ATLANTIC SAILFISH 



143 



<^'''^ *l ^Umnfc 



Figure 2. — Larva, 3.6 millimeters long (U. S. Nat. Mus. No. 111814). 



plane of the body (when opercle is closed), and 

 the ventromedial keel terminates anteriorly at the 

 posterior angle of the lower jaw. The upper 

 secondary preopercular spine is serrated and arises 

 from posterior edge of the preopercle on a serrated 

 keel continuous with the dorsomedial keel of the 

 main preopercular spine. (See figure 3 for arrange- 

 ment of head spines in the dorsal view of a 3.8- 

 mm. specimen.) The keel on the face of the oper- 

 cle is serrated and possesses a dominant, acute, 

 and medially situated protuberance. Keels on 

 lower jaw are serrated, and two in number; one 

 arising from the lateral surface of the posterior 

 portion of the jaw and possessing a dominant 

 protuberance, and the other comprising the lower 



edge of the lower jaw. Teeth are few in number, 

 large, with the anterior ones tusklike. The eye 

 is large, with a diameter one-third the length of 

 the head. The nostril is a single opening in the 

 swollen anterior-basal portion of the orbital crest. 



Body. — The body is short and deep, the visceral 

 sac distended with food, and mj'omeres and the 

 rodlike urostyle are prominent. 



Fins. — The dorsal, caudal, and anal are a con- 

 tinuous fold with indistinct supporting structures 

 developing in the caudal portion. The pectoral 

 is round, with indistinct supporting structures. 

 No pelvic fins are present. 



Pigmentation. — Pigment has faded from long 

 preservation, and that remaining is limited to a 



Figure 3. — Larva, 3.8 mm. {Theodore N. Gill collections), dorsal view of head showing spination and pigmentation. 

 PS, pterotic spine; USPS, upper secondary preopercular spine; PFS, spine on face of preopercle; MPS, main 

 preopercular spine (directed at 90° from sagittal plane of body as opercles are open, angle is 45° when opercles ure 

 closed); OC, orbital crest (showing heavy spine over eye). 



389133 O— 57- 



