Koumansetta Whitley 1940

Kovačić, Marcelo, Bogorodsky, Sergey V., Mal, Ahmad O. & Alpermann, Tilman J., 2018, Redescription of the genus Koumansetta (Teleostei: Gobiidae), with description of a new species from the Red Sea, Zootaxa 4459 (3), pp. 453-481 : 455-456

Koumansetta Whitley 1940

Koumansetta Whitley 1940: 425 , type species Koumansetta rainfordi Whitley 1940 , by original designation and monotypy. Seychellea Smith 1957: 726 , type species Seychellea hectori Smith 1957 , by original designation and monotypy.

Diagnosis. (1) pelvic fins united to form a complete pointed pelvic disc; (2) cephalic suborbital row a absent; (3) oculoscapular transverse rows trp and tra long, extending dorsally well above level of rows x1 and x2; (4) snout pointed, prominent, long, 0.7–0.8 in eye diameter, 2.8–3.0 in head length, with gently sloping dorsal profile, overhanging mouth; (5) mouth subterminal; (6) the upper limb of first gill arch with 1–2 slender, weak and soft gill rakers anteriorly, followed by 1–5 short, also soft, broad structures ( Fig. 1 ); (7) first two dorsal-fin spines longest and elongate, remaining spines progressively shorter; (8) pelvic frenum absent; (9) color mostly brown to browngreen with narrow yellow or orange longitudinal stripes on body and head and two black spots posteriorly, one ocellated, partly or completely on the second dorsal fin, and another spot dorsoposteriorly on caudal peduncle; (10) scales mostly ctenoid, predorsal area scaled at midline.

This diagnosis distinguishes members of the genus Koumansetta from 15 valid species presently assigned to Amblygobius , and from two other genera of the “ Valenciennea -lineage” ( Signigobius and Valenciennea ) sensu Agorretta et al. (2013). Characters (1) and (2) distinguishes the genus from Valenciennea , character (2) from Signigobius . The diagnosis was confirmed to be different compared to all comparative material examined of 13 valid species presently assigned to Amblygobius and compared to published data in the species descriptions of two additional recently described Amblygobius species ( Allen & Erdmann 2016) in characters (3)–(9) ( Table 3). Character (10) distinguishes Koumansetta only from " Amblygobius nocturnus species group” sensu Allen & Erdmann (2016) and Amblygobius sewardii (Playfair 1867) .

Description. Body moderately elongate, laterally compressed. Depth at anal-fin origin 4.8 (4.5–5.2) in SL. Head slightly laterally compressed. Snout pointed, prominent, long, 0.7–0.8 in eye diameter, 2.8–3.0 in head length, with gently sloping dorsal profile, overhanging mouth. Eyes lateral, interorbital broad. Anterior nostril short, tubular, erect, without process from rim; posterior nostril slit-like, with a low, raised ridge, closer to anterior nostril than to anterior margin of eye. Mouth subterminal, moderately small, oblique. Posterior angle of jaws below anterior edge of eye or slightly in front or behind the vertical. Teeth in upper and lower jaws unicuspid and pointed, more or less curved inward. Upper jaw with caniniform teeth of similar size at the front, followed with inner row of smaller slender sharp teeth laterally; lower jaw with an outer row of caniniform teeth of similar size at the front ending laterally with single large curved canine and the inner row of smaller slender sharp teeth. Tongue reduced, adnate, truncate in front. Chin without fold or barbels. Cranial roof covered by dorsal axial musculature. Gill openings lateral, ending forward at pectoral-fin base. Branchiostegal membranes attached to entire lateral margin of isthmus. Gill rakers poorly developed, rakers on lower limb of anterior arch slender, weak and soft, 6–7 in number, the upper limb of first gill arch with 1–2 slender, weak and soft gill rakers anteriorly, followed by 1–5 short, also soft, broad structures ( Fig. 1 ). Two dorsal fins, first fin with VI spines, first two dorsal-fin spines elongate, remaining spines progressively shorter, second fin I/15–17; anal fin I/15–17. Pectoral-fin rays 15–18. Pectoral girdle without flaps on anterior edge. Uppermost rays of pectoral fin within membrane. Pelvic fin united to form a complete pelvic disc, pointed. Pelvic frenum absent. Caudal fin rounded, shorter than head length, with 13 branched and 16–17 segmented rays. Body covered with small, mainly ctenoid scales, 49–61 in lateral series; transverse scale series 14–19. Predorsal area, including nape, breast and belly with cycloid scales, the area between first dorsal-fin base and pectoral fin also with cycloid scales. No scales on cheek and opercle (a few small cycloid scales occasionally present on upper opercle). Predorsal area scaled, scales not reaching the vertical through the posterior edge of eye, predorsal scales 16–26. Head with anterior oculoscapular canal with pores B’, C (single), D (single), E, F, G, and H’; posterior oculoscapular canal with K’ and L’; preopercular canal with M’, N, and O’. Suborbital rows of sensory papillae: row a absent, row b longitudinal, short, beginning anteriorly below posterior part of eye, not reaching above row d, row c as 10–16 transverse sub - orbital rows of sensory papillae, row d longitudinal. Oculoscapular transverse rows trp and tra long, extending dorsally well above level of rows x. No interorbital papillae. Head and body brown, reddish brown to greenish brown or brownish to greenish grey with narrow yellow or orange longitudinal stripes, black ocellus entirely on or partially on the second dorsal fin, and black spot dorsoposteriorly on caudal peduncle.

Figures

FIGURE 1. Gill rakers and structures of Koumansetta hoesei sp. nov.: A) gill rakers on lower limb, B) gill rakers on upper limb, C) gill structures on upper limb. Non-type material, SMF 35872, 32.4 + 8.3 mm, Al Lith, Saudi Arabia.