Lepadicyathus mendeleevi Prokofiev 2005

This species is distinguished by the following characters: partial lateral asymmetry, the head slightly asymmetrical when seen from the front; vertebral column bent towards theleft in males, to the right in females, at an angle of 40°-45°, with bending starting slightly before level of anus; anus towards the right-hand side of the body in males, towards the left-hand side in females; position of guts is slightly asymmetrical; gills 3; pelvic fin disc rudimentary, in two parts, with a few rudimentary papillae basally in region B; dorsal-fin rays 11-12; anal-fin rays 10; caudal fin with 10 principal rays; naked skin, the surface of head and body covered with a dense pattern of obliquely arranged striae consisting of minute tubercles (Ref. 117884).Description: This very small species is characterized by the following: low cylindrical body and a strongly flattened head; gill membranes fused with the isthmus; reduced gill rakers; seismosensory system: NC 2, LC 2, PO 2, PR 2, MN O; pore po-2 found midway from the posterior eye margin to the gill slit; pore pr-1 slightly spaced apart from the posterior-lower eye margin; very small, terminal mouth; incisor-type teeth on jaws, in one row; double sucking disc, surface almost smooth, no zones bearing papillas; length 5.0-5.6 times in SL; dorsal and anal fins are connected with the caudal fin; vent equidistant from the posterior disc margin and origin of the anal fin; 5 light-colored longitudinal stripes (dorsal and 2 pairs of lateral) on the body; vertebrae 31 (Ref. 75705).

Dorsal soft rays (total): 11 - 12; Analsoft rays: 10; Vertebrae: 31

Collected from corals (Millepora) at 1 m depth, its association with the coral is unknown. The specimens were collected together with Gymnothorax buroensis (juvenile individual), Pseudogramma polyacantha, Gobiodon sp., Balistapus undulatus, Enchelyurus kraussi, and 3 unidentified blennies (Ref. 75705).

Mendeleev's clingfish (Lepadicyathus mendeleevi) is a species of fish in the family Gobiesocidae endemic to Madang Province in Papua New Guinea. This species is the only known member of its genus. This species was described in 2005 by Artem Mikhailovich Prokofiev, the type being collected near the village of Bongu in Madang Province from the research vessel Dmitrii Mendeleev, referred to in its specific name. The vessel was in turn named in hours of the Russian chemist Dmitrii Mendeleev (1834-1907), the creator of the most widely recognised periodic table.