FISHERY BULLETIN: VOL. 82, NO. 4 



of stock structure of the lobster detailed in this 

 report was one part of this overall program (Shak- 

 lee and Samollow 1980). 



Two general questions regarding lobster sub- 

 population structure were asked in the present 

 study. First, was there any detectable stock 

 heterogeneity within the entire Hawaiian Ar- 

 chipelago? Second, and specifically relating to the 

 potential impact of the emerging fishery in the 

 NWHI on the existing fishery in the main islands, 

 was there evidence that populations in the main 

 islands were differentiated, and thus independent, 

 from populations in the NWHI? 



The spiny lobster, Panulirus marginatus, is 

 endemic to the Hawaiian Archipelago where it oc- 

 curs in large numbers from Hawaii in the south- 

 east to Kure Atoll in the northwest (Fig. 1). High- 

 est apparent abundances are localized at Necker 

 Island and Maro Reef (Uchida et al. 1980), the two 

 localities where the lobster fishery is presently 

 concentrated. Panulirus marginatus is generally 

 found in waters deeper than 10 m. Panulirus mar- 

 ginatus has an annual fecundity of from 125,000 

 to 450,000 eggs per female (Honda 1980). After 

 mating, females carry one or more sper- 



matophores ventrally on the thorax until the eggs 

 are extruded and fertilized. Embryonic develop- 

 ment in this species takes about 30 d during which 

 time the embryos remain attached to the pleopods 

 of the female (Morris 1968). Based on studies of 

 related species it appears that, after hatching, the 

 larvae are planktonic for a period of 6-12 mo 

 passing through 8-12 phyllosoma larval stages 

 (Johnson 1956, 1968; Johnson and Knight 1966; 

 Inoue 1978). The larvae metamorphose into 

 puerulus postlarvae. The postlarvae settle from 

 the plankton and assume the benthic lifestyle 

 characteristic of the adults. Based on tag- 

 recapture studies at Kure Atoll and French 

 Frigate Shoals (MacDonald 4 ) and similar studies 

 at Oahu (Morris 1968), adults appear to be rela- 

 tively sedentary, not exhibiting large-scale move- 

 ments. 



4 C. MacDonald, Zoology Department, University of Hawaii, 

 Honolulu, HI 96822, pers. commun. May 1982. 



FIGURE 1. — Map of the Hawaiian Islands showing sampling 

 localities. Note the 200 m depth contours. 



25 



2 0°. 



KURE 



I 



® 



G> 



+ EMERGENT LAND 

 CO 200 METER CONTOUR 



&t? 



MARO REEF 



W NECKER 



^ 



cs 



OAHU 



FFS 



#• 



KAUAI 



HAWAII 



MOLOKAI 



J 



NORTHWESTERN HAWAIIAN ISLANDS 



1000 KILOMETERS 



'MAIN' HAWAIIAN ISLANDS 



500 MILES 



25 



20 



175 



170 



165 



160 



155 



694 



