216 



Fishery Bulletin 91(2), 1993 



and 17.6-19.7, respectively. Body depth oft/, floridana, 

 however, was found to overlap extremes of U. tenuis 

 and U. regia, while U. regia exhibited the greatest 

 variation in this character, overlapping the extremes 

 of P. chesteri and all other species of Urophycis 

 studied. 



Mandible length and height of pelvic fin fTable 

 4, Fig. 4) Height of the pelvic fin plotted against 

 mandible length separated larval P. chesteri from 

 other hake at sizes between ~6 and 35 mm. At sizes 

 > 3 5 mm 



P. chesteri was similar to Urophycis with respect to 

 this character because P. chesteri became more slen- 

 der-bodied and the pelvic-fin origin moved closer to 

 the ventral margin of the body. Ranges of pelvic-fin 

 height as percent of mandible length in cleared and 

 stained larvae ranging in length from 6 to 35 mm 

 varied from 44 to 74% in P. chesteri in-29), but the 

 highest value of this ratio in five species of Urophycis 

 (n = 131) was only 42%. 



Distribution and abundance of hake larvae 



Urophycis chuss Urophycis chuss was found only in 

 summer and fall plankton collections from the MAB, 

 and was the only species of larval hake found in Au- 

 gust and early September. Densities of U. chuss in 

 summer collections off the coast of New Jersey were 

 up to two orders of magnitude greater than densities 

 found off Virginia (Fig. 5). In October 1975 and No- 

 vember 1976, U. chuss were still present off both Vir- 

 ginia and New Jersey, but were far less abundant than 

 during summer. 



Densities of larval U. chuss also varied with dis- 

 tance from shore (Fig. 5), particularly during summer 

 when lowest densities occurred inshore and highest 

 densities were found in midshelf regions in water 

 depths of 40-120 m. Variations in larval density with 

 both latitude and water depth were not well defined in 



1 



1 



collections. 



"" E 



II 

 *> > 



»- o ' 

 o CD 

 0) ». 

 (/) o 



■2 S, 



en 



P "° 



2- 

 u_ to 



= 1 



to o 

 Q 



2 3 4 5 



Length of Mandible (mm) 



Figure 4 



Height of the pelvic fin plotted against mandible length for larvae and juveniles of Phycis 

 chesteri and five species of Urophycis. 



An increase in mean size of 

 U. chuss was evident in fall col- 

 lections (Fig. 6). As larval size 

 increased in fall collections, the 

 number of larvae collected with 

 bongo nets decreased greatly. 

 More than 1300 specimens were 

 collected in October 1975 and 

 November 1976, but only 25 of 

 the larvae were collected with 

 bongo gear. Onshore-offshore 

 variation in size of U. chuss was 

 most evident in fall collections off 

 both Virginia and New Jersey; 

 size tended to increase with de- 

 creasing water depth. 



Urophycis regis Urophycis re- 

 gia was collected in the MAB 

 from October until May, with 

 highest densities of larvae occur- 

 ring in fall collections off the Vir- 



