Bedotia geayi

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Bedotia geayi
male

male

Systematics
Ovalentaria
Superordinate : Earfish relatives (Atherinomorphae)
Order : Earfish (Atheriniformes)
Family : Bedotiidae
Genre : Bedotia
Type : Bedotia geayi
Scientific name
Bedotia geayi
Pellegrin , 1907

Bedotia geayi , called red-tailed earfish , is a member of the Bedotia fish genus, which is endemic to Madagascar . The specific epithet honors the explorer and editor of the magazine "La Science Française" MF Geay, who discovered the fish. Bedotia madagascariensis , which wasintroduced to France in 1953 foruse in aquaristics , was incorrectly identified as B. geayi and was traded under this name for a long time.

distribution and habitat

The species, which lives exclusively in freshwater, lives in small rivers in the Mananjary catchment area between 300 and 650 meters above sea level. In the sometimes fast-flowing streams and rivers, B. geayi prefers quiet areas shaded by bank vegetation.

The syntypes come from a tributary of the Mananjary, north of the main stream, near Morafeno . Finds from some southern tributaries are also known. B. geayi is no longer to be found in the Namorona catchment area , which is immediately adjacent to that of Mananjary in the south ; instead, there is a relative that has not yet been scientifically described. A northern limit of the distribution area cannot be precisely defined due to the lack of usable data material.

Appearance

In field studies, the largest specimens reached a standard length of just over seven centimeters. The body, covered with large cycloid scales , appears graceful and relatively elongated. While the back is slightly curved up to the first dorsal fin, the belly line is relatively straight. Both sexes have a dark longitudinal stripe on the sides of the body and have transparent pectoral fins , but differ in the pattern of the unpaired fins. Males have red edges on the dorsal , anal and caudal fins and a distinct red point on the chin. Female B. geayi are significantly less colorful. At the base of the caudal fin there is a significant dark spot, which clearly distinguishes the species from also longitudinally striped relatives such as B. madagascariensis .

The first dorsal fin is carried by five weak hard rays , the second by eleven to 14 soft rays, the first four or five of which are undivided. Of the 17 to 19 soft rays of the anal fin, three or four are undivided. The short pectoral fins are set high on the body and have twelve soft rays. A hard ray and five fan-like divided soft rays support the pelvic fins. The caudal fin is slightly notched. On the gill arches there are 15 to 16 clearly serrated gill spines .

behavior

The stomach contents of caught specimens suggest that the species feeds primarily on approach food. Like B. madagascariensis , B. geayi lives in swarms of different sizes. The available data suggests that there is broad similarity in the behavior and predators of both species.

status

B. geayi is common within its range in the Mananjary catchment area . However, there are concerns about the habitat destruction caused by human influence in the lower areas of the river basin and the presence of introduced viviparous toothcarps , especially Gambusia holbrooki . In the medium term, there is also danger from the snakehead fish, Channa maculata , which has also been introduced; it has not yet reached the distribution area of B. geayi , but is already settling in the neighboring Namorona river basin. The IUCN assesses the species as "endangered" ( vulnerable ).

supporting documents

  1. ^ Peter Schubert: Bedotia geayi Pellegrin, 1907. Rotschwanz-Ährenfisch. In: Claus Schaefer, Torsten Schröer (Hrsg.): The large lexicon of aquaristics. Eugen Ulmer, Stuttgart 2004, ISBN 3-8001-7497-9 , p. 140.
  2. ^ J. Pellegrin: List des poissons recueillis à Madagascar par MF Geay. Description d'une espèce nouvelle. Bulletin du Musée National d'Histoire Naturelle, 30, pp. 201–206, 1907
  3. ↑ Paul Loiselle, Damaris Rodriguez: A new species of Bedotia (Teleostei: Atherinomorpha: Bedotiidae) from the Rianila drainage of Eastern Madagascar, with redescriptions of Bedotia madagascariensis and Bedotia geayi . In: Zootaxa . No. 1520, 2007, ISSN  1175-5326 (print) ISSN  1175-5334 (online), pp. 7, 8 ( PDF, 390 kB )
  4. ↑ Loiselle, pp. 10, 11
  5. ↑ Loiselle, pp. 8, 9
  6. ↑ a b Loiselle, p. 9
  7. ↑ Loiselle, p. 8
  8. ↑ a b Loiselle, p. 11

Web links

Commons : Bedotia geayi  - collection of images, videos and audio files