Astatoreochromis alluaudi

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Astatoreochromis alluaudi
Adult male from the Rugwero lake

Adult male from the Rugwero lake

Systematics
Order : Cichliformes
Family : Cichlids (Cichlidae)
Subfamily : Pseudocrenilabrinae
Tribe : Haplochromini
Genre : Astatoreochromis
Type : Astatoreochromis alluaudi
Scientific name
Astatoreochromis alluaudi
Pellegrin , 1904

Astatoreochromis alluaudi is a species of African cichlid found in the East African lakes Viktoria , Kyoga , Edward , Georg , Nabugabo , Kachira , Rugwero and Nakavali , as well as in the rivers connected to these lakes. The species was named after Charles A. Alluaud, the catcher of the type specimens , and is known in English as "Alluaud's Haplochromis" or "Alluaud's Haplo". Local names for the fish are "Ifuro muhunde", "Ifuro y'itanza" and "Ifuro y'ikomagi", where "Ifuro" is the local name for all haplochromine cichlids.

features

Astatoreochromis alluaudi becomes 16 to 19 cm long and has the typical beefy shape of a haplochromine cichlid with a slightly flattened trunk. The body height is 33.8 to 43.3% of the standard length , the head length 32.1 to 40% of the standard length. The head profile can become concave on old specimens. The mouth is horizontal or slightly inclined upwards. The jaws are the same length or the lower jaw protrudes slightly. The rear edge of the maxillary extends to the front edge of the eye. The gill rakes are short and thick, 8 to 10 are found on the lower section of the first gill arch. The scales are cycloid , the scales ctenoid along the sidelines . In the upper jaw there are 28-48 single- or double-pointed teeth in the outer row of teeth and 20-42 in the lower jaw, the number of teeth depending on their size. In both jaws there are one or two, more rarely three inner rows of teeth with three-pointed, occasionally single-pointed teeth. The lower pharynx is covered with strong molar-shaped teeth. The gill rakes are very short, 7 to 19 are found on the lower section of the first gill arch.

  • Fins formula : dorsal (XVI) XVII-XIX (XX) / (6) 7-8 (9), anal IV-VII / 6-8 (9), pectoral 13-14 (15).
  • Scale formula : SL 16-22 / 10-14, mLR 29-32 (without the small scales on the caudal fin base, with these 32-34).

Front body and back are gray-yellow, the sides and belly gray-green to bluish, the lower jaw gray-blue. A black to dark brown stripe runs from the top of the head through the eye to the lower edge of the gill cover . The fins are gray-yellow, the dorsal fin a little darker than the rest and has black spots on their soft-rayed section. The rounded caudal fin is also spotted, the pelvic fins blackish at their outer end. In specimens (both males and females) longer than 8 cm, the anal fin shows 2 to 3 horizontal rows of eggspots. In the case of smaller ones, these are not yet available or difficult to recognize.

The species shows a less clear sexual dimorphism than other haplochromine cichlids. Reproductive males differ from the females only in a more speckled soft-rayed dorsal fin section, chestnut-colored fin rays in the hard-rayed dorsal fin section and in the caudal fin and a clearer head markings.

Astatoreochromis alluaudi differs from Astatoreochromis straeleni , the second species of the genus, primarily in the greater number of hard rays in the dorsal and anal fin (16) 17-20 vs. 16-18 (19) and 4-7 vs. 3 - (4)).

Way of life

Astatoreochromis alluaudi can be found above all in shallow water above 20 meters, often in papyrus swamps , and feeds on snails , if present, but also on detritus , algae and other bottom-dwelling invertebrates. Like all haplochromine cichlids, Astatoreochromis alluaudi is a mouthbrooder . The species is likely to reproduce at the end of the short rainy season from November to December.

The species was introduced to many areas in East Africa (e.g. in the Akagera swamps ), to Yaoundé (Cameroon), in the Republic of the Congo to control snails ( schistosomiasis and fasciolosis risk ) and is now more widely distributed than originally. The introduction of Astatoreochromis alluaudi resulted in a 64 to 98% reduction in the snail population . Further releases of the species to the upper Benue Basin (North Cameroon), the Democratic Republic of the Congo , Central Africa and Zambia were unsuccessful.

literature

Web links

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