Spiny lobster, continued 



Reproduction 



Mode : Reproduction is sexual, sexes are separate 

 (gonochoristic), and fertilization is external. Hermaph- 

 roditism has not been reported (GMFMC 1982). 



Mating and Spawning : Mating may occur up to a month 

 prior to spawning, and consists of placement of a 

 spermatophore by the male onto the female's sternum. 

 In Florida, the mating season is principally from March 

 to August, but some may occur throughout the year 

 (Hunt et al. 1991). After mating, the spermatophore 

 adheres to the female's sternum; at spawning she 

 scratches it to initiate and achieve fertilization. Spawn- 

 ing occurs offshore in open waters and is principally 

 associated with reef habitats. The season extends 

 from March to July with some spawning occurring in 

 August. In the Florida Keys, it peaks in May and June. 

 Some spawning throughout the year has been re- 

 ported (Little 1977, Warner et al. 1977, Lyons 1981, 

 Lyons et al. 1 981 , GMFMC 1 982, Gregory et al. 1 982, 

 Williams 1 984, NOAA 1 985, Marxand Herrnkind 1 986). 



Fecundity : Fecundity is proportional to size (Mora- 

 Alves and Bezerra 1968). Recent Florida fecundity 

 studies show that a 76 mm CL female lobster can lay 

 320,000 eggs, an 87 mm CL female 500,000 eggs, a 

 1 1 3 mm CL female 1 ,000,000 eggs, and a 1 41 mm CL 

 female was observed with 1 ,952,000 eggs (Matthews 

 pers. comm.). A second and potentially a third mating 

 and spawning may occur during the season, increas- 

 ing the spawning potential two or three fold (Hunt et al. 

 1 991 ). It has been estimated that nearly half of the egg 

 pool is contributed by females in the 75-85 mm CL size 

 class (Gregory et al. 1982). 



Growth and Development 



Egg Size and Embryonic Development : Eggs are spheri- 

 cal and about 0.5 mm in diameter. Embryonic develop- 

 ment lasts about 3 weeks. During this time the eggs 

 adhere to pleopodal setae on the underside of the 

 female's abdomen. The phyllosome larvae emerge 

 from the egg membrane and disperse in the water 

 column (Marx and Herrnkind 1986). 



Age and Size of Larvae : Phyllosome larvae develop 

 through about 1 1 stages increasing in size from 2 mm 

 total length at hatching to nearly 34 mm before meta- 

 morphosis. Duration of the phyllosome stages is about 

 6 to 1 2 months (Richards and Potthoff 1 981 , Marx and 

 Herrnkind 1986, Acosta et al. in press). 



Juvenile Size Range : The phyllosome larvae meta- 

 morphose into a transparent swimming stage called a 

 puerulus which may last several weeks. They begin to 

 acquire reddish-brown pigment within 3 to 6 days after 

 arriving in nursery areas, and within days molt into the 

 first juvenile stage. Juveniles are 6 mm CL when they 



first settle out of the water column beginning the spiny 

 lobster's benthic juvenile phase (Eldred et al. 1972, 

 Andree 1981, Marx and Herrnkind 1986, Butler and 

 Herrnkind 1 991 ). Growth of juveniles is estimated at 5 

 mm carapace length (CL) per month (Eldred et al. 

 1972). Other estimates are 12 mm in first year of 

 benthic existence (GMFMC 1982), from 6 mm to 90 

 mm CL in the first three years of life (Sutcliffe 1 957), 5.4 

 mm per molt (Warner etal. 1977), 0.46 mm CL/ week 

 (23.9 mm CL/year) (Hunt and Lyons 1986), 0.76 mm 

 CL/week (Davis and Dodrill 1989), and 0.95 mm CL/ 

 week (Forcucci et al. 1994). In general, there are 4 

 molts per year (GMFMC 1982). Growth decreases 

 dramatically between 74 mm CL (0.46 mm CL/week) 

 and 76 mm CL (0.23 CL/week) signifying a shift in 

 energy use from growth to the onset of maturation 

 (Hunt and Lyons 1986). Difference of sex does not 

 appear to affect growth rates in juveniles (Davis and 

 Dodrill 1989, Forcucci et al. 1994). Injury appears to 

 have the greatest effect on growth rates in lobsters less 

 than 60 mm CL, and confinement of juveniles in traps 

 may also affect growth (Hunt and Lyons 1 986, Forcucci 

 etal. 1994). 



Age and Size of Adults : Onset of maturation begins 

 near 70 mm CL in south Florida, but a few are reproduc- 

 tively functional at 66 mm CL (Warner et al. 1977, 

 Gregory et al. 1 982, Hunt and Lyons 1 986). Histologi- 

 cal examination of ovaries, however, indicates that 

 most south Florida spiny lobsters are not reproduc- 

 tively active until reaching 90-95 mm CL (Lyons 1 986). 

 Injury does not affect growth rate in adults as much as 

 in juveniles (GMFMC 1982, Hunt and Lyons 1986). 

 Adult males grow faster than adult females, and growth 

 rates during the summer are faster than in the winter 

 (Davis and Dodrill 1 989). Intermolt periods range from 

 3 to 6 months for subadults and adults (Andree 1 981 ). 



Food and Feeding 



Trophic Mode : Throughout their benthic juvenile and 

 adult stage, spiny lobsters are nocturnal predators, 

 locating their food by means of antennae and chemore- 

 ceptive filaments that line the antennules and dactyls 

 of the legs (Marx and Herrnkind 1986). The lobster's 

 mandibles are used to crush the shells of molluscs, 

 crustaceans, and urchins. Spiny lobsters are probably 

 the dominant carnivores in their habitat and have 

 important ecological effects on the marine benthic 

 commuinity (Marx and Herrnkind 1986). 



Food Items : Spiny lobster phyllosome larvae are pre- 

 sumed to feed on plankton; laboratory-reared 

 phyllosomes fed on chaetognaths, euphasiids, fish 

 larvae, medusae and ctenophores (Marx and Herrnkind 

 1 986). Pueruli stage lobsters are not known to feed at 

 all. The spiny lobster is a nocturnal forager throughout 

 the benthic juvenile and adult stages (Cox et al. 1 997). 



91 



