114 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Figure 2. — Upper: Large pelagic prejuvenile Pseudopri- 

 acanthus alius from Massachusetts, showing early meta- 

 morphic characteristics (49.3 mm. standard length, 

 CNHM 55986). Lower: Small bottom-dwelling P. alius 

 from off St. Augustine, Fla., showing late metamorphic 

 characteristics (47.2 mm. standard length, BLBG). 



fins (figs. 16, 17, and 24), while the transform ed 

 juvenile and adult pattern shows an unmaculate 

 fin with a distinct dark edge (figs. 19-23). Fins 

 on larvae and early prejuveniles are immaculate, 

 and there is no dark edge on fins of a nontrans- 

 forming late prejuvenile. The transition in color 

 pattern appears to be a migration of the spot- 

 forming pigment to the edge of the fin, where it 

 accumulates to form the dark border. The tran- 

 sition pattern is shown in the two specimens illus- 

 trated in figure 2. In figure 3 the specimens which 

 appear as intergrades in fin coloration lie between 



the specimens showing the extremes in color pat- 

 tern, and the entire group forms an integrated, 

 though overlapping, series. The individuals from 

 north of Cape Hatteras (table 1) with an inte- 

 grated fin coloration were taken inshore, and even 

 if washed there, they could have begun the rapid 

 transformation (Hubbs, 1958: p. 282). Most of 

 the individuals from north of Cape Hatteras had 

 the pure pelagic fin coloration (immaculate or 

 spotted, depending on their size), however large 

 they were, further evidence of arrested develop- 

 ment (other than increase in size) with main- 

 tenance of the pelagic environment. The trans- 

 forming specimens from the geographical range of 

 the adult usually were trawled or were from in- 

 shore situations and thus were probably under- 

 going successful transformation. Some small 

 spotted-fin bottom specimens, all from the geo- 

 graphical range of the adult, probably had just 

 reached the bottom habitat when collected. 



Even within the geographical range of the adult, 

 the size at which the prejuveniles settle to the 

 bottom varies (perhaps based on their geographical 

 origin), for of two specimens collected at the same 

 time (Silver Bay station 1299, table 1) the larger 

 (49.4 mm.) retained the pretransformation (spot- 

 ted) fin coloration, while the smaller (48.6 mm.) 

 exhibited the transitional coloration. 



This phenomenon is exhibited in four other 

 collections also, all from Massachusetts. These 

 collections are old, taken without complete and 

 precise ecological arid locality data, which pre- 

 cludes definite conclusions as to transitional 

 relationships. The four collections, indicated in 

 table 1, are — 



(1) CNHM 55986, 2 specimens, the larger 

 (57.1 mm.) with the pretransformation fin pattern 

 and the smaller (49.3 mm.) with the transforming 

 fin color. (2) USNM 49664, 6 specimens, one of 

 the middle-sized ones (42.4 mm.) with the trans- 

 forming fin color and the others (30.8, 39.3, 42.9, 

 44.9, and 47.3 mm.) with the pretransformation pat- 

 tern. (3) USNM 68129, 4 specimens, the largest 

 and smallest (34.5 and 55.9 mm.) with the trans- 

 forming fin color and the two middle-sized ones 

 (49.3 and 50.8 mm.) with the pretransformation 

 pattern. (4) USNM 58833, 2 specimens, the 

 larger (41.1 nun.) with the pretransformation fin 

 color and the smaller (35.7 mm.) with the 

 transforming color. 



