Glossogobius macrocephalus Hoese & Allen, 2015

Family:  Gobiidae (Gobies), subfamily: Gobiinae
Max. size:  11.2 cm SL (male/unsexed)
Environment:  benthopelagic; freshwater
Distribution:  Oceania: Papua New Guinea
Diagnosis:  Dorsal spines (total): 6-7; Dorsal soft rays (total): 9-10; Anal spines: -1; Anal soft rays: -8; Vertebrae: -28. Diagnosis: Preoperculum without a spine, but with small flat projection adjacent to lower preopercular pore; mental fraenum low with short lateral lobes; mouth small; reaching to below anterior margin of eyes; jaws forming an angle of 40–50° with body axis; upper margin of upper jaw in line with lower margin of pupil; head robust and large, cheeks slightly bulbose and tapering; interorbital narrow, less than eye length; predorsal area scaled forward to just behind eye, with a narrow naked patch between and behind eyes; cheek naked; operculum naked; pectoral base with 1–3 vertical rows of scales; prepelvic area about 3/4 scaled in 7–8 rows, naked anteriorly; belly largely scaled, with a very small naked patch behind pelvic insertion; 1st dorsal fin spine 3–5 extending beyond other spines when fin depressed; 1st dorsal fin with black spot posteriorly on membrane surrounding 6th dorsal spine, spot faint in female; pelvic fin thin, length much greater than width, reaching anus; 2nd dorsal rays I,9–10; anal rays I,8; pectoral rays 17–18; longitudinal scale count 30–31; predorsal scale count 15–18; transverse scale count (TRB) 9.5–10.5; gill rakers on outer face of 1st arch 1+1+6–8=8–10; lower gill rakers on outer face of 2nd arch 6–7; branched caudal rays 14–15; vertebrae 12+16=28; papillae, Line 1 (before nasal pore) composed of 2 rows of papillae (sometimes incomplete); line 2 (between nasal pores) composed of a single row of papillae usually continuous across snout; line 5 (suborbital) composed of single row of papillae (double in 1 specimens on 1 side of head below infraorbital pore), joining line 7 below posterior nostril; line 6 (suborbital branch) absent; lines 7, 9, 10 (LL cheek rows) composed of a single row of papillae, but irregular anteriorly appearing double, reaching to posterior preopercular margin; lines 8 and 11 (LT row) reaching just short of posterior preopercular margin; line 12 (outer POP–mandibular) composed of single row of papillae, appearing double along lips, without gap at end of lips; line 13 (inner POP–mandibular) composed of 2–3 rows of papillae; line 20 (opercular VT row) composed of single row of papillae dorsally, and double ventrally; line 21 (upper opercular OT) composed of single row of papillae, strongly curved ventrally meeting or almost meeting line 22; line 22 (lower opercular OT) composed of single row of papillae, curving upward along posterior opercular margin; several vertical papillae rows on belly; a single curved line anteriorly on most body scales (often obscure dorsally and posteriorly); chin with an oval patch of papillae behind mental fraenum, with a notch posteromedially without papillae (Ref. 103536). Description: based on 6 specimens 23–112 mm SL, data not taken on smallest; 1st dorsal spines 6(5*); gill rakers on outer face of 1st arch 0+1+7(1), 1+1+6(1). 1+1+7(2), 1+1+8(1); segmented caudal rays 9/8(5*); branched caudal rays 7/7 (2), 7/8(1), 8/7(2*); vertebrae 12+16(3*); head large, slightly depressed, length 32.9–34.9% SL, depth 17.3–18.3% SL, width 18.7–21.2% SL; snout rounded in dorsal view, straight in side view; 9.4–11.7% SL; eye about 1.2–1.5 in snout, 6.2–8% SL (6.2–7% SL in specimens over 70 mm SL); small bump below anterior nostril present; anterior nostril at end of short tube, 1 nostril diameter above upper lip; posterior nostril a pore, midway between eye and upper lip, 3–4 nostril diameters from eye and 1–2 from anterior nostril; preoperculum short, distance from end of eye to upper posterior preopercular margin slightly less than eye length; postorbital long, subequal to distance from tip of snout to posterior half of eye; gill opening reaching to below posterior preopercular margin; teeth in upper jaw, outer row of teeth conical, slightly enlarged and wideset, 3 inner rows of smaller depressible, inwardly directed teeth, innermost row larger than middle rows; teeth in lower jaw, teeth in outer row conical, slightly enlarged and wideset anteriorly, 2 inner rows of smaller depressible teeth, teeth in innermost row larger than teeth in middle row; tongue tip bilobed; gill rakers on outer face of 1st arch short and broad, 1/3 to 1/4 filament length; rakers on inner face of 1st arch and other arches short and denticulate; body covered mostly with large ctenoid scales, cycloid predorsal area, pectoral base, prepelvic area and midline of belly; 1st dorsal fin round to triangular shaped; 2nd dorsal fin subequal in height to 1st dorsal fin; anal fin slightly lower than dorsal fins; pectoral fin with pointed margin, reaching to above a point just before anus to anal origin; pelvic disc thin, length greater than width, reaching about 3/4 of way to anus or just reaching anus; 5th ray with 10 terminal tips of rays at posterior margin of fin in holotype; Head pores, nasal pore before and medial posterior nostril; anterior interorbital pore present posterior interorbital pore present; postorbital pore behind eye present; infraorbital pore below postorbital present; lateral canal pore above preoperculum present; lateral canal pore above posterior preopercular margin absent; terminal lateral canal pore above anterior operculum present; short tube above operculum, with pore at each end present or represented by open trench; 3 preopercular pores, upper in line with lower margin of eye; widely separated from lower 2 (Ref. 103536). Coloration in alcohol: Head and body brown; a dark brown bar from anteroventral margin of eye extending to upper lip; posterior end of lips whitish; an oval brown blotch at posteroventral margin of eye, followed by a small irregularly shaped dark brown blotch; an irregular dark brown blotch on cheek below anterior half of eye; sometimes a series of small dark brown spots forming a horizontal line on cheek; chin pale to faint grey, lighter than top of head; operculum with dark brown mottling; pectoral base with an upper dark brown spot followed by a curved brown bar on bases of pectoral rays; a 2nd dark brown spot ventrally; body with faint brown mottling on back forming indistinct saddles; midsides with series of vertically elongate spots, usually occurring in groups of 2 spots; 1st group below front of 1st dorsal fin, 2nd below posterior end of 1st dorsal fin, 3rd below beginning of 2nd dorsal fin, 4th below 2nd dorsal fin origin, 5th below middle of 2nd dorsal fin, 6th below posterior end of 2nd dorsal fin, 7th on middle of caudal peduncle, 8th at posterior end of caudal peduncle, extending onto base of caudal fin, a triangular (apex forward) brown spot on base of caudal fin, just touching last caudal peduncle spot; individual spots in each group coalesced into single large spot in largest specimen (110 mm SL); all fins grey; 1st dorsal fin with mottling; a black spot on membrane surrounding middle of 6th dorsal spine; 2nd dorsal fin with small dark brown spots forming rows; caudal fin grey with brown spots forming 3–5 short oblique rows, fin darkest ventrally (Ref. 103536). Coloration in Life: head and body yellowish tan; dark brown to blackish markings on head and pectoral-fin base similar to those described for preseserved specimens; fins translucent to slightly yellowish; 1st dorsal fin with mottling and reddish-yellow margin; a black spot on membrane surrounding middle of 6th dorsal spine; 2nd dorsal fin with brownish outer margin and small dark brown spots forming rows; caudal fin dusky yellowish brown to dark grey along posterior and ventral margins and with dark-brown spots forming 3–5 short oblique rows in central portion of fin (Ref. 103536)
Biology: 
IUCN Red List Status: Vulnerable (VU); Date assessed: 05 December 2019 (D2) Ref. (130435)
Threat to humans:  harmless
Country info:   
 


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