flattened sides, suggesting the cluster had been 

 part of a larger mass. A small piece of an encrust- 

 ing sponge, Halichondria panicea, was found at- 

 tached to the eggs. Small tubules (0.14 mm in 

 diameter) were also found on the surface of some 

 of the eggs and were assumed to belong to some 

 species of polychaete. Eggs have been described by 

 Warfel and Merriman (1944). At the time of 

 collection, embryos were already well developed 

 in all of the eggs. Pigmentation on the body con- 

 sisted of melanophores arranged in vertical bars 

 corresponding to the location of the myomeres. 

 The retina was black and the iris had a silvery 

 appearance. The median fin fold and pectoral buds 

 were formed. The former originated close behind 

 the hindbrain. By 16 December, large melano- 

 phores developed on the hindbrain and dorsal half 

 of the yolk sac. The body pigmentation ended 

 abruptly on the caudal peduncle about three- 

 fourths of the total length from the snout. This 

 characteristic pattern, to be referred to as the 

 truncated pigmentation pattern, persisted 

 throughout the development of all specimens. The 

 mouth was formed and open. The single oil 

 globule (ca. 0.8 mm in diameter) inside the yolk 

 sac was located at the anterior confluence of the 

 abdomen and yolk sac. 



Newly Hatched Larvae 



The larvae (Figure 1) began hatching on 3 

 January 1975, 55 days after collecting the already 

 well developed eggs, and continued through 30 

 January. The newly hatched larvae averaged 12.8 

 mm TL (range 11.7-12.7 mm). Warfel and Mer- 

 riman (1944) noted the larvae emerged head 

 first. This was not always true in the case of my 

 material. Nearly one-half of the larvae which 



were observed hatching emerged tail first. The 

 large ovoid yolk extended forward to or beyond the 

 posterior margin of the eye. The head was not 

 flexed over the anterior of the yolk sac. Body 

 pigmentation became more dense and uniform 

 but was lacking over the forebrain, ventral half of 

 the yolk sac, and the posterior one-fourth of the 

 body. Melanophores lined the base of the dorsal fin 

 fold to the level of the truncated body pigment. A 

 few melanophores were present along the post- 

 anal fin fold base, near the posterior margin of the 

 body pigment. The preanal fin fold was barely 

 perceptible. No gas bladder developed. The mouth 

 was very large. The maxillary extended to or 

 slightly behind the middle of the eye. The lower 

 jaw contained four sharply pointed, conical teeth 

 on each side. The fourth tooth was somewhat 

 smaller and located lower on the dentary. Body 

 proportions and total myomeres (38 or 39) were 

 similar to those reported by Warfel and Merriman 

 (1944) at this stage. The larvae remained mostly 

 on the bottom of the container, spending much of 

 the time on their sides possibly as a result of the 

 enlarged yolk sac. Efforts to swim were very 

 awkward and only made when the larvae were 

 disturbed. 



Further Development 



Near the end of January, the larvae were 

 observed to be positively phototactic. The yolk of 

 many of the larvae was absorbed by the end of the 

 first week in February. The peritoneum appeared 

 silvery through the skin. The pigmentation be- 

 came uniform olive grey over the body (Figure 2). 

 Specimens ranged between 14.0 and 17.0 mm TL 

 on 6 February. Those longer than 16.1 mm had 

 rudimentary caudal rays. The larvae were more 



Figure l. — Hemitripterus americanus. Prolarva (newly hatched), 8 January 1975: 12.6 mm TL. 



468 



