Pethia didi (Kullander & Fang 2005)

A member of the Puntius conchonius group and is most similar to P. cumingii, P. meingangbii and P. tiantian by having a dark vertical bar anteriorly on side and a dark round blotch on caudal peduncle. Differs from P. cumingii by 12 vs. 10 circumpeduncular scales and 3 1/2 vs. 4 1/2 scales above midline; from P. meingangbii by 40.4-48.2% SL vs. 33.3-39.6% SL body depth of adults; and from geographically close P. tiantian by having last unbranched dorsal fin ray thick and strongly serrated instead of slender, flexible and with short serrations posteriorly, body depth 40.4-48.2% SL vs. 35.4-39.8% SL, dorsal fin length 26.6-31.8% SL vs. 23.2-26.0% SL, lateral line limited to six to seven, rarely up to ten anterior scales, vs. continued to caudal fin base, and males with two series of black marks in dorsal fin and one series of black marks in anal fin, vs. a single dark bank in each fin in male P. tiantian. Distinguished form P. phutunio by wider infraorbitals 3+4, extending posteriorly to the margin of the preopercle instead of only halfway to the preopercle, 12 vs. 10 circumpeduncular scales, absence of a dark blotch anteriorly at the base of the dorsal fin, and absence of a dark bank extending obliquely rostrad and ventrad from immediately posterior to the dorsal fin base (Ref. 54351). Description: D. iii.8, iv.8; P. i.12, i.13, i.14; V. i.7, i.8; A. iii.5 (Ref. 54351).

Dorsal spines (total): 0; Dorsal soft rays (total): 11 - 12; Analspines: 0; Analsoft rays: 8; Vertebrae: 29 - 31

The type locality was a stream with fast flowing, clear, brownish water, pH 6.5, temperature 23.2°C. Land vegetation consisted of bamboo forest providing 60% shadow, but no aquatic vegetation; bottom mud mixed with stones. Associated species encountered were Acanthocobitis botia (Balitoridae), Xenentodon sp. (Belonidae), Parambassis sp. (Ambassidae), Danio strigillifer, Oreichthys sp., Puntius puntio auct., P. sophore, Rasbora daniconius, R. rasbora (Cyprinidae), Mastacembelus sp. (Mastacembelidae), and Notopterus notopterus (Notopteridae), with P. puntio auct. By far the most abundant (112 out of 164 specimens preserved). Other localities were also small streams with a similar associated fish fauna of small fishes, predominantly cyprinids, and include localities reported for Badis kyar, Badis corycaeus, Dario hysginon, Danio kyathit, and Pillaia kachinica (Ref. 54351).

Inhabits stream with fast flowing, clear, brownish water and with bottom consisted of mud mixed with stones (Ref. 54351).

Pethia didi is a species of cyprinid fish which has only been recorded in the vicinity of Myitkyina and Indawgyi Lake in the north of Myanmar.

This is a small fish which can reach a length of 4 centimetres (1.6 in) SL. It is generally brownish with a dark vertical bar just behind the operculum and a round dark blotch on the caudal peduncle. The species P. tiantian – with a range close to P. didi – is similarly marked, but P. didi can be distinguished by its truncated lateral line, deeper body and longer dorsal fin, with two rows of dark markings rather than one.