PLESIOBRANCHIUS, Costa, 2018

SUBGENUS PLESIOBRANCHIUS SUBGEN. NOV.

urn:lsid:zoobank.org:act:60E816B8-7280-4866-BEC5-181827A47B4D

Type species: Nothobranchius virgatus Chambers, 1984 .

Diagnosis: lateral portion of second pharyngobranchial truncate in dorsal view [60.1] (vs. pointed); and fifth ceratobranchial broad, triangular in dorsal view [69.1] (vs. narrow, boomerang shaped). Also distinguished from all other Nothobranchiini , except Adiniops , by: expansion on sub-distal portion of anterior margin of autopalatine [21.1] (vs. expansion absent). Plesiobranchius is similar to Cynobranchius and distinguished from all other Nothobranchiini by five unique apomorphic conditions: posterior process of quadrate short, its length distinctively shorter than basal portion of bone without process [27.1] (vs. about equal or slightly longer); osseous flap between distal and posterior processes of third epibranchial extending beyond line between processes [54.1] (vs. not surpassing line); first post-cleithrum absent [93.1] (vs. present); pelvic bone broad, wider than long [97.1] (vs. longer than wide); pelvic fin with seven well-developed rays [128.1] (vs. five or six well-developed rays, sometimes plus one rudimentary).

Etymology: The name Plesiobranchius refers to the superficial resemblance between N. virgatus , the type species of this new subgenus of Nothobranchius , and some species of the South American aplocheiloid genus Plesiolebias Costa, 1989 (from the Greek plesios = primitive, taken from the name Plesiolebias , and branchius = gills, taken from the name Nothobranchius ). Gender masculine.

Included species and distribution: A single species, N. virgatus Chambers, 1984 , endemic to the middle White Nile River drainage, Nile River basin, South Sudan and Ethiopia.