A New Species of Miniature Fish of the Genus Microphilypnus Myers, 1927 (Gobioidei: Eleotridae) from the Upper Rio Negro Basin, Amazonas, Brazil
A new species of the eleotrid genus Microphilypus from the Upper Rio Negro basin is described herein. It differs from all congeners in the presence of 5–6 arched rows of melanophores on the abdominal region, posterior to the base of the pelvic fins, followed by six large irregularly oval black blotches, with the tips of the three posteriormost blotches visible in lateral view; a dark teardrop-shaped blotch on the caudal peduncle, extending to the base of the ventral caudal rays; five light brown blotches along the dorsal profile of the body, between the origin of the second dorsal fin and the caudal peduncle; and the poorly developed laterosensory system on the head, with horizontal rows of head papillae b and d absent. A key to the species of Microphilypnus is presented.
Microphilypnus hypolyrasimeion, new species, MZUSP 121679. Holotype in dorsal (upper), lateral (middle), and ventral views (lower). Photograph by Eduardo Baena.
Microphilypnus hypolyrasimeion, new species, drawing of head in lateral view. Abbreviations: 1–4—infraorbital transverse rows; oi—opercular inferior longitudinal row; os—opercular superior longitudinal row; ot—opercular transverse row.
Diagram of body in ventral view of Microphilypnus hypolyrasimeion (upper), M. acangaquara (middle), and M. tapajosensis (lower).
Microphilypnus hypolyrasimeion, new species, live specimen photographed right after capture. Photograph by Ralf Britz.
Map of central and northern South America indicating Rio Negro basin (rectangle) and surroundings of Santa Isabel do Rio Negro (detail), showing the distribution of Microphilypnus hypolyrasimeion, new species. Type locality (red circle) and other collection sites (yellow circles).
Locality at Igarapé Tibarrá, tributary on left margin of Rio Negro, approximately 1.5 h upstream of Santa Isabel do Rio Negro, where some of the paratypes of Microphilypnus hypolyrasimeion were collected. Photograph by Manoela Marinho.
Contributor Notes
Associate Editor: R. E. Reis.