DUBLIN NATURAL HI8T0BT 80CIETT. 133 



all seem to relish, as she began her old o4role-sailing immediately. Neither this 

 male pinkeen nor that first mcntiuned would allow a second female, on anj pre- 

 tence, near the nest, chasing' them awayeren more rancorouMlj than the males, 

 from which 1 believe those hsh to be strictly monoeamous, though authors state 

 the contrary. I could not remark the fishes in their contest using any other 

 weapon than their teeth, though I watched carefully for the side charge with 

 their dorsal spines, described so fully by authors. From the quantity of oTa in 

 this nest you may form some slight idea of the pest that the fish can become in 

 a pond, though there is a great check put on their numbers by the numerous in> 

 dividuals doToured by the full grown males of other nests. 



MARCH 10, 1854. 



ON THI DE8TRDCTION CAUSED BY THE SMOOTH- TAILED STICKLEBACK (O A STE- 

 B08TEUS LEIDRUS) IN FISH-PONDS AND VIYARIA. BY J. B. KINAHAN, M.B. 



During the former session I had the honour to submit to your Society some 

 observations on the spawning of the above fish ; to-night I have occasion again 

 to call your attention to it with reference to a very different matter, the destruc- 

 tion it causes among young fry, a subject of economic importance, since the 

 breeding of fish has become not only a fashionable amusement, but even an ob- 

 ject of commercial speculation. That the smooth-tailed stickleback, and indeed 

 all the fresh-water fish of that genus are, when grown, most destructive to fry, 

 even of the fish much larger than themselves, such as gudgeon, rudd, dace, 

 minnow, trout, &c., has been long established by Baker and others, and any one 

 anxious to verify it for himself need but to watch the shallows adjacent to the 

 spawning-beds where the fry congregate, to have ample proof of it among the 

 myriads of pinkeens which swarm in such places. In fact, the voracity of the 

 mature or half-grown stickleback almost exceeds credibility. Nothing comes 

 amiss that has life — small crustaceans, molluscs, fry, often double their own 

 size, worms, grubs, all alike are acceptable to the little tyrant. Thus I have 

 often been amused by the struggles and efforts of a pinkeen to engulf one of those 

 large white moths which in the autumn are so often found floating on the water ; 

 the fish, being unable to get a sufficient purchase to enable him to overcome the 

 resistance offered by the insect's outspread wings, wotild return again and again 

 to the charge, spinning the moth round and round on the water, and often, in 

 his eagerness, springing completely out of it himself. I once had a remarkable 

 instance of this greediness myself, having, when bait-fishing, captured a pinkeen 

 scarcely more than an inch long on a No. 5 hook, armed with a gentle nearly as 

 big as himself, which the little brute had the impertinence to swallow, and was, 

 in consequence, hooked through the lip. But, though acquainted with the vora- 

 cious appetite of the full-grown fish, I must confess I was not prepared to find it 

 more strongly developed in the fry scarely six weeks old, rendering them the 

 terror and scourge of the fish-pond — a fact first brought under my notice by the 

 same accurate observer who called my attention to their nest-building powers, 

 Mr. C. Brunetti, to whom I am principally indebted for the details. In the 

 month of September the following fish were placed in a long glass jar, viz., two 

 dace, about naif an inch long, four gold-fish, hatched in June, about an inch in 

 length, one gudgeon, a minnow, and a single smooth-tailed sticklfback, the last 

 . measuring about a fourth of an inch in length. For about three weeks the fish 

 ^lived in harmony together, and seemed to oe thriving, feeding freely on bread 

 crumbs, but at the end of that time my informant remarked that the stickleback 

 had given up feeding on the bread, while the gold fish seemed out of sorts, lan- 



§uid and pining, lying more at the bottom than had been their wont, and evi- 

 ently not thriving ; this led him to watch them, when he was witness to a sin- 

 gular scene. He saw the pinkeen, after deliberately setting one of the gold-fish, 

 as a dog would a hare, make a dart at it, and bite a piece out of one of the gold- 



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