White shrimp, continued 



Biological Interactions 



Predation : Finfish prey heavily on this species. Known 

 predators include tiger shark {Galeocerdo cuvier), At- 

 lantic sharpnose shark (Rhizoprionodon terraenovae), 

 bull shark, ladyfish (Elops saurus), hardhead catfish, 

 crevalle jack, red snapper (Lutjanus campechanus), 

 southern kingfish (Menticirrhus americanus), spotted 

 seatrout, sand seatrout, red drum, black drum, cobia 

 (Rachycentron canadum), code goby, Spanish mack- 

 erel, southern flounder, and gulf flounder (Gunter 1 945, 

 Kemp 1949, Miles 1949, Darnell 1958, Springer and 

 Woodburn 1960, Boothby and Avault 1971, Stokes 

 1977, Overstreet and Heard 1978a, Overstreet and 

 Heard 1978b, Danker 1979, Creel and Divita 1982, 

 Overstreet and Heard 1982, Saloman and Naughton 

 1984, Sheridan et al. 1984). Some predation by bay 

 squid (Lolliguncula brevis) is possible (Hargis 1979). 

 Penaeid shrimp are an important link in the energy flow 

 of food webs by feeding on benthic organisms, detritus, 

 and other organic material found in sediments (Odum 

 1 971 , Carr and Adams 1 973). 



Factors Influencing Populations : The commercial 

 shrimp fishery may be impacting the white shrimp 

 population (Nance and Nichols 1988, Nance 1989, 

 Nance et al. 1989). Catch statistics indicate that 

 current harvest levels may be over-exploiting the re- 

 source, causing a decline in adult recruitment. Patho- 

 gens also affect the white shrimp. It is susceptible to 

 diseases and parasites, but the extent of resultant 

 mortality is largely unknown (Couch 1978, Muncy 

 1 984). Predation and episodic catastrophes probably 

 play more important roles as limiting factors of natural 

 populations. Penaeid shrimp infected with biosymbionts 

 may be weakened and die in low oxygen situations 

 (Overstreet 1978). In the Mississippi Sound, adult 

 white shrimp are infected with a cestode which invades 

 the hepatopancreas (Muncy 1 984). White shrimp tend 

 to aggregate, forming a patchy distribution pattern in 

 estuaries. The environmental factors that govern this 

 type of distribution are not known (Zimmerman et al. 

 1990, Zimmerman pers. comm.). Suitable estuarine 

 habitat is critical to survival and recruitment of juveniles 

 (Turner 1 977, Nance et al. 1 989). However, develop- 

 ment has destroyed or altered large portions of these 

 estuarine areas to a point of low productivity (Christ- 

 mas and Etzold 1977). Continued loss of this habitat 

 may result in declines in recruitment and harvest 

 (Christmas and Etzold 1 977, Nance et al. 1 989). Epi- 

 sodic weather events such as hurricanes and freezes 

 also impact white shrimp populations (Kutkuhn 1962, 

 Barrett and Gillespie 1973). Hurricanes can result in 

 high mortality of a spawning class by causing adverse 

 environmental conditions. Such conditions include 

 high tides and extensive flooding, higher salinities, 

 excessive turbulence, turbidity, and habitat destruc- 

 tion. Freezes can cause mass mortalities by reducing 



the watertemperature to lethal levels. Other factors felt 

 to be related to penaeid shrimp population dynamics 

 are productivity of estuarine nursery areas, food avail- 

 ability and content, refuge from predation, amount of 

 freshwater inflow, light intensity, tide, and rainfall (Christ- 

 mas and Etzold 1977, Gracia 1991). 



Personal Communications 



Nance, J.M. NOAA National Marine Fisheries Service, 

 Galveston, TX. 



Patella, F.J. NOAA National Marine Fisheries Service, 

 Galveston, TX. 



Whitaker, J.D. South Carolina Wildlife and Marine 

 Resources Department, Charleston, SC. 



Zein-Eldin, Z.P. NOAA National Marine Fisheries 

 Service, Galveston, TX. 



Zimmerman, R.J. NOAA National Marine Fisheries 

 Service, Galveston, TX. 



References 



Anderson, W.W., J.E. King, and M.J. Lindner. 1949. 

 Early life stages in the life history of the common marine 

 shrimp, Penaeus setiferus (Linneaus). Biol. Bull. 

 (Woods Hole) 96:168-172. 



Barrett, B.B., and M.C. Gillespie. 1973. Primary 

 factors which influence commercial shrimp production 

 in coastal Louisiana. Louis. Dept. Wildl. Fish. Tech. 

 Bull. No. 9, 28 p. 



Baxter, K.N. , and S.L. Hollaway. 1981. A summary of 

 results of Louisiana white shrimp tagging experiments, 

 1 977. NOAA Tech. Memo. NMFS-SEFC-72, 1 1 2 p. 



Baxter, K.N., and W.C. Renfro. 1967. Seasonal 

 distribution and size distribution of postlarval brown 

 and white shrimp near Galveston, Texas, with notes on 

 species identification. Fish. Bull., U.S. 66:149-158. 



Boothby, R.N., and J.W. Avault, Jr. 1971. Food habits, 

 length-weight relationship, and condition factor of the 

 red drum (Sciaenops ocellata) in southeastern Louisi- 

 ana. Trans. Am. Fish. Soc. 100(2):290-295. 



Burkenroad, M.D. 1939. Further observations on 

 Penaeidae of the northern Gulf of Mexico. Bull. Bingham 

 Oceanogr. Coll. Vol. 6, Art. 6, 62 p. 



77 



