location of several segments of the crab population and partially 

 explains the five crab migration patterns that were observed in the 

 estuary. 



Pages 5-24 are particularly relevant to productivity of estuarine 

 areas. One chapter describes the physical environment in terms of 

 blue crab habitat and associated hydrologic conditions. Barataria 

 Bay is found to be a shallow and dynamic blue crab habitat characterized 

 by marked fluctuations in salinity, water temperature, circulation, and 

 other hydrologic variables. The blue crab population must be able to 

 adjust to such a dynamic ecosystem. The following section on the life 

 history of the blue crab describes relationships between salinity, food 

 supply, and life stage and patterns of distribution and migration. 

 The section on crab fishing patterns contains field data on the relation- 

 ships between the crab and its subhabitats. 



A second chapter traces the life history of the blue crab with a 

 description and discussions of its life cycle in an estuary, salinity 

 and osmoregulation, and food items and trophic level. The blue crab 

 is described as a motile, euryhaline organism which occupies particular 

 subhabitats according to the physiological requirements of each life 

 stage, including salinity, water temperature, and food supply. (A. A. 

 and G.S.) 



Keywords: blue crab, fisheries, estuarine habitat, life histories, 

 Louisiana 



IV-E-23 



Darnell, R.M. 1959. Studies of the life history of the blue crab 



( Callinectes sapidus Rathbun) in Louisiana waters. Transactions 



of the American Fisheries Society 88:294-304. 



Analysis of 133 plankton, 462 otter trawl, and 124 shore seine 

 samples from Lake Pontchartrain and adjacent waters of southeastern 

 Louisiana suggests the following pattern for the life history of the 

 blue crab in the area. Mating takes place in the fresher areas, 

 followed by migration of the mated females to more saline waters. 

 After hatching, the young migrate in toward the estuaries where most 

 of the growth takes place. The first wave of young seems to arrive 

 in Lake Pontchartrain in May, and crabs spawned in the spring appear 

 to reach a size of about 65 mm by September of the first year. The 

 relative absence of adults from winter collections suggests migration 

 or hibernation. Food habits, parasites, and periodicity are discussed. 

 (A. A. modified) 



Keywords: blue crab, life history, Louisiana 



190 



