eS 
CHAPTER V 
ADAPTATIONS OF FISHES 
PINES of the Catfishes.—The catfishes or horned pouts 
(Siluride) have a strong spine in the pectoral fin, one 
or both edges of this being jagged or serrated. This 
spine fits into a peculiar joint and by means of a slight downward 
or forward twist can be set immovably. It can then be broken 
more easily than it can be depressed. A slight turn in the opposite 
direction releases the joint, a fact known to the fish and readily 
learned by the boy. The sharp spine inflicts a jagged wound. 
Fig. 35 —Mad-tom, Schilbeodes furiosus Jordan and Meek. Showing the poisoned 
pectoral spine. Family Siluride. Neuse River. 
Pelicans which have swallowed the catfish have been known to 
die of the wounds inflicted by the fish’s spine. When the catfish 
was first introduced into the Sacramento, according to Mr. Will 
S. Green, it caused the death of many of the native ‘‘Sacra- 
mento perch” (Archoplites interruptus). This perch (or rather 
bass) fed on the young catfish, and the latter erecting their 
pectoral spines in turn caused the death of the perch by tear- 
ing the walls of its stomach. In like manner the sharp dorsal 
and ventral spines of the sticklebacks have been known to cause 
the death of fishes who swallow them, and even of ducks. In 
Puget Sound the stickleback is often known as salmon-killer. 
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