COLLETTE ET AL.: SCOMBROIDEI 



599 



Table 153. Comparison of Characters among Larvae and Juve- 

 niles OF Scombrolabrax, of known Gempylidae and of the Scombrid 

 Tribe Scombrini. 



Scombrolabrax 



Gempylidae 



Tnbe Scombrini 



Rexea solandri (Fig. 3\1).—Rexea larvae are poorly known. 

 Parin and Bekker (1972) reported a 10.5 mm larva but did not 

 describe it. Six cleared and stained Rexea (21.7-28.9 mm SL) 

 from the "Dana" collections were identified by PotthofT from 

 meristics, but pigment was lost due to the age of specimens 

 which had been collected in the 1920s. In general, Rexea larvae 

 look similar to Promethichthys larvae. The pelvic spine is short- 

 er and does not reach the anus in Rexea, whereas in Prometh- 

 ichthys the spine reaches past the anus. Also, Promethichthys 

 has 3 elements associated with the first anal pterygiophore: Rex- 

 ea has only 2. All our Rexea larvae had one long serrate spine 

 and a miniscule vestige of a ray in each pelvic fin. The larvae 

 of Rexea promethoides are not known. Adult R. promelhoides 

 have a fully developed pelvic fin with a count of 1,5 rays. 



Promethichthys prometheus (Fig. 317). — The larvae and young 

 of Promethichthys are poorly known. Giinther (1889) described 

 and figured two larvae 5 mm and 10 mm as Thyrsites prome- 

 theus (=Promethichthys prometheus). These larvae are not Pro- 

 methichthys. The smaller one cannot be positively identified but 

 could be a serranid larva because of body shape and number of 

 myomeres. The larger specimen is definitively Diplospinus mul- 

 tistriatus. Roule and Angel (1930) described and figured two P. 

 prometheus larvae 6 mm and 10 mm. From their description 

 and figures it is impossible to confirm their identification. We 



APHANOPODIN/e DipLymus 



Fig. 319. Relationships of the Trichiuridae and the gempylid 

 subfamily Gempylinae (from Tucker, 1956: fig. 23). 



do not think they are Promethichthys because the pelvic rays 

 are too long and well developed, and there are 2 1 first dorsal 

 fin spines on the larger specimen. The larger specimen may be 

 Nesiarchus. Gorbunova (1982) described and figured two P 

 prometheus larvae 3.9 mm and 8.5 mm from the northern Ca- 

 ribbean Sea. The smaller specimen has only dorsal gut pigment, 

 a high first dorsal fin and long pelvic spines reaching past the 

 anus. The larger larva has a very high, moderately pigmented 

 first dorsal fin and a very long pelvic spine extending to the 

 anterior portion of the anal fin and a distinct pigment patch 

 near the hypurals. In body shape Promethichthys larvae resem- 

 ble those oi Re.xea. The first dorsal fin spine count in Parin and 

 Bekker ( 1972) for Promethichthys is a printing error. Total ver- 

 tebral counts for this genus given by Grey (1953) and Matsubara 

 and Iwai (1958) are 33 and 34 respectively, but ours were 34 

 or 35. This difference between our counts and Grey's and Mat- 

 subara and Iwai's is probably one of methodology. We counted 

 the urostyle as the last vertebra. 



Nealotus tripes (Fig. 3 1 7). —The larvae of Nealotus are not well 

 known. Liitken (1880) figured two advanced Nealotus larvae, 

 but we are not certain of his identification. Strasburg (1964) 

 described a size series of Nealotus from 9 mm-41 mm. The 9 

 mm specimen had fully formed fins and probably had attained 

 some juvenile pigmentation. Nealotus has a very long posterior 

 process in the first anal pterygiophore which is evident in larvae 

 as small as about 8 mm. This is an excellent character to separate 

 Nealotus from Nesiarchus. Nealotus and Nesiarchus can be dis- 

 tinguished by their pelvic fin ray count and by the number of 

 middle radials in the second dorsal and anal fins. In juvenile 

 Nealotus the middle of the three anal spines fuses lengthwise to 

 the posterior process of the first anal pterygiophore. Thus, in 

 adult Nealotus only 2 anal spines are visible. One of us (PotthofT) 

 obtained many vertebral counts from post-larval stages and 



Fig. 318. Lateral views of gempylid larvae from top to bottom: Nesiarchus nasutus. 7.5 mm SL. Gulf Stream off Miami, Virginia Key, Cr. 

 Fl, June 30, 1982, drawn by J. Javech; Gempylus serpens. 5.6 mm NL, Gulf of Mexico, OREGON II, Cr. 117, Sta. 34521, May 22, 1981, drawn 

 by J. Javech; and Diplospinus multistriatus, 7.1 mm NL, no data, drawn by J. Javech. 



