Brown shrimp 



Penaeus aztecus 

 Adult 



3 cm 



(from Perez-Farfante 1969) 



Common Name: brown shrimp 



Scientific Name: Penaeus aztecus 



Other Common Names: brownies, golden shrimp, 



green lake shrimp, native shrimp, red or red tail shrimp 



(Motoh 1977); crevette royale grise (French), camaron 



cafe norteno (Spanish) (Fischer 1978, NOAA 1985). 



Classification (Williams et al. 1989) 



Phylum: Arthropoda 



Class: Crustacea 



Order: Decapoda 



Family: Penaeidae 



Value 



Commercial : Shrimping has been ranked as the sec- 

 ond most valuable commercial fishery in the U.S., and 

 seventh in quantity (NMFS 1 993). U.S. landings of all 

 shrimp species combined in the Gulf of Mexico were 

 1 00.7 thousand mt in 1 992, and were valued at $316.6 

 million. Total U.S. brown shrimp harvest in the Gulf of 

 Mexico was 64,075 mt in 1991, and brown shrimp 

 typically comprise 57% of the total Gulf of Mexico 

 shrimp landings (NOAA 1 993). The fishery for Gulf of 

 Mexico brown shrimp is considered to be fully exploited 

 at this time (Nance and Nichols 1988, Nance 1989), 

 and a longterm potential annual yield of 63,001 mt has 

 been estimated (NOAA 1993). In 1991 an estimated 

 5,000 offshore vessels were participating in the fishery 

 with an unknown number of smaller boats fishing in the 

 inshore and nearshore waters. The season begins in 

 May, peaks from June to July and gradually declines 

 through April. Major fishing grounds are off the coasts 

 of Texas and Louisiana. Federal regulations have 

 annually closed the offshore fishery along the coast of 

 Texas from around mid-May to mid-July not more than 

 55 days to allow shrimp to grow to larger sizes (Klima 

 et al. 1 982, Klima et al. 1 987, Nance et al. 1 990). The 



majority of the brown shrimp are harvested for human 

 consumption. In addition, a smaller bait shrimp fishery 

 also exists (Swingle 1 972, Klima et al. 1 987, Nance et 

 al. 1991). 



Recreational : Recreational shrimping has become in- 

 creasingly popular along the Gulf coast in recent years 

 (Christmas and Etzold 1977). Fishermen use small 

 trawls for the most part, but seines, cast nets, and push 

 nets are used as well. Approximately 4,000 mt (heads 

 on) of total shrimp (brown, pink, and white) were taken 

 by recreational shrimpers in 1 979 in Texas and Louisi- 

 ana. Regulations pertaining to licensing and gear type 

 vary among the Gulf states, and catches are limited by 

 location and season of fishing (GMFMC 1981). 



Indicator of Environmental Stress : An experiment con- 

 ducted by Miligan (1983) indicated dredge material 

 free of significant concentrations of heavy metals, 

 pesticides, and waste metabolites was non-toxic to 

 brown shrimp. A second experiment demonstrated 

 better growth for shrimp in rearing ponds treated with 

 dredge material. Ward et al. (1981) determined a 

 concentration of 1 .2 mg/l selenium (96 hours LC50) to 

 be toxic to brown shrimp. Wofford et al. (1981) ob- 

 served the bioaccumulation of phthalate esters (plas- 

 ticizers) and demonstrated brown shrimp were better 

 biodegraders of the ester than oysters. A study of the 

 impact of production water from offshore oil platform 

 found toxic effects occurred in the immediate outfall 

 area on larval brown shrimp (Gallaway 1 980). Popula- 

 tion studies conducted around brine disposal sites 

 found no effects by brine on brown shrimp distribution 

 (Reitsema et al. 1982). Studies in areas treated with 

 aerial insecticides have found varying degrees of shrimp 

 mortality (Christmas and Etzold 1977). Couch (1978) 



55 



