596 



ONTOGENY AND SYSTEMATICS OF FISHES-AHLSTROM SYMPOSIUM 



Fig. 316. Lateral view of the gempylid larva Thyrsiles atitn 6.0 mm NL, modified after Haigh (1972a). 



in Lepidocybium is probably unique among scombrid and gem- 

 pylid larvae. In all known scombiid and gempylid larvae the 

 gut is intensely pigmented only dorsad with little lateral and 

 ventral pigmentation. 



Lepidocybium has more affinities to the Gempylidae than to 

 the Scomberomorini. With the Gempylidae it shares caudal 

 skeletal characters such as 2 uroneurals and 3 epurals: scom- 

 brids have 1 uroneural and 2 epurals. Larval Lepidocybium have 

 serrate pelvic and first dorsal and anal fin spines, which also are 

 present in known gempylid larvae, except Thyrsitops. The first 

 dorsal pterygiophore in Lepidocybium. as in all gempylids, in- 

 serts in the second intemeural space in Atlantic specimens, but 

 in Pacific Lepidocybium the first dorsal pterygiophore is found 

 in the third intemeural space; in all scombrids the first dorsal 

 pterygiophore inserts in the 3rd space. 



Ruvettus pretiosus.—T\\t larvae of Ruvellus are not known. This 

 lack of knowledge is surprising, because Ruvettus is caught as 

 by-catch in the tuna longline fishery (Nakamura, 1977). The 

 smallest Ruvettus known to us is 209 mm SL and has the features 

 of adults. 



Epinnula magistralis (Fig. 315).— The larvae of Epinnula are 

 not well known. Gorbunova (1982) reported the capture of 3 

 larvae from the Gulf of Mexico and one larva from the Straits 

 of Yucatan. In larval Epinnula, the first dorsal fin is not as high 

 and not as intensely pigmented as in Neoepinnula and the first 

 dorsal fin is inserted more anteriorly in Neoepinnula than in 

 Epinnula. In Epinnula the preopercular spine is shorter than in 

 Neoepinnula. We believe that the 17.8 mm specimen figured in 

 Belyanina (1982b) is a specimen of Epinnula not Neoepinnula 

 because of the more posterior first dorsal fin insertion. 



Neoepinnula orientalis (Fig. 3\ 5). — Neoepinnula larvae have 

 been described by Nishikawa and Nakamura (1978) and one 

 7.3 mm specimen was figured by Gorbunova (1982). Belyanina's 

 (1982b) figure of a 17.8 mm Neoepinnula probably is an Epin- 



nula as mentioned above. The larvae of Neoepinnula are very 

 distinctive. They have a very high and intensely pigmented first 

 dorsal fin which inserts anteriorly almost on top of the head. 

 This causes the anteriormost first dorsal pterygiophores to insert 

 slanted in a posterior direction; no other gempylid or scombrid 

 larva has such a first dorsal fin. 



Tongaichthys robustus. —Tht larvae of this recently described 

 genus and species are unknown (Nakamura and Fuji, 1983). 



Thyrsitops lepidopoides (Fig. 315).— The larvae of Thyrsitops 

 were recently described by Sato ( 1 983). These are the only known 

 gempylid larvae which lack serrations on the fin spines. We 

 believe that the count of XVI-XXII first dorsal fin spines for 

 Thyrsitops given in Parin and Bekker's (1972) Table 4 is a 

 misprint and should be XVI-XVII. 



Thyrsites atun (Fig. 316). — Haigh (1972a) described the larvae 

 of Thyrsites captured in plankton tows. Pigmentation is dis- 

 tinctive with 2 to 3 dark pigment blotches on the ventral tail 

 margin unlike any other known gempylid, but similar to the 

 trichiurid Benthodesmus. Haigh (1972a) gave counts for Thyr- 

 sites: XVIII-XXI first dorsal fin spines and 34-35 vertebrae. 

 Grey (1953) gave XX first dorsal fin spines and 37 vertebrae 

 and Parin and Bekker (1972) gave XX-XXI first dorsal fin 

 spines. 



De Jager (1955) fertilized the eggs of a ripe Thyrsites female 

 with sperm from a male in the laboratory. The eggs hatched 

 and the larvae were fed drops of human blood. After 9 days 

 they died, visibly undernourished. De Jager illustrated the de- 

 velopment of the eggs and very early stages of the larvae. The 

 illustrations are not helpful for identification of wild caught 

 gempylid larvae because of starvation and underdevelopment. 



The larvae figured by Regan ( 1 9 1 6) as Thyrsites are probably 

 Promethichthys or Rexea because the first dorsal fin in the figure 

 of the largest specimen shows XVIII spines and no pelvic fin 

 rays. Regan stated in the text that total vertebrae were 35. 



Fig. 317. Lateral views of gempylid larvae from top to bottom: Promethichthys promelheus. 8.5 mm SL, modified after Gorbunova (1982); 

 Rexea solandri. 21.7 mm SL, Indian Ocean, DANA, Cr. 3915II1, from a cleared and stained specimen drawn by J. Javech; and Nealotus tripes, 

 9.0 mm SL, modified after Strasburg (1964). 



