Nothobranchius jubbi Wildekamp & Berkenkamp, 1979

&

Nothobranchius cyaneus Seegers, 1981

Last update 21/12/99

Introductory note

Following Wildekamp's 1986 study of various N.jubbi and N.cyaneus populations, he came to the conclusion that both species should in fact be considered as identical. Because N.jubbi had been described earlier, it should receive priority in the species' denomination. N.cyaneus Seegers, 1981 should therefore be regarded as a recent junior synonym of N.jubbi Wildekamp & Berkenlamp, 1979. Since we are not fully convinced of all arguments put forward and since it is believed that, in this specific case [as opposed to what is observed in N.korthausae, N.eggersi or in other Nothobranchius species], there must be much more to it than just polychromatism in males, both "species" (whatever their status) are herewith presented next to each other. This would be the first species where both polymorphism [various body shapes] and polychromatism [various colour forms] would occur next to each other.

The aspect of polymorphism has thus far received very little attention [in Wildekamp's 1986 study, measurements were taken from different size and age groups], besides from the fact that little is mentioned concerning the sub-species N.jubbi interruptus. Also the "definition" of intermediary forms [based in essence on various gradients of the red colour in the caudal fin] does not appear to be satisfactory; both "species" could in fact have a red form as observed in many other Nothobranchius species. In addition, some populations breed really through over several generations [both in shape and in color] without ever an intermediary form appearing.

Based on published literature information and on practical breeding experience with both "species", we tend to favour the idea that one could either be dealing with species in "creation" or with two sub-species (as proposed by Seegers, 1985) with very similar intermediary forms. The definition of a species requires that hybrids be sterile, but what is generally called hybrids or intermediary forms in this case could in fact correspond to subordinate males of both "species". Non-red chromatic forms in N.guentheri and N.foercshi are far less dominant and far less aggressive than the red morphs. When brought together in one same tank, non-red forms will always be pushed back and will only participate to the species' spawning success if and when sufficient space is made available. Although not investigated thus far, it would appear that in Nothobranchius the red colour must, in one way or the other, be directly linked to aggressive and territorial behaviour, and thus to spawning success. In these two species, the red and non-red forms maintain however an identical body shape, which is imprinted in the species' specific gene pool. It would thus appear that more investigation is required in this field - in fish, colours appear also to be influenced by environmental and relational conditions. What about general body shapes?

• Jubbi: The Latin adjective jubbi constitutes a dedication name in honour of Dr. R. A. Jubb of South Africa, as a mark of appreciation for his pioneering work on the Nothobranchius genus.
• Cyaneus: The Latin adjective cyaneus refers to the light cyan-blue base colour in male specimens.

First Description

• Wildekamp, R. H. & Berkenkamp (1979): "Untersuchungen zur Identität von Nothobranchius neumanni (Hilgendorf, 1905) aus Tanzania, mit der Beschreibung einer neuen Art und Unerart aus dem Küstentiefland Kenias"; Deutch. Killfish Gem., Journal, 11(5): 65-75.
• Seegers, L. - 1981 "Nothobranchius cyaneus spec. nov., ein neuer Prachtgrundkärpfling aus Kenia." - Die Aquar. u. Terrar. Zeitschr. 34(11): 365-368.

Terra Typica

• For N.jubbi: "...pool along the roadside to Garsen, 17 miles north of Malindi in the coastal lowlands of Kenya, along the Indian Ocean."
• For N.cyaneus: according to Lung who collected the type specimens "about 20-km after Malindi towards Garsen, comes the village of Gongoni, about 4-km after Gongoni, on the right side of the road in a 10x5 m large, 30-cm deep isolated pool. There is no river in the vicinity", in eastern Kenya. The Lung location closely resembles the June 1962 Leaky collecting site; both must either be identical or lie in each other's vicinity.

Meristic & Morphometric Data

• For N.jubbi:
  D= 15-16; A= 16-18; 29-32 scales in mid-lateral line series.
  Karyotype: 2n= .34 (according to Scheel)

Table 1: Meristic data of N.jubbi (after Wildekamp & Berkenkamp, 1979)
[values expressed in % of standard length, averages for the Paratypes]

Table 2: morphometric data of N.jubbi (after Wildekamp & Berkenkamp, 1979)

• For N.cyaneus:
  There are = 27-30 scales in the longitudinal line in addition of 2-3 scales on the basis of the caudal fin. The openings of the lateral line system are well visible. In the oblique vertical line, measured from the beginning of the anal fin, there are 10-11 scales.
  On the dorsal fin of the males there are few, on the anal fin, numerous ctenoïd hooks. Finrays of dorsal and anal fins reach beyond the fin membrane.
  Karyotype: 2n= .34 (according to Scheel)

According to Wildekamp (1986), J. J. Scheel (1981 and 1983, pers. comm. to Wildekamp) carried out some cytological studies on live specimens of N.cyaneus from Shalanbod and Sunguni (blue phenotype), Somalia, and on specimens of N.jubbi and N.cyaneus, with intermediary forms, from Azenda Bader, Somalia. They were compared with forms of N.jubbi from Malindi, Kenya, and N.cyaneus from Warfa (N. sp. Warfa Blue), Somalia. This disclosed the close relationship existing between N.cyaneus and N.jubbi. Both "species" had "identical" karyotypes with 2n= 34 chromosomes. All elements distinctively had 2 arms, and one pair of typically derived metacentric chromosome. According to Wildekamp (1986), these karyotypes appeared to be identical to those of N.cyaneus Warfa and N.jubbi from Malindi studied previously and which gave an haploid number of n=17 chromosomes.

Table 3: Meristic data of N.cyaneus (after Seegers, 1981)
[values expressed in % of standard length, averages are for the 9 Paratypes]

Table 4: data as % of head length of N.cyaneus (after Seegers, 1981)

Table 5: morphometric data of N.cyaneus (after Seegers, 1981)

Description

• N.jubbi Wildekamp & Berkenkamp (1979)
  According to Wildekamp & Berkenkamp (1979), N.jubbi has a body shape corresponding to the Type species of the genus. The snout is relatively long, flat and wide. The mouth opening is directed upwards and the lower jaw protuberant. Upper and lower jaws carry several rows of small but well developed teeth's; those of the first row having the greatest length.
  
  The dorsal fin origin is placed slightly in front of the anal fin origin. The males present on anal and dorsal fin hook-like papillae, those in the anal fin are more numerous and larger than in the dorsal. The proximal [towards the front] part of both fins is - as in most Nothobranchius species - covered by skin tissue. The females possess around their genital opening a sort of fleshy genital purse, which surrounds the first two to three anal fin rays.

Seegers (1981) decided to define the new species N.cyaneus on the basis of a difference in number of rays in the various fins between N.jubbi, N.interruptus and N.cyaneus (Table 6).

Table 6: Distinction between N.jubbi, N.interruptus and N.cyaneus (Seegers, 1981)

Additional discriminating factors leading to the description of the new species included the fact that N.cyaneus was not as deeply build as N.jubbi, but did have a rather slender body and that the unpaired fins appeared to be shorter. In addition males of N.cyaneus have a blue caudal fin and females present, over the distal part of the body, dark V-like markings pointing towards the caudal fin. These dark V-like stripes are also known from certain populations belonging to the N.guentheri species-group [N.annectens, N.guentheri, N.rubripinnis, N.palmqvisti and N.patrizii].

In 1983, the Dutch hobbyist T. Hannink obtained in a batch of N.cyaneus originating from Warfa, Somalia, specimens with red in their tail, which further intensified with the second generation {KFN, 15(1): 16-17}. The report does however not mention whether the "slender-body" character also changed towards the "deep-bodied" N.jubbi morph.

Also, in an article published in 1984, Forstner (1984) reported on crossbreeding experiments between N.jubbi and N.cyaneus from the lower Tana drainage system. The author was not able to discriminate with 100% accuracy females of both simultaneously caught "species". He then separated the females according to his own personal feelings and left them with the corresponding males into a breeding session. Following a 2 weeks breeding period, the males were exchanged. Many eggs moulted, but many fry hatched as well. From amongst the 100 fingerlings he obtained, 3 could be identified as intermediary forms; the rest undoubtedly belonged either to the N.jubbi-type or to the N.cyaneus-type, which by further inbreeding remained pure [Wildekamp (1986) however reports that no further inbreeding with these supposedly hybrids was reported].

The discovery of intermediary forms in northeastern Kenya and southern Somalia confirmed scheel's insights that both species are closely related. In above-mentioned areas, entirely blue specimens can be found as well as specimens with red spots in their caudal fins. The more northerly found phenotypes always appeared to be entirely blue. This equally applies to the southern forms, which can be found together with N.jubbi. Based on results of his crossbreeding experiments with N.melanospilus, Scheel does not exclude a possible close relationship between N.cyaneus and N.melanospilus and N.interruptus. By this, N.cyaneus, and also N.jubbi, could belong to the N.melanospilus-group.

Research carried out by Wildekamp (1986) on different local forms has led to a synonymy of the blue form of N.cyaneus from Gongoni described by Seegers (1981) with N.jubbi. According to Wildekamp (1986), both N.jubbi and N.cyaneus should thus be considered as synonyms, with N.cyaneus representing a junior synonym of N.jubbi. N.jubbi was the third species of the genus, after N.korthausae and N.eggersi where polymorphism [more correctly polychromatism] was known to have occurred.

Wildekamp (1986) compared the meristic data of 16 populations of N.jubbi and N.cyaneus originating from all over the natural distribution area [Table 7 and Table 6].

Table 7: Range of measurements of various N.jubbi populations - Expressed in % of Stand Length (SL)
(after Wildekamp, 1986)

Origin of the studied populations:

1.        Red phenotype - Type material of N.jubbi, BMNH 1962.7.9:4-14, collector J.H.E. Leaky [11 specimens]

2.        Red phenotype - Malindi, Kenya, MRAC 79-07-P-156-162, collector E. Holler [6 specimens]

3.        Red phenotype - North of Malindi, Kenya, collector M. Forstner & M. Willert [2 specimens]

4.        Red phenotype - Aquarium strain originating from Leaky's collection [8 specimens]

5.        Blue phenotype - Type material of N.cyaneus, SMF 16397-16402 and BMNH 1981.9.30:2-5, collector K.Lung

6.        Blue phenotype - Shalanbod, Somalia, MRAC 84-50-P-25-39, collector R.Wildekamp & al. [11 specimens]

7.        Blue phenotype - Durbane, Somalia, BMNH 1983.3.14:77-78 and NAS collection [10 specimens]

8.        Blue phenotype - Dur e Kalin, Somalia, MRAC 84-50-P-11-19 and BMNH 1984.5.9:56-59, [13 specimens]

9.        Blue phenotype - North of Garsen, Kenya, collector M. Forstner & M. Willert [4 specimens]

10.     Blue phenotype - Dekta, Somalia, MRAC 84-50-P-20-24, collector R. Wildekamp & Al. [3 specimens]

11.     Blue phenotype - Warfa, Somalia, collector R. Haas [10 specimens]

12.     Blue phenotype - Haya, Somalia, collector R. Haas [10 specimens]

13.     Intermed. phenotype - Goba, Somalia, MRAC 84-50-P-1-5, collector R. Wildekamp & Al. [5 specimens]

14.     Intermed. phenotype - South of Garsen, Kenya, collector M. Forstner & M. Willert [2 specimens]

15.     Intermed. phenotype - Halima Adai, Somalia, collector R. Haas [10 specimens]

16.     Intermed. phenotype - Afmadu, Somalia, collector R. Haas [18 specimens]

Table 8: Fin ray and scale counts on various N.jubbi populations - (north south distribution after Wildekamp, 1986)

Colour description

This species belongs to the mid-sized Nothobranchius species. In opposition to most other species within the genus, N.cyaneus can be at times a rather dull to colourless species, other populations display light blue-green colours. N.cyaneus can be distinguished from the other Nothobranchius species by its typical blue caudal fin.

Preserved specimens

Preserved males (in formalin and kept in alcohol) of N.cyaneus present a light blue-gray base coloration, over the backside rather brownish. Each body scale is edged with a red-brown border creating a reticulated pattern over the body. This pattern covers uniformly the entire body and generates the impression of a enveloping red-brown shine over the body. Unpaired fins have a dark gray base coloration on which runs some light gray stripes, creating the impression of a more or less intensive pattern. The caudal fin has a thin white marginal hem, a little thicker along the dorsal side. A white marginal band can also be found in the dorsal fin and often the tips of the anal fin rays are also white. Ventral fins are dark grey and pectoral fins transparent, often with a white marginal band (Seegers, 1981).

Preserved females of N.cyaneus (Seegers, 1981) present a gray-brown base coloration, more whitish towards the belly and reddish-brown towards the backside. Here also the scale borders are coloured with a thin red-brownish hem. Over the posterior part of the body, females display dark V-shape circular bands, with the tip of the V pointing towards the caudal fin and lying over the longitudinal line. Unpaired and ventral fins are gray-brown, reddish around their base and further colourless. Pectoral fins are entirely colourless.

Live specimens

Males: At the time of the first description of the species in 1979, Wildekamp & Berkenkamp (1979) wrote that males from the Leaky [re-discoverer of the species in 1962] material are easily distinguishable from the other Nothobranchius species. "Characteristic is a wide, dark gray-blue band in the caudal fin. In older males a thin white marginal band often follows this zone. The wide gray-blue band over the normally red caudal fin can in some instances be reduced or even fail entirely. As at times a large proportion of the males had an entirely gray-blue caudal fin, Tuner (1964) spoke of polymorphism [appearance in one and the same species of specimens with different shapes, it would have been preferable to speak of polychromatism (=several color forms)]. It was however observed that all the sexually mature and active males had the red colour in the proximal part of the caudal fin [near the body], and that it extended into the caudal peduncle" (Wildekamp & Berkenkamp, 1979).

According to Wildekamp & Berkenkamp (1979) original description of the species the body colour of N.jubbi males is gray-blue, the back being darker, the belly lighter to whitish. The scales are edged by a thin dark border, which creates a reticulated pattern over the body. The dorsal fin is blue-gray with numerous dark spots, which at times flow together into irregular stripes. The "dorsal" [it should read in fact the anal] fin is light gray-blue, with some dark spots in its posterior part. The caudal peduncle and the anterior part of the caudal fin are red (in young males blue-gray), following this appears a wide dark gray-blue band (in older males this band is absent or strongly reduced). The ventral fins are light bluish, the pectorals are colourless with a light blue edge.

Males of N.jubbi have a red, blue or an intermediary colour pattern. The various populations, which identified themselves on the basis of their origin, can easily be identified as N.jubbi like N.jubbi "blue" from Dur-e-Kalin/Somalia and N.jubbi "red" from the neighborhood of Garsen/Kenya. Pectoral and anal fins are colourless with a light bluish to white marginal band. The ventral fins have a dark marginal band, which runs along the fin basis. A similar dark band can be found running along the dorsal fin basis. These bands run first in patches, later in a series of small spots towards the external end of the fins. The caudal fin possesses a whitish marginal border and on its base, two dark to deep red circular bands. Scales have deep red to darker margins.

Instead, live males of N.cyaneus display a uniform light bluish green body coloration. The intensity of the blue color can vary amongst populations. Around the scales one can distinguish a small red-brown margin. The colour of these margins is less bright than in preserved specimens. They are partly broader over the posterior part of the body where they form lateral "chevron"-like markings. These markings are present with most populations. In the southern populations, the lower part of the head is generally light bleu, in the lower Uebi Scebeli populations, light yellowish. The chin region is yellow. The caudal fin is also bleu-gray with vague darker markings made of small spots, partly also forming concentric bands. Its border always ranges from light blue to white. Around its base, one can find, by the northern populations, red spots, which can melt together into a single band. In populations displaying intermediary characteristics towards N.jubbi, red spots can appear within the central part of the caudal fin. Dorsal and anal fins are similarly coloured as the caudal fin, but intermediary populations never display any red markings. The white margin in dorsal and caudal fins is also present in live specimens.

Females:
According to Wildekamp & Berkenkamp (1979) original description of the species the body colour of N.jubbi females is light grayish. A thin gray border, appearing at times as spots edges the scales. All fins are colourless, one exception being the dorsal fin, which can present at its base a few darker spots.

Females of N.jubbi have a light blue to light brown body coloration. At the level of the mid-body, on the lower side there are small dark spots. Over the distal part of the body, run thin dark vertical stripes. Fins are colourless and finrays in anal and caudal fins are often slightly golden. Over the operculum there are some reflecting glitter scales. Scheel studied some of Leaky's 1962 material from Malindi in Kenya and observed that the females had a small fleshy pouch around the genital papilla, as can be observed in certain Fundulus species (Wildekamp et al., 1979). This structure, which enfolds the first anal fin rays, is in fact to be found in sexually active females of all cNothobranchius species. This structure must either play a role in channeling the egg through the duct formed by the anal fin at the time of spawning (Wildekamp et al., 1979) or at the level of hardening the egg shell just after spawning and before release in the soil.

Live female N.cyaneus present a light fresh gray-brown to gray-yellow body coloration and, on the posterior part of the body, diffuse gray spots or markings. Fins are colourless to light yellow. According to Seegers (1981) the female colour is typical; the body brown can be more yellowish and the dark V-shape circular markings over the posterior part of the body are well visible (these chevron-like markings can also be found in certain female N.patrizii populations).

Synonyms

For N.jubbi:

Nothobranchius neumanni "Malindi" Leaky, 1962
Nothobranchius spec. "Malindi" Wildekamp, 1977
Nothobranchius jubbi jubbi Wildekamp & Berkenkamp, 1979
Nothobranchius cyaneus Seegers, 1981
Nothobranchius spec. "Warfa Blue" - Somalia.
Nothobranchius jubbi K96/23 - Kenya

For N.cyaneus:

Nothobranchius neumanni, sensu Goldstein (1972)
Nothobranchius spec. "Warfa-blue", sensu Haas (1981)

The discovery of several Nothobranchius populations in northeastern Kenya and southern Somalia, consisting of males, some of which could be related to N.jubbi, others to N.cyaneus, was initially explained as polymorphism or polychromatism (Turner, 1964; Goldstein, 1972), later it was explained as the result of an hybridisation between two distinct species living in synpatry (Seegers, 1981 & 1985; Willert 1984). Most of these populations also include males displaying a colour pattern intermediary to N.jubbi and N.cyaneus, the size of the red spot on the caudal fin, ranging from a minuscule dot to an almost entirely red caudal fin, edged with blue-gray (Wildekamp, 1986). In 1985, Seegers (1985) considered that the blue morph would constitute a sub-species of N.jubbi, namely N.jubbi cyaneus, distinguishing itself from the red N.jubbi jubbi form by a slimmer body shape and higher counts in rays in the unpaired fins and scales.

As mentioned by Wildekamp (1986), it is obvious that in cases where polychromatism is present, the use of colour patterns as discriminating factors between Nothobranchius species, as advocated by Jubb (1969 & 1975), is of less practical use.

Wildekamp (1986) reports results of crossbreeding experiments with the "intermediary" populations of Azenda Bader [Figure 1] and Goba A, Somalia. He mentions that "F-1 specimens resembled their parents with the colour pattern of the caudal fin ranging from entirely blue as in the N.cyaneus phenotype to almost entirely red as in the N.jubbi phenotype. Intermediary colour types, with red spots of different sizes, were in majority. Similar results were obtained in successive generations of the Goba A population. All sorts of intermediary colour specimens were present and produced viable offspring's". Although dealing with the polychromatic aspect, above observation does not mention the polymorphic variability, which also must have been present if N.jubbi and N.cyaneus were to form one single species.

Apparently, one type of experiments is missing [or is still unknown to me]: crossbreeding of specimens belonging to different and not-intermediary populations such as the slender Somalia N.cyaneus Warfa blue population with deep-bodied and red N.jubbi specimens from Kenya. In case N.jubbi and N.cyaneus would form one single and the same species, one should be able to re-create the entire range of observed intermediary forms [both the colour intermediaries as well as the morph intermediaries].

According to Wildekamp (1986), N.jubbi is one of the larger species belonging to the N.orthonotus (Peters, 1844) group. Its' close relatives are N.melanospilus, N.guentheri, N.jubbi interruptus and N.elongatus. It distinguishes itself from these close relatives by a deeper body height, the position of dorsal and anal fins and its colour pattern in both sexes. Females of N.jubbi present irregular grayish marks over the body, reminding of the transversal V-shape bars in males. In the N.orthonotus group, body markings in females are common in several species; the body markings in N.jubbi closely resemble those observed in N.guentheri females, which are considered to form its' closed relatives (Wildekamp, 1986).

Availability in the hobby

Populations still in the hobby between 1996 -1999 are few and very uncommon; they include N.jubbi [or N.cyaneus] "Warfa" blue and N.jubbi "K96/23" [collected and introduced in the hobby by Seegers]. All efforts should therefore be made to secure a wider availability of these species.

Behaviour

Wildekamp (1986) mentions that N.jubbi from Goba "A" showed, both in its natural environment and in a confined environment, a peculiar behaviour. When frightened: they jumped out of the water. This behaviour is quite unique in the Nothobranchius world as nearly in all species, when scared, the fish swims towards the bottom and even hide in it. Although less marked, the F-1 generation also displayed this behaviour.

Holotype

For N.jubbi:

Adult male with a total length of 44.5 mm and a standard length of 36.0 mm, collected by J. H. E. Leaky in July 1962 in a pool along the road to Garsen, 17 miles north of Malindi on the Kenyan coastal lowlands. British Museum (Natural History) London [BMNH 1962-7-9; 4]

For N.cyaneus:

The type material for N.cyaneus is kept in the Forschungsinstitut und Museum Senckenberg in Frankfurt and in the British Museum (Natural History) in London.

Male of 40.0 mm total and 32.9 mm standard length; collected by K. Lung in August 1980 between Malindi and Garsen, 4 km beyond the village of Gongoni. SMF 163-97.

Allotype

Male of 31.2-mm total and 25.3-mm standard length collected with the Holotype SMF 163-98.

Paratypes

For N.jubbi:

• Seven males and three females (standard length 31.8 - 37.7 mm, total length 37.5 - 45.5 mm) with same collection date as the Holotype [BMNH 1962-7-9;5-14] (Wildekamp & Berkenkamp, 1979)

For N.cyaneus:

• Male of 31.2-mm total and 25.3-mm standard length collected together with the Holotype, SMF 163-98.
• 3 males and 1 female, F2-generation of wild caught specimens, from 25.2-38.8-mm standard length (31.8-47.6-mm total length); SMF 163-99 to 164-02.
• 3 males and 1 female, F2-generation of wild caught specimens, from 25.0-35.4-mm standard length (31.0-42.8-mm total length) BMNH 1981.9.30.2-5.

Size

Aquarium males can reach a total length of about 80-mm; females remain some 10-mm smaller.

Code

JUB

CYA

Distribution & Habitat

In 1986, Wildekamp proposed that N.cyaneus be considered as a junior synonym of N.jubbi. He published a list of localities from where N.jubbi specimens were collected in southern Somalia and northern Kenya (Wildekamp, 1986) [Table 9]. These localities are indicated in Figure 1

Table 9: List of known localities of N.jubbi in Somalia and Kenya (after Wildekamp, 1986)

A reminder of the collecting sites of Nothobranchius species in Kenya is given in Figure 2.

For N.jubbi:

The distribution area of N.jubbi species can be brought back to temporary pools in coastal lowland areas of northeastern Kenya and in pools in southern Somalia.

For N.cyaneus:

Lung collected the type specimens of N.cyaneus in eastern Kenya, "about 20-km after Malindi towards Garsen, comes the village of Gongoni, about 4-km after Gongoni, on the right side of the road in a 10x5 m large, 30-cm deep isolated pool. There is no river in the vicinity".

Somalia

In Somalia, N.cyaneus can be found in temporary pools, swamps and road ditches belonging to the lower Uebi Scebeli and lower Juba River systems and within the drainage system of the lower Tana and Sabaki rivers in northeastern Kenya. Apart from the collection localities known from these river systems, some more or less isolated populations have also been found in dryer continental locations in mid-eastern Somalia. According to Wildekamp (1984), the isolation of these inland populations must have happened rather recently on the historical time scale as no important genetic shifts have thus far occurred between them. Most likely because all these isolated populations and localities are to be found in areas belonging to ancient rivers or wadi's, geological sings of more humid times. The most recent of which occurred in 1996 and 1998 when large areas in southern Somalia and northern Kenya experienced severe floods.

In southern Somalia, between the monoliths and cities of Bur Acaba and Bur Eibi, Wildekamp (1984) discovered N.cyaneus in several "whar's" belonging to the intermediary villages. He inspected the "whar's" of Dekta [Sampling site n° 1], Warfa [S-2], Hogay [S-3], Kaisany [S-4] and Durbane [S-5]. All these localities harboured a similar Nothobranchius ichthyofauna namely: N.microlepis and N.cyaneus, of which N.species "Warfa blue" was a synonym. N.microlepis always appeared to be superior in numbers, with a slight preference for the deeper parts, but this was certainly not the rule. In each locality the water was very turbid, ranging from grayish to rusty-brown, depending on the local soil composition. The total water hardness varied between 5 and 15 DH, the carbonate-hardness between 4 and 6 DH, the acidity had an almost neutral pH value of 6.3-8.3. At the measured high water temperatures [always around 30° C], the dissolved oxygen content was evidently rather low with values ranging between 3 and 5.5 mg/l. The highest DH and pH values were recorded at Hogay, a "whar", which at the time of the visit, had almost dried up. As accompanying species Wildekamp consistently found Protopterus amphibius (Peeters, 1844), some frogs, water insects, numerous freshwater crabs and waterscorpions (Wildekamp, 1984).

At the foot of the Dur e Kalin [meaning silver hill] [S-6] monolith, south-east of Baidoa, in the middle of a flat and dry bushy country and only reachable through a long tall and dusty path of which the last part had to be made on foot, Wildekamp discovered a series of pools partly covered with a layer of duck-weed. All the pools contained a particularly beautiful, but rather very isolated population of N.cyaneus as well as freshwater crabs and tadpoles (Wildekamp, 1984).

The region of the lower Uebi Scebeli River, roughly between Afgoi and Merka, covers a flat area, separated from the ocean by a belt of sand dunes. Collecting Nothobranchius in this region is far less easy than in the northern area around the monoliths. Most often the open water can only be reached after crossing dense thorny bushes or marshy shores, and, once the open water reached, the scoopnet can only be moved around with great difficulty because of dense watervegetation (mainly consisting of waterlilies, Nymphea zanzibarensis) (Wildekamp, 1984).

Close to Shalanbod, in two road ditches [S-7 and S-8] along the road to Genale, Wildekamp discovered half-grown N.cyaneus. In contrast to previously discovered populations, these ones showed duller colours, the throat area was more yellowish, the fins showed less markings and the caudal fin presented a larger white marginal border. In the same waters, he also discovered some young specimens of N.patrizii who's males started to colour-out (Wildekamp, 1984).

On the road to Genale, in a swamp and also on both sides of an irrigation canal, which had not yet been infested with the Cichlid Oreochromis spilurus, Wildekamp discovered some very pretty N.patrizii specimens. Close to Corriole, he found N.cyaneus and N.patrizii living "syntopically" (= living together in the same habitat) in two locations [S-10 and S-11]. In the lower Uebi Scebeli River system, the water hardness ranged between 19 and 31° DH (total hardness) and between 4 and 14 DH carbonate hardness. The acid level was always above pH 7.5 whilst the oxygen content was rather low, as would be expected from a marshy environment: 1.2 to 3.2 mg/l with rather high water temperatures, between 28° and 33° C (Wildekamp, 1984).

In the area of the lower Juba River system, the monsoon influence becomes again more apparent at the level of Buale. Various fishing trials were carried out along the road from Gelib over Giamana to Kismayo, which all produced a similar picture: N.patrizii and N.cyaneus, interchanging with Clarias and lungfishes (Wildekamp, 1984).

In the vicinity of Azenda Bader, Wildekamp discovered that several males of the there living N.cyaneus population displayed a red spot on the caudal fin [S-13], reminding him of N.jubbi Wildekamp & Berkenkamp, 1979. Near Sunguni, in a swamp like ditch [S-14] in the system of the lower Juba, more N.cyaneus and N.patrizii were collected. More to the south of the Juba river mouth, at the level and just before entering the settlement of Goba [= Golba] [S-15], Wildekamp again discovered a N.cyaneus population displaying red spots in the caudal fin. With one specimen, this was even so obvious that initially he thought to have captured N.jubbi. In the same locality, one could also find a N.patrizii population, body very dark and large spots on dorsal and anal fins. Noteworthy was also the presence of a dark band in the caudal fin (Wildekamp, 1984).

Past the village of Goba [S-16], where the road was also flooded, Wildekamp discovered, beside N.cyaneus "red-in-the-tail" a N.microlepis related species [= tiny scales and females with prolonged first anal fin rays] "N.spec.affinis microlepis Goba B" (Wildekamp, 1984).

Kenya

In northeastern Kenya, N.cyaneus can be found in temporary pools, swamps and road ditches belonging to the lower Tana and Sabaki rivers.

In June 1962, a fish was improrted into the USA under the name N.neumanni. J.H.E. Leaky, the son of the reknown Kenyan anthropologist Dr M. D. Leaky, had found this fish in a pool with standing trees, 17 miles north of Malindi, along the road towards Garsen. In June, the pool was covered with water lilies and algae and was bordered with reed. At a following visit in December, the pool had already dried-up. Ten specimens of this collection were send to the British Museum (Natural History) where they were registered as N.neumanni (Wildekamp & Berkenkamp, 1979). Various aquariologists questioned the denomination of this import and the then unknown species was re-labeled N.spec. "Malindi". Later this Malindi species from the Kenyan coastal plains was designated as Nothobranchius jubbi and had thus nothing to do with N.neumanni from the Tanzanian central highlands.

It is only after Goldstein's publication in 1972 of excerpt from letters between Leaky and Turner that it appeared that this pseudo-N.neumanni had been caught in different locations. In his 1982 publication, Wildekamp (1982) mentioned that Leaky had also collected in a second very similar pool, 8 miles further north and that he again captured this pseudo-N.neumanni species. Wildekamp (1982) further unravelled that amongst Leaky's fish, which entered the USA on July 4^th 1962, were specimens with a blue caudal fin and others with a red caudal fin. From this observation, Turner proposed the idea of polymorphism.

In August 1978, E. Holler collected similar material in two locations north of Malindi, Kenya. The first locality was situated just behind Malindi's golf course, the second about 30-km more north on the right hand side of the road to Garsen near Ras Kitua in the southern part of the Tana delta (Wildekamp & Berkenkamp, 1979). These collections yieled however only fish with a red caudal fin.

In August 1980, K. Lung managed to re-collect near Gongoni, north of Malindi, Kenya, the form with the blue caudal fin which would bee described one year later, in 1981, by Seegers as N.cyaneus.

In 1968, P. Nagy collected a species with similarities to N.spec. "Malindi". This fish was collected from a swampy area around Kikambala, somewhat 15-km north of Mombasa, Kenya. The collector's location gave Kikambala at 45-km north of Mombasa, however topographical maps and Holler's notes confirmed the location of Kikambala at 15-km north of Malindi. Nagy provided several specimens of his collection to the Koninklijk Museum van Midden Afrika [KMMA] in Tervuren, Belgium, and to the Zoologische Staatssammlung München [ZSM]. Wildekamp & Berkenkamp (1979) assumed that possibly an aquarium population was also established under the codename Nothobranchius spec "U-6", one of them having become part of the KMMA collection. These Nagy Kikambala specimens where later described as Nothobranchius jubbi interruptus by Wildekamp & Berkenkamp (1979).

In northern Kenya, Willert and Langnickel collected N.jubbi in 1985 in a residual pool of a small stream flowing to the lower Tana River. The locality is given as 1-km from the road junction between the road to Mnanzini and the Garsen to Garissa road, in the direction of Mnanzini" {01°59' S-40°08' E}. The species lives there syntopic with N.willerti {= spec. "Mnanzini"} and N.patrizii.

Four Nothobranchius species are presently known from the lower Tana river system in the coastal plains of north-eastern Kenya.: N.jubbi Wildekamp & Berkenkamp, 1979, the most widely distributed species; N.patrizii (Vinciguerra, 1927), N.microlepis (Vinciguerra, 1897), only known from three localities which have been studied by Wildekamp & Haas (1992), and N.willerti which was discovered in the early eighties by Willert & Langnickel. In general, N.jubbi is found living in synpatry [=together] with one of the above mentioned three species.

In July 1985, during a collecting trip in Kenya, which led Willert and Langnickel towards the north, from Mombassa via Malindi and Garsen, they drove along the Tana River, on their way to Garissa. The wood-like terrain gradually changed from a bushy- into a sandy-Savannah. During the entire trip no single Nothobranchius could be netted, not even at an, already in 1983 known, collecting site for N.microlepis {between garsen and Hola}. All pools along the road had already dried out during this late season period. In Garissa Willert and langnickel gave up their courage and began the return trip to Mombassa.

Because no remnant waters could be found on the onward journey, they tried to reach closer to the Tana River, in order to try their luck in remaining marshes and inundated areas. Twice this didn't produce any result. By the third trial to reach closer to the river (the road to Mnanzini), the road led over a small brook where once again they threw out their nets. At last and for the first time on their long journey towards the north, a Nothobranchius of about 2-3 cm length was netted. After some hours the catch yielded 3 males and 6 females. In the same brook two other syntopically living Nothobranchius species appeared: N.patrizii and N.jubbi. Some 30 Nothobranchius specimens were caught in this particular habitat. During the return journey to Mombassa, close to the Tana River, they always could find inundated grasslands where, almost always, some Nothobranchius could be found, namely N.patrizii and N.jubbi.

Wildekamp (1982) further observed that the species N.elongatus, N.jubbi and N.interruptus could be considered as "bordering species" in Huber's sense (1980); forming a transitional group of species between, on the one hand, the N.melanospilus-N.palmqvisti species-group inhabiting the Kenyan southeastern [south of the Ramisi River] and Tanzanian northeastern coastal lowlands [Tanga & Pangani] and, on the other hand, the N.cyaneus and N.jubbi species-group inhabiting the northern Kenyan and Somalian coastal lowlands and forming a counter-group of possibly "bleu" species, related or equal to N.cyaneus, with a large distribution area in southern Somalia. N.jubbi and N.interruptus seem to occupy an intermediary position between both coastal lowland species-groups [the Kenyan/Tanzanian N.melanospilus-N.palmqvisti on the one hand and the Somalian N.cyaneus on the other hand]. N.jubbi has indeed a same number of chromosomes as N.cyaneus [both with n=17] and N.elongatus and N.melanospilus have n=19. The position occupied by N.interruptus is however still unknown.

History

Initially, both N.jubbi and N.cyaneus where identified as distinct and separate species (Wildekamp & Berkenkamp, 1979; Seegers, 1981). However, the discovery in the late seventies early eighties, in northern Kenya and southern Somalia, of several populations, some of which presented specimens displaying all intermediary color patterns and forms between both species, linkable to both N.jubbi and N.cyaneus, created an unsatisfactory taxonomic situation. Wildekamp resolved this confusing situation in 1986 by placing them in synonymy (Wildekamp, 1986). Both species are still recognised as very closely related and were described from collecting sites laying in each other vicinity near Gongoni, some 25-km north of Malindi, eastern Kenya.

Although some Nothobranchius from Kenya, dating back to 1892, had been preserved in the British Museum (Natural History) in London, one had to wait until 1962 to obtain a first larger fish collection from J. H. E. Leaky. The type material of N.jubbi originates from a batch of aquarium fish, send by Leaky to the U.S.A. He had collected the fish from a temporary pool along the road from Malindi to Garsen. Leaky and B. J. Turner thought these fish belonged to N.neumanni (Hilgendorf, 1905) and distributed them as such (Wildekamp, 1979, 1986). Wildekamp & Berkenkamp (1979) recognised this and, based on the study of the type material of N.neumanni (Hilgendorf, 1905) and from a study of Neumann's trip report, a more precise identification of the original Type locality of N.neumanni in central Tanzania could be established. Following this first identification correction, Wildekamp & Berkenkamp described this red-tailed fish as N.jubbi in 1979.

In a correspondence over Leaky's collection with ichthyologist B. J. Turner, which was made public in 1972 by Goldstein, it became clear that the as N.neumanni in the hobby erroneously distributed fish, originated from two collecting sites. One collecting site was "17 miles north of Malindi, along the road to Garsen (Kenya)" and the second site produced "also 7 specimens (larger) of the same species from a similar pool, somewhat 8 miles further north" (Seegers, 1981). This correspondence further mentions that in the original import, there were many specimens with a uniformly blue caudal fin and only a few with a large red spot in the caudal fin. On this basis Turner (1964) concluded that the species was polymorphic, implying that the species could have different external colour forms, in this case blue- and red-tailed male specimens. Over the years, the entirely blue form seems to have disappeared from the hobby as only the red form seemingly attracted the hobbyists. On the other hand, if one had a real polymorphic species, as proposed by Turner in 1964, one would always, on genetic grounds, find sooner or later, a certain percentage of differently coloured specimens in a large amount of offspring's.

Subsequent to Leaky's collection, two other imports from Kenya arrived in Europe and the USA. In 1968 Nagy collected near Kikambala, about 15 km north of Mombasa. Another import made by Walpole originated from northwest of Mombasa. According to Wildekamp & Berkenkamp (1979) it is probable that amongst these imports there was a fish which got described as N. jubbi interruptus.

In August 1978, a fresh visit by Holler to the initial discovery site north of Malindi, Kenya yielded only the red phenotype. He also brought back the true N.palmqvisti from Mrima, N.melanospilus, N.jubbi interruptus and N.elongatus.

In August 1980, K. Lung, a German hobbyist, collected the type material of the other related species, N.cyaneus, during a collecting trip to eastern Kenya. All males from his population presented an entirely blue colour pattern and were recognized as Turner's blue phenotype of 1964 (Seegers, 1981, Lung & Seegers, 1981). During this trip K. Lung also undoubtedly collected N.jubbi interruptus near Kikambala, about 25 km north of Mombasa. The collecting site for the second species is given by Lung as "about 20-km after Malindi towards Garsen, comes the village of Gongoni, about 4-km after Gongoni, on the rightside of the road in a 10x5 m large, 30-cm deep isolated pool. There is no river in the vicinity", eastern Kenya. The Lung location closely resembles the Leaky collection site; both must either be identical or occurr in each other's vicinity. The blue phenotype collected by Lung in 1980 did not live syntopic with the red-form as previously thought. The entire population only comprised blue forms. LUNG provided Seegers with material for further research and it appeared that also in following generations this blue phenotype remained stable.

Much to people's surprise, Lung thus re-discovered the blue phenotype under its pure form. In 1981, Seegers described this blue phenotype as N.cyaneus. Seegers (1981) differentiated N.cyaneus and N.jubbi not only on the basis of their tailfin colour, but also found a slimmer bodyshape, higher counts in number of fin rays in both dorsal and anal fins and a smaler dorsal and anal fin in N.cyaneus. Also the fact that, worldwide in the hobby, N.jubbi had already reproduced for over 20 years according to a single pure red-tailed lineage, and that N.cyaneus had produced two pure blue lineages, constituted sufficient grounds for Seegers (1981) to recognize in these species two, genetically distinct, sympatrically living species (Wildekamp, 1986).

Dr. R. Haas, on a World Health Organization's (W.H.O.) assignment, collected additional material originating from mid-eastern Somalia in January 1979. These specimens could be linked to N.cyaneus and originated from Warfa, in the middle Uebi Scebeli River drainage system, Somalia. This population was introduced into the hobby as N.sp. "Warfa blue" (Haas, 1982, Foersch, 1981). The very close similarity of this fish with N.cyaneus was pointed out by Wildekamp (1982), who considered it to belong to N.cyaneus in 1983 and 1984 (Wildekamp, 1986). The resemblance between N.cyaneus and the "Warfa-blue"-form from Somalia remains striking. The latter form presents a somewhat slimier body but can produce offsprings with a red colour in their caudal fin base, which tend to indicate a possible relationship with N.jubbi.

Haas (1982) collected in January-February 1979 N.microlepis and the then undescribed N. spec. "Warfa-Blue" [first described as N.cyaneus, presently considered as a junior synonym of N.jubbi] in a large depression ["War"] holding rainwater. The location was some 180-km north-west of Mogadishu, near the village named Warfa in the bush, some 18-km East of a large monolith called Bur Hacaba on the road from Mogadishu to the town of Baidoa. In this area, over 150-km away from any river or other permanent water body, rainwater is collected in large depressions, which have been enlarged by local residents to collect rainwater. These "Wars", in contrast to the more southerly situated roadside ditches where N.patrizii were collected by Haas (1982), were completely without any aquatic vegetation. The water in these "Wars" was completely opaque with a very reddish cast. The bottom consisted in red clay and the water temperature ranged between 26.5 and 31°C [80-88 °F], the pH was around 7.8, and the dGH 36-39. Haas (1982) was informed that most "Wars", except in very dry years, are more or less dry for no more than two months and that most have had deep wells dug in their centres where water remains available in very dry periods.

Haas (1982) reports that N.patrizii, N.microlepis and N.cyaneus "Warfa-Blue" were brought to the United States in 1979, as eggs collected with the mud from their temporary ponds.

Dr. R. Haas has provided Wildekamp with specimens from his personnal collection and with fieldnotes on collecting sites from where he did collect Nothobranchius species. Haas found N.cyaneus near Genale, Bur Heibi and Haya, as well as mixed populations of N.jubbi and N.cyaneus near Afmadu and Halima Adai (Wildekamp, 1986).

A subsequent expedition to Kenya by M. Forstner and Manfred and Brigitte Willert in June and July 1983, showed that N.cyaneus presented a vast distribution area in north-eastern Kenya, while N.jubbi had on the contrary a distribution restricted to the lower Galana and Tana river systems in north-eastern Kenya.

Their base of operations was Mombasa. From here, different collecting trips were organised. On the first collecting journey they drove northwards and collected N.interruptus near Kikambala [same locality as Lung]. Near Kaloleni however they could not find N.elongatus. In the direction of the south towards the Tanzanian border they collected a 6-cm long N.palmqvisti male. Afterwards they moved once again northwards towards the drainage system of the Tana River. Past Malindi, about 3 km after the village of Gongoni, they collected in a pool N.cyaneus {air temperature 23.5°C, water temperature 27.3°C.}. 22 km before Garsen, in a sort of flooded grassland with a water temperature of 29°C°, they captured N.cyaneus and N.jubbi together in the same pool. 53-km north of Garsen, in the direction of Garissa, N.cyaneus was captured together with N.microlepis. Somewhat further north, it became too dry and no suitable biotopes could be found. In all, between Malindi and Garissa they collected N.jubbi and N.cyaneus in eight different localities: in four of these localities only blue phenotypes, corresponding to N.cyaneus, were found. In the four other localities, the population was composed of a mixture of blue and red phenotypes, but also specimens representing all intermediary forms in the red colour pattern of the caudal fin. Willert (1984) identified these populations as belonging to N.jubbi and N.cyaneus, whilst the intermediary forms were recognised as hybrids. On the return trip to Mombasa, 45-km north of Malindi, they captured once again N.cyaneus and N.jubbi together in the same pool, but also specimens, which looked like crossings between both species. Strangely N.patrizii was also discovered in the same pool, which had until then a distribution extending far more to the north, in Somalia (Wildekamp, 1986).

In the most southern part of eastern Somalia and in the lower Tana river system, populations were discovered which resembled both N.jubbi and N.cyaneus, but also specimens which displayed all possible intermediary colour gradations between both types. This phenomenon had been declared on several occasions as a sympatric co-habitation of two different species, in which the intermediary forms could then be declared as hybrids. These hybrids should then be sterile in order to guarantee the survival of the real bio-species. The thought of polymorphism - as proposed by Turner in 1964 - had been generally dismissed. Because of this, a taxonomic un-satifying situation resulted and a comparative morphological study was carried out between 16 different populations of N.jubbi, N.cyaneus and their intermediary forms, originating from Kenya and Somalia. Also a cytological study of 5 populations was conducted. In addition, the behaviour of 16 and reproduction of 7 different Somalia populations was studied. All the studied populations showed very close similarities and could no longer be discriminated and considered as different species. As conclusion, N.cyaneus should therefore be considered as a synonym of N.jubbi.

Maintenance & Breeding

N.cyaneus is probably one of the least wanted species of the genus. Until now, the species has not shown to be particularly difficult to breed and to maintain, but this is based on experiences from more experienced hobbyists.

Water hardness plays only a secondary role in the maintenance, as in nature values ranging between 5 to 40 DH have been observed. Analysis of stomach contents did show that the natural diet mainly consisted in copepods, waterfleas, but also mosquito larvae. In order to attain proper grow and good health conditions, it is advised to use clean soft and, some breeder even recommend slightly acidic, water. These fishes grow rather rapidly and are very active which implies that regular partial water changes will be absolutely necessary. Water pollution must be avoided at all costs and the water temperature should preferably range between 23 and 27°C. It is also advised to add salt [1 teaspoon of kitchen salt per 5 or 10 litres of tank water] as preventive measure against velvet [Oödinium].

Reproduction of the species can be achieved by using 1 male and from 2 to several females in a small and simply arranged aquarium. In order to improve on productivity, it is advised to breed with several trios in a slightly larger aquarium. In case the humid peatmoss containing the eggs is stored at 20-22°C, the incubation period will be between 6 weeks and 3 months. During this period, one can regularly inspect the eggs for "eyed-up" embryos. During one of the water immersions, the hatching rate will be larger, but one will have to re-dry the peatmoss containing the non-eyed-up eggs and check for them once per month. Once sufficient peat bags have been collected, one can hatch eggs nearly every month and, in doing so, one can have at one's disposal, adults and fingerlings the whole year round.

Young fish grow very rapidly and, with frequent water changes and plenty of food at their disposal, they can reach sexual maturity after only 5-6 weeks. They are particularly active and always on the move looking for food or for a partner.

Water temperatures will best be kept around 22° C., as otherwise the fish becomes sensitive to velvet (Oödinium). Ideal would be a temperature of 24° -26° C. pH values are best kept somewhat higher than the neutral point. A few couples of the species can be kept in a medium sized tank, provided one secures for females and secondary males many shelter opportunities. To this end, plenty of vegetation and several pieces of peat fiber are already enough. Filtering the water is not absolutely necessary when it is being regularly and partially changed. They require rich feeding, comprising all sorts of mosquito larvae and worms. Daphnia are not eagerly taken whilst Cyclops seem to enhance general body coloration and egg ripening.

For reproduction, a 20-30-l tank with a 2-3 cm thick peatmoss layer is already enough. A trio can easily be maintained for spawning during 1-2 weeks in such a tank. Every 2 weeks, the peatmoss is removed and replaced with new one. Peatmoss containing eggs is slightly pressed and left to dry for one to two days on kitchen-roll paper until the outer layer takes a light brown colour. The development time for the eggs depends on several factors. Eggs of wild caught and F-1 specimens can already be developed after only 6 weeks, if they are being kept at temperatures ranging between 25° -30° C. At similar temperatures the development time is usually around 10-12 weeks. Eggs preserved in relatively dry peatmoss will develop faster than those kept in more wet peat. Hatching the eggs happens in soft water of about 15°-18°C. Fry will usually hatch all together such that a second drying period is often not necessary.

The fry can handle freshly hatched Artemia nauplii, later Cyclops and Grindal worms. The species is very productive, producing many eggs and fry. These will thus have to be transferred to larger tanks. A regular and partial water change is required. At an age of 4-6 weeks the young have reached sexual maturity. Keeping sexes separated from this moment onwards is often recommended, unless males are kept without females.

Literature

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