8-28 



first is that water temperature in the harbor during June averages 

 approximately 16 to 19 °C and increases to greater than 20 °C during July 

 and August. Optimal growth of Cancer irroratus larvae occurs at 15°C, 

 and at temperatures above 20 °C the metabolic rate is reduced (Saila and 

 Pratt, 1973). Thus, larvae hatched in deeper waters during late spring 

 and summer would not be subjected to deleteriously high water temper- 

 atures. Secondly, if, as is indicated, a substantial amount of larval 

 development occurs in deeper waters , larval entrainment by the Harbor 

 Station would be minimized. 



Most rock crabs collected in the harbor were relatively 

 small, ranging in size (greatest carapace width) from 2 to 80 mm, while 

 most were from 45 to 55 mm (adult carapace width averages approximately 

 95mm [VJilliams, 1965] and reaches 140 mm [Gosner, 1931]). No temporal 

 or spatial trends in size of Cancer were evident. Low abundance of 

 crabs and a lack of size data during summer may prevent detection of 

 possible seasonal size patterns. 



Ovalipes ocetlatus 



Ovalipes ocellatus , the lady or calico crab, ranges from 

 Prince Edward Island, Canada, to Charleston, South Carolina and is 

 common on a variety of bottoms, particularly sand (Williams, 1965). 

 Like most portunid crabs, Ovalipes is quick, highly aggressive, and 

 pugnacious (Gosner, 1971) . The annual abundance of Ovalipes has shown 

 considerable yearly variation (Table 8-3) . Lowest abundances were 

 collected during 1974 (60 individuals) and 1976 (200 individuals) , 

 while highest abundances were collected during 1975 (1400 individuals) 

 and 1977 (3220 individuals) . A comparable trend in annual abundance is 

 apparent in the impingement data for the New Haven Harbor Station (Table 

 8-5, page 8-44). Generally, Ovalipes has been most abundant in the 

 inner harbor and Morris Cove. Moderate numbers occurred in the middle 

 harbor (Station 11) and relatively few in the outer harbor (Stations 19 

 and 20) (Table 8-3) . During 1975 and 1977 when annual abundances were 

 high, Morris Cove (Station 13) accounted for 80% of the total catch of 

 Ovalipes. 



