.>04 REPORT ON FISHES. PART I: COBTTinAE 



til 111.'' 'Hic four t'lrrciitial species, N. stolicckac, .\ . i^racilis. W li-iniiaiitilii and A'. iiiiiT(>ps, 

 witli i;Tcatl\- reduced I)ladder ami witli the lower iol)e of the caudal liii better developed than 

 the upper, were found either in small, rapidly flowing streams or in springs and pools to 

 which they resort for breeding purposes. In the specimens of A^. ladaccnsis from Alinazar- 

 Kurghan, the bladder is like that of A^. /'0/>i7/o-/a6i(;/!<j (Text-figure IC) and it is likely that 

 the fi.sh leads a bottom life in still or slowly Howing waters. The two loljes of its caudal 

 tin arc almost symmetrical, suggesting that the lish does not perform any regular vertical 

 movements. 



The three species collected from the plains of Turkestan near Varkand were obtained 

 from marshes, lakes or canals and, in consequence, the bladder is considerably modilied. 

 The structure of the bladder of A^. yarkaudcusis is referred to above (]>. 300) ; and that of 

 Neiiiailiiliis sj). prox. tariiiiriisis is similar. Tiie liladder of A'c nun hi I us sp. from Kaliat 

 Utsang is like that of A^ papillo-hibiatus. Jt is thus seen that all the three species of 

 Ne)iia<liiii(s from Turkestan are adapted to live at the bottom in the marshy areas and do 

 not swim alx)ut much. In A', yarkaiidetisis and A^. iariiiicnsis the upper lolx; of the caudal fin 

 is longer as is the case in A'. I'itlatus {ride supra, \). 300), while that of Xriiunliilus sp. 

 is almost symmetrical. It is thus seen that the study of the material obtained by the Nether- 

 land Karakorum Expedition supports the hypotheses advanced regarding the ecology and 

 bionomics of the species collected by the Yale North India I'^xpedition. 



GEOGRAPHICAL DISTRIBUTION AND OKICIN OK T UK KISll FAUNA 



r have often remarked that the i'lsh fauna of the high altitudes of Central ;\sia is derived 

 from the fauna of the low-lying lands of the neighbouring countries, and this hypothesis 

 is supported 1)\' the geographical distribution of the species and the modilicatioiis undergone 

 by the air-bladder of the forms living in stationary waters at great heights, .\linost all 

 the species of Nciiuichilus found along the slopes of the llimalay.'i are characterised by the 

 great reduction of their air-bladder, but when they enter lakes, etc., a functional bladder is 

 developed once again. The three new .species of the Panggong complex are no doubt 

 descendants of forms once living in torrential streams. When acknowledging the prelimi- 

 nary determinations of the fish collected by the Expedition Mr. liutrhinsoii made the ful- 

 lowing observations regarding the distribution of the new s[)eeies : 



"As you will sec from tlie map, one species ( N. hutchinsoni) whieh now seems 

 to occur in small ponds and the very small lake Tsar Tso occui)ies a regitjii formerly 

 filled by the great freshwater lake which represented Panggong in the late glacial 

 and which extended far to the west. The species from Man (N. deTerrai) 

 occurred only in a .small lagoon, cut otT from the edge of the lake. I saw one 

 specimen actually in the lake, almost certainly of this species, and think that it may 

 have been washed out from the lagoon during a rather heavy storm the nighl 



before It is quite clear that all fish are extremely rare in lake Panggong 



itself at the ])re.sent time. This is due no doubt ])artly to its high salt content and 

 still more to its com])lete lack of higher vegetation which is abiiiidarit in the 



"Hora & Mukerji, Visser's Karakorum I, pp. 426-445 (193.S). 



'Hora, Rec. hid. Miis. XXIV, p. .S8 (1922) ; Phi!. Trans, h'oy. .Sor. Loudon (P.) CCXVIII, p. 268 (1930) ; 

 Rec. hid. Mus. XXXVI, p. 281 (1934). 



