Nothobranchius annectens

Nothobranchius annectens Watters, Wildekamp & Cooper, 1998
Last updated 19/10/2000

annectens: Latin adjective derived from the Latin verb annectere [to connect, link, join], relating to the position the species occupies in linking N.guentheri living on Zanzibar [Ungunja] Island to the other species belonging to the same N.guentheri-group but living on the mainland. The authors believe that N.annectens represents the mainland species that is probably most closely related to N.guentheri itself.

Photograph 1: N.annectens red chromo-type {photo: St. Valdesalici}

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.annectens was collected for the first time in 1995 by Wildekamp, Watters and Sainthouse and named N. sp. "Bagamoyo TAN 95/13".

Meristic Data

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

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

Males:

Measurements	Holotype	Variation in Paratypes	Average	Stand. Deviation	Variation Bagamoyo	Variation Somanga
SL	21.3	No data	No data	No data	33.4	34.1
Head length	33.3	"	"	"	30.2	29.6
Body height	35.2	"	"	"	30.8	29.3
Body width	14.1	"	"	"	15.0	15.0
Eye diameter	12.7	"	"	"	10.2	10.3
Inter-orbital width	12.2	"	"	"	12.9	12.9
Snout length	8.0	"	"	"	6.6	7.0
Distance snout-Dorsal fin	57.7	"	"	"	56.0	63.0
Distance snout-Anal fin	59.2	"	"	"	64.4	63.9
Distance snout-Ventral fin	45.1	"	"	"	43.7	49.9
Length caudal pedicel	21.6	"	"	"	21.0	17.6
Height caudal pedicel	14.1	"	"	"	9.9	13.5

Females:

Measurements	Variation in Paratypes	Average	Stand. Deviation	Variation Bagamoyo	Variation Somanga
SL	19.1 - 23.5			21.5 - 26.6	29.4
Head length	31.1 - 37.6	33.8	2.44	30.4 - 35.6	34.7
Body height	28.5 - 32.3	30.3	1.78	28.2 - 32.3	30.6
Body width	15.3 - 18.8	16.5	1.43	17.0 - 20.5	22.4
Eye diameter	10.2 - 12.2	11.5	0.78	10.0 - 12.0	10.9
Inter-orbital width	11.1 - 12.7	11.9	0.65	10.1 - 12.6	12.2
Snout length	6.0 - 7.9	7.0	0.67	5.7 - 7.4	5.8
Distance snout-Dorsal fin	58.3 - 64.8	61.6	2.30	56.7 - 61.3	64.6
Distance snout-Anal fin	59.6 - 68.1	65.0	3.29	60.0 - 66.0	67.3
Distance snout-Ventral fin	46.8 - 52.4	50.0	2.36	47.0 - 51.2	53.1
Length caudal pedicel	18.1 - 20.5	19.5	0.90	20.5 - 27.1	18.0
Height caudal pedicel	12.9 - 14.4	13.9	0.57	12.1 - 14.8	12.6

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

# dorsal fin rays	15 - 17
# anal fin rays	15 - 16
Scales in mid-lateral line series	25 - 26	+ 3-4 scales on caudal fin
# scales around body along ventral fins	11
# scale around caudal peduncle	7

Synonyms

N.annectens was collected for the first time in 1995 by Wildekamp, Watters and Sainthouse and named N. sp. "Bagamoyo TAN 95/13". In 1997, Wildekamp, Watters and Cooper collected again the species from two additional locations, designated as N. sp. "Somanga North TAN 97/34" and N. sp. "Kitonga South TAN 97/36". From another trip in May 1998 in southern Tanzania, from Dar-es-Salaam to Ndundu on the Ruhoi River, Larsen, Rosenstock, Watters and Agnew brought back three additional populations from within the Ruhoi River system, so that at present following populations are known:

N.sp.'Bagamoyo' TAN 95/13
N.annectens 'Bagamoyo' TAN 95/13
N. sp. 'Somanga north' TAN 97/34
N.annectens 'Somanga north' TAN 97/34
N.sp. 'Kitonga South' TAN 97/36
N.annectens 'Kitonga south' TAN 97/36
N.annectens 'Ruhoi River' TAN 98/11 (red chromo-type)
N.annectens 'Ruhoi River' TAN 98/12 (red chromo-type)

Larsen, (1999a & b) mentions a N.annectens 'Kiparanganda' TAN 98/13 population collected during the 1998 trip. However, Watters (pers. comm.) corrected the Larsen reports and mentioned that the only two Nothobranchius species collected at the TAN 98/13 locality were N.albimarginatus and N.rubripinnis (males only).

Holotype

Male of 21.3 mm standard length [SL], collected 5.5-km south of Kitonga in a pool in a ditch along the western side of the road from the ferry over the Rufiji River in the direction of Nyamwage, in the vicinity of the Rufiji floodplain [39°00'13" E - 08° 04' 37" S] - MRAC 97-82-P-22. B.J. Cooper, B.R. Watters and R.H. Wildekamp collected the fish on June 9, 1997. The specimen was preserved in the field. Both the Type and Paratype specimens are kept at the Royal Museum for Central Africa, Tervuren, Belgium.

Paratypes

Four females of 19.1 to 23.5 mm SL collected together with the Holotype - MRAC 97-82-P-23-26.

Additional material

Additional material used during the description of the species included:

Male of 33.4-mm SL and eight females of 21.5-26.6-mm SL [MRAC 98-08-P-19-27], collected west of Bagamoyo in a pool along the northern side of the road from Bagamoyo to the Ruvu-Ferry, in the floodplain of the Ruvu River [38° 51'32" E - 06° 28' 51" S], Tanzania. This fish were preserved in the field and were collected by I.F.N. Sainthouse, B.R. Watters and R.H. Wildekamp on June 12, 1995.

Male of 34.1-mm SL and female of 29.4-mm SL [MRAC 97-82-P-27-28], collected 3-km north of Somanga in a pool on the west-side of road B2 [or T7 or other maps] leading from Nangurukuru, near Kilwa, to Nyamwage [37°16'49" E - 08°22'40" S], Tanzania. B.J. Cooper, B.R. Watters and R.H. Wildekamp collected the fish on June 8, 1997. The specimens were preserved in 70% ethanol after one month of deep-freezing and 2 months of aquarium maintenance.

Size

N.annectens belong to the small Nothobranchius species. Males reach total lengths of about 45-mm females remain somewhat smaller.

Code

ANN
Distribution & Habitat

The Type locality [TAN 97/36] consisting in a series of annual pools in a depression situated on the western side of the Rufiji-Ferry road from Ndundu to Kitonga in the direction of Nyamwage. At collection time, these pools were covered with high grasses, water lilies and reed. Besides from N.annectens, Watters et al. caught as accompanying fauna N.melanospilus, N.janpapi, N.ocellatus and Clarias gariepinus. The water had a temperature of 25°C [77°F]. It had a conductivity of 100µS, a pH-value of 7.25 and was murky (Watters et al., 1998).

Several annual pools located in the floodplains of the Ruvu River, west of Bagamoyo [TAN 95/13]. These pools were heavily covered with grasses and reed and the water vegetation comprised Aponogeton abyssinicus and Nymphaea zanzibariensis. As accompanying fauna, Watters et al. (1998) found N.melanospilus, N.foerschi, and N.janpapi, Clarias gariepinus and several barb species. The water conductivity was 640 µS with a pH-value of 6.90 at 25°C [77°F]. Sainthouse (1995:141) mentioned about this collecting site: "Roadside pools and flooded grassy areas on the floodplain of the Ruvu River, a few kilometres from the ferry terminal west of Bagamoyo". Sainthouse (1996c:108) mentions the close similarity of this species with N.foerschi found at the same site. He further mentions that he had heard of a report that fertile eggs had been obtained with one barred N.annectens and one N.foerschi. If these two species were to represent two distinct species, this could not have happened.

A large annual pool on the western side of the road B2 [T7 on other road maps] from Nangurukuru near Kilwa to Nyamwage. This pool is located about 3-km north of Somanga [TAN 97/34]. Here Watters et al. (1998) reported that the water conductivity was 280 µS with a pH of 7.49 by a water temperature of 29°C [84°F]. Besides from N.annectens, they also caught N.melanospilus and N.janpapi. As water vegetation, they found here Ceratopteris cornuta, Lagarosiphon cordofanus and Urticularia inflexa.

During the May 1998 journey, from Dar-es-Salaam towards Ndundu on the Ruhoi River crossing, Watters, Rosenstock, Agnew and Larsen caught just south of the Ruhoi River, hidden between trees, scrubs and high grasses, at some distance from the road, in a small pool (4 x 2 m and 20-25-cm deep) five different Nothobranchius species in one single pool [Ruhoi River, TAN 98/11]: N.melanospilus, N.janpapi, P.ocellatus, N.eggersi and N.annectens. Additional fish present in the pool were Ctenopoma muriei, Aplocheilichthys kongoranensis and some barbs (Larsen, 1999). However, only a few specimens of each species were found, presumably because of the presence of the predator P.ocellatus (Larsen, 1999). They succeeded in capturing three males and two females of P.ocellatus. In an adjacent shallow [1 - 0.3-m wide and 2-3-cm deep] pool [1 to 1 1/2 m away] covered in high grasses, they also found some N.eggersi.

A few kilometres south of the previous locality [TAN 98/11], the same collectors fished a flooded area covered with high grasses and connected to a drainage channel or a large ditch (Larsen, 1999). In this last locality [Ruhoi River, TAN 98/12] they caught N.eggersi, N.annectens, N.melanospilus, and N.janpapi, Aplocheilichthys kongoranensis together with Ctenopoma muriei and some barbs and cichlids.

Figure 2: Collecting sites of N.annectens in Tanzania.

Figure 3: Collecting sites of N.annectens in Tanzania.

History

N.annectens was first collected in 1995 by Wildekamp, Watters and Sainthouse and was given the provisional name N. sp. "Bagamoyo TAN 95/13". In 1997, Wildekamp, Watters and Cooper collected again the species from two additional locations, designated as N. sp. "Somanga North TAN 97/34" and N. sp. "Kitonga South TAN 97/36".

During the May 1998 journey to southern Tanzania, from Dar-es-Salaam towards Ndundu on the Ruhoi River crossing, Watters, Rosenstock, Agnew and Larsen caught just south of the Ruhoi River, in a small pool (4 x 2 m and 20-25-cm deep) five different Nothobranchius species in one single pool [Ruhoi River, TAN 98/11]: N.melanospilus, N.janpapi, P.ocellatus N.eggersi and N.annectens (Larsen, 1999). As about 20-km north of the Rufiji River the road was flooded, they had to turn back. A few kilometres south of the previous locality [TAN 98/11], they fished a flooded area covered with high grasses and connected to a drainage channel or a large ditch (Larsen, 1999). In this last locality [Ruhoi River, TAN 98/12] they caught N.eggersi, N.annectens, N.melanospilus, and N.janpapi, Aplocheilichthys kongoranensis together with Ctenopoma muriei and some barbs and cichlids. Both the "Ruhoi River TAN 98/11" and the "Ruhoi River TAN 98/12" are red-forms.

Description

Medium sized Nothobranchius-species, which distinguishes itself from all other species of the genus by the anal fin pattern. In addition in males, with the exception of N.guentheri and N.rubripinnis Seegers, 1985, it is characterised by the presence of an irregular red spot on the gillcover [operculum]. N.annectens distinguishes itself from N.guentheri by the smaller body length and a greater body depth and, from N.rubripinnis, by a typical and different male colour pattern (Watters et al., 1998).

The terminal mouth is large and directed upwards. The lower jaw is thin. There are no hook-like teeth on pre-mandible and on dental parts of the jaw, the teeth in the external rows are larger than in the others. The beginning of the dorsal fin lies before the beginning of the anal fin and behind the middle of the body.

There is only one scale row under the eye. Most of the scales in the mid-lateral line series have a shallow groove, not connected to an underlying neuromast system. The anterior and middle supra-orbital neuromast systems are not connected and form two times two deeper grooves. Over their sides, these grooves are not or hardly covered with short body tissues. The posterior supra-orbital neuromast system runs over the posterior-border of the eye, not very visible and bend in an angle of less than 90°. The head-scales lie freely over the head. The pattern presents Hoedeman's (1958) G- head scalation type, whereby the G-scales, and in certain specimens the E-scales, have merged. 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 annectens as given by Watters, Wildekamp and Cooper (1998) is presented as follows:

Males are deep-bodied. All unpaired fins are rounded. In the near body third, dorsal and anal fins are covered with a thin skin layer. The rays of the anal fin are covered along their lower 3/4 with small papillae. The dorsal fin rays are covered with small papillae in their external half. These papillae stick through the skin layer only in the anal fin. The upper ray of the pectoral fins has relatively large papillae. The branchiostegal membrane extends beyond the entire gill cover [operculum].

Females are also deep-bodied but smaller than males and have rounded anal and dorsal fins. The anal fin is in addition prolonged and rays 3/5-8/10 are long and hardened. In larger females, the anterior part of the anal fin is covered with a thin skin layer. The dorsal fin is placed more towards the body-end than in males. There are neither papillae nor a thin skin layer on the dorsal fin. There are also no papillae on the anal fin. The branchiostegal membrane does extend only slightly beyond the gill cover [operculum]. The anal and the genital openings are separated and the basis of the first two anal fin rays lie in a surrounding pocket-like depression.

Colour description

The colour description of N annectens as given by Watters, Wildekamp and Cooper (1998) which only concerned the yellow-blue chromo-type was presented as follows:

In males, body and head scales are light green-blue reflecting each with a thin red border. Along the end-part of the body, these red scale borders build-up chevron-like circular bands. Between the circular stripes, the scale borders are lighter and thinner. The chin is bluish; the belly-side is bright yellow to white-yellowish. The dorsal and anal fins are light yellowish-green. The dorsal fin has a pattern of red spots, which at times form, as part of extensions of the body markings, concentric rings around the posterior half of the body. The anal fin is covered with red spots, which are only situated near the body. A few males present white tips at the end of the dorsal fin rays. The caudal fin is red transparent. Near the caudal peduncle, the colour is more intense and deep red. Along the upper and lower fin rays the tail colour present a deep red border. In sexually active males, the entire tail becomes deep red. The ventral fins are light green with a white marginal border and a few red dots. The pectoral fins are light yellow transparent with a light blue marginal band. The part of the branchiostegal membrane, which extends beyond the gill cover, is yellow with a white border; under the chin, this border becomes red.

The colour pattern of red chromo-type males can be seen from the picture below.

Photograph 5: Male of N.annectens of the red chromo-type
{Photograph: St. Valdesalici}

In females, the head and the body are brown olive to grey-brown. The dorsal backside is somewhat darker. The belly side is light whitish-brown. The body scales have a thin greyish border, which in the end-part of the body form concentric bands around the body. All fins are transparent, pale yellowish to 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

According to Addis & Green (1998) this species is very prolific. They lay small eggs and a trio can lay 500 eggs in a week. The males appear to be much more active than females. These authors report to keep Notho eggs in water for a couple of weeks and, after 3 weeks, eggs where hatching out in numbers, none of which were belly sliders Addis & Green (1998).

Addis (1999) found that both N.annectens and N.albimarginatus, when water incubated for 3 weeks, start hatching albeit in small numbers. With the N.annectens, he found that about 15 eggs hatched from about 1.000 eggs. From these 15 fry, 12 were raised normally and ended-up fit and healthy. Kept in the dark under a cover of duckweed, he found the colours of adult fish to be a lot deeper than in the parents.

Bibliography

Addis, T. & A., Green (1998): "Fish house diaries" - Journ. Brit. Killif. Assoc., Killi News; N° 394:96-98

Addis (1999): Excerpt from KillieTalk Digest, 6-VII-99, Amer. Killifish Assoc.

Hoedeman, J.J. (1958): "The frontal scalation pattern in some groups of toothcarps (Pisces, Cyprinodontiformes)" - Bull. Aquatic. Biol., 1: 23-28.

Larsen, F. (1999a): "Tanzania 1998" - Akvariebladet, Danske Akvaristers Tidsskrift, N° 1, Januar 1999:4-11, 20 figs.

Larsen, F. (1999b): "Tanzania, 1998" - Journ. Brit. Killif. Assoc., Killi News; N° 407:103-108, 8 figs.

Sainthouse, I. (1995): "Tanzania 1995, Locations and Species collected" - Journ. Brit. Killif. Assoc., Killi News, 361: 139-141

Sainthouse, I. (1996): "Tanzania 1995, Part I" - Journ. Brit. Killif. Assoc., Killi News; 369: 78-85

Sainthouse, I. (1996): "Tanzania 1995, Part II" - Journ. Brit. Killif. Assoc., Killi News; 370:92-97

Sainthouse, I. (1996): "Tanzania 1995, Part III" - Journ. Brit. Killif. Assoc., Killi News; 371:107-113; 8 figs.

Watters, B.R.; R.H. Wildekamp & B.J. Cooper (1998): "Zwei Neue Nothobranchius-Arten aus der Küstenebene Tansanias" - Journ. Deut. Killif. Gemein., 30(3): 52-63, 14 figs, 2 tabs.

Wildekamp, R.H. (1977): "Zur Identification von Nothobranchius guentheri (Pfeffer, 1893) und Nothobranchius palmqvisti (Lönnberg, 1907), zwei Saisonfischen aus dem südöstlichen Kenia und dem nordöstlichen Tansania; mit der Bescreibung von Nothobranchius steinforti species novum" - Journ. Deut. Killif. Gemein., 9: 33-46.

Wildekamp, R.H. (1981): "Zum Thema Nothobranchius guentheri und Nothobranchius melanospilus " - Journ. Deut. Killif. Gemein., 13: 25-31.