746 



SCANDINAVIAN FISHES. 



'I'lio internal organs agree with the descri]ition given 

 above of the strueture of the Brachyeiitei'ic Cvj^rinoids. 

 Tiie stoin;ich extends back to about a line with the in- 

 sertions of the ventral tins, from whicii point the in- 

 testine first runs forward, to the left of and above the 

 stomach, until at the very front of the abdominal cavity 

 it bends suddenly back to return straight to the vent. 

 The entire length of the digestive canal is only about 

 ^/., of the length of the body. The dorsal part of the 

 musculature contains on each side an ellipsoidal organ 

 of hitherto unexplained signification, jiroximally and 

 dorsally attached to the fourth rib (tlic first of the nor- 

 mal ribs). This organ is wliite and fairly large, being 

 nearly 3 mm. long in a Gudgeon 110 mm. in length. 

 It consists of transversely striped muscle fibres, exter- 

 nally longitudinal, internally transversal, and is attached 

 by connective tissue to tlie said r\]). As for its mor- 

 phological signiticance, we can find no better comparison 

 than witli the above-mentioned (p. 704) iiifroitiis cap- 

 Ktdir rpsiae in the Cobitoids. 



The Gudgeon has a wide geographical range to tiie 

 east and west, from Anuir and China" to England and 

 Ireland. To the north and south its range extends in 

 Europe from Southern Einland (Lat. 62° <3r 6.3° N.), the 

 extreme south of Sweden, and Liim Ejord, to Central 

 Italy. In Greece and Spain it is unknown. Its Swedish 

 range consists principally of Scania, wiiere it is fairly 

 common in several localities. When Ketzius in 1800 

 introduced it into tlie fauna of Sweden, it already pos- 

 sessed at Lake Finja a special Swedish name, SIdffint/ 

 (slat = smooth). The species is also known to occui' in 

 Scania in Lake Vester and the Ronne River to tlie west, 

 where according to Scuagekstuom it is called GrnJdn- 

 nliKj, and in the streams of Helge and Arup to the east. 

 From the River Morrum in Blekinge Baron G. C. Ce- 

 DERSTROM in 1856 forwarded several specimens to the 

 Royal Museum. Tlie Zoological Museum of Upsala, 

 according to Lilljeborg, has received specimens through 

 Dr. ScHEUTZ from the neighbourhood of Wexio. Accord- 

 ing to NiL.ssoN the (xudgeon also occurs in tlie River 

 Nissa at Halmstad and is there called steiisi((/arc (Stone- 

 sucker)'. Kr0YER did not know it from the Danish is- 

 lands; but in recent times it has been found in Zealand 

 (Feddersen). In Jutland it is common south of Liim 

 Fjord. In Germany and the Baltic Pi'ovinces of Russia 



it is also connnon, as well as in Central and W^estern 

 Euroj)e. It is one of the inhabitants of the Cavern ot 

 Adelsbcrg. In the water-courses of Switzerland it ascends, 

 according to FATnj, to a height of about 800 metres 

 above the level of the sea; soutli of the Alps it is of 

 rarer occurrence. 



The habits of the (iudgeon arc fairly well expres- 

 sed bv its Swedish name of Saiiilkri/jiare (Sand-creeper). 

 As it lies, usually in com]mnies, close to the bottom, 

 with the paired fins iiorizontally ex])anded, on a bed ot 

 sand, gravel, stone, or even of mud, it still keeps a 

 careful watch, and by fits and starts displays great ac- 

 ti\it\-. It takes a hook freely. It is fairl}- tenacious of 

 life, but like all the Cypi'inoids, sensitive to changes in 

 I the weather and inca|)able of enduring bad respiration. 

 The living specimens in our aquaria kept close to the 

 bottom and remained still in a packed mass, as long as 

 the water was fresh; but as soon as it had stood an 

 hour or so the crowd dispersed, and its members ascended 

 severally to the upper layers of the water. In spite of 

 this the Gudgeon can live in muddy or even polluted 

 streams, and readily haunts the openings of sewers, 

 provided they are in running water. 



Valenciexxes' experimented on this fish in (n'der 

 to ascei-tain the effect produced on it by atmospheric 

 rarefaction. The air-bladder became completely empty, 

 its gas passed into the intestine, the lielly swelled up, 

 and the fish Hoated on its back, but was alive and 

 seemed to steer its course in the water. After 24 hours' 

 continued operation of the air-pump he restored the 

 fishes to a normal atmospheric pressure; and after the 

 lapse of 6 hours thev were quite recovered, with the 

 air-l)ladder full almost exclusively of nitrogen. 



As we have remarked above, the com})aratively 

 short intestinal canal of the (jludgeon indicates that its 

 food is chiefly animal. It lives principally on insects 

 and their larvaj, crustaceans, worms, and the roe and 

 fr}' of various fishes; but it is fond of rooting up its 

 food in sand and mud, and also devours decomposing 

 substances, both animal and vegetable. 



The spawning-season of the Gudgeon occurs in 



Sweden at midsummer or earliei in more southern 



countries even at the beginning of Ajiril. Before this 

 time it has ascended from its winter-quarters to shal- 

 lowei- sj)ots in rivers or brooks. In the River Hofdala, 



" Herzenstein and Warpachowsky, 1. c 



' Renewed attempts to procure the Giulgeon from tliis Ideality have, however, failed. 



"^ Cuv., Val., 1. c, p. 14. 



