SCOTCAT.COM  

Johnny Jensen's Photographic Library (1) Poll 1971 (Line Drawing 1)

Description: Like all members of the genus Synodontis, S. omias has a strong, bony head capsule that extends back as far as the first spine of the dorsal fin. The head contains a distinct narrow, bony, external protrusion called a humeral process. The shape and size of the humeral process helps to identify the species. In S. omias, the humeral process is 1+1/2 as long as it is wide, and has two or three spines directed backwards. All members of Synodontis have a structure called a premaxillary toothpad, which is located on the very front of the upper jaw of the mouth. This structure contains several rows of short, chisel-shaped teeth. In S. omias, the toothpad forms a short and broad band. On the lower jaw, or mandible, the teeth of Synodontis are attached to flexible, stalk-like structures and described as "s-shaped" or "hooked". The number of teeth on the mandible is used to differentiate between species; in S. omias, there are 40 to 50 teeth on the mandible. There has been confusion centered around this species as there has not been a life-like identification process carried out since Boulenger in 1911 which the original description by Gunther was matched to a species from Jebba in the upper Niger, West Africa. This very well could be the same species as S. budgetti from the upper Niger. The difference between the two species is that S. omias has a membrane to the maxillary barbels which S. budgetti lacks but this could be sexual dimorphism. Habitat: In the wild, the species has been found in the inland Niger River basin, although the entire range is not currently known. Reproduction: The reproductive habits of most of the species of Synodontis are not known, beyond some instances of obtaining egg counts from gravid females. Spawning likely occurs during the flooding season between July and October, and pairs swim in unison during spawning. The growth rate is rapid in the first year, then slows down as the fish age. Colouration: The body colour is a uniform brownish. Diet: As a whole, species of Synodontis are omnivores, consuming insect larvae, algae, gastropods, bivalves, sponges, crustaceans, and the eggs of other fishes. Etymology: The specific name omias: Etymology not explained, perhaps from hmos, shoulder or humerus, referring to humeral process “armed with a series of three or four compressed, triangular spinous processos [sic], running along the lower margin of the bone, the last being placed at its extremity”.

None

None

Mochokidae

Africa: Niger basin. Type Locality: Jebba, Upper Niger, West Africa.

36.0cm. (14½ins)

23-26°C (73-79°F)

6.5-7.5.

Boulenger, George Albert (1909). Catalogue of the fresh-water fishes of Africa in the British museum (Natural history). London: British Museum. pp. 401–402.
Cuvier, Georges (1934). The Animal Kingdom Arranged in Conformity with its Organization, Volume 10. Translated by Griffith, Edward. London: Whittaker and Co. p. 406.
Ferraris, C.J. Jr., 2007. Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types. Zootaxa 1418:1-628.
Olaosebikan, B.D. & Lalèyè, P. 2020. Synodontis omias. The IUCN Red List of Threatened Species 2020.
Poll, M.,1971 Révision des Synodontis africains (famille Mochocidae). Ann. Mus. R. Afr. Centr., Sci. Zool., 191:1-497.
Seegers, L. 2008 The catfishes of Africa. A handbook for identification and maintenance. Aqualog Verlag A.C.S. GmbH, Germany. 604 p.
The ETYFish Project Fish Name Etymology Database © Christopher Scharpf.