamp (1977, 1981) recognises that the locality of Longo Bay was most probably located near the coast, probably near the present town of Tanga, which is indicated as Logo (Wildekamp, 1981:27) or Longo Wildekamp 1977:34) on some ancient maps.

Wildekamp (1977:34) reported that in 1893, Pfeffer described N.guentheri based on a large number of specimens collected by Dr. Franz Stuhlmann some years earlier, on 6-Aug and 26-Oct-1888, in "Zanzibar". These specimens were housed at the Zoologischen Institut und Museum der Universität Hamburg under the codes H 440, H 441 and H 442. The Museum designated specimen H 440 as Lectotype, specimens H 441 and H 442 as Paralectotypes (Wildekamp, 1981:26). In his 1893 description of N.guentheri, Pfeffer noted that this species differed from Peters' 1844 N.orthonotus and could be designated as a valid species, identical to Playfair's material from Zanzibar (Pfeffer, 1893:39-40).

In 1896, Pfeffer re-described the species in an improved format, but at the same time adding specimens from other localities. These included specimens collected by Playfair in Zanzibar, at that time designated as "N.orthonotus", as well as specimens collected by Emin Pascha and Dr. F. Stuhlmann from Longo Bay [or Longo Bach], which had been recognised by Hilgendorf as "N.guentheri" (Wildekamp, 1977:34). Based on Pfeffer's re-description (Pfeffer, 1986), Boulenger (1915:36) assigned to the specimens which had been collected by Playfair in Zanzibar and which were preserved in the British Museum (Nat. Hist) under reference number 1857-3-7 and 1864-2-10-9 the status of Type for the species N.guentheri (Wildekamp, 1981:26).

In those days, Pfeffer could not separate in the collection at hand females from males as the smaller specimens had lost their colors. However, he separated the specimens of "N.guentheri" which showed a spotted pattern, described them as N.melanospilus, and wrote that the males of this species were unknown. Playfair considered the spotted specimens to be females of the by him collected species, which he considered to be N.orthonotus (Peters, 1844) (Playfair & Günther, 1866). Specimens collected by Playfair, and for which the collection site was given as Seychelles, were considered by Pfeffer to be N. melanospilus.

Pfeffer's 1896 re-description was accompanied by a copy of a drawing of a male from Playfair & Günther's "Fishes of Zanzibar" (Pfeffer, 1896:47-48, fig. 19). Wildekamp (1981:28) however mentions that the morphological re-description does not correspond exactly to the drawing, in which the dorsal fin is placed more backward (Hilgendorf, 1905:416).

It remained unclear to Pfeffer why the spotted specimens of Playfair and Günther, 1866 and Günther, 1866 got identified as N.orthonotus. He considered them to be identical to his N.melanospilus. The drawing in the description of N.melanospilus was that of a female, whilst the males were unknown to Pfeffer. This drawing is however also a copy issued from the Playfair & Günther's "Fishes of Zanzibar", after a specimen from the Seychelles (Pfeffer, 1896:48, fig.19a).

N.melanospilus was described based on 4 females originating from Longo Bay and which had been collected by Emin Pascha and Dr. Franz Stuhlmann. Pfeffer took the Seychelles to be the type locality for this new species as reported by Günther (1866:326) (in Wildekamp, 1981:26). It is possible that based on this last observation in Pfeffer's description, Boulenger assigned to the Playfair material, which had apparently been collected in the "Seychelles", the status of Type material for N.melanospilus (Boulenger, 1915:34) (in Wildekamp, 1981:26). These specimens are kept under reference number 1865-3-18-98-9 in the British Museum (Nat. hist.), London.

The syntypes originating from Longo Bay had already been considered to belong to N.orthonotus (Peters, 1844) by Hilgendorf before Pfeffer's description (Wildekamp, 1981:26). The collecting date was given as 27-May-1890 and, in this article, the locality Longo Bay had been replaced with "Longo Bach" (Hilgendorf, 1891:19-20). These syntypes were kept at the Zoologisches Museum der Humboldt Universität, Berlin. Later these specimens were not any longer traceable in this Museum and have most probably been destroyed during the last World War (Wildekamp, 1981:26).

Wildekamp (1981: 27) mentions the existence of a Stuhlmann-Emin Pascha expedition report in which Stuhlmann kept daily records on the expedition's advancements. This report also includes an itinerary map relating the journey. The expedition report apparently provides more clarity on the complex issue of the discovery of N.guentheri and N.melanospilus. "During the period that the type material of N.guentheri was collected by Dr. Stuhlmann he still was on Zanzibar, busy assembling the expedition and Emin Pascha had not yet joined it. However, during this period, Dr. Stuhlmann traveled also to mainland where he also made some fish collections. Both Pfeffer (1889, 1893) and Hilgendorf (1891) report over these collections, which, besides form fishes, also comprised reptiles, amphibians, mollusks and crabs. In these articles, all localities were exactly reported. Localities from the mainland were labeled with a village-location or a river-location name, those collected on Zanzibar were simply reported as Zanzibar". On the ground of this fact, Wildekamp (1981:27) concluded that the specimens used by Pfeffer to described N.guentheri must all have originated from the island Zanzibar.

Wildekamp (1981:27) further adds that on May 27, 1890, also the day that the Type specimen of N.melanospilus was collected, the expedition had reached the ancient village of Farhani on Longo Bach. The expedition stayed there for a few days in order to enable consultations with the Arabs of nearby Kondoa [the present Kilosa] about the recognition of the newly established German Colonial Empire. The catholic mission of "La Longa", also on Longo Bach, is found 1/2 an hour walk distance away (Stuhlmann, 1894:19). Wildekamp (1981:28) mentions that according to the attached map this locality is situated at about 37°02' E - 06°48' S. These coordinates roughly correspond to the location of the present village of Ilonga [37°01' E - 06°47' S]. Changes of location names over time are a common feature with African names.

On the ground of precise mainland locality descriptions of the early collections as well as the area where the Stuhlmann-Emin Pascha expedition was residing at the time the N.melanospilus Type specimens were collected, Wildekamp (1981:27) concluded that the specimens used by Pfeffer to describe N.guentheri must all have been collected on Zanzibar, making the island the Type locality of N.guentheri; and, the Type locality of N.melanospilus must thus have corresponded to the present village of Ilonga, northwest of Morogoro, on mainland Tanzania.

In those days, Pfeffer was unable to separate in the collections at hand females from males as the smaller specimens had lost their colors. However, he separated the specimens of "N.guentheri" which showed a spotted pattern and described them as N.melanospilus. In addition, he also wrote that the males of this species were unknown. Playfair considered the spotted specimens to be females of the by him collected species, which he considered to be N.orthonotus (Peters, 1844) (Playfair & Günther, 1866), in the same way as Hilgendorf (1891) considered the specimens from Longo Bay. Also, specimens collected by Playfair, and for which the collection place was given as Seychelles, were considered by Pfeffer to be N. melanospilus.

Wildekamp (1981:28) could study some of the paralectotypes of N.guentheri from the Hamburg Museum and observed that in all specimens the dorsal fin was placed more in front than what he had observed in own collected specimens from the mainland, which had also already been observed by Hilgendorf.

In 1905, Hilgendorf also reported on N.guentheri, which had been collected between 1893 and 1895 by O. Neumann (Hilgendorf, 1905). Neumann collected these specimens on Zanzibar Island proper, in the near vicinity of the main town, as well as close to Amboni, a village near Tanga on the mainland. However, according to Hilgendorf (1905), these specimens differ from Pfeffer's drawings [copy in Günther and Playfair, 1866], as in Neumann's specimens the dorsal fin is placed more in front, the body is slender and under the eyes there are 3 rows of scales. Females are in this case light olive-brown, without any dark spots over the rear body end. Wildekamp (1981:29) however noted that the distinguishing character Hilgendorf thought to have found in the number of scales under the eye could not be used. In the studied paralectotypes of N.guentheri, Wildekamp (1981:29) was able to distinguish the males from the females on the ground of the skin outgrowths, which surrounds the genital opening and the basis of the first anal finrays in females. These females did not have black spots, neither on the posterior body part nor of the unpaired fins. The British Museum (Nat. Hist.) specimens from the "Seychelles", which have a similar conservation time, clearly show these black spots.

The since long as N.guentheri known species, of which the females did not present irregularly set dark spots on the posterior part of the body and over the unpaired fins, originated from Zanzibar Island (Scheel, 1968). This species had meristical and morphological data corresponding to the N.guentheri found by Neumann and described by Hilgendorf (Hilgendorf, 1905).

R. G. Bailey (1969, 1972) placed, following biological, ecological and taxonomical investigations, N.melanospilus (Pfeffer, 1896) in synonymy with N.guentheri (Pfeffer, 1893). His conclusions were based on the false Type specimens present in the British Museum (Nat. Hist.) created by Boulenger (1915:34 & 36). It was in a pool on the grounds of the Central Agricultural Research Center in Ilonga, near Kilosa, that R. G. Bailey collected his material of "N. guentheri (Pfeffer, 1893)", which he used for biological and ecological research studies carried out between 1963 and 1965 (Bailey, 1972). Taxonomic studies carried out on this material as well as on material originating from near Bagamoyo, and apparently belonging to "N. guentheri", and N. melanospilus (Pfeffer, 1896) material belonging to the collections of the British Museum proved that the Ilonga/Bagamoyo material was identical with "N. guentheri". Bailey's study (Bailey, 1972) thus apparently proved that N. melanospilus would have to be considered as a later synonym of N. guentheri (Wildekamp, 1977).

However, Bailey's material originated from near the Type locality of N.melanospilus, near Ilonga, and comprised several Topotypes [material collected at the Type locality]. It appeared from this later description that all females of his "N.guentheri" had black spots over their rear body half and their unpaired fins. And, as could already be observed by Bailey, only the N.melanospilus-phenotype can be found in the vicinity of Ilonga. His synonymy must thus be considered as invalid (Wildekamp, 1981:29).

In June 1976, Wildekamp (1976) together with some KFN [Killi Fish Nederland] members R. van Haarlem, J. Lourens, Th. Steinfort and J. Pap visited the Central Agricultural Research Center in Ilonga near Kilosa. Bailey's original collecting site was however unknown in the Research Center.

Meanwhile, in the near vicinity of the station, Wildekamp and his colleagues discovered a Nothobranchius species, which did not differ much, neither in colour pattern nor in morphological characters, from Bailey's description. Females displayed the typical black spotted pattern along the posterior part of the body. Wildekamp considered therefore this Ilonga material as co-type of "Bailey's N. guentheri". In the near vicinity of Ilonga, near Chanzuru, Bailey's "N.guentheri" was again discovered - living syntopic with N.steinforti Wildekamp 1977 - along the road from Morogoro to Kimamba (Wildekamp, 1977).

Several crossbreeding experiments were also carried out between N.melanospilus and N.guentheri, all of which, when succesfull, produced sterile F-1 generations. N.melanospilus (Pfeffer, 1896) has thus also to be considered as a valid species with a very wide distribution area on coastal mainland Tanzania [north of the Rufiji delta] and southern Kenya. The species growth larger than N.guentheri and males present in their colour and body pattern quite some similarities with N.guentheri. Females however show quite some differences; especially the black spotted pattern on unpaired fins and rear body part in N.melanospilus.

Wildekamp found a further argument to distinguish between both species in the long geological isolation, since mid-Pleistocene, of mainland and Zanzibar Island. Therefore, considering that in live specimens N.melanospilus and N.guentheri can easily be distinguished from each other by their different colour pattern, especially in females, Wildekamp (1977:35) had already proposed that the Zanzibar form be assigned the temporary name of N. spec. "Zanzibar". With his 1981 investigations, Wildekamp is now convinced that the N.guentheri from Zanzibar is the real N.guentheri (Pfeffer, 1893. His closest relatives are N.palmqvisti (Lönnberg, 1907) and N.foerschi (Wildekamp & Berkenkamp, 1979), which both originate from mainland just opposite Zanzibar island and whom female do not have black spots.

N.palmqvisti was described in 1907 on the ground of material collected in the vicinity of Tanga by Dr. Y. Sjöstedt during his Mweru-Kilimanjaro Mountains expedition. Lönnberg indicated in his description that the caudal fin's red coloration could also be found as spots and stripes in anal and dorsal fins, which in addition presented irregularly running yellowish stripes. In 1977, Wildekamp thought that Ahl's description of N.vosseleri in 1924 could possibly also be based on specimens of N.palmqvisti, as the Terra Typica of the specimens originated from Mombo, a locality situated only slightly westwards of Tanga, and the colour description corresponded to that of female N.palmqvisti.

As mentioned earlier, Hilgendorf reported on N.guentheri collected between 1893 and 1895 by O. Neumann (Hilgendorf, 1905). Neumann collected these specimens on Zanzibar Island proper, in the near vicinity of the main town, as well as close to Amboni, a village near Tanga on the mainland. Based on Bailey's diagnosis it's not possible to recognize Neumann's specimens as N.melanospilus. Neither is it possible to consider this species to be N.guentheri from Zanzibar because since mid-Pleistocene times the island of Zanzibar, just like the island of Mafia, has been separated from the mainland. In earlier times, the ocean level must have been some 60-m lower than at present such that a connection with the mainland could have existed. Also, on this basis, Neumann's Amboni-specimens can not be identical to those from Zanzibar Island. Comparing description and locality, the Amboni-form is most likely identical to N.palmqvisti (Lönnberg, 1907).

According to Scheel, Fma Tropicarium [Frankfurt/Germany] imported in 1957 a Nothobranchius species with the name "N.palmqvisti". This species got widely distributed in the hobby. The original collecting site was unknown, but possibly the species originated from north of Dar-Es-Salaam as this form corresponded with specimens collected by J. H. E. Leaky in some pools situated in a sisal plantation north of this town. Leaky also collected in a swampy area between Tanga and Pangani, 5-miles north of Pangani, a form that closely fitted the description of N. palmqvisti made by Lönnberg; especially the colour description and the drawing pattern along dorsal and anal fins. Considering the collecting site near the Terra Typica of N.palmqvisti and that both forms originate from the lower Pangani River basin and show a pronounced similarity in colour pattern, this form was considered by Wildekamp (1977) to represent the real N.palmqvisti form. Amongst hobbyists, this N.palmqvisti form got known as N. spec. "Tanzania". This name represents however a distortion of N. palmqvisti "Tanga", under which the fish got distributed in the USA by B. J. Turner.

Recent collections indicate that this other dubious "N.guentheri" [now considered to be N.palmqvisti] occupies a distribution area on the mainland's coastal lowlands [below the 1 000-m mark], from northern Tanzania and southeastern Kenya. The lowland area between Mombassa and Dar-Es-Salaam comprises the river systems of the Ruvu, Wami, Pangani, Umba and a quantity of smaller rivers, all running towards the Indian Ocean. More to the north, this species is replaced by N. spec. "Malindi", the former N. neumanni of hobbyists, which was identified as N.jubbi by Wildekamp. South of Dar-Es-Salaam, between Dar-Es-Salaam and the Zambezi mouth, the investigations continued, although N.orthonotus is known from the Zambezi River system, where it replaces our N.melanospilus.

Wildekamp et al. (1977) discovered "N guentheri" [in fact N.melanospilus] near Kimamba, Chanzuru and Ilonga within the upper Wami River system. Pap and Lourens collected this species some times earlier near Mikuni and Mbana in the Mikuni National Park, near Dakawa, Mvomero, Turiani and Morogoro. Wildekamp collected this species near Kwaraza, within the Ruvu River system, just behind the bridge over the Ruvu. It lived here syntopic with two other, at that time, undescribed Nothobranchius species [one is presently known as N. steinforti]. This species also occurred in a pool linked to the Ruvu River, 40-km from Dar-Es-Salaam. Morphologically and meristically, all these forms are very similar. Only minor differences in colour pattern and intensity are noticeable and these variations apparently do not warrant the creation or definition of under-species. In all cases, the posterior part of the female's body displays the typical black spots, which individually can vary in placement, intensity, size and number. With increasing age, the number of spots also appears to increase.

In a few cases, the accompanying fauna comprised species from permanent waters such as Alestes affinis Günther, 1894, Clarias mossambicus Peters, 1852 and several Barbus representatives. The presence of permanent water species could indicate that these waters maintain a minimal critical level during the entire dry season. In one case however, Lourens observed in early 1976 that at Kwaraza location the water dried up entirely, implying that fish had to be brought back into the pool by main river floods.

Crossbreeding experiments carried out by H. O. Berkenkamp showed that the N.palmqvisti from Tanga/Pangani and the "N.palmqvisti from near dar-es-Salaam" [in fact N.melanospilus] from hobbyists were not identical. From above observations, it appeared to Wildekamp (1977) that only the Tanga/Pangani form deserved the rightful denomination of N.palmqvisti and that the form from Dar-Es-Salaam would temporarily have to be named N. species "Dar-Es-Salaam" as long as no original Type material for the description of this species had been identified.

A more recent discovery made by E. Khorthaus on Zanzibar also showed that this species presented two distinct colour forms [phenotypes], whereby the presence or absence of a wide black marginal band in the caudal fin can be regarded as the most striking difference. E. Khorthaus regarded the form without black marginal band in the caudal fin as N.palmqvisti, the other with the black band as N.guentheri. However, Wildekamp (1977) reported that according to Scheel's crossbreeding experiments between E. Korthaus' black banded N.guentheri and her non-banded "N.palmqvisti " yielded fully fertile offspring's'. On the other hand, crossbreeding experiments between this N.guentheri and "N.palmqvisti from near dar-es-Salaam" carried-out by Th. Steinfort did not produce a single viable hybrid.

From all above observations it became increasingly evident to Wildekamp (1977, 1981, 1982) that the name "N.guentheri" applied in fact to three distinct and valid species (1) N.melanospilus (Pfeffer, 1896) with a very wide distribution area on coastal mainland Tanzania [north of the Rufiji delta] and southeastern Kenya, (2) N.guentheri is, as far as presently known, restricted to the Island of Zanzibar and (3) N.palmqvisti seems to be limited to the southeastern Kenyan and the northeastern Tanzanian coastal lowlands.

N.melanospilus growth larger than N.guentheri and N.palmqvisti but males of these three species present in their colour and body pattern quite some similarities with each other. Females however show quite some differences; especially the black spotted pattern on unpaired fins and rear body part in N.melanospilus.

N.seychellensis Ahl, 1935 and N.emini Ahl, 1935 which were regarded in the past as synonyms of N.guentheri (Bailey, 1972; Wildekamp, )

N.emini Ahl, 1935, has been brought into synonymy with N.melanospilus (Pfeffer, 1896) by Wildekamp (1981), and its position there has been confirmed by Paepke & Seegers (1986).

To make the matter worse, Seegers reported in 1985 that a N.melanospilus had been collected on Zanzibar Island. This discovery raises again the question regarding the proper identification of the two species N.guentheri and N.melanospilus.

The fish was first imported alive into Europe around 1913, but one had to wait until 1959, before Koch published the first accounts of successful breeding attempts in DATZ journal.

L. Seegers collected the species N.guentheri on Zanzibar in the near vicinity of the Amman-Stadium in Zanzibar town {figure 3}.

In 1997, Wildekamp, Watters and Cooper collected N.guentheri in 2 locations on Zanzibar: TAN 97/2 and TAN 97/4.

Males are richly coloured. The body coloration presents a metallic bleu base colour whereby the scales are edged with deep Bordeaux-red, what gives the body a netted pattern. Some specimens [ a function of the strain at hand] display also vertical and darker chevron-like marking over the rear body end extending towards the caudal fin. The chin area is deep yellow. This coloration spreads into the base of the pectoral fins, which in addition are distally edged with a light sky-bleu marginal band. The dorsal fin presents a yellowish-green base coloration and is sprinkled with numerous irregularly placed and small red spots whilst the edge is darker and bordered with a light sky-bleu marginal band. The anal fin is also yellowish with red spots and short stripes. The caudal fin, together with the tail base, is heavily deep red and a dark to sharp black external marginal band edges finally the caudal fin.

N.guentheri can be kept and bred without too many trouble in water with following characteristics: pH of 6.8 to 7.0 and even to 8.0; water hardness between 9-18 and water temperature between 22 and 26°C. Such water can be obtained by mixing regular tapwater with rainwater, although such an operation is usually not necessary and the fish adapts easily to almost any water conditions. The water should be well buffered and preferably not too hard or too soft.

Temperatures around 20-22°C. are favourable to their already short and active lifetime [1 year and even up to 18 months]. Temperature changes, especially at night, whereby these are allowed to drop to 18°C prolong markedly their lifetime. The addition of kitchen salt [1 teaspoon per 10-litre water] is also been advised as preventive measure against Oödinium. N.guentheri is prone to [but also not hypersensitive] Oödinium when the circumstances of its maintenance are far from optimal [i.e. neglecting to apply regular water changes]. One of the most effective medicines against this disease is zinc-free malachite-green {in very low concentrations} but this could have a negative impact on the general fertility level of the species during a treatment with the product.

N.guentheri are continuous spawners and one can observe every day in a species-tank the numerous spawning acts.

Breeding of the species should only be practised with full-grown specimens and with carefully selected individuals as in case of inbreeding a rapid degeneration of the species can be observed, producing smaller and far less colourful individuals. Reproducing N.guentheri does not pose any particular problem. The eggs are laid in the bottom substrate but the parents do not dive into it like in the related South American Cynolebias and Pterolebias species. A small tank of about 10 litres with soft or slightly acidic to neutral water is sufficient for the reproduction. Middle hard water gives however also good results. Or the entire bottom is covered with a 1 cm thick peat-moss layer or the 2 mm thick peat-moss layer is kept together in a small plastic container with a 5 cm diameter opening in its cover lid. The latter method has the advantage of reducing contamination of the spawning medium with excrements and reducing the required amount of spawning medium allowing the eggs to be more visible during the incubation period.

The eggs of N.guentheri are stored for a period of 2-3 months at a temperature of 20-26°C. Opinions differ quite somewhat when incubation times are discussed: some speak of only 6 weeks, others of 6 months [Eckert (1964)]. Personally I wet the eggs for the first time after 3 months but I have observed that I can wait, with only an effect on the number of hatching fry, up to 6 months before wetting for the first time.

Because the freshly hatched fry is very small, they need infusoria of the right size during the first few days. Therefore it is advised to prepare some infusoria rich solution one to two days before wetting or to add some infusoria production enhancing products [1-2 crushed leaves]. Only the larger fry will be able to handle freshly hatched Artemia-nauplii and only that of smaller size. As freshly hatched fry is small it is difficult to find over a dark substrate, and it is only after feeding Artemia-nauplii that they can easily be located for carriage into a larger tank with the same water composition. The peatmoss can be re-dried for another 4 weeks and re-wetted for a second hatch.

Aelbrecht (19..) mentions as possible problem the occurrence of "females-only" batches [i.e. 2 males in 200 females and 2 in 70], whilst other hobbyists mention batches producing "males-only". According to some hobbyists, under who present author, this could be the result of circumstances under which the parents and eggs are being maintained as opposed to the natural and more ideal conditions [food, space, temperature, hormone concentrations, and others]. Non-ideal maintenance circumstances would thus produce far too many females and/or males, away from the 50:50 ratio, whilst more ideal conditions would tend to produce a 50:50 ratio.

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