Ophiocara ophicephalus (Valenciennes, 1837)

Keith, Philippe & Mennesson, Marion I., 2021, Review of Ophiocara (Teleostei: Butidae) from Indo-Pacific Islands, Cybium 45 (2), pp. 89-108 : 100-102

Ophiocara ophicephalus (Valenciennes, 1837)

( Figs 2-3 , 6-7 ; Tabs II-III)

Eleotris viridis Bleeker, 1849 ; Madura Straits near Surabaya and Kammal, Java, Indonesia, Bleeker coll.; syntype: RMNH 6197.

Agonostoma darwiniense Macleay, 1878 ; Port Darwin, Northern Territory, Australia; syntype: AMS I.14855 .

Lindemanella iota Whitley, 1935 ; Freshwater creek on Lindeman Island, northern Queensland, Australia; holotype (unique): AMS IA.6411.

Eleotris kuak Montrouzier, 1857 ; Woodlark Island, Papua New Guinea; MGHNL (lost).

Material examined

Holotype (unique). – MNHN-IC-A-1569 (113 mm SL) Java, Indonesia.

Others. – MNHN-IC-A-1574, syntypes of Eleotris porocephala Val. in Cuvier & Valenciennes, 1837; 2 males (134- 164 mm SL), New Ireland Island, Bismarck Archipelago, Quoy & Gaimard coll. RMNH 6197, syntype of Eleotris viridis Bleeker, 1849 ; Madura Straits near Surabaya and Kammal , Java, Indonesia. AMS I.14855, syntype of Agonostoma darwiniense Macleay, 1878 ; 106 mm SL, Port Darwin , Northern Territory, Australia. AMS IA.6411, holotype (unique) of Lindemanella iota Whitley, 1935 ; juvenile (165 mm SL), Freshwater creek on Lindeman Island , northern Queensland, Australia. MNHN-IC-2000-1269, female (109 mm SL), New Caledonia, 1999, Marquet coll. MNHN-IC-2001-2910, female (87 mm SL), New Caledonia, 1999, Marquet coll. MNHN-IC-2020-0182, 1 female, 1 juvenile (52.3-78.3 mm SL), Bilata , Choiseul , Solomon Is., 19 Oct. 2019, Keith, Boseto, Lord & Causse coll.; tags 17579, 17584. MNHN-IC-2020-0183, male (84.3 mm SL), Tukutu, Choiseul, Solomon Is., 19 Oct. 2019, tag 17596. MNHN-IC-2020-0184, male (94 mm SL), Simbe, Choiseul, Solomon Is., 20 Oct. 2019; tag 17562. MNHN-IC-2020-0185, female (77 mm SL), Venoui, Santo, Vanuatu, 15 July 2005, Keith & Marquet coll.; tag 12537. MNHN-IC-2020-0475, juvenile (51 mm SL), small river, Palau, 02 March 2011, Keith et al. coll.; tag 6843. MNHN-IC-2020-0476, 1 male, 2 females (of 6) (68.7-82.6 mm SL), Petroglyphs , Pohnpei, Micronesia, 14 March 2012, Keith et al. coll.; tags 5246, 5247, 12528 .

Diagnosis

The species usually has 32-34 lateral scales, 22-24 predorsal scales, 8-9 zigzag scales and the jaw length is 16-17% SL.

Description

The scale counts are given in table II and selected morphometrics in table III.

The body is more ovoid than elongated. The body depth at anus is 20-24% SL, at first dorsal fin 22-26% SL, and the caudal peduncle depth is 15-16% SL. Predorsal length 44-48% SL and preanal length 63-69% SL. Size: up to 26 cm SL.

The head 37-39% SL is depressed, the snout is convex. The anterior nostrils are long, reaching lower margin of upper lip. The mouth and jaw length 16-17% SL are large with inwardly curved teeth set on both jaws and larger on outer row of upper jaw. Posterior end of maxillary extending below 1/2 or 2/3 of posterior margin of eye. Eye diameter 6-8% SL and interorbital length 11-13% SL.

Dorsal fins VI-I,8 with no filamentous rays. The first dorsal fin is with second, third and fourth rays longer. Anal fin I,7 directly opposite to the second dorsal fin. The caudal fin is with 14-15 branched rays and its posterior margin is rounded. Pelvic fi ns separate, I,5. Pectoral fi ns 15, with the posterior margin pointed. Lateral scales usually 32-34 (1 specimen with 35), with ctenoid scales on flanks and caudal peduncle. Cycloid scales from snout to top of head and anterior part of D1, on operculum, on base of pectoral fi ns and on belly extending to anus. Scales of top of head and back bigger than those of belly. Scales in transverse back series 11-12, in transverse forward 16-19, in predorsal usually 23 (1 specimen with 22 and 1 with 24) and in zigzag usually 8 (4 specimens with 9). Usually 26 vertebrae. Gill opening extending beyond the posterior end of urohyal. Gill rakers 11-13.

Cephalic sensory pore system as described by Akihito and Meguro (1974) and Akihito (1986), with oculoscapular canal nasal to post-temporal with the pores A to L except for G; preopercular canal long with the pores M to Q; oculoscapular canal grooves on nasal, frontal, pterotic and post-temporal; inner side of oculoscapular canal on frontal walled continuously from C to F; preopercular canal groove long. Head sensory papillae as described by Akihito and Meguro (1974) and Akihito et al. (1988).

Males with a rounded/elongated urogenital papilla with distal tip rounded. The females have rectangular or chaliceshaped bulbous urogenital papilla with crenulated outer edges around distal opening.

Colour in preservation

Background of body brown on the back. The flanks are brownish with some greyish patches. Belly greyish. Top of head brownish, as lateral parts; with sometimes 2 or 3 dark brown stripes radiating from the eye to the cheeks and operculum. The first and second dorsal fins are greyish with 4-5 rows of aligned dark spots along rays. The pelvic, pectoral and anal fins are greyish and without spots.

Colour in life

Adults. – Most common pattern similar for male and female. Usually, background of body brownish to greyish with dark brown or black on the back. Two light whitish or light brown vertical bands on the flanks, sometimes not very visible. The first one from the anterior part of the second dorsal fin to the anterior part of the anal fin, the second one around the caudal peduncle. Two white or light brown spots on hypural base. Top of head brownish, with several whitish or light brown parts between eyes and on nose. Lateral parts brown with 3 dark brown stripes radiating from the eye to the cheeks and operculum. Isthmus and belly dark grey to brown. Bigger specimens mostly brown ( Fig. 7A ), without any white bands or white spots on the flanks, head or hypural base (white marks less marked on old specimens). The first and second dorsal fins are greyish or light brown with 4-5 rows of aligned dark spots along rays. The pelvic, pectoral and anal fins are grey or light brown. The anal and caudal fins have a light yellow distal part.

A second pattern occurs sometimes in males with a background of body entirely dark grey and covered with numerous small silver or bluish spots, including the caudal fin (named here ‘silver or golden dotted pattern’; found in New Caledonia, Palau, Papua New Guinea, Solomon Is. and Vanuatu). The belly is whitish or light grey. The anal, pelvic and caudal fins are grey with a yellowish band at the distal part. The pectoral fins are translucent to grey ( Fig. 7B ).

Juveniles. – Background of body greyish to black on the back. Flanks greyish to black. Two flashy white vertical continuous bands on the flanks, the first one from the anterior part of the second dorsal fin and the medium part of belly, the second one around the caudal peduncle. 2-3 white spots at hypural base. Top of head brownish, with whitish parts between eyes and on nose. Lateral part greyish with 3 dark brown stripes and a white one radiating from the eye to the cheeks and operculum. Isthmus and belly whitish to greyish. The first and second dorsal fins are greyish with 4-5 rows of aligned dark spots along rays. The pelvic, pectoral and anal fins are translucent. The anal and caudal fins have a light yellow distal part ( Fig. 7C ).

Ecology

The species occurs mainly in the vegetation or under rocks in the lower parts of rivers, from tidal influence to 20 m high in altitude, with sandy, muddy or gravel bottoms. In Australia, its distribution is typically confined to short coastal systems but it does penetrate a moderate distance upstream ( Pusey et al., 2017). It is carnivorous and feeds on crustaceans, molluscs and fish ( Allen and Coates 1990; Marquet et al., 2003; Nanjo et al., 2008; Keith et al., 2010).

Distribution

Ophiocara ophicephalus is known from the Pacific Ocean from Ryukyus Islands, Taiwan Philippines and Micronesia in the north-west to Indonesia, Papua New Guinea, Solomon Islands, Australia, where it has a patchy northern distribution, New Caledonia, Vanuatu and Fiji Is. in the south-east ( Fig. 6 ).

Comparison

Ophiocara ophicephalus differs from the other species sequenced by having a significant percentage of divergence in COI gene (8.2%%) (Suppl. data). Moreover, it differs from O. porocephala by a combination of characters including fewer scales in lateral series (32-34 vs 35-37), transverse backward series (11-12 vs 12-13) and zigzag series (usually 8 vs usually 9-10), and a greater jaw length (16-17 vs 14-16% SL). The ‘silver dotted pattern’ ( Fig. 7B ), known for this species, is unknown for O. porocephala and the juveniles have usually fewer vertical interrupted white bands (usually 1) on the flanks than O. porocephala (usually 3). O. ophicephalus differs from O. cantoris by fewer scales in lateral series (32-34 vs 37-39) and predorsal series (22-24 vs 25-27).

Figures

Figure 2. – Bayesian tree of the cytochrome c oxidase subunit (COI; 446 bp) for sequenced specimens of Ophiocara. Numbers at each node represent posterior probabilities.

Figure 3. – Barcoding NJ K2P trees of the cytochrome c oxidase subunit for sequenced specimens of Ophiocara including three syntypes from MNHN collection; Eleotris porocephala Valenciennes, 1837 from New Ireland (Papua New Guinea) (MNHN-IC-A-1574) and from Seychelles (MNHN-IC-A-1573), and E. madagascariensis Valenciennes, 1837 (MNHN-IC-A-2709). Numbers at each node represent bootstrap values. For all trees, MNHN syntypes are in bold. In tree (A) [199 bp], the three specimens from the Museum & Art Gallery of the Northern Territory (NTM,Australia) are highlighted with a star; Tree (B) [110 bp]; Tree (C) [106 bp].

Figure 6. – Distribution of Ophiocara species.

Figure 7. – A: Ophiocara ophicephalus, male, New Caledonia (Photo N. Charpin); B: Ophiocara ophicephalus, male, ‘silver dotted pattern’, New Caledonia (Photo L. Taillebois); C: Ophiocara ophicephalus, juvenile, New Caledonia (Photo E. Vigneux).