Longjaw Goby

Characterized by pale grey body color with irregular brown blotches on cheek, without pronounced dark patch covering top of head; presence of four dark brown saddles (including one on nape) dorsally on side; caudal fin base with diffuse blackish bar; presence of dark wedge-shaped mark on pectoral fin base; fully united pelvic fins, frenum present; rounded caudal fin; longitudinal scale series 36-44; presence of barbels on snout, tip of chin, and ventrally below lower jaw (except none on posterior mandible); strongly ctenoid scales; cheek and opercle without scales; deeply embedded nape scales; presence of sensory pores on head, including two preopercular pores; depth of body about 5.9 in SL (Ref. 90102).

Amphidromous. Refers to fishes that regularly migrate between freshwater and the sea (in both directions), but not for the purpose of breeding, as in anadromous and catadromous species. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.Characteristic elements in amphidromy are: reproduction in fresh water, passage to sea by newly hatched larvae, a period of feeding and growing at sea usually a few months long, return to fresh water of well-grown juveniles, a further period of feeding and growing in fresh water, followed by reproduction there (Ref. 82692).

Dorsal spines (total): 6 - 7; Dorsal soft rays (total): 10; Analspines: 1; Analsoft rays: 8 - 9

Inhabits mud and rock bottoms near shore in 0-4 m (Ref. 90102). Found in coastal waters, estuaries (Ref. 4833), tidal rivers, canals and creeks (Ref. 12693). Feeds on small fishes, crustaceans and insects. Not seen in markets (Ref. 12693).

fisheries: of no interest

Gobiopsis macrostoma Steindachner

Gobiopsis macrostomus Steindachner, 1861:291, fig. 6 [type-locality: Bombay].—Koumans, 1941:245 [from Steindachner, 1861].

Gobius macrostoma Günther, 1861:548 [from Steindachner, 1861].—Day 1876:286 [from Steindachner, 1861]; 1889:252 [same data as Day, 1876:286].

Gobius planifrons Day, 1873:108 [type-locality: Bombay]; 1876:293, pl. 63: fig. 9 [Bombay]; 1889:264, [Bombay].

Pogonogobius planifrons H. M. Smith, 1931:37 [Paknam and Chantabun River, Siam]; 1945:520 [Paknam and Chantabun Estuary].—Fowler, 1935:161 [Paknam].—Koumans, 1941:246 [Bombay and Hingi Basin].

Barbatogobius asanai Koumans, 1941:242 [type-locality: Kosamba Creek near Bulsan, Western India].

DIAGNOSIS.—Sensory pores NA, PITO, AT, and PT present; 2 POP pores, SOT absent; only 1 chin barbel on each side; posterior mandibular, postmandibular, and posterior gular barbels absent; scales strongly ctenoid, size moderate, about 36–44 in horizontal series; jaw moderate to long, about 16–23 percent of SL; dark head wedge not noticeably developed; light to dusky base of pectoral fin divided or nearly so by dark wedge; trunk brownish with moderately dark saddles.

DESCRIPTION.—Dorsal fin rays VI–I, 10(24); anal fin rays I,8(1), I,9(23); pectoral fin rays 19(1), 20(16), 21(21), 22(7); pelvic fin rays I,5(24); segmented caudal fin rays 17(10); branched caudal fin rays 15(9), 16(1); lateral scale rows 36–44(11); transverse scale rows 16–21(10); predorsal scales 14–20(8).

Scales strongly ctenoid, the anterior field with 15–19 primary radii; posterior field narrow, with about 4 short radii; scale highly eccentric, focal area moderate; ctenii on margin of posterior field number 18–25.

Vertebrae 10+16(23), 10+17(1).

Head length 340 (324–352) 5; snout length 82 (79–87) 5; postorbital length 213 (208–218) 5; greatest diameter of orbit 50 (44–52) 5; bony interorbital width 56 (51–62) 5; pectoral fin length 255 (251–260) 3; pelvic fin length 219 (195–236) 5; caudal fin length 297 (268–328) 3; predorsal length 408 (378–421) 5, greatest depth of body 172 (157–189) 4; least depth of peduncle 116 (109–121) 5; postanal length 388 (355–436) 5; lower jaw length 194 (159–234) 22; pelvic fin insertion to anal fin origin 310 (300–319) 5.

A large, robust species, the largest male 79.5 mm SL, the largest female 67.2 mm SL, a gravid female 32.4 mm SL. Head broad; snout rounded from above; trunk deep; fleshy interorbital wide, width almost equal to length of snout, about 1.5 times orbit diameter; lower jaw moderate to long, longer in larger specimens (Figure 4) 16–23 percent of SL; origin of second dorsal fin just posterior to vertical through anal opening; depressed pectoral fin extending to or posterior to anal opening but not reaching anal fin origin, moderately rounded and longer than deep; pelvic fins long, about three-fourths length of distance from pelvic fin insertion to anal fin origin (Figure 3).

Number of teeth on outer row, upper jaw about 20–22, lower jaw about 12–14. No evidence of recurved canine teeth medially on inner row of upper jaw in both sexes.

The cephalic sensory pore and canal system has the AT and PT pores and canal and lacks the SOT pores (Tables 1, 2).

The cutaneous papillae system is pattern 4. The cheek rows are long, reaching end of preopercle, and the papillae in the cheek rows as well as other rows on the head are typically smaller than those of other species of Gobiopsis (Plate 2b).

The groups of barbels not present are: posterior mandibular, postmandibular, and posterior gular; the intermandibular row is occasionally absent. The number of barbels in other groups are: intermandibular, 0–4 (mean 1.78); anterior cheek tuft 1–3 (1.41); anterior internasals 1–3 (1.32); posterior internasals 1–2 (1.10). The lower barbel on the anterior cheek tuft is very long, much longer than other barbels on the tuft and longer than those of most other species of Gobiopsis.

COLOR IN PRESERVATION.—Head and trunk of larger specimens more or less uniform brownish with traces of light and brown motling, the trunk saddles faint to moderately developed; smaller specimens with well developed saddles and mottling on head and trunk, especially laterally on trunk. Head dorsally and laterally brownish, irregularly mottled in smaller specimens, the dark preopercular wedge obscure (Plate 2b), chin slightly dusky and remainder of lower head and breast light to pale brown; trunk with 4 wide dark brown saddles, the first saddle bridging base of upper pectoral fins, a light transverse band precedes first saddle and a dark bar or saddle crosses the occipital area anterior to the light band; anterior portion of the fourth saddle touches the end of the second dorsal fin, a small saddlelike mark on end of caudal peduncle, at upper procurrent caudal rays; saddles in smaller specimens descend to midside or ventrolaterally on trunk in an anterior oblique direction, the saddles almost always not joining laterally and not forming a wavy lateral stripe, areas between saddles light, lower trunk uniform brownish, a dark, irregular vertical bar at base of caudal fin.

Light to dusky base of pectoral fin divided or nearly so on upper portion by dark wedge that extends forward from dark sickle-shaped mark on pectoral fin, lower base of pectoral fin in larger specimens uniformly dusky or with brownish mottling, remainder of fin with dark, elongate, irregularly arranged spots on rays and membranes appearing as wavy vertical bands; pelvic fins dusky, the interradial membranes dark in larger specimens, base of frenum with some pigment, pelvic fins clear to transparent in small specimens; first dorsal fin with 2 broad, dark bands separated by a light area, the outer portion of fin pale to light; second dorsal fin with dark and light markings arranged in 5–6 irregular stripes; anal fin with lower half dusky to brown, an irregular band on outer portion, the fin margin pale to white; caudal fin highly mottled with irregular brown and light spotting or marking, the brown spotting arranged in 5–6 irregular, vertical bands; coloration of fins on some larger specimens faint or obscure (Plate 9c, d).

GEOGRAPHIC DISTRIBUTION.—Known from 3 areas: the Bombay area and the Gangetic delta of India, and the northern Gulf of Thailand (Figure 7).

ECOLOGY.—Specimens from the Gulf of Thailand were taken over muddy and rocky bottoms in brackish water, some captured in bamboo stake traps (GVF Reg. No. 1592, 1593, 1595). H. M. Smith (1945:521) states that the species was found locally in brackish and fresh water.

MATERIAL EXAMINED.—Males, 19 (25.7–79.5 mm SL); females, 8 (21.8–67.2); unsexed, 3 (36.0–50.0).

INDIA, west coast: NMW 29593-95, three syntypes of Gobiopsis macrostomus Steindachner, 2 males (48, 61), female (58), Bombay, Baron Hgel, 1839; ZSIC Reg. No. 97, putative holotype of Gobius planifrons Day, male (79.5), Bombay; ZSIC 5283/2, holotype of Barbatogobius asanai Koumans, unsexed (49.0). Kosamba Creek, Gujarat, India, J. J. Asana, May 1925; ZSIC 5532/2, paratypes of B. asanai Koumans, male (54.6), unsexed (36.0), same data as ZSIC 5283/2; ZSIC 1720, (ca. 50.0), shallow water near Bombay, T. S. Patrick Stewart Townsend. East coast: ZSIC, uncataloged, (25.5) Gangetic delta.

THAILAND: USNM 119633, (57.7, 67.2), Chantabun Estuary, Southeastern Siam, H. M. Smith, 17 Jul 1928; ANSP 63125, (58.6), Paknam, 15 mi (24 km) SSE of Bangkok, R. M. deSchauensee, 28 Aug 1934; CAS 33614, (22.0, 50.5), rock jetty S of Chol Buri between Bangsaen and Chol Buri, GVF Reg. No. 1542, collection date unknown; CAS 33615, (26.4), Chantaburi Province, Mae Nam, Chantaburi River at Tha Chalaep harbor, GVP Reg. No. 1592, 24 Dec 1957; CAS 33616, 10 (21.8–47.3), rocky shore of south side of Goh Proet Island, GVF Reg. No. 1593, 25 Dec 1957; USNM 216191, 4 (27.7–42.6), 2 cleared and stained, same data as CAS 33616; CAS 33618, (26.3), Mae Nam, Welu River at Ban Klong Sone village, GVF Reg. No. 1595, 25 Dec 1957.

Gobiopsis macrostoma, the longjaw goby, is a species of goby found in the Indo-West Pacific from western India to the Mekong River.