Commercial Shark Fishing in the Caribbean Area 15 



lar offenders in this regard. Sharks which are sluggish 

 in their movements are less aroused by the scent of food 

 than the swifter swimmers, and to these species the scent 

 of blood is most stimulating. 



A few, such as the smooth dog fishes, migrate regu- 

 larly northward and southward along the coast of North 

 America, while others are swept northward each year 

 during the warm seasons for long distances by the Gulf 

 Stream. In general, however, most of the kinds remain 

 in the same localities the year around except as they 

 range to and fro in search of food. 



Some of these sharks will be easy for you to identify, 

 but others will be more difficult because they look so 

 much alike. Fortunately it is fairly easy to recognize 

 the sharks which you should avoid catching. All of the 

 species, however, can be distinguished by some feature 

 or group of features which set each one apart from the 

 others. The two keys which follow are based upon these 

 differences and will enable you to identify 35 different 

 species found in the Caribbean area. 



In general the two keys are set up as follows : Of the 

 35 sharks described here, 30 have an anal fin and 5 do not. 

 'Those with an anal fin are divided into 3 groups, depend- 

 ing on the number of gill openings they have. One 

 species has 7 gill openings, another 6 openings, and the 

 remaining 28 have 5 gill openings. All of the sharks with 

 no anal fin have only 5 gill openings. In both anal and 

 non-anal groups, sharks are further subdivided into 2 

 groups, those with ordinary shaped heads (that is, not 

 expanded sidewise at the eyes) and those with hammer 

 or shovel-shaped heads. All of the sharks in Key I, for 

 example, have an anal fin, 5 gill openings and an ordinary 

 shaped head.) Sharks in each one of the above groups 

 are further separated from one another by some distinc- 

 tive feature or groups of features, such as a ridge along 

 the middle of the back, the mouth at the tip of the snout, 

 a barbel at the nostril, all five gill openings in front of 

 the pectoral fins and so forth. 



To use these keys for identification, first turn to Figure 

 19 in Appendix A which shows a simple outline of a 

 shark with all the important features clearly marked 



