Nothobranchius albimarginatus
Watters, Wildekamp & Cooper, 1998

Last updated 01/05/2000

 

albimarginatus: Latin adjective derived from albus [white], and marginatus [edge, margin, border] - in reference to the distinctive white marginal border on dorsal and anal fins in males.

First Description

Watters, Wildekamp & Cooper - 1998 - "Zwei neue Nothobranchius-Arten aus der Küstenebene Tanzanias" - D.K.G.-Journal, 30(3): 52-63, 14 figs., 2 tabs

Terra Typica

N.albimarginatus "Kiparanganda TAN 97/40" was collected by Watters, Wildekamp and Cooper on June 11, 1997 in Tanzania, at location Kiparanganda, TAN 97/40, about 0.5 km south of the Lukwale River, Eastern Tanzanian coastal plains.

Figure 1: Location of the Type locality of N.albimarginatus in Tanzania.

 

Meristic Data

The morpho-meristic data of N.albimarginatus as reported by Watters et al. (1998) are presented in Table 1.

Table 1: Morpho-meristic data of N.albimarginatus in % of standard length (SL). SL in mm.
[After Watters et al., 1998]

Males:

Measurements

Holotype

Range in Paratypes

Average

Stand. Deviation

SL

32.5

22.5 - 26.6

 

 

Head length

32.6

30.5 - 33.7

32.4

0.91

Body height

27.7

23.8 - 27.3

25.8

1.09

Body width

14.8

12.0 - 15.4

13.5

1.08

Eye diameter

8.6

09.6 - 10.6

9.9

0.42

Inter-orbital width

12.3

10.6 - 12.6

11.7

0.65

Snout length

6.5

06.4 - 08.0

7.2

0.52

Distance snout-Dorsal fin

54.4

56.9 - 62.8

59.1

1.76

Distance snout-anal fin

56.9

57.1 - 61.0

58.4

1.28

Distance snout-ventral fin

46.2

44.3 - 46.9

45.5

0.81

Length caudal peduncle

21.8

20.8 - 23.1

22.7

1.13

Height caudal peduncle

12.3

11.9 - 13.2

12.7

0.47

Females:

Measurements

Range in Paratypes

Average

Stand. Deviation

SL

20.6 - 21.7

 

 

Head length

33.3 - 35.9

34.6

0.92

Body height

22.7 - 24.3

25.3

0.57

Body width

13.4 - 16.7

15.6

1.82

Eye diameter

10.1 - 10.8

10.4

0.29

Inter-orbital width

10.8 - 11.7

11.3

0.37

Snout length

06.1 - 07.4

6.8

0.54

Distance snout-Dorsal fin

59.6 - 63.1

61.2

1.29

Distance snout-anal fin

61.0 - 63.1

61.8

0.81

Distance snout-ventral fin

46.6 - 49.3

47.9

1.11

Length caudal peduncle

22.6 - 24.4

23.5

0.68

Height caudal peduncle

11.5 - 13.1

12.2

0.64

 

Table 2: Fin ray and scale counts [After Watters et al., 1998]

# dorsal fin rays

13 - 15

 

# anal fin rays

14 - 16

 

Scales in mid-lateral line series

24 - 27

+ 2-5 scales on caudal fin

# scales around body along ventral fins

10 - 11

 

# scale around caudal peduncle

7 - 8

 

 

Synonyms

The first report of N.albimarginatus was from B.J. Cooper, B.R. Watters and R.H. Wildekamp who collected the fish on June 11, 1997 at location Kiparanganda, TAN 97/40, about 0.5 km south of the Lukwale River. From a 1998 collecting trip, Rosenstock, Agnew, Watters and Larsen brought back an additional population, indicating that at present there are two known populations:

N. sp. 'Kiparanganda' TAN 97/40 = N.albimarginatus 'Kiparanganda' TAN 97/40
N. sp. 'Kiparanganda' TAN 98/13 = N.albimarginatus 'Kiparanganda' TAN 98/13

Watters (1998b) mentions that "these are two populations (TAN 97/40 and TAN 98/13) of the same species collected from different pools in the same general area". He further reported that "the pools were not far away from one another but they were not interconnected. The village of Kiparanganda lies approximately equidistant from both pools, hence the use of that location name for both populations". However, Larsen (1999a & b) mentions that during their 1998 collecting trip, they did not keep the N.albimarginatus population found south of the Mbezi River as they "were told where to go for more fish. We found the place quickly, a shallow pool with many water lilies. Here we caught N.albimarginatus again and N.annectens" [this is incorrect and should read N.rubripinnis (Watters pers. comm.)]. Some ambiguity arose from Larsen's travel reports (1999a & b), which Watters (pers. comm.) clarified: "We were told where to find more fish by a group of local inhabitants. Initially, we stopped at the original location (TAN 97/40) and, because of very dense, thorny vegetation around the pool could only get to the edge at one place where it was almost impossible to use a net. I did, however, manage to find a couple of males only, which we did not retain. We showed the fish to some local people who were watching our activities and they immediately directed us to another locality (TAN 98/13) where we found both males and females of N.albimarginatus as well as a few males only of N.rubripinnis. ...The fish from the two localities are very similar but the localities are quite distinctly different".

Holotype

Male of 32.5 mm standard length [SL], collected near Kiparanganda in a pool on both sides of road B2 [or T7 on other maps] from Dar-es-Salaam to Kibiti and/or Ikwiriri, about 0.5 km south of the Lukwale River [39° 10' 31" E - 07° 11'40" S] - MRAC 97-82-P-9. B.J. Cooper, B.R. Watters and R.H. Wildekamp collected the fish on June 11, 1997. The specimen was preserved in 70% ethanol after one month of deep-freezing and six month of aquarium maintenance.

The Type and Paratype specimens are kept at the Royal Museum for Central Africa, Tervuren, Belgium.

Paratypes

Eight males of standard length ranging from 22.5 to 26.6-mm [MRAC 97-82-P-10-21] and four females of 20.6 to 21.7 mm SL collected together with the Holotype.

Size

Males can reach a maximum length of 50-55 mm. Females remain somewhat smaller, 45-50 mm.

Code

ALB

Distribution & Habitat

At the time of its description in 1998, Watters et al. (1998) only knew one single collecting site for N albimarginatus, that of the type locality [Kiparanganda, TAN 97/40], about 0.5 km south of the Lukwale River. In June 1997, this locality consisted of two swampy pools located on both sides of the main road B2 [T7 on other maps] from Dar-es-Salaam to Kibiti and/or Ikwiriri. The pools are interconnected through several large culverts running under the road. The pools are situated in the land-triangle formed by the Lukwale and the Mbezi Rivers, which join each other about 1-km more to the East of the B2 [or T7] junction. As accompanying fauna, Watters et al. (1998) also collected in these pools N.melanospilus, Barbus kersteni Peters, 1868 and Brycinus affinis Günther, 1894.

At the time of collection, the water in the western pool had a temperature of 24 °C [74°F], a pH-value of 6.02 and a conductivity of 120µS. The water was clear and had a rich aquatic vegetation, amongst which Nymphaea zanzibariensis and Urticularia inflexa (Watters et al., 1998).

During their May 1998 journey, Rosenstock, Agnew, Watters and Larsen caught N.albimarginatus south of the Mbezi River along the road from Dar-es-Salaam to Kibiti, but did not keep the captured specimens. A little further down the road, near the village of Kiparanganda [locality Kiparanganda, TAN 98/13], in a shallow pool covered with many water lilies, Larsen reported that they collected N.albimarginatus and also N.annectens (Larsen, 1999a & b). However, Watters (pers. comm.) corrected the Larsen report and reported that the only two Nothobranchius species collected at the TAN 98/13 locality were N.albimarginatus and N.rubripinnis (males only).

Description

The body is rather slim, the snout pointed and the end-standing mouth is small and only slightly directed upwards. The lower jaw is thin. The beginning of the dorsal fin lies before, over or slightly behind the beginning of the anal fin and behind the middle of the body.

There are two rows of scales below the eye. Most of the scales in the mid-lateral line series have a flat groove not connected to an underlying neuromast system. The anterior and middle supra-orbital neuromast systems are connected and form two shallow grooves extending over the snout until between the eyes. Over their sides, these groves are covered with short extensions. The posterior supra-orbital neuromast system is not strongly curved and forms an angle of less than 90°. The head scalation pattern is not like in most other species of the genus covered with a thin skin layer but lies freely and present Hoedeman's (1958) G-pattern scalation. The pre-opercular neuromast system lies in an open grove, of which the posterior border slightly covers the gill cover [operculum].

The description of N albimarginatus as given by Watters, Wildekamp and Cooper (1998) is presented as follows:

Males are slim with all unpaired fins rounded. In their near body third, dorsal and anal fins are covered in a thin skin layer. The rays of the anal fin and the upper part of the dorsal fin rays are covered with small papillae. These papillae are made visible by the thin skin layer. The upper ray of the pectoral fins has relatively large papillae. The branchiostegal membrane slightly extends beyond the gill cover [operculum].

Females are also slim and smaller than males and have rounded anal and dorsal fins. The anal fin is in addition prolonged and rays 4/5-12/13 are long and hardened. Compared to males, the anal fin in females is more inserted towards the back. There are no papillae or a thin skin layer on either dorsal or anal fins. The branchiostegal membrane does not extend beyond the operculum. The anal and the genital openings are joined and the first anal fin rays do not lie in a surrounding pocket-like depression.

Colour description

The description of N albimarginatus as given by Watters, Wildekamp and Cooper (1998) is presented as follows:

In males, body and head scales are reflecting light blue with a deep-red border. Along the end-part of the body, these dark scale borders build-up chevron-like circles. The chin and the belly side are bright yellow. The dorsal and anal fins are light greenish with a pattern of deep red spots, which at times form arch -like stripes. Both these fins have a clearly marked white to white-blue outer band. The caudal fin is deep red without marginal band. The ventral fins are light yellow-green, some irregularly set red spots and a white-blue marginal band. The pectoral fins are transparent light yellow with a whitish marginal band.

In females, the head and the body is light yellowish brown. The backside is somewhat darker. The belly side is light whitish-brown. Scales on the operculum and over the first body half are light blue. All fins are transparent and colourless.

Relationships

Watters et al. (1998) consider N albimarginatus to be a small species belonging to the N.guentheri-group, distinguishing itself from all the other species of this group - with the exception of N.korthausae Meinken, 1973 and N.palmqvisti Lönnberg, 1907 - by the presence in males of a clearly marked white border on the edges of dorsal and anal fins. N.albimarginatus distinguishes itself from both above-mentioned species by a more pointed snout-end, by large hook-like teeth in the outer rows of the pre-mandible and dental jawbones and by the male body coloration.

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]. 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 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 a second sister-group with the N.guentheri-species-group. This second sister-group is made up 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).

Maintenance & Breeding

N.albimarginatus is straightforward to breed, using the standard Nothobranchius techniques. The fry should hatch after 3 months of wet-dry incubation. The fry is small, so the use of very freshly hatched Artemia is recommended. One should use the first hatched nauplii for feeding the fry.

When incubated for 3 weeks in water, Addis (1999) found that both N.annectens and N.albimarginatus will start hatching albeit in small numbers. With the N.annectens, he found about 15 hatched from about 1000 eggs. From these 15 fry, 12 were raised normally and ended-up fit and healthy. Both species are also very productive.

Bibliography