65 



These are to be found in our various rivers, and are so 

 well known that they need no description. Victorian and 

 New Zealand Rivers have been successfully stocked from 

 Tasmania with the River Perch, the Tench, and the Crucian 

 Carp. 



Of these latter the Tench is the only fish of importance 

 which has become really abundant in Tasmania. The Perch 

 seems to thrive well in certain lakes where introduced, but 

 not to the same extent as the Tench. 



With respect to the exact nature of the Derwent migratory 

 Salmonoids, there has been much discussion as to whether 

 the Salmo salar has really established itself or not. The 

 handsome fish which is now so numerous in the estuary of 

 the Derwent is within certain limits a most variable form, 

 — some individuals being almost identical in all specific 

 characters with the grilse form of S. salar^ while others 

 partake more of the character of the equally valuable 8. 

 trutta and its still more closely allied congener, S. Cam- 

 hricus. It is clear to me, however, that the prevailing form 

 found in salt water is a mean between these, and it is this 

 overlapping of the closely agreeing characteristics of these 

 so-called species which renders it so puzzling to determine 

 to which of them any one individual belongs. The question, 

 which has excited much interest in Tasmania, is confused 

 by the notions of imperfectly informed persons, who, by 

 the use of such a misleading common name as^ Bull Trout,* 

 have led many to think that we have only succeeded in 

 acclimatizing the common Brown Trout and its varieties in 

 our waters, and they often, in ignorance, speak of our fine 

 migratory fish as if it were a coarse, destructive fish of no 

 value. It is to be regretted, where legislation may be con- 

 cerned, that erroneous notions should be circulated in this 

 way. By such people the fanciful views of amateur pisci- 

 culturists or sportsmen are deemed to be of equal value to 

 the utterances of learned ichthyologists such as Dr. Giin- 

 ther, whose profound knowledge forces them to speak with 

 extreme caution. 



We only know as yet that we have a fine non-migratory 

 Trout (the Brown Trout), and a splendid sea-going migra- 

 tory Salmonoid. The question is, not S. fario versus 

 S. trutta, or S. fario versus >S^. salar, but the more difiicult 

 one of determining whether the variable, handsome, migra- 

 tory fish, which is frequently captured far out at sea, is 

 (1) S. trutta, (2) S. Cambrnms, (3) S. hrachypoma, (4) 

 S. salar, (5) all of these in variable numbers, (6) a hybrid 

 partaking in varying degrees of the characters of the four 



