HOW TO IDENTIFY FISHES AND 

 FISH-LIKE VERTEBRATES 



Before attempting to identify a fish or fish-like vertebrate 

 (lamprey, shark, ray), the reader should become famihar 

 with the meaning of a few terms used in the identification 

 key which are listed below and illustrated on p. 6. 



1. DORSAL FIN: an unpaired (or single) fin on the 

 upper surface of the body. If more than one dorsal fin is 

 present, the fin nearest the head is called the first dorsal 

 fin, the next one behind it the second dorsal fin, etc. 



2. ANAL FIN: an unpaired fin on the lower surface 

 of the body, near the rear end. 



3. PELVIC FINS: a pair of fins located on the 

 lower surface of the body in front of the anal fin. 



4. PECTORAL FINS: a pair of fins located one on 

 each side near the front of the body. 



5. CAUDAL OR TAIL FIN: a single, tail-like fin 

 located at the rear end of the body. 



6. LATERAL LINE: a broken line of pores fre- 

 quently found along the length of the sides of the body. 



7. CAUDAL PEDUNCLE: the narrow region of the 

 body between the rear of the dorsal and anal fins and 

 the caudal fin. 



8. SNOUT: the region in front of the eyes. 



9. SPIRACLES: small openings located behind the 

 eyes of some sharks and rays. 



10. ORIGIN OF FIN: the front of the base of a fin. 



11. OPERCULUM OR GILL COVER: the bony cov- 

 ering protecting the gill. 



In identifying a specimen always start at page 8. The 

 identification key is based on a system of multiple choice. 

 On each page, characters separating two groups of fishes 

 are described under the headings I and II. If your specimen 

 fits the description under one of these headings you may 



