Synodontis longirostris

Synodontis longirostris
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Mochokidae
Genus: Synodontis
Species: S. longirostris
Binomial name
Synodontis longirostris
Boulenger, 1902

Synodontis longirostris, known as the eyespot Synodontis,[2] is a species of upside-down catfish that is native to the Democratic Republic of the Congo where it occurs in the Congo Basin.[3] It was first described by British-Belgian zoologist George Albert Boulenger in 1902, from speciments obtained in the Ubangi River at Banzyville.[2] The species name longirostris comes from the Latin word longus, meaning "long", and the Latin word rostrum, meaning snout, referring to the long snout on this species.[4]

Description

Like all members of the Synodontis genus, S. longirostris has a strong, bony head capsule that extends back as far as the first spine of the dorsal fin.[5] The head contains a distinct narrow, bony, external protrusion called a humeral process.[2] The shape and size of the humeral process helps to identify the species. In S. longirostris, the humeral process is rough, much longer than it is broad, and pointed at the end.[6]

The fish has three pairs of barbels. The maxillary barbels are on located on the upper jaw, and two pairs of mandibular barbels are on the lower jaw. The maxillary barbel is straight without any branches, without a membrane at the base.[6] It extends about  1⁄2 as long as the head.[6] The outer pair of mandibular barbels is a little under twice the length of the inner pair. They have short branches.[6]

The front edges of the dorsal fins and the pectoral fins of Syntontis species are hardened into stiff spines.[2] In S. longirostris, the spine of the dorsal fin is about  2⁄3 the length of the head, slight curved, smooth in the front and serrated on the back.[6] The remaining portion of the dorsal fin is made up of seven branching rays.[6] The spine of the pectoral fin is slightly longer than the dorsal spine and serrated on both sides.[6] The adipose fin is 3 times as long as it is deep.[6] The anal fin contains four unbranched and six branched rays, and is obtusely pointed in the front.[6] The tail, or caudal fin, is deeply notched.[6]

All members of Syndontis 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. longirostris, the toothpad forms a short, broad band.[6] On the lower jaw, or mandible, the teeth of Syndontis are attached to flexible, stalk-like structures and described as "s-shaped" or "hooked".[2][5] The number of teeth on the mandible is used to differentiate between species; in S. longirostris, there are about 24 teeth on the mandible.[6]

The base body color is olive-brown, with large round black spots in three series on the body.[6]

The maximum total length of the species is 66 centimetres (26 in).[3] Generally, females in the Synodontis genus tend to be slightly larger than males of the same age.[7]

Habitat and behavior

In the wild, the species is known throughout the Congo River basin, with the exception of the southern tributaries.[1] The species is harvested for the aquarium trade.[1] The reproductive habits of most of the species of Synodontis are not known, beyond some instances of obtaining egg counts from gravid females.[8] Spawning likely occurs during the flooding season between July and October, and pairs swim in unison during spawning.[9] The growth rate is rapid in the first year, then slows down as the fish age.[7]

References

  1. 1 2 3 Moelants, T. (2010). "Synodontis longirostris". IUCN Red List of Threatened Species. Version 2016.2. International Union for Conservation of Nature. Retrieved 29 October 2016.
  2. 1 2 3 4 5 "Synodontis longirostris Boulenger, 1902". Planet Catfish. 29 Nov 2008. Retrieved 29 October 2016.
  3. 1 2 Froese, Rainer and Pauly, Daniel, eds. (2016). "Synodontis longirostris" in FishBase. June 2016 version.
  4. ↑ Scharpf, Christopher & Kenneth Lazara (12 Sep 2016). "Order SILURIFORMES: Families MALAPTERURIDAE, MOCHOKIDAE, SCHILBEIDAE, AUCHENOGLANIDIDAE, CLAROTEIDAE and LACANTUNIIDAE". The ETYFish Project. Retrieved 29 Oct 2016.
  5. 1 2 Cuvier, Georges (1934). The Animal Kingdon Arranged in Conformity with its Organization, Volume 10. Translated by Griffith, Edward. London: Whittaker and Co. p. 406.
  6. 1 2 3 4 5 6 7 8 9 10 11 12 13 Boulenger, George Albert (1909). Catalogue of the fresh-water fishes of Africa in the British museum (Natural history). London: British Museum. pp. 448–449.
  7. 1 2 H. M. Bishai & Y. B. Abu Gideiri (1965). "Studies on the biology of genus Synodontis at Khartoum". Hydrobiologia. 26 (1–2): 85–97. doi:10.1007/BF00142257.
  8. ↑ Wright, J.J. & L.M. Page (2006). "Taxonomic Revision of Lake Tanganyikan Synodontis (Siluriformes: Mochokidae)". Florida Mus. Nat. Hist. Bull. 46 (4): 99–154.
  9. ↑ John P. Friel & Thomas R. Vigliotta (March 2, 2009). "Mochokidae Jordan 1923: African squeaker and suckermouth catfishes". Tree of Life Web Project. Retrieved 19 October 2016.

Data related to Synodontis longirostris at Wikispecies

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