ON A NEW SPECIES BADIS TRIOCELLUS ( PISCES : PERCIFORMES : BADIDAE ) FROM NORTH EAST INDIA

Badids are small freshwater fish normally inhabit small streams or hill streams with slow to moderate flow. In the past, the genus Badis was generally treated as a member of the family Nandidae together with other genera like Nandus, Polycentrus, Monocirrhus, Afronandus and Polycentropsis (Ruber et aI., 2004). Barlow et aI. (1968) erected a separate family, Badidae for the genus Badis alone based on morphological and behavioral data. Following Kullander and Britz (2002), the family Nandidae is now restricted to the genus Nandus and the other genera like Polycentrus, Monocirrhus, Afronandus and Polycentropsis are classified in the family Policentridae.


INTRODUCTION
Badids are small freshwater fish normally inhabit small streams or hill streams with slow to moderate flow.In the past, the genus Badis was generally treated as a member of the family Nandidae together with other genera like Nandus, Polycentrus, Monocirrhus, Afronandus and Polycentropsis (Ruber et aI., 2004).Barlow et aI. (1968) erected a separate family, Badidae for the genus Badis alone based on morphological and behavioral data.Following Kullander and Britz (2002), the family Nandidae is now restricted to the genus Nandus and the other genera like Polycentrus, Monocirrhus, Afronandus and Polycentropsis are classified in the family Policentridae.Kullander and Britz (2002) in their taxonomic revision revealed that the family Badidae currently assigned to two genera Badis (with 12 species) and Dario (with 3 species).The distribution of the Badidae includes the Indian subcontinent, Pakistan, Nepal, Bangladesh, Myanmar, Peninsular Thailand, the Mae Khlong drainage and part of the Mekong basin in South East Asia as well as the Upper Irrawaddy in southern Yunnan, China.
While studying the Badis specimens collected from Subansiri river, Lower Subansiri district Arunachal Pradesh; Dilpai river, Dhemaji district Assam and Mynsor river, laintia Hills district Meghalaya, the authors came across some interesting specimens which were strikingly different from other known species of the region having three prominent spots (two on dorsal fin and one on anal fin).A detailed morphological study reveals its identity as new to science.

MATERIALS AND METHODS
The specimens are preserved in 5% formaldehyde.Twenty four morphological characters have been taken into consideration and measurements were done with a digital caliper, expressed in percentage in relation to standard length.The range, mean values and standard deviation (SD) are also incorporated.Counts and measurements were done according to layaram, 1999.4 specimens, 36.67-45.27 mm TL, India, Assam, Dhemaji District, Dilpai River downstream, 3-vii-2007, Alt. 103  Diagnosis: Badis triocellus sp.nov. is characterized by the presence of three distinct black blotches on fins; two on anterior and posterior end of dorsal fin respectively and one on anal fin; anterior blotch on dorsal fin is present in between 3 rd _5 th dorsal spine, posterior one present slightly above base of last 3-4 soft rays.On anal fin, blotch is present a little above the base of last 3 soft rays.A light to dark brown blotch on middle of the opercle, a brownish blotch at middle of the base of caudal fin and a faint pattern of alternating light to brown irregular stripes along the sides of the body are additional combination of characters.

Budis triocellus
Description: D 15/9; P 12; V 1/6; A 3/8; C 14. Body moderately elongated, slightly compressed laterally, its depth 27.67% in SL.Head laterally compressed its length 27.44%, width 16.05%, and depth 18.48% of SL.Dorsal profile gradually rising from tip of snout to the base of 3 rd _4th dorsal spine, then sloping gently towards the end of dorsal fin and slightly concave or straight on caudal peduncle; ventral profile almost horizontal from end of opercle to the origin of anal fin, then almost straight on the caudal peduncle.Mouth small and slightly protrusible; lower jaw slightly projecting and maxilla extending beyond anterior margin of orbit.The eye is situated laterally in anterior half of head, its diameter 5.70%, interorbital space 8.65%, length of snout 6.86% of SL.Operculum triangular with slender spine proj ecting posteriorly (Table -1).Dorsal fin single and large with the spinous portion being of much greater extent than the soft part; length of dorsal fin base 55.01%, height of spinous dorsal fin 12.89%, soft dorsal fin 17.32 % of SL.Anal fin with 3 spines, its rayed portion (17.53% of SL) similar to that of the dorsal fin; tips of soft dorsal and anal fins are rounded.Tip of pectoral fin is rounded and its length slightly shorter (22.11 % of SL) than pelvic fin (23.01% of SL) which is pointed and not reaching anus.Distance between pectoral and pelvic fins (7.17%) is more than four times the distance between pelvic and anal fins (30.29%).Distance between anus and anal fin (3.13% of SL) is more than eight times the distance between pelvic fin and anus (26.22% of SL).Caudal fin is rounded, its length 21.36% of SL, length of caudal peduncle is more (16.26% of SL) than its height (14.96% of SL) (Table -1).Lateral line scales 28; Lateral transverse scales 8; Predorsal scales 9; scales around caudal peduncle 14.
Colouration : Body brownish dorso-Iaterally, pale brown to white ventrally.Brownish irregular stripes present along lateral side.Thin brown preorbital stripe runs through chin.Postorbital stripe thicker and darker than preorbital stripe.Brownish suborbital stripe run across the underside of the head.A light to dark brown blotch present on middle of opercle.Spinous portion of dorsal fin dark brown, soft part lighter.One blotch present anteriorly in between the base of 3 rd _5 th dorsal spine and another at slightly above the base of the last 3-4 soft dorsal rays.Spinous part of anal appears lighter and paler than the soft part with a prominent black blotch a little above base of the last 3 soft anal fin rays.Caudal fin with a brown blotch at middle of its base.Pelvic fin slightly brownish (Plate-I A, B).
Etymology : The species is named based on the presence of 3 (Three) distinct blotches on fins.

DISCUSSION
The new species has been compared with its related species of North East India including Bangladesh (Table -2 and 3).
Badis triocellus sp.nov. shares similarity with Badis badis (Plate-II A, B) in head length, head width, snout length, distance between tip of snout and origin of anal fin, distance between origin of pectoral and pelvic fin, distance between origin of pelvic and anal fin, anal fin base, distance between anus and anal fin and least height of caudal peduncle, but differs in head depth, eye diameter, inter orbital distance, body depth, distance between tip of snout and origin of pectoral fin, distance between tip of snout and origin of pelvic fin, height of spiny dorsal fin and height of soft dorsal fin, length of anal fin, dorsal fin base, length of pectoral fin, length  Badis triocellus sp.nov. shares similarity with Badis assamensis (Plate-III & IV A, B) in head length, length of snout, length of pelvic fin, distance between tip of snout and origin of pectoral fin, distance between tip of snout and origin of pelvic fin and least height of caudal peduncle, but differs in head width, head depth, eye diameter, inter orbital distance, body depth, distance between tip of snout and origin of anal fin, distance between origin of pectoral and pelvic fin, distance between origin of pelvic fin and anal fin, height of spiny dorsal fin and height of soft dorsal fin, length of anal fin, dorsal fin base, anal fin base, length of pectoral fin, distance between pelvic fin and anus, distance between anus and anal fin, length of caudal peduncle and length of caudal fin (Table -2).Moreover, dorsal fin spines and soft rays are relatively less in B. triocellus sp.nov.than B. assamensis; depth of body (25.47-34.97% versus 23.98-31.91 %), interorbital width (7.05-10.52%versus 6.49-8.48%)are more than that of B. assamensis.Lateral line scales are less (28-29 versus 29-32) in B. triocellus  sp.nov.than B. assamensis (Table-3).
Badis triocellus sp.nov.shares similarity with Badis tuivaiei (Plate-VA, B) in length of snout, anal fin base and least height of caudal peduncle but differs in head length, head width, head depth, eye diameter, inter orbital distance, body depth, distance between tip of snout and origin of pectoral fin, distance between tip of snout and origin of pelvic fin, distance between tip of snout and origin of anal fin, distance between origin of pectoral and pelvic fin, distance between origin of pelvic fin and anal fin, height of spiny dorsal fin and height of soft dorsal fin, length of anal fin, dorsal fin base, length of pectoral fin, length of pelvic fin, distance The Badis triocellus sp.nov.differs from B. kanabos in having relatively less number of dorsal spines, less soft dorsal (9-9 versus 8-10), less body depth (25.47-34.97%versus 29.9-35.4%),less circumpeduncular scales (12-15 versus 16-17); more interorbital width and more lateral line scales (28)(29).
The Badis triocellus sp.nov. is similar to B. blosyrus in numbers of soft anal fin rays but differs from it in having more interorbital width (7.05-10.52 % versus 6.4-8.0 %), less number of dorsal spines (14-16 versus 16-17) and less number of soft dorsal fin rays.B. triocellus sp.nov.has relatively more number of lateral scales rows than B. blosyrus (Table-3).
Badis triocellus sp.nov.(Lateral view) B : Dorsal and Anal fins showing three spots PLA'IE-II A B (Varieties of Badis badis)

Table - I
: Proportional length (in millimeter), counts of rays and scales and different morphological measurements in percentage of Standard length in different specimens of Badis triocellus sp.nov.

Table - 3
: Comparison of proportional measurements in percentage of standard length and counts of Badis triocellus sp.nov.with related species.