502 Transactions. — Miscellaneous. 



Francis Francis : — " They are more like salmon than the common brown 

 trout, and are brilliantly silver in colour, very short and thick in make, and 

 weigh heavier for their length than almost any fish I know." Otago trout, 

 of the same species as those referred to by Francis, show great variations in 

 colours, and that not confined to age or sex ; yet these variations appear to 

 be limited. At the same time, they evidently depend on the colour of the 

 water and river bottom, mainly ; but very little, if at all, on the nature of 

 the food-supply. A general feature, and the most noteworthy, is that the 

 females, of any age and from any stream, are silvery with black spots, red 

 ones seldom present or numerous, while the males are darker, with a 

 tendency to yellow on sides and belly, at times very golden, and they have 

 always, or nearly always, red spots, sometimes large and numerous. The 

 shape of the black spots, always round on the gill covers, shoulders, dorsal, 

 and adipose fins, varies on the body from round to rectangular and x-shaped 

 towards the tail. The theory that residence in salt water is shown by the 

 black spots assuming the x shape, is not altogether borne out by facts. For 

 example, trout of both sexes, in such water as the Shag river, Pomahaka, 

 and Wakatipu Lake, where there is clear or white water and a light bottom, 

 are silvery, and have black spots mostly x-shaped ; indeed I have often seen 

 bright silvery females with fine heads and x spots that might easily be taken 

 for sea-trout ; while the Waiwera and Waipahi Kivers, which have dark 

 bottoms, produce trout of the golden variety, with most of the black spots 

 rounded in form. The food in these four rivers is much the same. Brown 

 trout taken in Otago Harbour show a tendency to acquire x-shaped spots, 

 and take on a sea-trout appearance, but not always. On July 2nd, 1883, 

 among the trout taken out of the Leith for stripping, we had a beautiful 

 silvery female of about 161bs., which I have no doubt had been resident in 

 the harbour ; yet the black spots on it, which were large and numerous, 

 were of a rectangular shape. During the spawning season the males show 

 much brighter colours, and extra red spots appear faintly which at other 

 times might not be discernible; white the deciduous scales give place to 

 thick fleshy ones. The females, also, at that season, and when young, show 

 reddish spots, which might be very hard to distinguish during the summer, 

 or when older. The red and some of the dark spots are sometimes beauti- 

 fully ocellated, or surrounded by a lighter ring of colour. The fins, too, 

 vary apparently with age and water within certain limits. The adipose 

 nearly always has a pink edge or margin ; the pectoral fin is generally olive 

 brown in adults and olive yellow in young specimens, while the ventral and 

 anal fins are of the same hue but lighter, and sometimes almost white. In 

 dark individuals the anal and ventral fins have occasionally a white anterior 

 margin. 



