The stimuli for this change to parlors could 

 be associated with (1) the conversion to the 

 hydraulic hauler by the majority of fishermen, 

 and (2) the more powerful engines resulting 

 in faster boats. These factors possibly led 

 to an increase in the number of traps and 

 trap-hauls per fisherman. If the number of traps 

 set out exceeded the number that could be 

 hauled in a day, then there would be an increase 

 in the number of set-over-days, thus creating 

 the reason for a change to a trap design 

 that might reduce escapement over time. Of 

 course there could be many more explanations 

 for this change, but this speculative premise 

 seems most plausible. 



BIOLOGICAL NOTES 



In accordance with the stated objectives, 

 but as a supplement to the probability sampling 

 plan for the commercial lobster fishery, we 

 calculated: (1) the premolt and postmolt rela- 

 tionship, (2) the size ranges of berried females 

 in relation to size at maturity, (3) the fecundity 

 of females from historical data, and (4) the 

 alternatives to the maximum size limit. 



These relationships either have management 

 implications or make it possible to compare 

 these collected data with measurements in 

 other publications. 



Premolt and Postmolt Relationship 



We calculated the premolt and postmolt 

 relationship to help in determining the percent 

 increase in carapace length with shedding. 

 This has direct application in the analysis of 

 the length frequencies in the commercial catch. 

 In addition, the calculated regression coeffi- 

 cients can be compared with the corresponding 

 estimates by Wilder (1953) in order to determine 

 if there were differences. 



We collected lobsters from along the coast 

 and held them in laboratory tanks if they 

 appeared ready to molt. Of these, 44 lobsters 

 shed (33 males and 11 females). They ranged 

 in premolt sizes from 20- to 176-mm carapace 

 length. 



The premolt and postmolt lengths are linear 

 in character; therefore, we ran a linear re- 

 gression and solved the equations by the method 

 of least squares, where (x) is the premolt 



carapace length in millimeters. These equations 

 by category are : 



y = 0.64986 + 1.07578.V (males) 



y =-0.46448 + 1.09612a: (females) 



y = 0.59543 + 1.07619.1- (sexes combined). 



The 95% confidence limits about the slopes 

 or b values are ± 0.10142, ± 0.19753, and 

 ± 0.04352 respectively. 



Using these solved equations, the increase 

 in carapace length is about 8%. Wilder (1953) 

 and Dow (no date) calculated a 14% increase 

 in length; however, both authors demonstrated 

 some variability in the growth of individual 

 lobsters by size and sex. 



Wilder (1953) cautioned that lobsters held 

 in tanks in the laboratory before ecdysis might 

 not increase in length at the same percentage 

 as those lobsters in the natural environment. 



Cognizant of these factors, we analyzed the 

 length frequencies of the commercial catch 

 by two methods: (1) 14% increments in cara- 

 pace length and (2) probability analysis as 

 described by Harding (1949) and Cassie (1954). 

 With the latter method, the percent increase 

 between certain consecutive modes does ap- 

 proximate the 8% that we calculated from the 

 laboratory study. 



Berried Female Measurements 



To aid in determining the range of sizes 

 that female lobsters become mature (extrude 

 eggs), we have measured the carapace lengths 

 of berried females each year since 1966. 



The State purchases these females from 

 pound owners. Perhaps some background on 

 this operation would be beneficial: 



In order to fill the pounds (usually in May) with 

 boat -run, legal-sized lobsters for the summer demand, 

 pound owners in Maine purchase males and non- 

 berried females from fishermen in this State and 

 from dealers in Canada. From the time these lobsters 

 are impounded until they are sold in July or August, 

 some of the females become berried. Because it is 

 illegal to sell berried females on the market, the 

 pound owners have an arrangement to sell these 

 berried females to the Department of Sea and Shore 

 Fisheries; then the coastal wardens cut a "v" notch 

 in the telson and release these females in the ocean. 



I will not comment on the validity of such a 

 management plan; however, if the intent were 



