FISHERY BULLETIN: VOL. 71, NO. I 



shrimp try trawl with a cod end of 1-inch stretch 

 mesh; and (5) a variable mesh monofilament 

 gill net (four 25-ft sections of 1-, 2-, 3-, and 4- 

 inch mesh) . SCUBA divers were also employed 

 on a few occasions to collect small male lobsters 

 from which supplemental data were obtained for 

 our maturity studies. 



Of the aforementioned types of gear, consid- 

 erably more fishing effort has been expended 

 with wire traps. This disproportion of effort 

 resulted from early fishing success experienced 

 with wire traps and their relative suitability 

 for hauling from a 17-ft Boston Whaler.' Sub- 

 sequently, only 67 i2.6^/f ) of 2,582 lobsters were 

 captured with the other types of gear. 



Carapace length (distance measured along 

 midline from posterodorsal edge of carapace to 

 posterior margin of eye socket) and total length 

 (distance measured dorsally from tip of rostrum 

 to tip of telson) were determined to the nearest 

 millimeter for all lobsters sampled. Wet weights 

 were recorded to the nearest 10 g. 



MATURITY STUDY— 

 GONAD EXAMINATION 



Males 



The vas deferens and/or testes of 204 male 

 lobsters (carapace lengths ranged from 36 to 

 95 mm) were examined for the presence or ab 

 sence of spermatophores (Figures 1 and 2). 

 Males having spermatophores were considered 

 mature. Because it was economically objection- 

 able to sacrifice large numbers of lobsters, a 

 method whereby the internal sex organs could 

 be probed or extracted without any detrimental 

 effects to the lobster was desirable. Initially, 

 I attempted to withdraw sperm samples through 

 a blunt hypodermic needle inserted into the vas 

 deferens via its valvular orifice on the fifth pair 

 of pereiopods. This technique produced incon- 

 sistent results and had to be abandoned. I then 

 discovered that both the vas deferens and testis 

 could be extracted with a forceps introduced 

 through a small incision at the base of the fifth 



Figure 1. — Reproductive system dissected from a male 



lobster. 



* Reference to trade names does not imply endorsement 

 by the National Marine Fisheries Service, NOAA. 



Figure 2. — Lobster sperm cells photographed under oil 

 immersion at 970X. 



pair of walking legs. This procedure yielded 

 reliable results and had no noticeable deleterious 

 effects upon lobster survival throughout a post- 

 operative period of several months. 



Females 



Ovaries were dissected from 158 female lob- 

 sters and then ovarian color and ova diameter 

 (to nearest 0.1 mm) were recorded. Egg di- 

 ameters were based on the average of a random 

 sample of 10 eggs (distorted eggs were rejected) 

 from each ovary. Using the criteria of ovarian 

 color and ova diameter, ovaries were assigned 

 to one of the following stages of development: 



166 



