VENOMOUS AND POISONOUS FISHES 447 



Enemies of snakes should be encouraged. The Mussurana, or 

 Oxyrhopus cloeha, is a harmless colubrine, which is said to feed 

 exclusively on other snakes and to be addicted particularly to the 

 venomous kinds, overcoming and swallowing them in a most heroic 

 manner. This would probably be a good variety for the preparation 

 of sera (Alcock). 



VENOMOUS AND POISONOUS FISHES. 



Tropical and temperate seas abound in poisonous fishes about 

 which little is known. Pending further knowledge we classify them 

 thus : — 



(i) Fishes which poison by their bite. 



(2) Fishes which poison by their spines connected with poison 

 glands. 



(3) Fishes which poison after their consumption as food. 



The former two are venomous, but their flesh can be eaten with 

 impunity. The latter is poisonous and produces its effects when eaten,, 

 e.g., lamprey. 



The genus Cattus is only venomous during the spawning season. 



All these venoms are alike in kind, but differ in degree. 



The effects are : local pain, swelling, suppuration, spreading 

 gangrene, excitation, insensibility and paralysis. 



The treatment is for snake-bite, with the exception of the anti- 

 venene. 



(1) Fishes which poison by their Bite. 



The tvpe is the genus Alura^na. All have powerful teeth. They 

 abound in the Tropical Atlantic and Mediterranean. The poison 

 pouch, capable of holding up to h c.c, lies above the covering of the 

 palate, and is lined bv epithelial cells. There are three or four strong 

 curved conical teeth with an anterior convexity. These teeth are 

 enclosed in a sheath formed by the mucosa of the palate. The poison 

 collects between the teeth and flows down into the wound. 



(2) Fishes which poison by their Spines connected to Poison Glands. 



The poison glands are generally placed at the base of the dorsal 

 or anal fins or under spines on the operculum. 



The glands communicate with one or more rays of fins. 



The barbs may be : — 



Grooved, the muco-membranous sheath converting this into a 

 canal which must be ruptured before excreting externally. 



Canalised by channels which lead to apertures near its tip. If 

 these barbs enter the skin after being trodden upon, the poison is 



