THE LOWER FISHES 



159 



17 feet and 1,500 pounds. The little 5-foot bonnet shark, Sphyrna tihuro, is 

 found north to New Jersey and San Diego. It is a shallow-water, bay species, 

 and is harmless. The kidney-shaped head separates it from the three tvpical 

 hammerheads. 



Squaloid Sharks: Superfamily Squoloidea 



This is the third and last subdivision of the modern sharks. The best field 

 characteristic is the complete lack of the anal fin. They also possess two dorsal 

 fins both of which are sometimes preceded by a stout spine and fine gill slits 

 which are short and entirely in front of the pectoral fins. Spiracles are present 

 and reproduction is ovoviviparous. Presumably, this group gave rise to the rays. 



SPINY DOGFISHES: Family Squalidae 



The dorsal fin spines are large and the labial furrows are long. These are 

 small slim sharks of world-wide distribution. Many of them live in deep water, 

 and all have very large eyes. The tail fin has no subterminal notch. 



SPINY DOGFISH (piKED DOGFISH, grayfish) : Sqiialus acanthhis 



Size: Averages 2^2 to 3 feet. Up to 4 to 5 feet. The females are the largest. 



Weight: Averages 7 to 10 pounds. Up to 20 pounds. 



Distrihution: Subarctic North Atlantic south to Cape Hatteras. North Pacific 

 south to Point Conception. 



Identification: Slate to brown color with yellowish spots on sides. The shape 

 is very slim and subcylindrical. 



Hahits: This is neither a swift nor very active shark. Nevertheless it is 

 voracious, feeding avidly on small fishes such as herring, menhaden, and small 

 mackerel. It also eats invertebrates, such as jellyfish, and refuse. It is a cold- 

 water form, characteristic of waters of 43° to 59° Fahrenheit. Both its northern 

 and southern movements are determined by these temperatures, and it is thus 

 like the common mackerel except that its temperature range is a little lower. 

 During the hot months and in the south it is found in deep waters down to 

 100 fathoms. It is by far the most numerous shark in cooler waters, usually 

 found traveling in huge schools inshore, in brackish water, or a few miles 

 offshore. These schools are constantly on the move, so their appearance is 

 somewhat erratic. From one to fourteen young are born in the late autumn 

 offshore after two years of gestation. When caught, this shark thrashes violently 

 curling its body like a bow and striking out with the slightly poisonous dorsal 

 fin spines. The wounds these produce may be painful. The flesh is good and 

 is usually sold as "grayfish." 



Fig. 68. Spiny dogfish. 



