Grass shrimp 



Palaemonetes pugio 

 Adult 



1 cm 



(from Heard 1979) 



Common Name: grass shrimp 



Scientific Name: Palaemonetes pugio 



Other Common Names: daggerblade grass shrimp 



(Williams et al. 1989), glass shrimp 



Classification (Williams et al. 1989) 



Phylum: Arthropoda 



Class: Crustacea 



Order: Decapoda 



Family: Palaemonidae 



There are several Palaemonetes species in U.S. es- 

 tuarine waters, which are known collectively as "grass 

 shrimp" (Camp pers. comm.). For the purposes of this 

 life history summary, "grass shrimp" refers specifically 

 to P. pugio, also known as "daggerblade grass shrimp" 

 (Williams et al. 1 989). Closely related "sister species" 

 include P. vulgaris (marsh grass shrimp), P. interme- 

 dius (brackish grass shrimp), P. kadiakensis (Missis- 

 sippi grass shrimp), and P. paiudosus (riverine grass 

 shrimp) (Hedgepeth 1966, Williams et al. 1989). 



Value: 



Commercial : The grass shrimp has little commercial 

 value. It is available for sale through commercial 

 biological suppliers for use in toxicity testing (Buikema 

 et al. 1 980). It is also sometimes sold in pet stores as 

 live food for aquarium fish (Anderson 1985). 



Recreational : The grass shrimp has little recreational 

 value (Anderson 1 985). Anglers catch grass shrimp to 

 use as live bait for game fish (Huner 1979). In Louisi- 

 ana, preserved grass shrimp are also sold as bait in 

 some fishing shops. 



Indicatorof Environmental Stress : This species is often 

 used for LD50 bioassays for petroleum hydrocarbons 

 because it is usually a common inhabitant of estuarine 

 systems. It has also been used to study toxicity and 

 bioaccumulation of heavy metals, insecticides, petro- 

 leum hydrocarbons, and suspended particulate sedi- 

 ments (Schimmel and Wilson 1977, Anderson 1985, 

 Khan et al. 1 989, Moore 1 989, Rice et al. 1 989, Thorpe 

 and Costlow 1989, Burton and Fisher 1990, Fisherand 

 Clark 1990, Lindsay and Sanders 1990, Rule and 

 Alden 1990, Long et al. 1991). 



Ecological : This grass shrimp and other members of its 

 genus are among the most widely distributed and 

 abundant shallow water benthic macroinvertebrates in 

 Gulf of Mexico estuaries (Odum and Heald 1972, 

 Anderson 1985, Zimmerman et al. 1990). Its abun- 

 dance in estuaries can enable it to have a substantial 

 impact on the dominant energy sources of these sys- 

 tems while channeling significant quantities of that 

 energy through its own population (Welsh 1975). The 

 grass shrimp's importance as a prey item in the diet of 

 many estuarine fishes and as a link in the marine food 

 web makes this a valuable species ecologically. It is 

 also important in estuarine trophic dynamics in speed- 

 ing detrital breakdown by breaking up large detrital 

 particles during its feeding activities. This serves to 

 prevent blockages or accumulations from occurring 

 due to pulses of detrital material into the environment. 

 The grass shrimp also transfers refractory organic 

 matter and detritus to higher trophic levels by repack- 

 aging this material into feces, heterogeneous frag- 

 ments, dissolved organic material, and shrimp biom- 

 ass, thus making this food source more available to a 

 variety of trophic levels (Welsh 1 975, Anderson 1 985, 

 Killametal. 1992). 



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