Four new species of Trimma (Pisces: Gobiidae) from Papua New Guinea and Indonesia

Four new species belonging to the gobiid genus Trimma are described from the Indo-Australian Archipelago. Trimma abyssum is described from two specimens, 28.8–31.6 mm SL, collected in 107 m depth at Siladen Island, North Sulawesi, Indonesia. Diagnostic features include the combination of 7–8 segmented dorsal rays, the second and third spines longest with short filamentous tips reaching base of first two segmented rays of the second dorsal fin when adpressed; anal rays I,8; pectoral rays 16, all unbranched; unbranched fifth pelvic ray 48–55% length of fourth pelvic ray; bony interorbital 53–65% pupil diameter; fully scaled nape with 12–13 scales in midline of predorsal; scales covering cheek and opercle; ctenoid scales on breast (prepelvic); and prominent dark bar at caudal-fin base and scale pockets strongly outlined with melanophores. The remaining three species were collected at Milne Bay Province, Papua New Guinea. Trimma chledophilum is described from 19 specimens, 13.5–22.2 mm SL, collected in 17–18 m depth near the town of Alotau. Diagnostic features include the combination of 9 (rarely 10) segmented dorsal rays, second spine elongate and filamentous, reaching caudal-fin base when fully developed; segmented anal rays 8 (rarely 9); pectoral rays 16–18 (usually 17); fifth pelvic ray branched, 62–71% length of fourth pelvic ray; bony interorbital 46–62% pupil diameter; midline of predorsal broadly scaleless; cheek and opercle scaleless; and mainly bright orange red in life except white on breast belly, and lower half of head, also white stripe on midline of snout. Trimma nauagium is described from 3 specimens, 17.4–20.3 mm SL, collected in 24 m depth from a shipwreck off the village of Waga Waga. Diagnostic features include the combination of 8 segmented dorsal and anal rays, the second and third dorsal spines elongate, reaching to base of fifth or sixth segmented ray of second dorsal fin when adpressed; pectoral rays 16; fifth pelvic ray branched, 56–64% length of fourth pelvic ray; bony interorbital equal to pupil diameter; predorsal, cheek, and opercle fully scaled; predorsal scales 12; pattern of cephalic sensory papillae includes five transverse rows below eye; and brownish in life with pink zone along upper side and seven darker brown saddles on back interspersed with smaller golden saddles, narrow white bar behind eye, and yellowish bar at base of pectoral fin. Trimma multiclitellum is described from a single specimen, 17.4 mm SL, collected in 17–18 m depth near the town of Alotau. Diagnostic features include the combination of 8 dorsal and anal segmented rays; pectoral rays 17; caudal fin emarginate with pointed upper lobe and rounded lower lobe; fifth pelvic ray branched, 74% length of fourth pelvic ray; basal membrane 41% length of fourth pelvic ray; bony interorbital about equal to pupil diameter; midline of predorsal mainly scaleless, but with patch of about 4 scales on middle portion; cheek scaleless; opercle with a few scales dorsally; and highly distinctive colour pattern consisting of seven, alternating brown and white bars on upper side, a nearly eye-sized black spot at base of caudal fin, and pair of yellow bars on head, one below eye and another on opercle