SOME FISH NOTES 291 



found to be covered with fungoid growths, and in many cases 

 infested with parasites. 



Early in August, 1906, I met a lad coming from the allot- 

 ment ditches with a pickle bottle full of sticklebacks, and 

 knowing that most, if not every fish would be affected by 

 parasitic " spots," I examined them, and found my surmise 

 correct. I begged a couple off him, and placing them in a 

 tube of formalin which I carried, I eventually sent them with 

 other specimens to Mr. Robert Gurney, of Ingham Hall, 

 Stalham, who replied : 



" I am returning your beasts . . . the most interesting of 

 them is the stickleback. I found Thersites gasterostei for the 

 first time this year, and thought myself only the second 

 finder in these islands. But I never saw such a crop of them 

 as you have there. I think it is probably quite common if 

 looked for. It is only found under the opercula of fishes. 

 The black spots [that gave the fish a leopard-like appearance] 

 have nothing whatever to do with it, and are probably due 

 to sporozoa (or fungi). I found Thersites in the muckfleet 

 [a very dirty stretch of water in the Broads] and the Yare 

 this year." 



The stickleback seems quite at home in water absolutely 

 fresh, brackish, or salt, although he does not enter the 

 last-named from choice. He has a habit of congregating at 

 the entrances of the sluice-gates, which are now and again 

 opened to allow of surplus water running into the rivers. 

 There is much food usually gathered there ; and when the 

 gates are lifted, he is carried downstream with the current. 

 This does not greatly inconvenience him ; and I have not 

 infrequently observed shoals on the riverward side of the 

 iron sluice-gates, as if waiting a chance to return. But this 

 does not happen. Many are carried down into the sea, and 

 are probably soon devoured by various marine fishes. I 

 have seen the stickleback drawn ashore with young herrings 

 and kicking about among the seaweeds. 



In May, 1906, my small son John brought home some 

 sticklebacks. An example three-parts grown I allowed to 

 remain two days in fresh water. I then took him out and 

 placed him in a tank of sea-water, in which were two whelks, 

 an anemone, and two Risso's crabs (Xantho rivulosa) taken 

 from the deep water. He lived here apparently comfortably 



