MULLIDAE OF THE WESTERN' NORTH ATLANTIC 



445 



60.7 nun. taken by bottom trawl exliibit a com- 

 pletely clilleient appearance from the dip-netted 

 si)ecimens of the same .size taken usually over 

 deep water. The metamorphosed specimens from 

 shallow water are more robust. The changes that 

 occur in dimensions of body parts between 40 and 

 60 mm. are reflected in the graphs of body propoi-- 

 tions (figs. 9 through 21). A metamorphosed 

 juvenile and a pelagic juvenile of similar size are 

 shown in figure 34. The specimen uppermost in 

 the photograph is 54.6 mm., taken at 15 fathoms 

 by bottom trawl, and has the adult appearance. 

 The lower specimen in the photograph is 52.5 mm., 

 taken at the surface over deep water (800 

 fathoms) by dip net, and shows no evidence of 

 metamorphosis. 



A 67.9-mm. specimen taken by bottom trawl 

 at a depth of 27 or 26 fathoms has the slender 

 pelagic shape, but its coloration is intermediate 

 between pelagic and bottom types. The juvenile 

 pigmentation is still present on the snout and 

 upper half of the body, but stripes are evident on 

 the dorsal fins, and bars are present on the caudal 



fin (probably a melamorpjiosing form which has 

 just reached its adult habitat). 



GROWTH AND DEVELOPMENT 



Young V . parvus below approximately 50 mni, 

 had neither the vomerine nor the palatine teeth 

 typical of the genus Upeneus. 



Unlike M. auratux and P. maculatns, U. parvus 

 had no visible minute first dorsal spine. 



Gill i-aker counts (fig. 35) should serve to dis- 

 tinguish U. parvus from M. martinicus at sizes 

 before the scales and teeth develop. Xo M. 

 martinicus below 82.5 mm. have been examined, 

 however, and the separation on gill raker counts 

 is based on the assumption that the number of 

 lower-limb gill rakei-s in M. mnrtinicus prior to 

 82.5 mm. is not markedly smaller. 



The smallest specimen examined, 20.8 mm., (fig. 

 36) was a juvenile. There were no major changes 

 in the pelagic juvenile (fig. 34, lower) up to the 

 time of transition, which occurred between 40 and 

 60 mm., after which the juvenile had the appear- 

 ance of a young adult (fig. 34, upper). 



Figure 34. — Upper. Bottom-living .54.6-mm. I'prnrun parviin trawletl by Orvpim porsoniu'l. (I'F) 

 52.5-nim. Upeneus parvus dip netted b.v Oregon personnel. (CXH.M 04712) 



Lrnrcr. Pelagic 



