Ompok supernus

description

FIGURE 2. Ompok supernus, MZB 10983, holotype, 129.3 mm SL; Borneo: Kalimantan Tengah, Rungan River drainage. Dorsal, lateral and ventral views. Description. Biometric data in Table 1. Body laterally compressed; maximum body depth located ventral to dorsal-fin origin; head as broad as body and slightly depressed. Dorsal profile of head slightly convex. Anterior profile of snout rounded. Anterior pair of nostrils tubular and anteromedial to maxillary barbel base. Posterior pair of nostrils bordered by fleshy dorsal and ventral membranes and posteromedial to maxillary barbel base. Mouth terminal; gape almost horizontal, large and extending between anterior orbital margins. Welldeveloped rictal lobes present, subtended by deep submandibular groove; upper rictal lobe without skin fold. Thin, broad supralabial fold extending from ventral to orbit to maxillary barbel base. Jaw teeth depressible and villiform. Premaxillary teeth in narrow, slightly curved rectangular bands. Dentary teeth in similar, slightly narrower bands, narrowing posterolaterally, reaching from symphysis almost to mouth corners. First row of dentary teeth partially exposed when mouth is closed. Palatal teeth in two sl

Ompok supernus, a new catfish (Teleostei: Siluridae) from Borneo

diagnosis

Diagnosis. Ompok supernus can be distinguished from all Southeast Asian congeners, except for O. borneensis, O. fumidus and O. leiacanthus, in having a combination of a brown body without any melanophores forming a prominent black humeral spot (although the tympanic area appears darkened), the rictal lobes separated by a superficial groove extending from the corner of the mouth to the submandibular groove, a gape not reaching beyond the anterior border of the orbit, and 54 – 66 anal-fin rays. Ompok supernus differs from O. borneensis, O. fumidus and O. leiacanthus in having more dorsally-placed eyes (Fig. 2), which is also manifested in its smaller interorbital distance compared to the latter three species (42.6 – 48.7 % HL vs. 49.1 – 59.5). Ompok supernus is additionally diagnosed by a combination of a mottled body and a rounded anterior profile of the lower jaw, and further differs from O. fumidus in having a narrower head (14.7 – 17.4 % SL vs. 17.5 – 20.5).

Ompok supernus, a new catfish (Teleostei: Siluridae) from Borneo

distribution

Distribution. Known from the Rungan River drainage (a major tributary of the Kahayan River drainage) in southern Borneo (Fig. 5). Habitat. Most of the type series was obtained from the aquarium trade, but a single paratype (ZRC 51406) was collected in a blackwater stream (pH 3.4) with a sandy bottom flowing through secondary vegetation.

Ompok supernus, a new catfish (Teleostei: Siluridae) from Borneo

etymology

Etymology. From the Latin adjective supernus, meaning “ that is above ” or “ on high ”; in allusion to dorsally placed eyes of this species.

Ompok supernus, a new catfish (Teleostei: Siluridae) from Borneo