PISCES III 



less to man, but are often injurious in other ways. For example, the 

 small, dogfish sharks, Mustelus and Squalus, Fig. 82, are in many 

 places very destructive to lobsters, crabs and various food-fishes, and 

 to squid that are used for bait; they also seriously damage nets and 

 other fishing gear. It is estimated that these dogfish cause a damage 

 of at least $400,000 a year to the fisheries of Massachusetts. Other 

 larger sharks though less common are often very destructive in the same 

 way, as are the larger skates. It is not uncommon, in pulling a seine, 

 to enclose a 6- or 8-foot shark that, in dashing to liberty, tears a 

 great hole in the net that not only allows other fish to escape, but may 

 take hours to repair. On one small sandy beach, of a few hundred 



FIG. 82. Dog-fish, Squalus acanthias. 



yards length, on the coast of California, I once counted eight sharks 

 of an average length of about 5 feet that had been drawn out of the 

 sea in one morning by a group of fishermen who were seining there. 

 On the same beach were often seen a considerable number of large 

 rays that had been caught in the same way, and each of them had prob- 

 ably caused some damage to the nets. It is no wonder that the fish- 

 ermen despise these elasmobranchs. 



There are certain rays, known as sting-rays or "stingarees," in 

 which the tail is armed with one or more spines, barbed on the sides and 

 sometimes, in large species, 8 or 9 inches long. These rays are 

 more common in warmer waters and are much dreaded by fishermen 

 as they can, with a sudden swing of the tail, inflict an ugly wound that 

 may be excruciatingly painful, or even, according to Giinther, cause 

 death. The poison that enters the wound made by the spine may be 

 merely in the mucus of the body or it may be secreted by a definite 

 gland at the base of the grooved or hollow spine. 



