Breitensteinia cessator Ng & Siebert 1998 Diagnosis : Breitensteinia cessator is differentiated from its congeners by the following unique set of characters: eye diameter 3.9 - 5.3% LH; interorbital distance 25.4 - 26.9% LH; snout length 27.2 - 31.8; length of caudal peduncle 30.7 - 36·8; 44 - 45 vertebrae; and brown spots on the dorsal and pectoral fins evenly scattered. Proportional measurements : In % LS: head length 16.5 - 18.7, head width 12.0 - 18.2, predorsal distance 27.2 - 34.3, preanal length 54.7 - 62.3, prepelvic length 36.5 - 40.3, prepectoral length 16.5 - 18.1, body depth at anus 6.3 - 7.0, length of caudal peduncle 30.7 - 36.8, depth of caudal peduncle 1.2 - 2.0, pectoral-fin length 14.5 - 15.3, length of dorsal-fin base 4.2 - 6.0, pelvic-fin length 8.7 - 10.7, length of anal-fin base 9.0 - 10.8, caudal-fin length 8.1 - 10.5. In % LH: snout length 27.2 - 31.8,interorbital distance 25.4 - 26.9, eye diameter 3.9 - 5.3, nasal barbel length 5.8 - 7.5, maxillary barbel length 41.6 - 48.7, inner mandibular barbel length 12.8 - 21.1,outer mandibular barbel length 33.8 - 50.4. Counts : Fin ray counts: dorsal I,4,i (4); pectoral I,6,i (4); pelvic i,4,i (4); anal ii,6 (2), ii,6,i (1) or ii,7 (1); caudal 6/5 (4). Branchiostegal rays 5 (4). Gill rakers 1+3 (2).Vertebrae counts : 44–45. Fin spine characters : Dorsal spine with 7 (2), 8 (1) or 9 (1) large serrae posteriorly. Pectoral spine stout, with 8 (1), 14 (1), 15 (1), or 16 (2) large serrae posteriorly. Colour pattern : Dorsal surface of head brown, with dark-brown spots scattered randomly throughout. Dorsolateral and lateral surfaces of body dark brown, with about 11–13 light-brown spots on dorsolateral surface extending from predorsal area to base of caudal fin. Adipose ridge light brown. Small patch of light brown on predorsal area present occasionally. Belly, chest and ventral surface of the head cream or light brown, with few scattered brown spots. Dorsal and pectoral fins cream with numerous brown spots scattered throughout. Pelvic and anal fins cream with one or two dark-brown bands, one present occasionally at the base of the fins and another in the distal half of fins. Caudal-fin cream, with dark-brown band in the distal half and with a narrow midlateral prolongation. Barbels and pectoral spines cream or light brown, with dark-brown spots present sometimes on dorsal surfaces. Comparisons : Breitensteinia cessator resembles B. insignis closely, but is distinguished by its larger and more widely set eyes (eye diameter 3.9 - 5.3% LH v. 1.9 - 3.2; interorbital distance 25.4 - 26.9% LH v. 19.2 - 25.1). The brown spots on the dorsal and pectoral fins in B. cessator are also more evenly scattered (v. concentrated in a dark band near the edges). Distribution and ecology notes : Presently known from the Batang Hari and Tulangbawan drainages in Sumatra and the Kapuas River drainage in western Borneo. Two of the specimens examined by Roberts (1989) had small prawns in their stomachs. Etymology From the Latin cessator (idle fellow), in allusion to the sluggish nature of the fish.
Posted on: Sat, 08 Mar 2014 07:01:09 +0000