382 



A 



ONTOGENY AND SYSTEMATICS OF FISHES-AHLSTROM SYMPOSIUM 



'„CLI ■3(.W."1 Ij'A 



10 mm 



Fig. 203. (A) Eutaeniophorus festivus. paratype, 35 mm SL, with complete caudal streamer, 106 mm in length; (B) Eutaeniophorus festivus. 

 holotype. 53 mm SL; and (C) Paralaeniophorus gulosus. paratype, 21 mm SL. All from Bertelsen and Marshall (1956). 



soft rays, which are unbranched [except in the caudal fin of 

 megalomycteroids? Myers and Freihofer's (1966) drawing of 

 Megalomycter leevani shows the complete caudal rays ending 

 in actinotrichia, and they state that the dorsal and anal rays are 

 unsegmented]; (4) the dorsal and anal fins are opposed and 

 inserted on the posterior half of the body; (5) the pectorals are 

 laterally set and have numerous rays (D. 15-33, A. 14-29 in the 

 mirapinnatoids; D. 15-26, A. 14-20 in the megalomycteroids); 



(6) the pelvic fins are inserted below or before the base of the 

 pectorals, but are reduced or absent in the megalomycteroids, 

 whereas the pelvics of the mirapinnatoids are well developed; 



(7) the numbers of branchiostegal rays (on the epihyal and cer- 

 atohyal) are 3-5 + 4-5; (8) the vertebrae number 41-54 (45- 

 48 in the megalomycteroids). 



The main differences between the two groups concern the skin 

 (papillate or "hairy" in the mirapinnatoids, scaled in the me- 

 galomycteroids), olfactory organs (very large in the latter, small 

 in the former) [Goodyear's (1970) specimen was a ripe male but 

 Myers and Freihofer (1966) did not determine the sex of their 

 specimens. It is possible that the females have yet to be found 

 and are microsmatic]. The gape markedly oblique in the mir- 

 apinnatoids, somewhat oblique or horizontal in the megalo- 

 mycteroids. 



The mirapinnatoids resemble the cetomimoids in having soft 

 rays, a scaleless skin, opposed dorsal and anal rays on the pos- 

 terior part of the body and the same numbers and arrangement 

 of branchiostegal rays (mirapinnatoids 3-5 + 4, cetomimoids 

 3-4 + 4-5). There is also a marked resemblance between the 

 swimbladder of Barbourisia. which regresses after a presumed 

 functional stage in the early life history, and the swimbladder 

 of the mirapmnatoids (see Bertelsen and Marshall, 1956). In 

 both there are two posterior retia mirabilia that run forward to 

 an anterior gas gland. 



One main difference between these two suborders concerns 

 the head, which whether relatively large or small in the ceto- 

 mimoids, bears long jaws with a more or less horizontal gape. 

 This contrasts strongly with the relatively short, upturned jaws 

 of the mirapinnatoids. (Even so, it may well be that the fishes 

 of these suborders and the megalomycteroids feed largely on 

 copepods.) Secondly, in the two cetomimoids that have pelvic 

 fins {Rondcletia and Barbourisia) these are abdominal in posi- 

 tion whereas those of the mirapinnatoids are jugal. 



Beside the similarities considered above, the mirapinnatoids, 

 megalomycteroids and cetomimoids resemble each other in the 

 disposition of the red muscle component of their axial muscles. 

 Down the entire length of their myotomes red muscle fibres 



