Snakehead Goby

Dorsal spines (total): 7; Dorsal soft rays (total): 10 - 11; Analspines: 1; Analsoft rays: 9

Found beneath stones in muddy areas of tide pools.

Gobiopsis pinto (J.L.B. Smith)

Abranches pinto J.L.B. Smith, 1947:813 [type-locality: Ponte Mahone, Delagoa Bay, Mozambique]; 1949:331, fig. 909, pl. 72 [color]; 1959:211, pl. 12I.

DIAGNOSIS.—Sensory pores NA, AT, and PT present, 2 POP pores, the PITO pore usually absent; papillae on anterior portion of first cheek row (bordering cheek fold) replaced by a row of elongate, barbellike structures; scales cycloid, small, about 50–60 in horizontal series; 2–3 enlarged canines medially in inner tooth row of upper jaw of males; posterior mandibular, postmandibular, and posterior gular barbels absent; jaw moderate to long, about 15–22 percent of SL; dark head wedge not noticeably developed; light base of pectoral fin divided or nearly so by dark wedge; trunk uniformly dark or with faint saddles.

DESCRIPTION.—Dorsal fin rays VI–I,10(2) VI–I, 11 (7); anal fin rays I,9(9); pectoral fin rays 20(5), 21(11); pelvic fin rays I,5(9); segmented caudal fin rays 17(9); branched caudal fin rays 15(6), 16(1), 17(2); lateral scale rows 50–60(9); transverse scale rows 20–26(9); predorsal scales deeply embedded or rubbed off in all specimens.

Scales cycloid, primary radii in anterior field about 16 with a few secondary radii; focal area broad; posterior field narrow with about 10 short radii; some scales have the posterior field barely discernible.

Vertebrae 10+16(9).

Head length 340 (328–356) 7; snout length 81 (75–91) 7; postorbital length 208 (190–227) 7; greatest diameter or orbit 50 (47–54) 7; bony interorbital width 53 (44–57) 7; pectoral fin length 251 (244–259) 6; pelvic fin length 224 (214–237) 7; caudal fin length 298 (278–325) 5; predorsal length 418 (410–424) 4; greatest depth of body 157 (134–175) 6; least depth of peduncle 105 (100–112) 7; postanal length 353 (333–369) 7; lower jaw length 177 (148–216) 7; pelvic fin insertion to anal fin origin 322 (306–340) 7.

Body stout, head broad, fleshy interorbital width about equal to snout length and about 1.5 times orbit diameter; lower jaw moderate to long, longer in larger specimens and apparently longer in males than females, 15–22 percent of SL (Figure 4); origin of second dorsal fin over anal opening; depressed pectoral fin almost reaching vertical through anal opening, longer than deep and moderately round; pelvic fins comparatively long, about three-fourths length of distance from pelvic fin insertion to anal fin origin (Figure 3); largest male 51.0 mm SL largest female 42.7 mm SL.

Number of teeth on outer row, upper jaw about 21, lower jaw 12–14; 2–3 enlarged, posteriorly recurved canines medially on inner tooth row of upper jaw of males.

The cephalic sensory pore and canal system is characterized (Tables 1, 2) by the presence of the AT and PT pores, the absence of the SOT pores, and the absence of the PITO pore in all but the 2 smallest specimens.

The cutaneous papillae system is pattern 4, except that the papillae are modified or replaced by elongate barbels on the anterior portion of the first cheek row (on border of cheek fold), to a lesser extent on the fourth cheek row, and beneath the jaw on the outer preoperculo—mandibular row.

The following barbel groups (Table 3) are absent: posterior mandibular, postmandibular, and posterior gular; the intermandibular row is sometimes absent or eroded away. The number of barbels in other groups are: intermandibular 0-3 (mean 1.33); anterior cheek tuft 1–3 (2.42); anterior internasals 1–2 (1.42); poterior internasals 1 (1.00). The lower barbel on the anterior cheek tuft is elongate, much longer than others on the tuft.

COLOR IN PRESERVATION.—Head and trunk more or less uniformly dark, the saddles weakly developed (Plates 7c, 8c); midportion of head behind the eye pale to light, a dark band traverses the occipital area; the dark wedge on preopercle obscure (Plate 3b); 4 faint saddles on trunk extend ventrally to midlateral portion, apparently not joining to form a wavy, lateral stripe; areas between saddles pale to light.

Light base of pectoral fin divided, or nearly so, by dark wedge arising from dark sickle-shaped mark on proximal portion of pectoral fin; sickle-shaped mark darkest on upper portion, the dark wedge almost obscure on some larger specimens, remainder of fin dusky to pale. Pelvic fin pale to transparent. Anterior basal portion of first dorsal fin clear, remainder dusky brown. Second dorsal fin with 3 faint oblique stripes, one on lower anterior portion, one through middle, and one on outer posterior portion, remainder pale, stripes not evident on most specimens. Anal fin pale. Caudal fin pale to dusky, some traces of faint, small spots, not visible on most specimens.

GEOGRAPHIC DISTRIBUTION.—Known only from Delagoa Bay, Mozambique (Figure 7).

ECOLOGY.—Described by J.L.B. Smith (1947:814; 1949:331) as occuring beneath stones in tide pools of muddy areas.

MATERIAL EXAMINED.—Males, 5 (35.2–51.0 mm SL); females, 5 (27.0–42.7 mm SL). MOZAMBIQUE: RUSI 197, holotype, male (35.2), Ponte Mahone, Delagoa Bay, J.L.B. Smith; RUSI 3019, 5 (29.7–51.0), from type-locality, Oct 1953; USNM 210414, (27.0, 41.1), same data as RUSI 3019; USNM 210405, 36.0), from type-locality, Aug 1948; UZMK, uncataloged, (50.1), Polana beach, Lourenco Marques, sand coast, Th. Mortensen's Java and S. Africa Exp., 1929–1930, 9 Mar 1929.

Gobiopsis pinto, the snakehead goby, is a species of goby found in the Western Indian Ocean.