''Microsynodontis nannoculus'' is a species of upside-down catfish endemic to

Equatorial Guinea Equatorial Guinea ( es, Guinea Ecuatorial; french: Guinée équatoriale; pt, Guiné Equatorial), officially the Republic of Equatorial Guinea ( es, link=no, República de Guinea Ecuatorial, french: link=no, République de Guinée équatoria ...

where it occurs in the Kyé 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 ...

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. nannoculus'' 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. nannoculus'' 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. nannoculus'' can be distinguished from other members of the genus ''Microsynodontis'' by examining the size of the eye. The diameter of the eye is only about 10% to 12% of the standard length of the fish, whereas the diameter of the eye of all other species in the genus ranges from about 13% to 26%.

References

{{Taxonbar, from=Q3760391 Mochokidae Freshwater fish of Africa Fish of Equatorial Guinea Endemic fauna of Equatorial Guinea Fish described in 2004