43 



THE SALMON TROUT. 



By M. Allport, F.Z.S., F.L.S. 



Eead Sth August, 1871. 



Much doubt having been expressed by scientific men in 

 England as to whether young fish have really been reared 

 in this colony from one species of migratory salmon, viz., 

 the salmon trout (Salmo trutta), without allowing the parent 

 fish first to make the usual journey to sea, it was thought 

 advisable to send one of such parent fish (which had twice 

 deposited ova) to England, for the examination of all persons 

 interested in that which will probably prove the most useful 

 discovery in pisciculture yet made. 



Accordingly such parent fish was, in March last, sent to 

 the Zoological Society of London, together with two young 

 fish of different ages, the progeny of similar parents. 



By last mail Mr. Youl forwarded the following letter from 

 Dr. Giinther in reference to these fish : — 



British Museum, 



13th June, 1871. 



Dear Sir, — I have examined the three salmonoids sent by Mr. 

 Morton Allport, and mentioned in his letter directed to you, and 

 dated March 15th. 



(1.) The laiger specimen is very interesting ; it is a female fish, 

 with the ovaries well developed. With regard to the external 

 characters, it agrees perfectly with the migratory sea-trout ; it has 

 the dentition and scales, caudal fin, and prteoperculum of that 

 species ; it shows also ten parr marks, a number met with only in 

 migratory species. 



On the other hand, it has only thirty-six pyloric appendages, a 

 number which I have never met with in purely bred migratory 

 salmonidae, but very commonly found in the river-trout and hybrids 

 between river and sea-trout. (See my Catalogue of Fishes, &c. , 

 p. 27.) I think that this specimen does not serve to convince the 

 sceptical that one species of migratory salmon will thrive in fresh 

 water. The coloration of this specimen is altogether peculiar, and 

 I have never seen a fish marked with spots so deeply black, so 

 large, and so numerous as in this specimen. In ordinary sea-trout 

 of the same size the parr marks would have disappeared, but here 

 they are present, and their co-existence with the black spots gives 

 to this specimen quite a peculiar appearance. 



I need not give my determination of the species of the two 

 smaller fish, as it appears from Mr. Allport's letter that he is 

 acquainted with the parent fish ; but I think it right to state the 

 principal characters, which may lead to a proper determination of 

 these fish. 



(2.) The larger, in smolt dress, has eleven series of scales below 

 the adipose fin, 47 pyloric appendages, deeply cleft caudal ; parr 

 marks entirely absent. 



