Chlopsis slusserorum, Kenneth A. Tighe & John E. McCosker, 2003

Kenneth A. Tighe & John E. McCosker, 2003, Two new species of the genus Chlopsis (Teleostei: Anguilliformes: Chlopsidae) from the Southwestern Pacific., Zootaxa 236, pp. 1-8 : 2-5

Chlopsis slusserorum sp. nov. (Figs. 1, 2, 3A, 4)

Holotype: MNHM 2001-1079 , 141 mm total length, Fiji, Somo-Somo Strait , 16º 27' S, 179º 35.4' W, depth 426-487 m, captured with Waren dredge, Campagne Bordau 1, Station DW 1393, 23 February 1999.

Paratype: AMS I.17284-001 , 86 mm TL, Solomon Islands, Malaita Island, S of Aoki , 8º 24' S, 160º 35' E, depth ca. 366 m, collector: P. Coleman, 27 August 1973.

Diagnosis. The high vertebral count combined with the distinctive pigmentation differentiates this species from all others in the genus Chlopsis .

Description. Total vertebrae 138 (138), predorsal vertebrae 12 (12), preanal vertebrae 40 (41), precaudal vertebrae 60 (56). Proportions as percent of TL: predorsal length 13.2 (13.8), preanal length 33.5 (34.2), head length 11.1 (12.1), depth at anus 2.9 (2.6). Proportions as percent of head length: eye diameter 13.4 (13.5), interorbital width 12.1 (10.6), snout length 22.9 (22.1), tip of snout to rictus of jaw 35.0 (33.6).

Body moderately elongate, slightly compressed. Dorsal fin begins slightly more than one eye diameter posterior to gill opening (Fig. 2). Head moderate in length, relatively deep. Snout relatively broad. Gape short, rictus below posterior margin of eye. Anterior nostril tubular, slightly behind tip of snout, directed anterolaterally. Posterior nostril a postero-ventrally directed low tubular opening (not covered by a flap) on lip in front of vertical from middle of eye.

Lateral line on body absent except for one pore in branchial region, anterior to the gill opening (Fig. 2). Supraorbital pores three: first (ethmoidal) at anteroventral tip of snout, second anteromedial to base of anterior nostril, and last above and behind anterior nostril. Infraorbital pores four: first just posterior to anterior nostril, second midway between anterior and posterior nostrils, third just behind posterior nostril, and last below posterior edge of eye. Preoperculomandibular pores five; first near tip of lower jaw, second below interspace between anterior nostril and infraorbital pore 1, third below interspace between infraorbital pores 1 and 2, forth below posterior nostril, and last below and slightly posterior to infraorbital pore 4.

Maxillary teeth (Fig. 3A) conical, slightly recurved, in 2 irregular rows; inner row larger than outer, a total of 30-31 teeth in the inner row. Intermaxillary teeth conical, slightly recurved, with approximately 20 teeth in a round patch; median and posterior teeth somewhat enlarged. Mandibular teeth like those of the maxilla, except in 2-3 irregular rows anteriorly, reducing to 2 rows posteriorly, with 25-27 teeth in the inner row. Vomerine teeth similar in shape and size to enlarged inner rows of maxillary and mandibular teeth; in two longitudinal series, converging near the end of the tooth rows into a single, irregular median row of small teeth reaching slightly behind the maxillary tooth rows; total of 20-21 teeth in each longitudinal series and 2 small teeth in the median row.

Base color of body light tan; dorso-lateral surface of body overlaid with a series of circa 30-35 dark brown blotches (Figs. 1 and 4); blotches either do not extend to the dorsal surface (anterior to dorsal fin origin or near tail) or only weakly extend to the dorsal fin base (which is lightly pigmented for most of its length); blotches do not line up in pairs with blotches on other side of body (Fig. 4).

Etymology. We are pleased to name this distinctive eel in honor of Marion and Willis Slusser, in recognition of their keen interest in natural history and generous support of research and education.

Remarks. Chlopsis slusserorum is very similar in pigment pattern to C. dentatus from the western Atlantic and western Indian Oceans, which resulted in the paratype being misidentified as C. dentatus by Smith (1989). However, the higher vertebral count (138 versus 116-124) clearly separates the two species. All other species of the genus Chlopsis have either relatively uniform coloration or are distinctly bicolored.

Nearly all of the description is based only on the holotype due to the small size and poor condition of the paratype. The paratype apparently became dessicated some time in the past, and the position and number of pores could not be determined. In addition, the lower jaw was badly broken and teeth were missing. Therefore, tooth counts could only be approximated. However, we believe the two specimens to be conspecific, given the similarity in pigment pattern and vertebral numbers.