Genus Sutorectus

Author: Whitley, 1939

Diagnostic Features:
Dorsal surface of head, body and precaudal tail, and dorsal fin bases, with rows of large, conspicuous dermal tubercles, resembling warts. Head rather narrow, its greatest width slightly less than distance from snout tip to first gill openings; chin smooth, without a beard of dermal lobes; dermal lobes of sides and front of head small, short, unbranched, and forming isolated groups that are broadly separated from one another; nasal barbels simple and unbranched. Trunk moderately broad, width across pectoral insertions considerably less than head length; precaudal tail rather long, distance from pelvic insertion to lower caudal origin much greater than head length. Dorsal fins low and long, height of first about half its base length, length of first dorsal base greater than pelvic length from origin to free rear tip; origin of first dorsal fin in front of midbases of pelvics; interspace between first and second dorsal fins much shorter than first dorsal inner margin and less than a fifth of first dorsal base; pectoral and pelvic fins small and widely spaced from each other, distance from pectoral insertions to pelvic origins about twice length of pectoral bases and somewhat greater than pelvic lengths from origins to free rear tips. Colour: dorsal surface with a colour pattern of jagged-edged broad dark saddles and scattered dark spots on a light background, no reticulating narrow lines with spots at their junctions.

Remarks:
Whitley (1939) proposed the genus Sutorectus on the simple nasal barbels, tuberculate back, and narrower interdorsal space of the type and only species. This was recognized by Whitley (1940); Bigelow and Schroeder (1948), and Whitley and Pollard (1980) but considered a synonym of Orectolobus by Stead (1963) and Applegate (1974). The writer was inclined to Applegate's classification (e.g. Compagno, 1973c) prior to examining specimens of Sutorectus tentaculatus, but found additional characters by which this species may be distinguished from typical Orectolobus. The species tentaculatus is sufficiently aberrant to require some distinction from Orectolobus proper, but the Whitley-Bigelow and Schroeder generic arrangement adopted here may be alternatively downgraded to a subgenus of Orectolobus.

There is an undescribed species of Orectolobus from western Australia (B. Hutchins, pers.comm.) that the writer has examined, that shows a few characters, like its narrow interdorsal space, slightly lower dorsal fins, and longitudinal rows of small dermal knobs, that suggest that it is intermediate between typical Orectolobus and the bizarre Sutorectus tentaculatus. Further study of its morphology may indicate that Sutorectus should be ranked as a subgenus with the new species included in it, or the new species assigned to either the genus Orectolobus or Sutorectus.

Additional characters for Sutorectus are given in the Diagnostic Features section above. Sutorectus as a genus is phenetically closer to Orectolobus than the very distinct, highly derived and specialized Eucrossorhinus.

%LABEL% (%SOURCE%)