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| Macrognathus kris Ng & Tan, 2020 |
Abstract
A new species of Macrognathus of the M. aculeatus species group is described from the Kahayan River drainage in southern Borneo, Kalimantan Tengah, Indonesia. Macrognathus kris, new species, is distinguished from all Asian congeners in having the following unique combination of characters: rim of anterior nostril with two fimbriae and two fimbrules; 43–45 rostral tooth plates; 24–25 dorsal spines; 46–55 dorsal-fin rays; 51–59 anal-fin rays; 20–23 principal caudal-fin rays; 76–78 total vertebrae; body depth at anus 11.8–15.9% SL; color pattern consisting of light brown stripe on dorsum and 11–14 irregular pentagonal dark brown blotches on sides of body.
Synbranchiformes, Macrognathus, biodiversity, Pisces
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| Macrognathus kris, A. MZB 10978, holotype, 189.4 mm SL; B. ZRC 51203, paratype, 99.8 mm SL; C. ZRC 51202, paratype, 227.3 mm SL; D. ZRC 51204, 370.0 mm SL. |
Macrognathus kris
Distribution. This species is currently known only from the Rungan River sub-drainage of the Kahayan River drainage in Central Kalimantan, Borneo ( Fig. 2). We hypothesize that it may occur also in neighboring sub-drainages within the Kahayan River drainage, or even in adjacent river drainages (e.g. the Mentaya River drainage). Further surveys are needed to confirm this.
Habitat. Macrognathus kris inhabits blackwater habitats associated with peat swamp forests. Sungai Panta (where some of the paratypes have been collected) is a blackwater feeder stream flowing into Rungan River, with alluvial forest and flooded forest habitats. Syntopic fish species include: Brevibora cheeya Liao & Tan, Crossocheilus pseudobagarius Duncker, Desmopuntius foerschi (Kottelat), D. johorensis (Duncker), D. rhomboocellatus (Koumans), Eirmotus cf. insignis Tan & Kottelat, Malayochela maassii (Weber & de Beaufort), Osteochilus pentalineatus Kottelat, O. spilurus (Bleeker), Striuntius lineatus (Duncker) ( Cyprinidae), Kottelatia brittani (Axelrod), ...., Betta anabatoides Bleeker, B. edithae Vierke, Luciocephalus aura Tan & Ng, Parosphromenus filamentosus Vierke, Sphaerichthys acrostoma Vierke, S. selatanensis Vierke, Trichopodus leerii (Bleeker) ( Osphronemidae), Achiroides sp. ( Soleidae), and Pao palembangensis (Bleeker) ( Tetraodontidae). The inhabitants are a mix of riverine—with mainly swamp forest and peat swamp—taxa.
Etymology. The kris is a wavy-bladed dagger carried and used by local nobility and warriors. The name is used as a noun in apposition, in allusion to the wavy or zigzag pattern on the body of the spiny eel and the general resting posture of the fish when viewed from above.
Heok Hee Ng and Heok Hui Tan. 2020. A New, uniquely patterned Spiny Eel (Teleostei: Mastacembelidae) from southern Borneo, Kalimantan Tengah, Indonesia. Zootaxa. 4819(1); 170-178. DOI: doi.org/10.11646/zootaxa.4819.1.9
