2 NO. ANTENNA — 

 (UNIRAMOUS) 



CHELIPED 



PROPODUS 



Figure 2. — Diagram of female lobster (A. Dorsal view. B. ventral view). 



has had both a minimum and a ma.ximum carapace 

 legal size restriction since 1933. The minimum size 

 was increased from 3Vifi in. (78.6 mm) to 3V8 in. (79.4 

 mm) in 1942 and 3^/16 in. (81.0 mm) in 1957. The max- 

 imum size was increased from 4% in. (120.7 mm) in 

 1933 to 5 in. (127 mm) in 1935 and to SVie in. (131.8 

 mm) in 1957. In 1960 the maximum size was reduced 

 to 5 in. (127 mm) again. Frequency of moult of the 

 population as a whole probably varies more with sea- 

 water temperature than with any other factor. By the 

 time lobsters have reached approximately 127 mm 

 carapace length, a significant percentage are moulting 

 every other year, and very large lobsters may moult at 

 10- to 15-yr intervals. 



While moulting frequency is largely differentiated 

 by size, the frequency and time of moult for any given 

 size is primarily influenced by water temperatues, par- 

 ticularly during the spring and early summer. Fre- 

 quency is increased by high temperatures and reduced 

 by low. Although individual lobsters may moult at any 

 season, for the majority this debilitating experience 

 takes place sometime between May and October when 

 water temperatures are relatively high. 



The lobster is a comparatively slow-growing animal 

 and is believed to be long-lived. Moulting depends 

 upon growth and growth depends greatly upon food 

 intake. The frequency of feeding appears to be related 

 to general activity, which is influenced by water tem- 

 peratures. Post-moult feeding activity is high and is 

 generally associated in Maine with seasonally high 

 seawater temperatures. Those conditions concentrate 

 the catch of lobsters in the 5-mo period, July to 

 November, when about 75 percent of the annual catch 

 is made. 



Growth rates vary among individual lobsters. The 

 frequency of moult varies and the actual growth in- 

 crement made with each moult varies. From studies in 

 Maine (Taylor and Baird, 1948; Taylor, 1949), it is 

 likely that the most precocious lobsters in Maine wa- 

 ters reach minimum legal size (3Vi6 in. or 78.6 mm) 

 when they are 4 yr old. The number must be small 

 and probably does not exceed 5 percent. The majority 

 are believed to enter the fishery when they are 5 to 7 

 yr old, while another small percentage may be 9 

 yr of age or older before they reach minimum legal 

 size. 



