APPEXDIX. 20 1 



SLOB, OR TIDAL TROUT. 



THROUGH the kind exertions of Mr. William Ilay.ies, I have an opportunity of examining 

 one of these fish. Owing to the severity of the weather few had as yet (February 25th., 

 1879) made their appearance in the river, and Mr. Haynes was able to send me one specimen 

 only. From an examination of a single individual I am not able to speak at all with certainty 

 as to what these Slob Trout really are. The general appearance is that of a well-fed Common 

 Trout (5. fario), from which, however, it seems to me to differ in a few structural characters. 

 The maxillary in the specimen before me — a fish twelve inches in length, three in depth, and 

 weighing nearly twelve ounces — is not so strong as that organ is in fario, nor does it extend 

 perceptibly beyond the posterior orbit of the eye, as is the case in the Brown Trout. The tail 

 is very decidedly forked, while in Trout of this size the caudal fin is almost always truncate ; the 

 sides and belly below the lateral line are more silvery, and appear to be covered with smaller 

 and more deciduous scales than in fario. The dentition in the Slob Trout is rather feeble ; 

 the head of the vomer is without teeth ; on the body of this bone there is a single series of 

 teeth, fourteen or fifteen in number, arranged in a zigzag line; the dentition m fario is strong. 

 In these particulars, therefore, the Slob Trout bears some resemblance to 5. trutta, although 

 in general appearance it is more like 5. fario. 



The following is a description of this specimen : — Total length twelve inches ; greatest 

 depth three inches ; length of the head two inches and five eighths ; maxillary one inch long, 

 rather feeble, extending very slightly beyond the posterior orbit of the eye ; proeoperculum 

 crescent-shaped, with an indistinct lower limb ; suboperculum extending beyond the operculum ; 

 fins rather short. Dorsal fin pale brown, with pale purplish spots ; adipose fin edged with 

 red ; the caudal fin forked, the lateral margins edged with red ; fins without black and white 

 outer edge ; gill-cover with five or six purplish round spots ; back and sides light purplish 

 brown, with numerous large dark purple or red reticulated spots ; several of these spots are 

 surrounded with a whitish ring ; there are some red or vermilion spots on the lateral line and 

 below it ; scales small and rather deciduous ; belly and sides silvery, but in some lights this 

 part is somewhat cream-coloured. 



The specimen sent, which came in excellent condition, was amazingly fat; the stomach, 

 oesophagus, and mouth were absolutely crammed with elvers, or young Eels, about two inches 

 long; it had also been feeding on some Crustacea allied to the fresh-water shrimp. The 

 stomach and pyloric appendages were thickly spread over with fat. This specimen appears 

 to be a sterile male. Mr. Haynes's account of the habits of the Tidal Trout will be found 

 at page 114. They ascend the rivers with the flow of the tide, descending with the ebb; 

 they are to be caught from January to May. In the summer they disappear, probably 

 migrating to the sea, where they remain till the beginning of another year. Nothing is known 

 about their spawning. In very cold weather in January and February they remain in the slob, 

 and do not ascend with the tide. 



I am inclined to believe that these Tidal Trout are hybrids between the 5. fario and 5". 

 tnitta, both of which species they appear to resemble in some particulars. It may be that 

 the sexual organs do not develope ; consequently there is no spawning time. Did they spawn 

 in the rivers, such an occurrence would have been noticed by so patient and painstaking an 

 observer as Mr. Haynes. Is it possible that they spawn in the salt water of the sea? Such 

 a phenomenon would be an exception to what is known to occur in the Salmonidce. Moreover, 

 did these fish spawn in the sea, say in November or December, could they possibly appear 

 in the rivers, as early as January, in such splendid condition as they are known to show at 

 that time? They could not have "mended" themselves in so short a time. 



