COMMON MAEINE FISHES 15 



KEEL : A ridge along the side of the tail or caudal peduncle of some fishes. 

 LATERAL LINE : A series of pores along the side of the body forming what looks 



like a dotted line. Absent in some fishes and multiple in others. 

 LATERAL LINE, DORSAL BRANCH : An extra branch of the lateral line running 



back from the head, usually near the dorsal fin, found on some fishes. 

 MAXILLARIES : The main bones of the upper jaw. 

 OPERCLE : The principal and hind-most bone of the gill cover. 

 PALATINES : A pair of bones in the roof of the mouth which extend out and back 



from the vomer. 

 PECTORAL FINS : The first or uppermost of the paired fins. 

 PELVIC FINS : See ventral fins. 

 PERITONEUM: The lining of the abdominal cavity. 

 POSTERIOR : Behind. Opposite of anterior. 



PREMAXILLARIES : The paired bones forming the front of the upper jaw. 

 PREOPERCLE : The bone of the gill cover in front of the opercle. 

 PYLORIC CAECA : Appendages in the form of blind sacs, connected with the 



alimentary canal at the junction of the stomach, which are found in some fishes. 

 RAY : Herein, the supporting rods of a fin which appear to be composed of many small 



segments placed end to end. Never stiff or sharp and sometimes branched. Often 



called "soft rays". See spine. 

 SCALY APPENDAGE : A triangular projection formed from a scale and found just 



above the base of the ventral fin in some fishes. 

 SNOUT: The part of the head in front of the eyes. Its length is measured from the 



tip of the upper jaw to the front of the eye. 

 SOFT DORSAL : The part of the dorsal fin which is supported by rays. 

 SPINE: (1) The unsegmented, usually hard and sharp, rods which support parts of 



fins. (2) Any sharp projecting point. 

 SPINY DORSAL : The part of the dorsal fin which is supported by spines. 

 THORACIC : With reference to the chest region. 

 VENT : The opening at the end of the digestive tract. 

 VENTRAL : The lower part of the body. Opposite of dorsal. 



VENTRAL FINS : The pair of fins below or behind the pectoral fins. Also called pelvic 



fins. 

 VIVIPAROUS : Giving birth to live young. 

 VOMER : A bone in the roof of a fish's mouth just behind the middle of the upper jaw. 



