TABLE 6. Male to female sex ratios of lobsters caught in wire pots from May to October, 1978 to 1987. 



Jordan Cove 



Intake 



Twotree 



All Stations 



Recaptures not included 



ratios close to 1:1 were also reported by other 

 researchers working in waters close to shore 

 (Ilerrick 1911; Templeman 1935a; Ennis 1971, 

 1974; Stewart 1972; Krouse 1973; Thomas 1973; 

 Cooper et al. 1975; Briggs and Mushacke 1980). 



Reproductive Characteristics 



Female size at sexual maturity, development 

 and fullness of egg masses carried by females and 

 the percentage of berried females caught, were 

 compared for preoperational and operational 

 study periods. Female size at sexual maturity 

 was determined by measuring the second abdom- 

 inal segment and calculating the ratio of the ab- 

 dominal width to the carapace length, and plotting 

 that ratio against the carapace length (Templeman 

 1935b; Skud and Perkins 1969; Krouse 197.3) 

 (Fig. 4). Data for 1986 and 1987, represented as 

 (*) in Figure 4, were compared to mean values 

 collected from 1981 to 1985. Female size at sex- 

 ual maturity was similar under 2- and 3-unit op- 

 erating conditions. Females began to mature be- 

 tween 50 and 55 mm CL and all females were 

 mature at sizes greater than 95 mm CL. The 

 smallest berried females collected in our studies 

 (62 mm CL) were between 54-56 mm CL when 

 oviposition fu^st occurred assuming 14% growth 



per molt and thus confirms the small size at which 

 females mature in our area. Briggs and Mushacke 

 ( 1 979), working in western LIS, found that females 

 began to mature at about 60 mm CL and most 

 were mature at about 80 mm CL. In contrast to 

 the LIS lobster population, females in northern 

 waters (Maine) mature at a substantially larger 

 size (80 mm CL, Krouse 1973). This was attrib- 

 uted to low water temperatures which retard re- 

 productive maturation, whereas warmer summer 

 water temperatures of LIS favor early maturation 

 of females (Smith 1977; Aiken and Waddy 1980). 

 The sexual maturity of males has been well doc- 

 umented and therefore was not investigated in 

 our studies. Briggs and Mushacke (1979) reported 

 that males in western L.IS first reached maturity 

 (i.e., produced mature spermatozoa), at 40 to 44 

 mm CL and over half were mature at 50 to 54 

 mm CL; in Maine, male lobsters also began ma- 

 turing at relatively small sizes (50% mature at 44 

 mm CL, Krouse 1973). 



Egg masses were examined from 1984 to 1987 

 to determine if the complement of eggs carried 

 by females was normal. Smith (1977) expressed 

 concern about the fecundity of berried females in 

 western LIS when he found 10-14% of the berried 

 females carried abnormally low numbers of eggs 



130 



