Diagnos |
Diagnosis: It is distinguished from congeners by the absence of scales on the head, less the operculum, the presence of single and feeble leading spines in both the second dorsal and anal fins, a pelvic formula of I,5, the presence of an enlarged, bony operculum, and an overall more robust and heavier body, particularly in adults (Ref. 93144). Typhleotris pauliani is further distinguished from T. mararybe by the absence of pigment on the body and a longer prepelvic length (34.1-40.4% of standard length vs. 33.0-33.9% of standard length), and from T. madagascariensis by the absence of ctenoid scales on the flank and dorsum, except for a few weak ctenoid scales midflank in some individuals, more or less along the lateral midline (Ref. 93144).
Description: A robust and deep-bodied species of Typhleotris, growing to roughly similar adult size as T. madagascariensis (Ref. 93144). Body wide anteriorly, particularly posterior to snout, and head dorsoventrally compressed, particularly rostrally; operculum prominent and angular, yet head overall appearing more fleshy than congeners; snout and anterior portion of head markedly elongate and shovellike; body becoming progressively laterally compressed posteriorly; caudal peduncle laterally compressed and elongate (Ref. 93144). No eyes present; however, significant fat deposits present anteriorly over neurocranium, including orbital region (Ref. 93144). Anterior nostril relatively short, wide, and tubular, located just posterior to upper lip; posterior nostril very short and tubular, not slitlike (Ref. 93144). Mouth large, and gape moderately wide; oral jaw teeth small, conical, and moderately recurved; teeth numerous and arrayed in six to eight closely set and irregular rows along anterior portion of jaws, and tapering to fewer rows of somewhat smaller teeth posteriorly, as well as medially proximal to synthesis, where tooth rows become noticeably reduced and constricted, in both upper and lower jaws; teeth present along full length of premaxillary arcade and dentary; basihyal large, triangular, and fan shaped (Ref. 93144). Head asquamate, except for presence of scales dorsally on posterior portion of neurocranium; scales extending anteriorly approximately to posterior margin of frontals, and also onto operculum; scales on opercle and subopercle strongly ctenoid, all others on body cycloid, including posterior roof of neurocranium, except for occasional weakly ctenoid scale on midflank (Ref. 93144). Otherwise, body fully scaled to caudal fin, including along ventrum anterior of pelvic fin and on fleshy base of pectoral fin; scales on ventrum cycloid, not well ossified and strongly embedded; pectoral-fin axil asquamate (Ref. 93144). Two dorsal fins; first dorsal fin with 5 weakly developed spines and second dorsal fin with one weak spine and 7-8 segmented, branched rays; anal fin with one weak spine and 7-8 rays; pelvic formula I,4; pectoral rays 13-14; pelvic and pectoral fins elongate and produced, with filamentous trailing rays, particularly in larger individuals (Ref. 93144).
Colouration: Body without pigment and uniformly white in coloration (Ref. 93144). In life, body is relatively translucent, whereas translucency is lost and body becomes opaque white in alcohol (Ref. 93144). |