REDESCRIPTION OF BARILUS HOWESI BARMAN , 1986 , A VALID CYPRINID SPECIES ( PISCES : CYPRINIFORMES : CYPRINIDAE ) FROM NORTH BENGAL , INDIA

The cyprinid fishes of the genus Barilius Hamilton are known to inhabit freshwater systems and occurring throughout Southeast Asia. It is known to comprise 29 species (Froece and Pauly, 2010) in Asia and Menon (1999) recognized only 15 species from India. During the studies on the Cyprinid fishes belonging to the genus Barilius from India, three specimens of Bariilus were found lying unidentified in the National Zoological Collections in the Fish Division of Zoological Survey of India, Kolkata. On critical examination it was found that these specimens represent a distinct species and was described as a new species of bariline fishes Barilius howesi by Barman (1986). Subsequently, Talwar and Jhingran (1991), Husain et al. (1992), Menon (1999) and Jayaram (1999) considered B. howesi as conspecific with B. bendelisis (Hamilton, 1807). Although, the species was diagnosed as being allied to Barilus bendelisis (Hamilton), the later species can easily be separated by presence of black spots on all body scales at their bases and two spots on either side of lateral line in all lateral line scales.


INTRODUCTION
The cyprinid fishes of the genus Barilius Hamilton are known to inhabit freshwater systems and occurring throughout Southeast Asia.It is known to comprise 29 species (Froece and Pauly, 2010) in Asia and Menon (1999) recognized only 15 species from India.During the studies on the Cyprinid fishes belonging to the genus Barilius from India, three specimens of Bariilus were found lying unidentified in the National Zoological Collections in the Fish Division of Zoological Survey of India, Kolkata.On critical examination it was found that these specimens represent a distinct species and was described as a new species of bariline fishes Barilius howesi by Barman (1986).Subsequently, Talwar and Jhingran (1991), Husain et al. (1992), Menon (1999) and Jayaram (1999) considered B. howesi as conspecific with B. bendelisis (Hamilton, 1807).Although, the species was diagnosed as being allied to Barilus bendelisis (Hamilton), the later species can easily be separated by presence of black spots on all body scales at their bases and two spots on either side of lateral line in all lateral line scales.

bendelisis.
Barilus howesi Barman, 1986 1986.Barilius howesi Barman,1. Bombay nat. Rist. Soc.,83  bendelisis (Hamilton).Talwar and Jhingran (1991) have relegated B. howesi to the synonymy of B. bendelisis without assigning any reason.Husain et aI. (1992) compared several characters given in original description with that of B. bendelisis as described by other authors to conclude that both the species are conspecific.Menon (1999) and Jayaram (1999) followed the same to retain B. howesi under the synonymy of B.
bendelisis.But, Kar (2002) studied the Barilius species of India and could compare all species belonging to this genus to distinguish B. howesi from B. bendelisis.
In the original description (Barman, 1986), B. howesi was compared with B. barna (Hamilton) and B. barila (Hamilton), which were stated to be unrelated (Husain et aI., 1992).Among the Barilius species known from India, B. Further, in terms of posterior extension of maxilla these fishes can be placed under three distinct groups (Kar, 2002).In B. everzadi, B. radiolatus and B. shacra, maxilla reaches at most to anterior margin of eye.In Barilius species, number of barbels seems to differ within the species itself and size of the barbels is not a constant character (e.g., B. bendelisis, in Day, 1878).Hence, presence or absence or rudimentary nature of barbels (as used in Talwar and Jhingran, 1991;Jayaram, 1999) can not be considered as a differentiating structure to distinguish various species of the genus.
Four species, viz., Cyprinus bendelisis, C. cocsa, C. chedra and C. tila, described in Hamilton (1822) as from northern rivers of Bengal are clubbed together under the name Barilius bendelisis (Hamilton) (Day, 1878;Menon, 1999).All these species are distinct in having a spot on each scale but last two are said to devoid of barbels and C. cocsa with four barbels.The Cocsa type specimens are also known to bear a spot on the middle of each scale and a row of small oblong spots on each side of lateral line (Hamilton, 1822;Day, 1878;Shaw and Shebbeare, 1937).The argument in Husain et al. (1992)    (Tilak, 1967;Jayaram and Singh, 1977;Talwar and Jhingran, 1991), which is not present in B.
In view of the objections raised in Husain et 01.(1992)  howesi is a distinct species and can not be considered conspecific with B. bendelisis.

COMPARATIVE MATERIALS
Recently, the first author collected a number of specimens belonging to the genus Barilius from North Bengal (West Bengal).The specimens were identified as B. bendelisis and during the course of determination it was strongly felt that B. bendelisis and B. howesi are two distinct species represented in North Bengal.The present communication serves to resurrect Barilus howesi as valid species with its re-description to set aside errors committed in the original description and discusses the differences between B. howesi and B.
protractile.Maxilla extends to below middle of eye.Symphysial process of lower jaw poorly developed.Barbels two pairs, distinctly smaller than eye diameter.Suborbital bones are wide, the third one not covering cheek.Head length 4.32 to 4.62, body depth 3.15 to 3.33, predorsal distance 1. 72 to 1. 74 and preanal distance 1.29 to 1.41 in standard length.Depth of head 1.12 to 1.16, eye diameter 3.98 to 4.18, snout length 2.99 to 3.31 in head length.Ratio of interorbital width and eye diameter is 1.36 to 1.59.Gill rakers are 8 or 9 on lower arm of first arch.Dorsal fin rays ii, 7; anal fin rays ii-iii, 7-8; pectoral fin rays i, 13; pelvic fin rays i, 8; caudal fin rays 19.Height of dorsal fin is 5.79 to 6.01, height of anal fin 6.91 to 7.21, pectoral fin length 4.89 to 5.21 and pelvic fin length 7.45 to 7.92 in standard length.Origin of dorsal fin is nearer to base of caudal fin than to tip of snout.Caudal fin deeply forked with lower lobe slightly longer than upper.Lateral line complete with 42 or 43 scales.Lateral transverse scales 12; 8Y2 scales between origin of dorsal fin and lateral line, 3Y2 scales between origin of anal fin and lateral line.Predorsal scales 17 or 18 and circumpeduncular scales 12 to 14. Axillary scales, elongate with a fleshy border, present at base of pectoral and pelvic fins.Colour : Dorsal surface brown, sides and ventral surface silvery white.Upper sides of body with 14 or 15 vertical dark bands, that does not reach lateral line.Fins are hyaline.DISCUSSIONS Menon (1999) recognized 15 species from India but considered B. howesi Barman as conspecific with B.
dimorphicus Tilak and Husain, B. nelsoni Barman, B. radiolatus Gunther, B. shacra (Hamilton) and B. telio (Hamilton) are having higher lateral line scale count (55 to 75 vs.35 to 50 in others).Body is uniform in colour with no vertical bars or spots in B. everzadi Day and B. modestus Day.B. bakeri Day and B. canarensis (Jerdon) are characterized in having one or more rows of large spots on sides.In having bars on sides, the described species closely resemble but differs from B. barila (Hamilton), B. barna (Hamilton), B. gatensis (Valenciennes) and B. vagra (Hamilton), Rec.zool.Surv.India which have higher anal fin elements (13 to 17 rays).B. dogarsinghi Hora is known to have lower lateral line scale count (less than 40).A comparative chart of meristic and morphometric characters based on the materials examined are given (table 1) hereunder to distinguish B. howesi from B. bendelisis, both similar in having lower anal fin rays (7 or 8 branched rays), 40 to 43 lateral line scales and bars on sides of body.
Posterior extension of maxilla reaches to below anterior one-third of eye in B. barila, B. barna, B. bendelisis, B. canarensis and B. nelsoni.In case of rest of the Barilius species including B. howesi, maxilla extends to below middle of eye.At this point, B. howesi is unrelated not only to B. barila and B. barna, but also to B. bendelisis.It is rather closely allied to B. modestus in having lower jaw with a poorly developed symphysial process but differs in having vertical dark bands (no band or spot in B. modestus).
for B. howesi being 'a female or immature male of Cocsa type specimens of B. bendelisis Hamilton' does not hold good as the characteristic black spots on each scale at bases are absent.B. bendelisis can easily be distinguished from all other congener in Outline drawing of Barilius howesi Barman Barilius howesi Barman (Holotype) Barilius bendelisis (Hamilton) Lataguri, lalpaiguri Dist.North Bengal Barilius bendelisis (Hamilton) Rajabhatkhawa, Alipurduar In., North Bengal : 171-173 (type locality: Stream near Sulkapara, Jalpaiguri district, North Bengal in West Bengal).

Table - I
. Comparison of meristic and morphometric characters of B. bendelisis and B. howesi.
having all the body scales with black spots at their bases and two spots on either side of lateral line in all the lateral line scales.Presence of black dots in each scale of even younger specimens of B. bendelisis is also observed meticulous examination of type materials (no other material collected since then) were made and compared with a number of examples of B. bendelisis including that of North Bengal.The specimens of B. howesi in fact bear dorsal fin rays 8 (not 9), anal fin rays 10 (not 12) and predorsal scales 17-18 (not 20-21).Considering the differences in characters (table-I), especially smaller head, deeper body, shorter pre-dorsal length, longer pre-anal distance, larger eye, shorter snout and absence of black spots on each scale, it is concluded that B.