SALMO ESTTJAKITJS ; THE ESTUAKY TROUT. 29 



THE NATURAL HISTORY OF THE TROUT OF THE ESTUARY. 

 SALMO ESTUAKIUS. 



The Estuary trout is a red-spotted, handsomely-shaped trout, 

 living in brackish waters, that is, in the mouths of tidal rivers. 

 Its dentition resembles other trouts, but it differs specifically 

 from the common red-spotted trout of fresh waters or rivers. 

 The flesh is of a fine pink, or salmon-colour, and it eats as well 

 as the best Loch Leven trout. I found the same trout in the 

 mouth of the Nith, in a precisely similar locality, i. e., in the 

 waters into which the tide ebbs and flows ; and living on the 

 same sort of food, that is, small shrimps, shrimps which hang in 

 clusters by the banks. In weight it runs to four pounds or 

 more ; all that I have examined were taken with the net. 



I had an opportunity of examining two trout taken with the 

 trawl in the sea, amongst the western isles, and not far from 

 I3ute. They resembled the Estuary trout in all particulars. 



In the three great systems of organs which characterize the 

 structure, and consequently habits, of the salmonidae, as compared 

 with each other, namely, the respiratory and digestive (head and 

 gills), and the locomotive, or fins, the Estuary trout holds a 

 middle place between the Loch Leven and the common river 

 trout ; stronger than the first, ^but weaker than the last. They 

 probably belong to a large natural family of the salmonida3, not 

 yet investigated, at the head of which stands the many-spotted 

 salmon, which appear in the London markets towards the end 

 of September and beginning of October, and which, by most 

 London fishmongers, are simply called trout. Their natural 

 history is still to write. 



I have already mentioned the curious fact that trout, quite 

 similar if not identical with the Estuary trout, have been taken 

 in the trawl-net in the sea and sea lochs of the Western Isles* 

 They can live, then, in the sea. The food they prefer, and the only 

 kind of food I have ever found in their stomachs, is a small shrimp 

 (not at all microscopic), which abounds in estuaries and mouths of 

 tidal rivers. The remains of these shrimps are also found in the 



