5-30 



(Table 5-5) . This solitary tunicate can form fairly extensive assem- 

 blages on crowded panels because of its small basal area and upright 

 growth form (Osman, 1977) . Osman observed that Molgula spp. dominated 

 entire panels in the Woods Hole region. Settlement on short-term panels 

 occurred from July through October in New Haven Harbor (Figure 5-3), 

 and from May through October at Woods Hole (Osmann, 1977) . 

 Hoagland et al. (1977) observed settlement of M. manhattensis throughout 

 the fall in New Jersey. 



Dominant Taxa 



Balanus spp. 



Balanus eburneus , B. improvisus and B. crenatus were present 

 during some sampling periods on New Haven Harbor panels from 1971 

 through 1977 (Figures 5-6, 5-8, 5-9). Balanus spp., which consisted 

 mostly of difficult-to-identify juveniles, was recorded from 1975 to 1976 

 (Figure 5-7) . B. improvisus and B. eburneus were codominants in New 

 Haven Harbor with B. eburneus more abundant prior to 1976 and B. impro- 

 visus more abundant thereafter. B. crenatus was abundant only in 131 A. 

 B. eburneus and B. improvisus occurred at all sites, while B. crenatus 

 never occurred at Long Wharf. 



The three barnacle species have similar life history patterns. 

 Though hermaphroditic, barnacles usually cross-fertilize. Adults brood 

 the eggs in the mantle cavity and the nauplius larvae hatch as plankton. 

 Cypris larvae are the mature planktonic stage which subsequently settle 

 and metamorphose into adults. Barnacles are gregarious and preferably 

 set with other barnacles but in general any hard substrate will suffice. 

 There are a host of factors including texture, angle, and current rate 

 which influence barnacle settlement (Crisp and Barnes, 1954, Crisp and 

 Stubbings, 1957). Balanus improvisus has been reported to settle in 

 greater numbers in low salinity estuaries (NAI, 1977c). 



