Microsynodontis laevigata

description

Description. Biometric and meristic data as in Table 5. Body compressed. Predorsal profile steep; 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. Head depressed and broad, broadly rounded when viewed laterally and with rounded snout margin when viewed from above. Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine. Gill membranes united to, and attached across, isthmus. Bony elements of dorsal surface of head covered with thin skin. Nuchal shield large and terminating posteriorly with two rounded processes on each side. Supracleithral process thin, extending just short of vertical through posteriormost tip of nuchal shield. Barbels in three pairs. Maxillary barbel long and slender, extending to just beyond base of last pectoral­fin ray. Inner mandibular­barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3 – 4 long, thin branches on posterior half. Outer mandibular barbel originates posterolatera

The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species

diagnosis

Diagnosis. Microsynodontis laevigatus can be distinguished from all congeners (except for M. lamberti) in having a smooth (vs. serrated) anterior edge of the pectoral spine (Fig. 4), and a truncate (vs. emarginate or rounded) caudal fin (Fig. 9). It differs from M. lamberti (n = 4) in having a longer adipose fin (33.3 – 35.5 % SL vs. 25.4 – 31.4).

The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species

distribution

Distribution. Known only from the Ivindo River in northern Gabon (Fig. 5). Habitat. The type locality is a small, shallow blackwater creek draining into the Ivindo River. The water was extremely low and the substrate was sand with leaf litter, with the area having undergone severe human disturbance. The only other fish species found syntopically was Barbus sp. (Cyprinidae).

The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species

etymology

Etymology. From the Latin laevigatus, meaning smooth. In reference to the smooth anterior edge of the pectoral spine. Used as an adjective.

The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species