A revision of the genus Astatoreochromis (Teleostei, Cichlidae), East-Africa
Author
Banyankimbona, Gaspard
Author
Vreven, Emmanuel
Author
Snoeks, Jos
text
European Journal of Taxonomy
2013
2013-02-22
39
1
21
journal article
22326
10.5852/ejt.2013.39
e0694ecc-c114-4621-9209-ad8abdb60b9f
2118-9773
3814023
D40E1DD7-6472-4EA7-B2C2-242F601B1FD3
Astatoreochromis alluaudi
Pellegrin, 1904
Fig. 5
Alluaud’s haplo, local names: ‘Ifuro muhunde, Ifuro y’itanza, Ifuro y’ikomagi’ where ‘Ifuro’ is the local name given to all haplochromine species (Upper Akagera system,
Burundi
), ‘Icyasamyi’, ‘Ikaje’ or ‘Nyiramuhundi’ (Middle Akagera system,
Rwanda
).
Astatoreochromis alluaudi
Pellegrin, 1904: 385
.
Astatoreochromis alluaudi alluaudi
Greenwood, 1959: 174
, figs 1-3.
Astatoreochromis alluaudi occidentalis
Greenwood, 1959: 174-175
, figs 2-3.
Diagnosis
Astatoreochromis alluaudi
can be distinguished from
A. straeleni
by the possession of 4-7 anal spines (usually 5-6)
vs
. 3-4 (usually 3), 17-19 dorsal spines [rarely 16 (f2) or 20 (f2)]
vs
. 16-18 [exceptionally 19 (f1)].
Etymology
Named after Charles A. Alluaud, who collected the
type
specimens.
Type material
Lectotype
MNHN 1904.137
,
Kavirondo Gulf
,
Lake Victoria
,
Kenya
, designated by
Greenwood (1959: 167)
.
Paralectotypes
MNHN
1904.138–139,
BMNH
1904.6.281, same data as
lectotype
.
Specimens examined
KENYA
:
MNHN
1904.137,
lectotype
,
121.7 mm
SL
, Kavirondo Gulf Lake Victoria, coll. Alluaudi;
BMNH
1904.6.28.1,
paralectotype
, 116.0 mm
SL
, same data as
lectotype
;
MNHN
1904.138–139,
paralectotypes
,
92.8-113.8 mm
SL
, same data as
lectotype
.
UGANDA
:
AMNH
216258 (
3 specimens
),
53.5-70.7 mm
SL
, Lake Nabugabo, coll. L.J. Chapman & C.A. Chapman,
19 May 1994
;
BMNH
1964.7.1.109,
85.5 mm
SL
, Lake Nabugabo, coll. Cambridge University;
BMNH
1933.2.23.146 (
11 specimens
),
55.2-137.5 mm
SL
, Lake Nakavali, coll. E. Worthington;
BMNH
1958.12.5.74-75,
63.8- 121.4 mm
SL
, Lake Nakavali, coll. C. Pitman;
BMNH
1972.6.5.23-25,
44.8-101.6 mm
SL
, Lake George, coll. I. Dunn;
BMNH
1933.2.23.137-141,
61.4-79.8 mm
SL
, Lake Edward, coll. E.Worthington;
BMNH
1929.1.24.4,
87.8 mm
SL
, Lake Kyoga, coll. E. Worthington;
BMNH
1929.1.24.278,
70.9 mm
SL
, Lake Kyoga, coll. E. Worthington;
MRAC
A5.42.P.2-5,
66.3-128.4 mm
SL
, Lake Kayanza,
Kasese
factory, coll. M. Marquet,
22 Oct. 2005
;
MRAC
14862-3,
95.9-111.1 mm
SL
, Nyanza, Lake Victoria, coll. D.E. Bayon;
MRAC
90.035.P.
12, 124.2 mm
SL
, Gaba near
Kampala
, Lake Victoria,
0°15’ S
–
32°28’ E
, coll. D. Nyeko,
18 Mar. 1990
.
DEMOCRATIC REPUBLIC OF CONGO
:
MRAC
66003,
51.3 mm
SL
, Semliki River, Ishango, coll. H. Damas.
TANZANIA
:
MRAC
81.30.P.4-5,
94.5-96.5 mm
SL
,
Mwanza
gulf, Lake Victoria, collector. HEST-Collection,
1977-1980
;
MRAC
90.16.P.1-3,
73.7-79.7 mm
SL
, Kiboko, Lake Victoria.
BURUNDI
:
MRAC
81.P.47.512-535,
63.7-112.7 mm
SL
, Nyagisozi, Lake Rweru,
02°28’ S
–
30°18’ E
, coll. G. Ntakimazi,
6 May 1981
;
MRAC
93.149.P.27,
71.7 mm
SL
, Yaranda, maison Turquien, Lake Cohoha,
02°32’ S
–
30°06’ E
, coll. J. Snoeks
et al
.,
28-29 Jul. 1993
;
MRAC
93.149.P.41,
83.8 mm
SL
, Yaranda, maison Turquien, Lake Cohoha,
02°32’ S
–
30°06’ E
, coll. J. Snoeks
et al
.,
28-29 Jul. 1993
;
MRAC
93.149.P.28-40,
57.2-121.6 mm
SL
, Lake Rwihinda, ‘lac aux oiseaux’,
02°35’ S
–
30°06’ E
, coll. J. Snoeks
et al
.,
9-10 Aug. 1993
.
RWANDA
:
MRAC
87.11.P.
2827- 2828
,
73.6-83.4 mm
SL
, Lake Hago, Akagera park, coll. L. De Vos,
12 Oct. 1986
;
MRAC
87.P. 11.2852,
MRAC
87.11.P.
2852-55
,
61.5-71.9 mm
SL
, Lake Mpanga, ‘à l’entrée du parc Akagera’ coll. L. De Vos,
5 Nov. 1986
;
MRAC
86.01.P.1955,
99.2 mm
SL
, Lake Birengero, Akagera park, coll. L. De Vos,
14 Sep. 1985
.
Redescription
Based on
87 specimens
including
lectotype
and three
paralectotypes
. Morphometrics and meristics are given in
Table 5
. Small to medium-sized species [maximum size,
163 mm
SL (
Greenwood 1959
)] with moderately compressed body; dorsal head profile fairy steeply sloping, straight or decurved, becoming concave in large individuals. Mouth horizontal or slightly oblique. Jaws equal anteriorly or lower somewhat projecting; posterior tip of maxilla reaching, or almost reaching, vertical to anterior orbital margin. Gill rakers short and stout; generally 8 or 9 [7(f1), 8 (f30), 9 (f49), 10 (f7)] on the lower limb of the first gill-arch. Flank scales around lateral line ctenoid, elsewhere cycloid; generally 29-32 longitudinal line scales, excluding the small scales on caudal fin base [26 (f1), 27(f2), 28 (f5), 29 (f8), 30 (20), 31 (f29), 32 (f14)]; cheek with 3 (f24), 4 (f57) or 5 (f5) series of scales; scales between pectoral and pelvic fins 4 (f35), 5 (f40) or 6 (f8) [rarely 3 (f1)]. Dorsal fin spines 17-19 [rarely 16 (f2) or 20 (f2)], soft rays 7 (f29) or 8 (f51) [occasionally 6 (f2) or 9 (f5)]. Anal fin spines 4-7 [(4 (f7), 5 (f63), 6 (f17) and 7 (f2)], rays 6 (f9), 7 (f56) or 8 (f20) [rarely 9 (f2)]. Pectoral fin rays 13 (f32) or 14 (f54) [rarely 15 (f1)]. Caudal fin rounded. Posteriormost teeth in outer row of upper jaw unicuspid. In small specimens, outer row teeth unequally bicuspid and relatively stout (occasionally only stout unicuspid teeth in small specimens) becoming a mixture of weakly bicuspid and unicuspid in large specimens. 28-48 outer row teeth in upper jaw and 20-42 outer row teeth in lower jaw with numbers increasing with size, 1 or 2 (occasionally 3) inner rows of small tricuspid or occasionally unicuspid teeth in both lower and upper jaws. LPJ triangular, longer than, or almost as long as, wide (LPJ width 78.1-108.5% of LPJ length); lateral teeth in the posterior rows slender and cuspidate, the central two to four (occasionally six) rows with a mixture of molariform (anterior part of the dentigerous area) and enlarged but cuspidate teeth. The specimens from Lake Victoria have a more massive LPJ and a greater proportion of molariform teeth compared to the similarly sized specimens from other lakes and rivers in the Victoria basin.
Colour pattern of live specimens
See
Fig. 5
for general appearance. Anteriorly and dorsally grey yellowish, posterior-ventrally grey greenish to bluish. A dark band, continuous with lachrymal stripe, runs obliquely backwards through, or a little behind, the eye to near the gill opening. Lower jaw faint grey bluish. Fins grey yellowish, dorsal fin somewhat darker and with blackish spots on soft part; caudal fin with similar spots, pelvic blackish distally; anal fin of specimens (males and females) larger than
80 mm
SL with 2-3 horizontal rows of bright orange-yellow ocelli. In specimens less than
80 mm
SL, anal ocelli may be absent or hardly visible. According to
Greenwood (1959)
, sexual dimorphism is less marked in this species than in other haplochromine cichlids and the colour pattern of breeding males resembles that of females except that the soft dorsal fin is more densely spotted, the spinous dorsal and entire caudal fin are suffused with maroon, and the cephalic marking are more intense than in females.
Colour pattern of preserved specimens
General appearance greyish-brown to brown, lighter ventrally; five or six dark transverse bars often interrupted ventrally on the flanks (lacking in some specimens). No mid-lateral band present. A vertical, or posteriorly directed, blackish bar below the eye, runs to posterior corner of mouth, occasionally extending onto lower jaw. Blackish dots arranged in interrupted horizontal rows on soft dorsal fin and in interrupted vertical rows on caudal fin; these are strongly marked in large males. Edge of fins dark to blackish, anal ocelli in males, when present dark grey.
Fig. 5.
Adult ♂♂ of
Astatoreochromis alluaudi
Pellegrin, 1904
caught on 15 Dec. 2012 at Kumana village, Nyagisozi zone, Lake Rweru, Upper Akagera (Rwanda), 115,3 mm SL and 100,4 mm SL not catalogued. (Photographs by GB)
Distribution
Known from lakes Edward, Victoria, Kyoga, George, Nakavali and Kachira, and the rivers and streams associated with these lakes, including the Semliki (
Greenwood 1959
). The species has been introduced into many areas of East Africa for biological mollusc control (
Greenwood 1965b
;
Welcomme 1988
) and now has a widespread distribution within the Victoria basin (
Kenya
,
Uganda
&
Tanzania
including the Upper Akagera basin in the Bugesera depression (
Burundi
&
Rwanda
)).
Slootweg (1989)
discussed the possibility of the introduction of
A. alluaudi
into northern
Cameroon
(Benue River basin), which indeed took place (
Vreven
et al.
2007
). There are no reports that the introduction of this species in the
Congo Republic
, the
Democratic Republic of Congo
, the Republic of Central Africa and
Zambia
(
Welcomme 1988
) has succeeded.
Ecology
According to
Greenwood (1959)
,
A. alluaudi
is not confined to a particular
type
of substrate and is ubiquitous in all areas where the water is less than
20 m
deep. It also occurs in papyrus swamps and feeds mainly on molluscs.
Ntakimazi (1985)
confirmed the occurrence of the species in papyrus swamps in Lake Rweru, Bugesera depression (
Burundi
&
Rwanda
). However, he did not find any shell fragments of snails in the gut contents of
80 specimens
, but instead found a large amount of organic debris, algae, fish remains and benthic invertebrates. He concluded that
A. alluaudi
might be an omnivorous species that switches to the most abundant food source in its environment. He noticed, however, that the molariform teeth of the lower pharyngeal jaw are well developed, and suspected they are instrumental in crushing the exoskeletons of aquatic invertebrates and vegetal debris.
Reproduction
The species is a mouth-brooder. Most of the females caught in
December
2012
in Lake Rweru in
Burundi
had fry in their mouth. Though its breeding period is not well documented, the species may reproduce at the end of the short rain season from November to December. Whether this is the only reproductive season cannot be determined from our data.