Sundadanio margarition Conway, Kottelat & Tan, 2011

Family:  Sundadanionidae (Tiny danios)
Max. size:  1.97 cm SL (male/unsexed)
Environment:  benthopelagic; freshwater
Distribution:  Asia: Malaysia from the Rajang and Sarawak River drainages and probably in between.
Diagnosis:  Dorsal soft rays (total): 9-9; Anal soft rays: 9-9; Vertebrae: 34-34. Distinguished from all congeners by the following combination of characters: large adult size (largest specimen examined 19.7 mm SL); live males with emerald blue-green sheen present across dorsal body surface and an intense black-red marking across anterior portion of anal fin; preserved males with a well developed dark lateral stripe of roughly uniform depth along entire length, horizontal through ventral border of which, when brought forward, extending through dorsal half of eye; presence of a weak secondary lateral stripe of small melanophores running parallel to dark lateral stripe along its ventral margin from posterior to opercular opening to point opposite middle of anal fin; secondary lateral stripe of males not visible in live specimens; absence of reticulate pattern over dorsal body surface; absence of dusky markings on distal tips of dorsal and caudal fins; presence of enlarged scales next to window in body musculature; scales posterior to enlarged scales next to window in body musculature and anterior to anal-fin origin with a single small tubercle at center; complete covering of scales on caudal peduncle (Ref. 88800). Description: Dorsal-fin rays ii.6.i; anal-fin rays iii.6; pectoral-fin rays i.6-7.i-ii; pelvic-fin rays i.5.i (Ref. 88800).
Biology:  Inhabits swamp forests and blackwater streams (Ref. 88800).
IUCN Red List Status: Near Threatened (NT); Date assessed: 04 January 2019 (B1ab(i,ii,iii,iv)+2ab(i,ii,iii,iv)) Ref. (130435)
Threat to humans:  harmless

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