Rasbora argyrotaenia Blkr. – Zilverbandige Paraai [Silver-striped Paraai].
Atl. Cypr. Tab. L fig. 6.
A Rasbora with an oblong-elongate, compressed body, depth of body contained slightly over 4 to slightly over 5 times in its length, width contained twice to 2⅓ times in its depth. Head acute, not convex, contained 5 to 6 times in length of body with caudal fin, 3¾ to 4½ times in length of body without caudal fin, crown scaleless, depth of head contained about 1¼ to 1⅖ times in its length, width twice to 1⅔ times; eyes slightly posterior, eye diameter contained 2⅔ to 3 times in the length of the head, eye diameter contained slightly more than once to 1⅓ times in the postocular part of the head, distance between the eyes once to 1⅓ times their diameter; palpebral membrane covering the external margin of the iris only, the opening nearly circular; rostro-dorsal profile on the head sloping, nearly straight, on nape and back convex; interorbital line convex; snout acute, not convex, shorter than the eye, tip placed anterior to the upper part of the eye; nostrils closer to the orbit than to the tip of the snout, posterior nostrils more than twice as large as anterior nostrils; anterior suborbital bone nearly triangular, base shorter, pointing upward, sides longer, descending, united inferiorly into a slightly obtusely rounded or slightly truncate downward pointing angle, traversed by a longitudinal, obliquely backward descending crest; 2nd suborbital bone oblong-quadrangular, not or slightly higher posteriorly than anteriorly, length generally less than twice as great as depth, twice or less than twice as low as 1st suborbital bone; 3rd and 4th suborbital bones broad, nearly reaching the posterior margin of the preoperculum, much thinner than the eye diameter, but much less than twice as thin; jaws, oral margins acute especially anteriorly; upper jaw not shorter than lower jaw, moderately forward protrusable, lightly emarginate at the symphysis, ending anterior to the eye, contained about 3⅓ times in the length of the head; lower jaw lightly emarginate towards the symphysis, symphysis itself provided with a small tubercle, entering the intermaxillary incision, branches obliquely compressed, lower part generally with some little visible pores in one longitudinal row; lips thin, no visible transverse stripes; groove of upper lip ending slightly anterior to the angle of the mouth, groove of lower lip extending from the angle of the mouth up to the inframaxillary incision; gape strongly oblique; width of gill cover contained 1½ to 1⅖ times in its depth, lower margin nearly straight or slightly concave; gill opening ending below the posterior suborbital bones; Pharyngeal teeth predatory, conspicuously hooked, 2.4.5/5.4.2, each below the hook with a oblong, superficial, little visible small fossa, dorsal profile convex, not or not much lower than convex ventral line; belly flat anterior to ventral fins, behind ventral fins rounded, not ridged; scales nearly vertical, on the free half and the basal half with slightly ray-like longitudinal stripes, scales on the middle of the flanks larger than on the rest of the body, 30 in the lateral line, 9 (8½) in a transverse row of which 5 (4½) above the lateral line, 12 or 13 in a longitudinal row between occiput and dorsal fin; lowest ventral scales in three longitudinal rows, scales in medial row gradually increasing in size posteriorly, scales in those rows not or hardly larger than those in flanking rows; lateral line strongly curved, three times or more than three as close to the base of the ventral fins as to the dorsal line, gradually ascending posteriorly and ending on the middle of the base of the caudal fin, each scale marked by a simple tube reaching or surpassing the centre of the scale; scapular bone short, triangular, acutely or slightly acutely rounded, dorsal fin placed about halfway between ventral fins and anal fin, scaleless at the base, acute, convex, depth contained slightly more than once to 1⅓ times in the depth of the body, twice or less than twice as high as base length, the simple 2nd ray thin, cartilaginous, slightly to not shorter than the head; pectoral fins acute, lightly scaled at the base, considerably longer 449 than ventral fins, contained 5⅓ to 5⅔ times in the length of the body, not reaching ventral fins, the simple ray thin; ventral fins inserted in the lowest part of the belly, acute, not reaching anal fin; anal fin at the base enclosed in a scaled sheath, acute, emarginate, much lower than dorsal fin but much less than twice as low, slightly higher than base length, the simple third ray thin, cartilaginous; caudal fin scaled at the base, with a deep incision, lobes acute, lower lobe generally slightly longer than upper lobe, contained slightly over 4 times to 4¼ times in the length of the body; Colour: upper part of the body faintly green, lower part of head and belly silver, behind the belly hyaline; scales on the anterior part of the body on the middle of the flanks each with a transverse, crescent-shaped thin band, composed from dark speckles; silver head-tail quasi subcutaneous band broader posteriorly than anteriorly, on top a thinner or broader shining-green, after death blue bordered with blue or nearly covered with blue, frequently not visible because of the bluish band covering it; iris silver, fins, except on the caudal fin, white-hyaline, on the middle length or depth of the anterior margin sometimes decorated with a blood-red spot; caudal fin beautiful yellow, base frequently darkish-violet.
B. 3. D. 2/7 or 2/8. P. 1/12 or 1/13. V. 2/7 to 2/9. A. 3/5 or 3/6. C. 6/17/7 or 7/17/8, short flanking ones included.
Leuciscus argyrotaenia Blkr, Verh. Bat. Gen. XXIII Ichth. Midd. Oost-Java p. 21.
Leuciscus cyanotaenia Blkr, ibid. p. 21.
Leuciscus Schwenkii Blkr, Act. Soc. Reg. Sc. Ind. Neerl. III Zesde Bijdr. Vischf. Sumatra p. 47.
Tjetjerreh Mal.; Parai Sund.; Wader, Lundjar-andong, Lundjar-pareh Jav.
Java (Batavia, Perdana, Tjibiliong, Tjiringin, Serang, Tandjong-oost, Tjampea, Buitenzorg, Tjitjurup, Parongkalong, Banjumas, Gombong, Ambarawa, Purworedjo, Surakarta, Patjitan, Surabaya, Pasuruan, Grati, Ngantang, Lesti, Malang, Bondowosso), in rivers and lakes.
Sumatra (Palembang, Lahat, Telokbetong, Padang, Trussan, Meninju, Pajakombo), in rivers and lakes.
Bali (Boleling), in rivers.
Length of more than 100 specimens 45’’’ to 106’’’.
Remark. Closely related to Rasbora lateristriata Blkr. and Rasbora dusonensis Blkr, the species in question differs from these however by a remarkably less slender body, a little developed knob at the symphysis of the lower jaw, the absence of the upper anal fin spot, a further posterior position of the dorsal fin, remarkably less deep anal fin, etc.
On Java the species is very common and is found till rather high in the various drainages. The specimens from the higher regions usually have a more slender body and as a rule exhibit the blue stripe on the silver lateral band more clearly. Earlier I described this variety as a proper species under the name Leuciscus cyanotaenia, but since then I have observed so numerous stepwise transitions between both forms that it has become clear that all belong only to a single species.
Similarly Leuciscus Swenkii, which I described as a new species at the referred place after a specimen from Sumatra, now seems to me not to differ specifically from Rasbora argyrotaenia. The transverse crescent-shaped black-brown scale bands or spots recorded of that specimen often are also present in the specimens of Rasbora argyrotaenia from Java.