Larvae . The larval stage is 15 to 30 days long depending upon the water 

 temperature. Larvae remain in open waters until attaining the postlarval 

 stage at which time they use tidal currents and salinity gradients to enter 

 nursery areas. Pink shrimp use various portions of bays and tidal marshes for 

 nursery areas whereas rock shrimp use higher salinity bays and nearshore areas 

 out to depths of 10 fathoms. 



Juveniles . Growth is rapid; they require only 3 to 4 months to mature. 

 When water temperatures cool in the fall and the shrimp are 3 to 4 inches 

 long, they emigrate from nursery areas using tidal currents for transport to 

 offshore spawning grounds. Shrimp that do not emigrate may overwinter in 

 deeper portions of bays until spring and then move offshore. 



Adults . Major fishable concentrations of pink shrimp are along the 

 southwest coast from Fort Myers to Tortugas. Major populations of rock shrimp 

 live near Apalachicola Bay and from Cape Canaveral to Georgia, and to a lesser 

 extent in the Tortugas area. Pink shrimp mature when about 3.5-4.0 inches 

 long. They arrive in the offshore spawning grounds in fall and early winter 

 when they are 6 to 8 months old and about legal size (47 whole shrimp per lb 

 or 70 tails per lb). Maximum age is about 2 years, but few survive beyond 12 

 to 14 months. 



Diet . The larvae are planktivores that feed on algae and zooplankton. 

 Postlarvae, juveniles, and adults are omnivores, and feed on detritus and 

 microorganisms. 



Blue Crab 



The blue crab ( Callinectes sapidus ) supports a major shellfish fishery in 

 Southwest Florida and most are taken by traps (Adkins 1972). Baited longlines 

 and dip nets have been used with some success, but they generally are too 

 labor intensive. 



The annual blue crab catch for Florida in 1970-80 averaged about 17.3 

 million lb of which less than 16% were caught in Southwest Florida. Monthly 

 catches were generally heaviest from April through September. The landed 

 value of the 15.6 million lb State catch in 1980 was about $3.5 million, and 

 the dockside price was about $0.22 per lb (Prochaska et al . 1981). A brief 

 description oi^ the life history of the blue crab is given in the following 

 subsections (Perry 1975, Van Engle 1958). 



Spawning . Spawning is year-round except in northern waters of Florida 

 when water temperatures sometimes drop below 60°F. Longshore migration on the 

 west coast towards Apalachicola Bay by some females suggests this may be a 

 primary spawning area for the Florida gulf coast. Females spawn at least 

 twice, producing 700,000-2,000,000 eggs each time. Spawning usually peaks in 

 April -June. 



Larvae. The larval go through seven zoea stages lasting 31-49 days and 

 one megalopa stage lasting 6-20 days. Zoea are planktonic until molting into 

 the megalopa stage. Megalopa utilize tidal currents to move into estuarine 

 waters where they molt into the first crab stage [2-3 mm carapace width (CW)]. 



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