Black Back Snake Blenny

Found in silty environments, commonly among rotting vegetation (Ref. 9002).

Ophiclinus gracilis Waite

Ophioclinus gracilis Waite, 1906:207, pl. 36: fig. 6 [lectotype: AMS I.7711, New South Wales, Long Bay; designated below].

Ophiclinus greeni E.O.G. Scott, 1936:114, fig. 1 [holotype: QVML HT 805, northern Tasmania, Lady Lucy Beach].

DESCRIPTION.—Cirrus present on tube of anterior nostril; dorsal fin XLIV–XLIX,1 (XLIV and XLIX in only 1 each of 68 specimens); dorsal-fin origin at vertical over posterior 1/3 of opercle length; predorsal bones absent; anal fin II,27–31 (27 in only 2 of 68 specimens); anal-fin origin below vertical from base of 16th–19th dorsal-fin spine; interradial membranes of anal fin incised; pectoral-fin rays 11–13; pectoral-fin length 9.0–11.7 percent SL (in specimens 60.0–68.0 mm SL); caudal fin 3–5 + 13–14 (14 rarely in some large specimens) + 3–5; vertebrae 18–20 (18 in 3 of 69 specimens) + 32–35 = 51–55; vomerine teeth uniserial in specimens less than 85.0 mm SL and biserial in 2 specimens 85.0 and 101 mm SL; ventroanterior preopercular canal pore positions and all supratemporal canal pore positions usually with pared pores; tube of anterior nostril well removed posteriorly from dorsal margin of upper lip; hooklike process on cleithrum absent.

Lateral Line: Dorsoanterior series with 15–20 pores, connected by diagonal series of pits to posterior midlateral series of pits; pored series originating approximately above vertical at posterior 1/3 of opercle length, extending to point below vertical from base of 8th–10th dorsal-fin spine; posterior midlateral series of pits ending on posterior portion of caudal peduncle.

Color Pattern: No sexual dichromatism observed. Head: wide, dark-brown stripe beginning on snout, interrupted at orbit, continuing to posterior margin of opercle; above dark stripe, dorsal surface of head dark brown or pale; lower ½ of head light brown or pale, with large pale spots occasionally present; brown or pale stripes radiate from orbit, 1 of which may extend to posteriormost point of maxillary or continue onto pale ventral surface of head. Body: color on side often sharply demarcated, upper ½ with wide, dark-brown stripe that widens posteriorly and encompasses caudal peduncle, lower ½ lighter brown or pale; venter pale; midlateral series of 6–18 (mean 10) large, pale spots beginning posterior to pectoral fin insertion; spots may be absent or appear as semicircles. Dorsal and anal fins: pale or brown, with dark-brown bands appearing on posterior ½–1/5 of fins. Pelvic fins: diffuse brown bands may be present. Pectoral fins: brown with distal pale margin. Caudal fin: brown with 1–4 (usually 2 or 3) pale spots dorsally and 2 or 3 spots ventrally.

SYNONYMY.—Although we were not able to examine the type specimens on which O. greeni (E.O.G. Scott, 1936) is based, information in the original description, including an illustration of the holotype, together with specimens sent us from northern Tasmania identified as O. greeni, convinces us that O. greeni and O. gracilis are synonymous. E.O.G. Scott (1965) remarked that O. greeni and O. gracilis are closely allied and may be identical.



In his key to Tasmanian ophiclinins, E.O.G. Scott (1967) reported that O. gracilis has less than 45 dorsal-fin spines and O. greeni has more than 45 dorsal-fin spines. Seven O. gracilis syntypes have 44–48 dorsal-fin spines; thus, the number of spines does not distinguish the two species. E.O.G. Scott (1967) used the shape of the dorsoanterior segment of the lateral line to separate O. gracilis and O. greeni: “strongly arched” in O. greeni, “nearly straight” in O. gracilis. The degree of arching of the lateral line is not a consistent character even among specimens in a single collection. In one O. gracilis syntype the anterior portion of the lateral line is arched on the right side and straight on the left side.

MATERIAL EXAMINED.—N = 70, SL = 19.0–101 mm. SOUTH AUSTRALIA: YORKE PENINSULA, USNM 218783 (3: 56.0–74.0); KANGAROO ISLAND, AMS I.20167-022 (5: 16.7–19.8). NEW SOUTH WALES: SYDNEY: Long Bay, AMS I.7711 (lectotype of O. gracilis, 40.5), AMS I.7712 (3 paralectotypes: 42.0–50.0), AMS I.7713 (3 paralectotypes: 27.5–42.3), AMS I.9013 (3: 47.5–62.0), CAS SU20474 (5 paralectotypes: 22.3–44.6). VICTORIA: CAPE CONRAN, USNM 218794 (3: 67.0–101); BELLS BEACH, USNM 218795 (71.7). WESTERN AUSTRALIA: CAPE NATURALISTE, WAMP P.25195–012 (77.0); MURRAY BIGHT, WAMP P.5704 (65.0); POINT PERON, AMS I.15731-011 (71.7), USNM 211267 (2: 62.6–70.3); ROB ISLAND, AMS I.20216-001 (2:20.2–23.6); ROTTNEST ISLAND, AMS I.20245-024 (50.5); RECHERCHE ARCHIPELAGO: Mondrain Island, AMS I.20222-023 (21.8). TASMANIA: EAGLEHAWK NECK, AMS I.17545-002 (4: 60.0–70.0); GRANVILLE HARBOUR, AMS I.17556-001 (5: 68.0–85.0); THE GARDENS (north of Pinalong), AMS I.17555-001 (2: 60.5–68.0); COLES BAY, AMS I.17553-001 (8: 43.8-74.0); BOAT HARBOUR, AMS I.17586-001 (3:47.0–68.0), AMS I.17585-001 (57.0); BICHENO, AMS I.17554–001 (85.0), USNM 211879 (5: 49.0–86.1); DEVON: Greens Beach, USNM 201460 (2: 76.5–77.0, 1 cleared and stained), USNM 218772 (19.0), USNM 218773 (55.0), USNM 218780 (62.0).

Ophiclinus gracilis, the Black-back snake-blenny, is a species of clinid native to the coastal waters of southern Australia where it prefers areas with rotting vegetation on silty substrates. It can reach a maximum length of 10 centimetres (3.9 in) TL.