REVIEW OF THE PARROTFISHES 3 



or green markings lacking on the females. One of the difficulties 

 encountered in pursuing these studies has been the general disinte- 

 gration of the viscera in museum specimens, making it impossible to 

 recognize their sex. What is needed is a field study on fresh specimens 

 that will make it possible to relate sex to color markings, as was done 

 by Dr. Winn for Scarus croicensis and Sparisoma aurqfrenatum at 

 Bermuda in 1956. 



Although the color pattern is a highly suitable character for recog- 

 nizing species at nearly all sizes, there are other characters that have 

 been evaluated as to their constancy and have been found not to vary 

 significantly among all the species studied. These are (1) number of 

 dorsal, anal, caudal, and pelvic fir rays; (2) number of scales from 

 rear of head to base of caudal fin; (3) for fish of certain species, the 

 relation of increase in size to the number of canine teeth near the 

 corner of the mouth, the number appearing to increase from none to 

 2 or 3. The color of the teeth are only partially valuable in recognizing 

 species, since the teeth may change from whitish or pinkish in the 

 immature, to green in mature adults, or they may be white or green at 

 sizes greater than the juvenile stage. In the juvenile stage the teeth 

 are usually white. 



Proportional measurements were made on various species of Scarus 

 in an attempt to evaluate that type of measurement for recognizing 

 species. It was concluded that such measm'ements gave little help 

 except for a few species such as Scarus harid, with its longer snout, 

 but that species can be identified by better characters. 



Another character by which certain parrotfishes have been con- 

 sidered a distinct species is the swelling or enlargement of the forehead. 

 While this oedematous enlargement is useful for a few species, it has 

 its limitations, since it enlarges with increase in size and on some species 

 occurs only on the largest adults, measuring 15 inches and longer, or 

 on males. 



The pharyngeal mill of parrotfishes is designed to crush coralline 

 algae, coral fragments and other food items. The upper pharyngeals 

 are paired and fit snugly against the base of the skull. The number 

 of rows of teeth on each upper pharyngeal bone may vary from one to 

 three and is almost invariable for groups of species. The lower 

 pharyngeals consist of a single bone, with a flat or concave dentigerous 

 surface that opposes the two upper pharyngeals; powerful muscles, 

 attached to the shoulder girdle and base of the skull, have further 

 leverage by attachment to a secondary bone, one of the epibranchials 

 (Monod, Bull. Soc. Hist. Nat. Toulouse, vol. 8, pp. 191-194, 1951) 

 located just behind the last gill arch. Although Boas (Die Zahne 

 der Scaroiden, Zeitschr. Wiss. Zool., vol. 22, pp. 189-210, pi. 10, 

 1879) studied the teeth of parrotfishes, his material was Umited 



