population in the Gulf of Maine. Four generations of P^. minutus appear to 

 occur in Penobscot Bay in fall, winter, spring, and summer (Bertrand 1977). 

 In the upper bay only three generations appear to be present; the summer 

 brood does not appear (Bertrand 1977), Bigelow (1926) found that possibly 

 three to four broods were spawned during the year and that breeding occurred 

 mainly in March-April, May-June, July-August, and September. 



3.) Centropages typicus 



C^. typicus is one of the most abundant copepods during the fall in the 

 central coastal and offshore waters of the Gulf of Maine (Sherman 1970, and 

 Bigelow 1926) . This species has been observed in Penobscot Bay in small 

 numbers in late summer and fall to early winter (Bertrand 1926) . Sherman 

 (1976) observed a peak of abundance in C^. typicus in October and possibly 

 a second peak in May. According to Bigelow (1926) and Deevey (1952), this 

 species is relatively stenohaline, and generally does not survive well when 

 the salinity is lower than 31 o/oo. This may explain its scarcity in 

 Penobscot Bay, which has reduced salinity seasonally, and its presence in 

 Boothbay Harbor, where salinity is consistently high. Bertrand (1977) 

 suggests that the population present in Penobscot Bay consists of migrants 

 from the Gulf of Maine. Other observations in North Atlantic waters show 

 that the timing of its seasonal maximum is not affected by temperature 

 (Clark 1940; Fish 1925). Therefore, C^. typicus is abundant in coastal and 

 offshore waters from summer to late winter (Clark 1933) . 



4.) Centropages hamatus 



Centropages hamatus was found in maximum densities in summer in 

 Boothbay Harbor (Sherman 1976) and Penobscot Bay (Bertrand 1977) . In the 

 coldest part of the season (January-April) it was absent in Boothbay Harbor 

 (Sherman 1976) and found in very low numbers in Penobscot Bay (Bertrand 1977) 

 In the Gulf of Maine, Bigelow (1926) and Sherman and Schaner (1968) noted 

 that C^. hamatus was fairly scarce compared to C^. typicus . C^. hamatus is 

 thought to be euryhaline and more abundant in relatively shallow waters. 



Reproduction of C^. hamatus in the Penobscot Bay probably occurs in 

 spring; thus only one generation may be produced per year (Bertrand 1977). 

 Five generations per season for C^. hamatus were reported by Marshall (1949) 

 from Clyde Sea area of Scotland. In Block Island Sound only two generations 

 (winter and June-July) were observed by Deevey (1952). The increase in 

 population in the spring may be attributed to low numbers of overwintering 

 adults living near the bottom (Marshall 1949) or possibly a winter dormant 

 egg (Fish and Johnson 1937). Zillious and Gonzolex (1972) and Kasahara 

 et al. (1974) have noted the occurence of overwintering eggs of calanoid 

 copepods from estuarine and nearshore sediments. 



5.) Microsetella norvegica 



Microsetella norvegica is the most abundant copepod in the Penobscot 

 Bay during late fall and winter (Bertrand 1977). A major breeding period 



(Continued) 



4-F-2 



