SI'INKD LOACH. 



70i) 



the base shorter, on an average aljout 6 % of the length 

 of the hodv". Its shape varies otlierwiso exactly as tliat 

 of the dorsal fin. The lips of tlie vent protrude in a 

 tubular form witliiii a triangular depression, whicli is 

 situated just in front of the beginning of tlie anal lin, 

 or at a distance in front of this point hardly as great 

 as the diameter of tlie eyes. 



The pectoral fins consist of 8 or 9', sometimes 10 

 rays. In the last case we find two simple rays (the 

 first onh" rudimentary) at the anterior margin of the 

 fins: while (jtherwise oidy the fii'st ray is simple and 

 not much shorter than the second, which is Ijranched 

 and either longest or about equal in length to the third 

 ray. The remaining rays gradually decrease in length 

 and are all dei'ply branched, except the last, which is 

 simple and about ' 3 as long as the longest ray. The 

 fins are set low down and when expanded occupj' a 

 horizontal position. Besides the above-mentioned sexual 

 difference first remarked by Canestuixi in the structure 

 of the pectoral tins, we also find in the Spined Loach 

 a second one, which was pointed out by BoNizzi to 

 Canesthini. At the base of the ])usterior (upper or 

 inner) side of the pectoral fins we find a cartilaginous 

 lobe, set in an obliquely transverse position. This lobe 

 is large and of more general occurrence in the males', 

 smaller, rudimentary or, most commonly, entirely want- 

 ing in the females. Cederstrom noted a thii-d external 

 difference between the sexes, consisting in the fact that 

 ill the males the pectoral fins are as a rule longer, and 

 therefore more pointed, than in the females. In 7 males, 

 between 50 and 73 mm. long, the length of the pectoral 

 fins varied between 15 and 18 ^ (on an average 16' '3 %) 

 of that of the body; in h females, between 88 and 9G 

 mm. long, this percentage varied between 10 and 11' ^ 

 and was on an average 11''. 



The ventral fins are of the same structure as the 

 pectoral, but shorter and more rounded. In the males 

 their length is about 11 — 13 %, in the females about 



9 — 10 % of that of the body. In this relation, however, 

 we nuisl also take into consideration flu; changes of 

 growl h, for the relative length of the ventral fins de- 

 creases with increasing age. At the outer angle of the 

 insertion of each ventral fin — where in the Teleosts in 

 general a triangular dermal flap, free at the top and 

 pointing in a. backward directi(m, is furnished with sin- 

 gular, generally elongated scales — we find a small, ve- 

 siculate, oblong and posteriorly blunt, dermal swelling, 

 which is, h()we\er, without scales of a special type'. 

 The caudal fin, which in specimens between '2 and 



1 dm. long occupies about 13 — 12 % of the length of 

 the body, is truncate with rounded corners. The middle 

 14 rays are branched. The small, short, supporting 

 rays generally number 3 or 4 (sometimes h^) above and 



2 or 3 (sometimes 4-') below. The base of the fin ad- 

 vances, in the form of a thin ridge, forward along tJie 

 upper and lower margins of the peduncle of the tail. 



The digestive canal is extremely simjde, consisting 

 of a straight tube of almost uniform thickness from the 

 pharynx to the vent, with only a slight expansion in 

 the anterior half to indicate the presence of a special 

 stomach. The peritoneum is silvery white. The liver 

 is long, ^vith two lobes, the right lobe being generally 

 the longer". The ovary is simple, but the testicles are 

 paired. At the spawning-season both the ovarj' and the 

 testicles extend forward along almost the whole length 

 of the abdominal cavity''. When the ovary is as full 

 of eggs as possible, it is deeply forked underneath, thus 

 appearing double when seen from below. 



The ground-colour of the body is yellowish, some- 

 times even orange, on the back more or less dashed 

 with gray, on the belly white. The singular markings 

 consist of dark gray or even blackish spots and streaks. 

 Large spots are set in a longitudinal row at the middle 

 of the back, along the dorsal sides, and along the middle 

 of the sides of the body, where they sometimes coalesce 

 into bands, especially behind; and between these rows 



" Varying, acfiordiiig to Canestiuni's moasiircnieiits, between .5"4 and 7'1 "» of the length of the body. 



' Sometimes only 6 or 7, according to Heckel and Kneh, Canestrini, and Benecke. 



' Cf. the similar growth in the Branioids and Blennioids; see above, pp. 76 and 219. 



'' .According to Canestrini's ineasiiremenls this sexuul difference is less marked. 



' In the following species this dermal swelling is equally insignificant, in Misgurnas fossilis we have failed to find it at all. 



•' .\ccordiiig to Lilueborg. 



' .\s usual, however, varying in length. In a gravid female 108 mm. long the right lobe of the liver extends to a line with the tip 

 of the pelvic hones, the left to the end of the second third of the distance between the insertions of the pectoral and ventral fins. In a 

 male almost ready to spawn and 69 mm. lung, the left lobe of the liver is somewhat longer than the right and extends about as far back 

 as the left lobe in the female just mentioned. 



* In the female just mentioned the eggs were about ' , mm. in diameter. In another female, which had partly deposited its spawn, 

 ^ggs •'' 1 mm. in diameter were found. 



