FISHERY BULLETIN: VOL. 78, NO. 1 



I .5 w , 



2 mm 



FIGURE 25.— Escae ofMelanocetusjohnsoni: A. ISH 1261/71, 21 mm SL; B. ISH 753/71, 38 mm SL; C. MCZ 49849, 75 mm SL; D. ISH 



1534/71, 78 mm SL. 



and based on a much greater knowledge of varia- 

 tion within the genus, there can be little doubt 

 that this nominal form has been correctly placed 

 within the synonymy of M. johnsoni. 



Melanocetus ferox was described from a single 

 specimen (78 mm) collected in the Gulf of Panama 

 (Regan 1926). Two additional specimens of this 

 nominal form were listed by Regan and Trewavas 

 (1932). A thorough comparison of all known mate- 

 rial led Bertelsen ( 1951 , table 4) to suspect that M. 

 ferox might represent individual variation of M. 

 niger. The holotype of M. ferox, however, has rela- 

 tively long lower jaw teeth (longest, 12.0% SL; 

 Figure 21). In this, and in all other morphometric 

 and meristic characters used here, it fits well 

 within the material here recognized as M. 

 johnsoni. Although the esca of the holotype is in 

 poor condition, traces of a posterior crest remain. 

 For these reasons M. ferox is synonymized with M. 

 johnsoni. The two additional specimens identified 

 as M. ferox by Regan and Trewavas (1932) (ZMUC 

 P92210, 30.5 mm; BMNH 1932.5.3.6, 42 mm) have 

 short jaw teeth; in this and in other ways they fit 

 well within the material of M. polyactls (see p. 77). 



Melanocetus cirrifer Regan and Trewavas 

 (1932), described on the basis of two small females, 

 was tentatively maintained by Bertelsen (1951) 

 because of supposed differences in escal morphol- 

 ogy and pigmentation which now can easily be 



76 



shown to be part of the variation found within M. 

 johnsoni. Melanocetus megalodontis Beebe and 

 Crane (1947), based on a single specimen, was 

 distinguished from all other species of the genus 

 by ". . . the character of the illicium; in the great 

 length and robustness of the fangs . . . and in the 

 shortness of the lower jaw. . . ." However, speci- 

 mens of M. johnsoni may have longer teeth and 

 individuals of several species of Melanocetus may 

 have as short a lower jaw (Bertelsen 1951, table 4). 

 Further (as predicted by Bertelsen 1951), the 

 "peculiar minute distal flaps" of the esca are arti- 

 facts. In all ways the holotype of M. megalodontis 

 fits well within the variation now known to occur 

 within M. johnsoni. Thus these nominal forms, M. 

 cirrifer and M. megalodontis , are placed within 

 the synonymy of M. johnsoni. 



Finally, the holotype and paratype of M. rotun- 

 datus Gilchrist (1903) have been lost. The cir- 

 cumstances of their demise are the same as for the 

 holotype of Dolopichthys cornutus described 

 elsewhere (Pietsch 1972b; see also Barnard 1927, 

 Penrith 1967). Although Gilchrist's (1903) origi- 

 nal description is poor, the figure provided by him 

 shows rather long jaw teeth, a long illicium bear- 

 ing a relatively large escal bulb, and a large pec- 

 toral fin lobe. This combination of characters 

 makes it nearly certain that M. rotundatus is a 

 synonym of M. johnsoni (Penrith 1967). 



