134 REV. S. J. WHITMEE ON THE HABITS OF FISHES. [Feb. 5, 



spines, viz. protection against the attacks of those of the class which 

 are carnivorous. I have never seen a fish try to use its dorsal spines 

 actively to strike with. But I have seen a Batistes swim rapidly 

 past an antagonist, and graze its side with its file-like lateral spines. 

 I am strongly inclined to believe the dorsal and anal spines are used 

 for defence only. 



There is little doubt that most carnivorous fish capture their prey 

 by outswimming them, as most carnivorous quadrupeds capture theirs 

 by outrunning them. In the shallow waters within our reefs it is a 

 very common thing to see shoals of fish leaping out of the water 

 when chased by the larger ones which prey upon them. They pass 

 along with a series of springs at a great rate ; and the noise they 

 make is heard at a long distance. Most fishes thus chased would, if 

 captured, be seized from behind. If so, the strong spines on the 

 aual and dorsal fins, inclined as they are backwards, would often be 

 of immense value to their possessors in preventing them from being 

 swallowed. I am inclined to believe this is the chief, if not the sole, 

 use of these spines 1 . 



If this view be correct, those fish most exposed to the attacks of 

 others which are carnivorous ought (other things being equal) to be best 

 protected. I have not given sufficient attention to the subject to say 

 whether this be so or not. But from a merely superficial examina- 

 tion I fancy further investigation would prove that spiny fishes are 

 more frequently found in confined and shallow waters, where they 

 have little opportunity of escape : and that slow-swimming fishes are 

 most frequently protected with peculiar defensive armature. The 

 Biodon and Tetrodon may serve as examples of the latter. They 

 swim slowly, and if unprotected would be specially liable to be 

 preyed upon by carnivorous fish. Unless alarmed neither look for- 

 midable. In both of them the spines are ordinarily concealed in the 

 soft and loose skin ; and then they present a very different appearance 

 from the stuffed specimens or plates by which they are chiefly known. 

 But the individuals of both genera possess the power of very rapidly 

 inflating their loose skins, and thus erecting the spiues with which 

 they are more or less completely covered. In the case of the Biodon 

 there can be no doubt that its inflated and bristling appearance would 

 serve to protect it from attack ; and I imagine the most voracious 

 monster would think twice before attempting to feast on the less-pro- 

 tected Tetrodon. 



1 Since the above was written I have seen a proof of the correctness of this 

 view as to the use of spines. I was one clay passing along the lagoon on the 

 shores of Upolu, when my boatmen noticed a great splashing in the water at a 

 distance. Knowing the cause, they pulled for the place. There we saw a large 

 fish with a smaller one sticking in its jaws, caught apparently by the erected 

 spines. They got separated just as we approached, and before my crew could 

 secure them ; but the natives told me they not unfrcquently take fishes in that 

 way. Sometimes they find both dead, one firmly sticking by its spines in the 

 jaws of the other. — December 1877. 



