FISHERY BULLETIN; VOL. 69, NO. 2 



Figure 1. — General distribution of calico scallops and 

 four standard transects occupied during the 1967-68 

 survey off the Florida east coast. 



ploratory Fishing and Gear Research Base at 

 Pascagoula, Miss. 



The survey results are subdivided according 

 to spawning, age and growth, mortality, distri- 

 bution and abundance, and yield. 



SPAWNING 



Bourne and Bligh (1965) found sea scallop 

 (Placopecten niagellanicus) ovaries change 

 color during maturation, progressing from pink 

 at early stages to deep coral-red when ripe. 

 Color changes were also noted in calico scallop 

 ovaries, undeveloped ovaries being whitish, ripe 

 ovaries bright reddish-orange. 



Yellowish-orange coloration was seen in very 

 few scallops during the August cruise, but by 

 September the rate and incidence of color change 

 was highly noticeable. Coloration and incidence 

 increased into fall and winter and by February 

 ovaries were predominantly reddish-orange or 

 ripe. The majority of ovaries taken in April 

 were bright reddish-orange. June ovaries were 

 largely uncolored. 



Sexual maturation in sea scallops begins in 

 March, spawning occurring 7 months or so later 

 in September or October. Calico scallops ap- 

 parently have a similar maturation period based 

 on color change progression which begins in 

 August and ends in March or April. Protracted 

 spawning does take place in some areas since 

 small numbers of 5 to 30 mm scallops occur 

 throughout the year (Figure 2). 



A total of 1,483 drags was made during the 

 survey — 285 in transect A, 403 in transect B, 

 493 in transect C, and 302 in transect D. The 

 following were determined for each drag: total 

 catch in bushels (using a standard steel shrimp 

 basket averaging 70 lb.), number of bushels of 

 live scallops, pounds of meat per bushel, number 

 of pints of meat per bushel, number of meats per 

 pint, and size frequency (measured as shell 

 diameter in millimeters). Randomly selected 

 individuals were examined for gonad coloration 

 and .sexual maturation. The data were analyzed 

 with the UNIVAC 9200 computer at the Ex- 



Figure 2. — Monthly size/frequency distribution of scal- 

 lops for the combined transects off the Florida east coast 

 during the 1967-68 survey. 



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