with each hypural element. The notochord has 

 neural and haemal spines on nearly its full length. 

 Most neural arches, but only the anterior haemal 

 arches, are stained. Pterygiophores of the anterior 

 elongate dorsal fin rays are developing. About 40 

 dorsal and 24 anal fin rays are stained. The in- 

 teropercle has begim to ossify, and all four opercu- 

 lar elements show some ossification. The supra- 

 orbital bars are stained and are visible as anterior 

 extensions of the neurocranium. The auditory re- 

 gion of the neurocranium is partially stained, and 

 the post cleithrum is ossifying. 



By 10 mm. SL ossification has progressed con- 

 siderably, and many bones in the head, vertebrae, 

 and caudal fin can be recognized. At about 10 mm. 

 SL ossification is noted in the hypural elements, 

 the basal part of the urostyle, and the parapophy- 

 sis of the last abdominal (precaudal) vertebra. 

 The dorsal aspects of the posterior 14 and the an- 

 teriormost 3 or 4 vertebrae are lightly stained ; the 

 remaining vertebrae are not stained. All neural 

 and haemal spines and arches are ossified except 

 for those on the penultimate vertebra. There are 

 16 caudal fin rays : Four are associated with each 

 of the two inferior hypurals, the superior hypurals 

 are indistinguishable. Four to six pelvic fin rays 

 have developed on each fin base, and the pelvic 

 bone is beginning to ossify. The supraorbital bars 

 extend forward; their anterior edge is above the 

 nostril. The entopterygoid, which is immediately 

 above the pterygoid, is lightly stained. Bones of 

 the lower jaw suspension can be identified; the 

 quadrate, hyomandibular, and pterygoid are 

 lightly stained. The supracleithrum and post- 

 temporal region of the cranium can be distin- 

 guished. The upper jaw now has about 10 teeth 

 and the lower 16; those near the symphysis are 

 relatively small and close together. A "cartilagi- 

 nous" bar extends posteriorly along the ventral 

 median edge of the gut from the distal edge of 

 the pelvic fin base to below the liver. The anterior 

 ventral edge of the urohyal is hooked and pointed 

 forward. 



Ossification has changed little at about 14 mm. 

 SL except on the vertebrae (fig. 7). The first ab- 

 dominal (precaudal) vertebra is completely ossi- 

 fied, and the dorsal aspect and one-third to one- 

 fourth of the lateral surfaces of the other abdom- 

 inal vertebrae are ossified. The parapophyses of 

 the last four abdominal vertebrae are also ossified, 



but no ribs are seen. Ossification of the parapophy- 

 ses begins with the last abdominal vertebra and 

 proceeds anteriorly to the fifth vertebra, the last 

 one with a parapophyses. The first through the 

 18th caudal vertebrae show the same degree of 

 ossification ; posteriorly they become progressively 

 more ossified until ossification is complete on the 

 last four vertebrae. Interneurals and interhaemals 

 are developing between the fifth and 10th neural 

 and haemal spines. The enlarged pterygiophore, 

 which is associated with the first 10 to 12 anal fin 

 rays, is now lightly stained. 



My largest larva (14.5 mm. SL) is stained and 

 shows essentially the same degree of ossification as 

 the 14 mm. SL specimen. The vertebral column, 

 pterygiophores of the dorsal and anal fins, and all 

 bones of the neurocranium and branchiocranium 

 are not completely ossified. The supraorbital bars 

 extend forward onto the ethmoid region and form 

 the frontals. The right side supraorbital bar ap- 

 pears to be partially reabsorbed as suggested by 

 its upturned anterior medial edge in the sphenotic 

 region and its position and thimiess. The left su- 

 praorbital bar lias moved closer to the left eye. 

 After movement of the supraorbital bar is complete 

 the left side bar and part of the right side bar form 

 the interorbital bar, and the remaining part of the 

 right supraorbital bar is reabsorbed. At a larger 

 size the right eye will move under the dorsal fin 

 and stop at the interorbital bar. The sphenotic and 

 preopercular spines are still present at 14.5 mm. 

 SL but will eventually be reabsorbed or broken off 

 and leave the surface smooth. 



SPAWNING AND DISTRIBUTION 



Larvae were collected between Jupiter Inlet, 

 Fla., and Cape Hatteras, N.C. (fig. 1) in surface 

 waters over depths of 11 to 2,510 m. (6-1,372 

 fath.) ; 21 stations were in depths greater than 

 183 m. (100 fath.) and 54 stations in depths less 

 than 183 m. 



Specimens were collected primarily north of lat. 

 30° N. (70 collecting sites were north and only 5 

 were south of lat. 30° N.). Sixty-nine larvae were 

 taken at 35 stations occupied at night, and 102 were 

 taken at 38 stations occupied during the day. No 

 larvae were collected between November and 

 April ; one lan^a was taken in April and one in No- 

 vember; and the rest in May to October (fig. 15). 



278 



U.S. FISH AND WILDLIFE SERVICE 



