Shy Garden Eel

description

Biswas et al. (2012) reported a species resembling H. fugax from Kalakkam, east coast of India, as H. tomberua, based on a specimen (ZSI F- 10575 / 2) collected from the traveling water screen of the seawater cooling system of the nearby nuclear power station. The specimen was similar to H. fugax, having an extremely slender body (depth 1.16 % of TL), 191 total vertebrae, dark spots on the head and body, a large distinct white blotch on the opercle, spots on the head more numerous and denser than on the body, lips spotted, and body ground color uniformly cream, lacking microscopic dark speckles. However, H. fugax differed in having the dorsal-fin origin posterior to tip of the appressed pectoral fin (vs. above middle of pectoral fin), 2 – 3 rows of dark spots above and below the lateral line (vs. 3 – 4 rows of dark spots restricted to anterior half of body, faint or lacking posteriorly), 6 – 7 row of spots across interorbital area (vs. 11 – 13 rows of spots), and numerous crowded dark spots over entire head (vs. ventral half of head lacking dark spots) all from Biswas et al. (2012). Clearly, Biswas et al. ’ s (2012) specimen is distinct from H. fugax, as well as from all other know

A new garden eel, Heteroconger fugax (Congridae: Heterocongrinae), from the northwestern Pacific Ocean

description

Description. Pre-dorsal-fin vertebrae 8; Pre-anal-fin vertebrae 67; total vertebrae 197; lateral-line pores before pectoral fin 7; lateral-line pores before anus 65; pectoral-fin rays 9; dorsal-fin rays before anus 182; total dorsal-fin rays 590; anal-fin rays 425; caudal-fin rays 9 + 8. Head pores (left side): supraorbital series 1 + 4; infraorbital series 3 + 3; preoperculomandibular series 5 + 3; supratemporal series 3. As percent of TL: HL 3.4 %; Snout-anus length 30.1 %; pre-dorsal-fin length 4.0 %, trunk length 26.4 %; tail length 67.4 %; depth at gill opening 1.2 %; depth at anus 1.0 %. As percent of snout-anus length: HL 11.5 %; predorsal-fin length 13.7 %. As percent of HL: snout length 16.8 %; eye diameter 19.2 %; mouth width 24.5 %; gill opening 9.1 %; interbranchial distance 21.4 %; depth at gill opening 34.2 %; depth at anus 27.9 %. Body extremely elongate, body depth similar throughout; greatest depth at gill opening. Body slightly compressed laterally along head, progressively more so to tail tip; tail much longer than body, anus at about 30 % total length. Head slightly compressed ventrally; snout short, rounded. Mouth with fleshy lips; distinct fold extending to en

A new garden eel, Heteroconger fugax (Congridae: Heterocongrinae), from the northwestern Pacific Ocean

diagnosis

Diagnosis. A species of Heteroconger with the following combination of characters: body extremely slender, depth 1.2 % TL and 1.0 % TL at gill opening and anus, respectively; pre-dorsal-fin and pre-anal-fin vertebrae 8 and 67, respectively, total vertebrae 197; origin of dorsal fin slightly posterior to tip of appressed pectoral fin; numerus small conical cirri on chin; 2 – 3 rows of dark spots above and below lateral line; 6 – 7 rows of dark spots on interorbital space; large distinct white rectangular blotch on opercle; number and density of spots on head greater than those on body; lips spotted; ground color of body uniformly cream, without microscopic dark speckles.

A new garden eel, Heteroconger fugax (Congridae: Heterocongrinae), from the northwestern Pacific Ocean

discussion

Remarks. Heteroconger fugax sp. nov. resembles H. tomberua Castle & Randall 1999, both species having a very slender body with numerous small dark spots on the body and head, about 200 vertebrae, and similar counts of head pores (Castle & Randall 1999). However, a comparison of H. fugax with the holotype and the original description of H. tomberua (USNM 349761: Fig. 5) showed that the former can be distinguished by the dorsal fin originating posterior to the appressed pectoral-fin tip (vs. anterior in H. tomberua), numerous conical cirri on the chin (vs. absent) (Fig. 2), a large distinct white rectangular blotch on the opercle (vs. none), dense dark spots over the entire head, including lips (vs. absent on throat, snout and lower jaws), and lacking microscopic dark speckles on the body (vs. present) (Fig. 1). In addition, H. fugax differs from H. tomberua in having slightly higher counts of preanal vertebrae (67 in H. fugax vs. 58 – 64 in H. tomberua), lateral-line pores before the anus (65 vs. 56 – 63), and shorter head length (11.5 % in HL vs. 12.5 – 16.3 %) and eye diameter (19.2 % in HL vs. 22.8 – 27.6 %) (Table 1).

A new garden eel, Heteroconger fugax (Congridae: Heterocongrinae), from the northwestern Pacific Ocean