DANGEROUS SEA LIFE 



Sea urchin stings should be handled in the same way as other 

 venomous stings. Prompt attention must be given to the removal 

 of the pedicellariae, as it will continue to introduce venom if not 

 removed. Although the ordinary spines of some species may be 

 absorbed in the course of a day or two, most will require removal. A 

 purple discoloration in the area of the wound, due to a secretion of 

 the animal, is not a cause for concern. 



Sea urchins with long needle-like spines should not be handled. 

 Special protection must be arranged as ordinary leather or canvas 

 gloves and shoes do not afford adequate protection. Marine workers 

 and others must exercise critical care in working at night without 

 adequate light. This is especially important in those areas where 

 the lethal species may be encountered. 



B. Vertebrates 



The vertebrate marine animals that inflict injuries by means of 

 venomous stings may be divided into 2 groups: 



(1) Fishes, including a numerous and interesting variety. 



(2) Reptiles, limited to a few sea snakes. 



FISHES 



Dogfish Sharks 



The larger sharks, previously described, depend on speed or teeth 

 for defensive or offensive operations. Some of the smaller, less 

 powerful species are equipped with venomous spines for protection. 

 Many variations in poison spine arrangement exist in these sharks. 

 The common spiny dogfish, Squalits acanlhias, is a small shark, up to 

 3>2 feet in length, found along both coasts of the Atlantic and Pacific 

 Oceans. Closely related spiny dogfish are found throughout the 

 temperate and tropical seas of the world. 



^DORSAL FIN SPINES 



PECTORAL F 



PREOPERCULAR SPI 



OPERCULAR SPINE 



CAUDAL SPINE 

 eOOY SPINES 

 ANAL FIN SPINE 



PELVIC FIN SPINE 



COMPOSITE DIAGRAM 

 (showing iniury-producing structures on body of fish) 



Dogfish sharks may be recognized, in comparison to the larger 

 species, by the absence of the anal fin. Another feature peculiar to 

 all dogfish is, of course, the presence of two short, stout spines, one 

 situated immediately in front of each dorsal fin. Although dogfish 

 are somewhat sluggish, this does not prevent them from thrashing 

 around with much vigor when caught in commercial fishing nets. The 

 teeth of a dogfish are not feared too much, but the spines are capable 

 of causing painful wounds unless appropriate caution is taken. The 

 venom is a glistening white substance in a shallow groove of each 

 spine. The poison secretion enters the skin with the spine. These 

 smaller sharks appear to be dangerous only if handled and will not 

 attack. 



The poison sting brings on an intense, stabbing pain, which 

 starts immediately and may last for 6 hours. Much redness and 

 severe swelling may follow and local tenderness may last for several 

 days. Treatment is the same as for any other venomous fish sting. 

 Some dogfish stings have been fatal. 



Prevention of the sting depends, in most cases, upon adequate 

 care in handling the spiny dogfish. Removal of the fish from a net, 

 hook, or spear should be accomplished with caution. A sudden jerk 

 or reflex of the fish may drive one of the stings deep into the flesh of 

 the unwary. 



Stingrays 



Stingrays of many kinds are much feared inhabitants of coastal 

 areas. They form a serious menace to waders, not only because of 

 their abundance but also because of their habit of striking from a 

 concealed position on the bottom in shoal water. 



Most rays have a sharp spine near the base of a whipUke tail. 



The spines may be lost in an adversary but will be replaced. Deep, 

 glandular grooves of the spines contain poisonous tissues. While 

 some rays merely create a painful dirty wound, others may inflict a 

 mortal stab. 



Rays inhabit tropical, subtropical, and warm temperate seas of 

 moderate to shallow depths. Their favorite areas are sheltered sandy 

 bays, lagoons, and river mouths. They may be seen lying in 

 shallow water, on top of the sand, or partly concealed in mud or 

 sand with eyes, spiracles, and tail exposed. They can dig in with 

 their pectoral fins for the purpose of concealment or in order to feed 

 upon worms, molluscs, and crustaceans. 



Some rays are free swimmers, relying more upon speed for an 

 escape from an enemy than upon abihty at concealment on the 

 bottom. Because most rays are scavengers by habit, they will 

 readily accept a baited hook and may frequently appear in the com- 

 mercial fisherman's net, where they may cause as much trouble as 

 the dogfish shark. Sharks that commonly feed upon rays may be 

 branded with numerous "stings" imbedded in the skin area of the 

 shark's head and jaws. 



Stingrays ordinarily glide through the water by a rippling wing- 

 like motion of both fins. When at rest on the bottom they may, 

 quite suddenly, with a quick move of the wings, stir up enough sand 

 and mud to cover themselves, leaving only the eyes, spiracle, and 

 tail exposed. Under these conditions, water intake is by way of the 

 exposed spiracles located behind each eye. 



Because of their flat shape, the weight of a person stepping upon 

 a ray serves both as a target and a dead weight necessary for lever- 

 age. Thus anchored, the ray whips the barbed tail with great force 

 and precision. At times the spines are found to be driven clean 

 through a foot or through the flesh and into the leg bone of the hap- 

 less victim. 



Stingrays are a large group of venomous marine organisms to 

 which may be attributed several thousands reported attacks each 

 year. The rays may be divided into 7 families: 



1. Dasyatidae — stingrays or whiprays 



2. Potamotrygonidae — river rays 



3. Gymnuridae — butterfly rays 



4. Myliobatidae — eagle rays or bat rays 



5. Rhinopteridae — cow-nosed rays 



6. Mobulidae — devil rays or mantas 



7. Urolophidae — round stingrays 



Representative examples of some of these according to area are: 

 Diamond Stingray, Dasyatis dipterurus (Figure 17), British 



Columbia to Central America. 



Bat Ray or Spotted Eagle Ray, Aelobatus narinari (Figure 



17), tropical or warm-temperate belts of the Atlantic Ocean, 



Red Sea, Indian Ocean, and Pacific Ocean. 



Round Stingray, Urolophus halkri (Figure 17), waters of 



the Pacific between California and Panama. 



The stingray wound usually causes immediate and severe pain. 



A 



RgUTO 17. Left. SPOTTED EAGLE RAY 

 center. DIAMOND STINGRAY; 

 right. ROUND STINGRAY 



t 



32 



