''Microsynodontis nasutus'' is a species of
upside-down catfish endemic to
Gabon where it occurs in the
Ogowe River.
[ It was first described in 2004 by ]Ng Heok Hee
Heok Hee Ng is a Singaporean ichthyologist and researcher of biodiversity at the Lee Kong Chian Natural History Museum of the National University of Singapore. He specialises in Asian catfish systematics with particular focus on Sisoroidea, si ...
.[
The genus Microsynodontis is restricted to the rivers of western Africa (from the Saint Paul River drainage south and east to the Congo River drainage), and comprises small mochokid catfishes diagnosed by the following synapomorphies: a narrow mesethmoid, lack of free orbital margin, transverse ventral fold of branchiostegal membranes, slender cleithral process, and a rounded or truncate caudal fin (Howes, 1980).
]
Taxonomy
Before 2004, the genus ''Microsynodontis'' was believed to contain only four species, ''Microsynodontis batesii'', ''M. christyi'', ''M. lamberti'', and ''M. polli''.[ However, when examining previously collected specimens from the lower Guinea region that had been identified as ''M. batesii'', Dr. Ng discovered that the specimens actually consisted of nine distinct species, eight of them previously undescribed.][ He published the descriptions of the new species in 2004. ''M. nasutus'' is one of the new species that he described. Although the eight new species have been accepted by the scientific community, there is still some dispute among scientists as to whether the newly described species are actually separate species as the species are extremely difficult to tell apart.][
]
Description
''M. nasutus'' is a small fish, reaching a maximum standard length
Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.
Overall length
* Standard length (SL) is the length of a fish m ...
of .[ The mouth of the fish faces downward, with broad lips containing papilla.][ 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 front edges of the dorsal fins and the pectoral fins are hardened into stiff spines that can be locked into place.][ The body shape is cylindrical along its entire length.][
''M. nasutus'' can be distinguished from other members of the genus ''Microsynodontis'' by examining the length of the snout. In ''M. nasutus'', the snout is longer, with a length of about 50% to 53% of the standard length of the fish, whereas other species in the genus have shorter snouts, raning from about 36% to 50% of the standard length.][
personal profile gently convex; postdorsal body sloping gently ventrally. Preanal profile horizontal.
Anus and urogenital openings located at vertical through middle of pelvic fin. Skin
smooth. Lateral line complete and midlateral.
Mouth inferior and crescent-shaped lips plicate. Oral teeth in rows on all tooth-bearing surfaces. Premaxillae narrow, with narrow ventral shelf and partially exposed when
mouth closed. Primary teeth 13–14, conical and separated from secondary teeth by distinct gap
]
References
Boulenger, G.A. (1905) A list of freshwater fishes of Africa. Annals and Magazine of Natural History (Series 7),16, 36–6
Roberts, T. R. (1989) Systematic revision and description of new species of suckermouth catfishes
(Chiloglanis, Mochokidae) from Cameroun. Proceedings of the California Academy of Sciences (Series 4), 46, 151–178.
{{DEFAULTSORT:Microsynodontis Nasutus
Endemic fauna of Gabon
Mochokidae
Fish of Africa
Fish of Gabon
Fish described in 2004