REFERENGq COB" 

Do Not Remove from the L.ibr7r 

U. S. Fish and Wildlife Sert~ire 

Notional Wetlands Resear-h S?n?r 

FWSIOBS-82111.1 100 Cajun Dome Eot.r!e" .?!*(7 TR EL-82-4 

February 1983 Lafayette, Louisiana 70506 

Species Profiles: Life Histories and 

Environmental Requirements (Gulf of Mexico) 

BROWN SHRIMP 

Waterways Experiment Station 

Fish and Wildlife Service Coastal Engineering Research Center 

U.S. Department of the Interior U.S. Army Corps of Engineers 
FWS/OBS-82/11.1 

TR EL-82-4 

February 1983 

Species Profiles: Life Histories and 

Environmental Requirements (Gulf of Mexico) 

BROWN SHRIMP 

Dennis R. Lassuy 

U.S. Fish and Wildlife Service 

National Coastal Ecosystems Team 

1010 Gause Boulevard 

Slidell, LA 70458 

Project Manager 

Larry Shanks 

Project Officer 

Norman Benson 

National Coastal Ecosys tems Team 

U.S. Fish and Wildlife Service 

1010 Gause Boulevard 

Sl i dell , LA 70458 

This study was conducted 

in cooperation with 

U.S. Army Corps of Engineers 

Waterways Experiment Station and 

Coasta 1 Engi neeri ng Research Center 

Performed for 

National Coastal Ecosystems Team 

Division of Biological Services 

Fish and Wildlife Service 

U.S. Department of the Interior 

Washington, DC 20240 
PREFACE 

This series of profiles about coastal aquatic species of commercial, 

sport, and/or ecological significance is being jointly developed and funded by 

the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service. It 

i s designed to provide coastal managers, engineers, and fie1 d bi 01 ogi sts wi th 

an introduction to the subject species and a synopsis of the information 

necessary to relate expected changes (associated with coastal development) in 

the physicochemical characteri stics of estuaries to changes in these selected 

bi 01 ogical populations. Each profile includes brief sections on taxonomy and 

identification fol lowed by a narrative of 1 i fe hi story, envi ronmental requirements, ecological role, and (where applicable) the fishery of the subject 

species. A three-ring binder is used for this series to facilitate additions 

as new profiles are prepared. 

Suggestions or questions regardi ng thi s report should be di rected to: 

Informati on Transfer Speci a1 i st 

Na ti onal Coastal Ecosystems Team 

U.S. Fish and Wildlife Service 

NASA-Sl idel 1 Computer Complex 

1010 Gause Boul evard 

Slide1 1, LA 70458 

U.S. Army Engineer Waterwzys Experiment Station 

Atten ti on : WESES 

Post Office Box 631 

Vicksburg, MS 39180 

U .S. Army Coastal Engineering Research Center 

Kingman Building 

Fort Belvoir, VA 22060 

Thi s series should be referenced as fol lows: 

U.S. Fish and Wildlife Service. 1983. Species profiles: life histories and 

environmental requirements. U.S. Fish and Wi ldli fe Service, Division of 

Biological Services, FWS/OBS-82/11. U.S. Army Corps of Engineers, TR 

EL-82-4. 

This profile should be cited as follows: 

Lassuy, D. R. 1983. Species profi 1es : 1 i fe hi stories and environmental 

requirements (Gulf of Mexico) -- brown shrimp. U.S. Fish and Wildlife 

Service, Division of Biological Services. FWSIOBS-82/11.1. U.S. Army 

Corps of Engineers, TR EL-82-4. 15 pp. 
Figure 1. Brown shrimp. 

BROWN SHRIMP 

NOMENCLATURE/TAXONOMY/RANGE MORPHOLOGY/IDENTIFICATION AIDS 

Scientific name .... Penaeus aztecus 

I ves 

Common name ....... Brown shrimp 

(Figure 1) 

Class ............ Crustacea 

Order ............ Decapoda 

Family ........... Penaeidae 

Geographic range: Martha ' s Vineyard, 

Massachusetts, through the Gulf of 

Mexico to the Yucatan Peninsula, 

Mexico, except absent along the 

Florida coast between Sanibel and 

Apalachicol a Bay, with maximum 

density along the Texas-Louisiana 

coast (Figure 2). 

The following list of features 

which distinguish brown shrimp from 

white shrimp (P. setiferus) and pink 

shrimp (P. duoraruidapted from 

~erez-~arfanm'). A more deta i 1 ed 

description of the brown shrimp and 

clar.ification of terms may be found in 

that reference or Perez-Farfante 

(1969). 

Brown: adrostral grooves and crests 

long, extending almost to hind 

margin of carapace; postrostral 

crest well-developed as far back 
i GEORGIA 

ORPUS CHRISTI 

0 50 100 150 200 

AGUNA MADRE KILOMETERS 

GULF OF MEXICO 

Figure 2. Distribution of brown shrimp along the shore of the Gulf of Mexico. 
as adrostral grooves ; gastrofrontal crests present; dorso-1 ateral 

grooves on last abdominal section 

we1 1 -defined and broad; ratio of 

height of dorsal keel to width of 

dorso-1 a teral groove usually 1 ess 

than 2.25; dark lateral spot at 

junction of third and fourth abdominal segments usual ly absent. 

White: adrostral grooves and crests 

short, not exceeding anterior ha1 f 

of carapace; postrostral crest 

scarcely defined posteriorly; gastrofrontal crests absent. 

Pink: dorso-1 ateral grooves on 1 ast 

abdominal section we1 1 -defined and 

narrow; ratio of height of dorsal 

keel to width of dorso-lateral 

groove usually 4.5 or more, and 

with sharp lips sometimes nearly 

closed; dark lateral spot at junction of third and fourth abdominal 

segments usually present. 

REASON FOR INCLUSION IN SERIES 

The brown shrimp is prey to a host 

of finfish species and is the major 

contributor to the Gulf of Mexico 

shrimp fishery, the most valuable fishery in the United States. Fertile estuarine nursery areas, so susceptible 

to man's influence, "constitute an 

irreplaceable factor in the survival 

strategy of major shrimp resources, and 

perpetuation of such resources at commercial 1 eve1 s of productivity, apart 

from their continued existence per se, 

will be contingent upon our ability to 

minimize disturbance of the shrimp's 

estuarine habitat" (Kutkuhn 1966). 

LIFE HISTORY 

Spawning and Larvae 

Since the actual spawning event by 

brown shrimp has not been observed in 

situ, statements regarding the site and 

time of spawning are based upon the 

capture of eggs, larvae, or spent 

adults. Spawning is reported to occur 

primarily in offshore waters deeper 

than 18 m (60 ft) (Christmas et a1 . 1966), possibly as deep as 137 m 

(450 ft) or more (Kutkuhn 1966). The 

major spawning season extends from 

September through May, but may occur 

throughout the year, particul arly at 

depths greater than 46 m (150 ft) 

(Pearson 1939; Renfro and Brusher 

1963). While a single spawning peak, 

February to Warch, has been reported 

along the southeastern At1 antic coast 

(Will iams 1955; Joyce 1965), several 

studies have suggested two peaks, 

September through November and April to 

May, in the northern Gulf of Mexico 

(Renfro and Brusher 1963; St. Amant 

et al. 1966). The significance of 

separate spawning peaks will be discussed in another section (see The 

Fishery section). Spawning is reported 

by Cook (1965; cited by Perez-Farfante 

1969) to take place at night. 

External ly fertil ized, semibuoyant eggs are released into the water 

column and hatch within 24 hours into 

the first naupliar sta e (Kutkuhn 1966; 

St. Amant et al. 19661. Brown shrimp 

larvae, as with other penaeids, pass 

through five naupl iar, three protozoeal , and three mysis stages over a 10- 

to 25-day period before transforming 

into postlarvae (Pearson 1939; Anderson 

et al. 1949; Perez-Farfante 1969). It 

has been suggested that these early 

stages reauire the more constant environment of the open ocean (Gulf Coast 

Research Laboratory 1976). 

Pos tl arvae 

Peak recruitment of post1 arval 

brown shrimp to the estuaries may occur 

months after the peak in spawning (Van 

Lopik et a1 . 1979). While most authors 

refer to all stages from hatching to 

estuarine recrui tnent as planktonic 

(pel agic) , Temp1 e and Fisher (1967) 

suggested that o ~erwinteri ng brown 
shrimp in the Gulf of Mexico may burrow 

into the bottom and "await the advent 

of warmer temperatures" before entering 

the estuaries. There is laboratory 

evidence of this burrowing behavior in 

postl arval brown shrimp at temperatures 

below 18°C (64°F) (Aldrich et al. 

1967). St. Arnant et a1 . (1966) stated 

that brown shrimp postl arvae "winterover in a state of reduced activity as 

inshore water temperatures decl ine," 

but did not specifically mention burrowing. 

Estuarine recruitment of postlarval brown shrimp in the northern Gulf 

of Mexico apparently spans all months 

of the year as White and Boudreaux 

(1977) reported having taken postlarvae 

from January through June and St. Arnant 

et al. (1966) stated that "ingress" 

(recruitment) occurred from February 

through December. February through 

April is the most commonly cited period 

of peak recruitment (Baxter and Renfro 

1967; Gaidry and White 1973; White and 

Boudreaux 1977). Peak recrui bent to 

Pamlico Sound, North Carolina, is reported to occur in April to May (Hunt 

et al. 1980). 

Postlarvae are reported to move 

into the estuaries primarily at niaht 

on incoming tides, and to take on a 

demersal habit as they move to shallow, 

soft-bottom areas of the estuarine nursery grounds (Christmas et al. 1966; 

White and Boudreaux 1977). Transformation to the juvenile stage occurs within 4 to 6 weeks after entering the 

estuary (Perez-Farfante 1969). Growth 

and survival during the postl arval and 

early juvenile stages are thought to be 

critical factors affecting the harvestable adult population size (see The 

Fishery section). 

Emigration 

Young brown shrimp remain in shallow estuarine areas near the marshwater, mangrove-water interface or in 

seagrass beds which provide both predator protection and feedi nq habitat. 

As they reach 60 to 70 mmt' they move 

away from these interface areas into 

deeper, open water "staging areas" and 

at 90 to 110 m begin their gulfward 

migration (Gaidry and White 1973; Van 

Lopik et al. 1979). White and Boudreaux (1977) found emigrants as small 

as 50 mn in western Louisiana that were 

apparently prompted to leave the estuaries early by a strong freshwater input 

which had reduced nursery area sal inities to 3 to 4 ppt. St. Amant et al. 

(1966) suggested an inverse re1 ationship between population density on the 

nursery ~rounds and the size of migrating adolescent shrimp, possibly as a 

resul t of crowding or competition for 

food. 

The period of May through August, 

particularly June to July, is often 

cited as peak months of emigration 

(Copeland 1965; St. Amant et al. 1966; 

Gaidry and White 1973; White and Boudreaux 1977). The combined effect of 

increased tidal height and current 

velocities associated with full moons 

during these months has been suggested 

as a stimulus to emigrate (Copeland 

1965). While C1 ark and Caillouet 

(1975) reported 1 i ttle day/night difference, Blackmon (1974) reported that 

the highest percentage of emigration 

occurs at twilight. Blackmon also 

reported a die1 variation in use of the 

water col umn during migration, with 

peak densities near the bottom in daylight hours, midwater at twilight, and 

near the surface at night. While fishing during emigration is limited in 

some States, a major portion of the 

fishery in Louisiana occurs during this 

period. The minimum size at maturity 

of 140 mm (Renfro 1964; Van Lopik 

et al. 1979) is apparently reached 

during migration to offshore waters. 

Adults 

After exiting the estuaries, brown 

shrimp move rapidly to about 18 m I 

25.4 mm = 1 inch. I 
(60 ft) and then slowly make their way 

to spawning depths of 46 to 91 m (150 

to 300 ft) (St. Amant et al. 1966). 

Van Lopi k et a1 . (1979) reported that 

the largest catches up to August were 

from 20 to 37 m (66 to 120 ft) deep at 

a size of 30 to 40 tailsllb (18 to 24 g 

whole wet wtlshrimp) and by December 

from 48 to 55 m (156 to 180 ft) deep at 

a size of 15 to 20 tailsllb (37 to 49 g 

who1 e wet wtlshrimp) . Several studies 

have suggested that offshore adult populations in the northern Gulf of Mexico 

tend to move westward with the prevailing currents (St. hant et al. 1966; 

Gaidry and White 1973; Barrett and 

Ralph 1977). That the Mississippi 

River is not an absolute barrier to 

such westward movement by shrimp migrating from estuaries east of the delta 

was shown by the tagging studies of 

Kl ima and Benigno (1965). Most adults 

are assumed to spawn a single time (St. 

Amant et al. 1966), and apparently die 

soon after spawning, thus ending essential ly an annual 1 ife cycle. Results 

of more recent unpubl ished tagging 

studies , however, i nd i ca te that some 

may reach an age of 2.5 years or more. 

GROWTH 

Most pub1 ished studies of growth 

in the brown shrimp have addressed the 

post1 arval and juvenile stages. Since 

it is growth during these stages that 

has served as a basis for harvest prediction, this emphasis is understandah1 e. These estuarine and nearshore 

stages are a1 so re1 atively accessible 

as study subjects. This section, therefore, a1 so will be 1 imi ted to the review of postlarval and juvenile growth 

studies. As in many fisheries, growth 

is usually reported as change in length 

(total length in all cases cited here) 

over time. 

Laboratory growth studies of postlarvae and juveniles have generally not 

been able to achieve the same growth 

rates as have been observed in situ. 

These studies have typically shown mean 

growth rates of less than 1 m/day 

regardless of temperature, salinity, or 

type of food source (Pearson 193g2; 

Ogle and Price 1976), a1 though in one 

study, Zein-Eldin and Aldrich (1965) 

were able to attain a 1.4 mmlday growth 

rate in brown shrimp postlarvae. 

Field studies of postlarval and 

juvenile brown shrimp have usual ly 

demonstrated a mean growth rate of 1.0 

to 1.5 mmlday during the primary growth 

season of late spring and early summer 

(Will iams 1955; St. Amant et a1 . 1966). 

Maximum growth rate, at least in isolated cases, has been reported to be as 

high as 3.3 mm/day (Ringo 1965). 

Growth rates are usually much lower (0 

to 0.5 mm/ day) at winter temperatures 

of less than 16PC or 61°F (Ringo 1965; 

St. Amant et al. 1966) and can be quite 

low even during usual peak growth 

months if temperature and salinity conditions are poor. For example, unusual ly cool water temperatures and 1 ow 

sal i n i t y i n western Louisiana nursery 

areas resulted in an estimated mean 

growth rate of only 0.7 mmlday from 

late April through late May (White 

1975; White and Boudreaux 1977). A 

more extensive review of the effects of 

temperature and salinity on growth will 

be presented in the Temperature and 

Sal inity sections. An a1 ternative 

explanation for observed variation in 

growth rate will also be discussed in 

The Fishery section. 

The foll owirlg exponential function 

(~=aLb) describes the 1 ength-weight 

re1 ationship presented hy McCoy (1968) 

for brown shrimp, of 65 to 165 mm, from 

North Carol ina: 

W = 8.12 x 10'~ L 3.02 

where: W = whole wet wt (g) 

L = total length (mm) 

2 

Pearson's reference to Penaeus brasiliensis was probably P. aztecus. 
A list of the a and b parameters 

of other 1 ength-weigl'it studies appears 

in Table 1. As pointed out by McCoy 

(1968), insignificant difference between his experimental ly determined b 

value (3.02) and the theoretical "cube 

law" value of 3.0 indicates isometric 

growth within the range of sizes sampled. Mark-recapture data from this 

same study yielded the following von 

Bertal an.ffy- type growth equation : 

L = 177.7 (1-e -0.073T 

where: L = total length (mm) 

1 

T = age (weeks) 

Temperature and sal ini ty during 

the study varied between 23' and 28OC 

(73' and 82OF) and 17 and 19 ppt, respectively. 

THE FISHERY 

An extensive review of the Gulf of 

Mexico shrimp fishery, its biological, 

socioeconomic and legal basis, and management is provided by Van Lopik et a1 . (1979). Much of this section has been 

excerpted from their review. The Gulf 

of Mexico shrimp fishery is the most 

valuable commercial fishery in the 

United States, totaling 129,366,469 1b 

(58,680 mt)4 in 1 andings valued at 

$302,077,000 in 1980 (National Marine 

Fisheries Service 1981). Brown shrimp 

are the major contributor to this 

Table 1. Literature values for a and b growth parameters 

for brown shrimp (adapted from Van Lopik et al. 1979). 

Total length (TL) to total weight Carapace length (CL) to total weight* 

- a - b Size range (mmTL) a - b Size range (mmCL) Source 

Ma1 e 11.61 2.91 45-204 Fontaine 8 Neal 

(1971) 

Femal e 9.53 2.94 55-240 Fontaine & Neal 

(1971) 

Combined 10.52 2.94 45-240 Fontaine 8 Neal 

(1971) 

Ma1 e 0.00082 2.94 10-42 McCoy (1972) 

Femal e 0.00113 2.84 10-42 McCoy (1972) 

*The CL to TL conversion for North Carolina shrimp as derived by McCoy (1972) was: 

Male: TL = 3.50 + 4.16 CL 

Female: TL = 10.50 + 3.83 CL 

3 177.7 = L (mean asymptotic length); 

0.073 = k (Brody growth coefficient); 

t (hypothetical age at which length 

would equal zero had growth always 

been the same as the data indicate) Heads-off wet weight (heads-off wt x 

was assumed to be zero. 1.61 = heads-on wt). 
mu1 tispeci es fishery, having averaged 

59% of the total landings by weight and 

66% by number from 1963 to 1375 (Van 

Lopik et al. 1979). 

Brown shrimp fishing activities 

are concentrated within the 55-m 

(180-ft) contour, but extend to at 

least 90 m (300 ft). Fishing begins in 

May, peaks in June and July during 

their seaward migration, and continues 

through November in offshore waters. 

The majority of the harvest is destined 

for human consumption. There is also a 

bait-shrimp fishery in some areas of 

the Gulf of Mexico (Christmas et al. 

1976). 

Regulation of the shrimp industry 

is largely carried out by the coastal 

States and varies from State to State. 

Several States base their predictions 

upon a combination of pos tlarval abundance and environmental conditions 

(primarily temperature and salinity) in 

the estuaries during spring recrui toent 

and growth months (Barrett and Gillespie 1973; Van Lopik et al. 1979; 

Hunt et al. 1980). Such methods have 

met with some predictive success within 

a given year, but prediction of yearto-year variation remains unreliable. 

Two common assumptions seem to 

drive all current brown shrimp management in the U.S. Gulf of Mexico. First, 

since no one has yet demonstrated a 

good stock-recrui tment relationship, 

recruit overfishing is assumed to be 

essentially impossible, given present 

fishing technology. Second, a single, 

widespread stock throughout the Gulf of 

Mexico has been assumed. The assumption 

of stock unity, if untrue, could drastically affect present understanding of 

the variation in growth and mortality 

estimates and would require reconsideration of the possible effects of fishing pressure on stock condition. 

Recent5 thought (Gal laway and 

Gazey, ms. in prep.) is that two 

temporal ly segregated stocks, each producing cohorts with different growth 

characteristics, may exist. The separate spawning peaks mentioned earl ier 

are interpreted to represent two separate spawning stocks. By this scenario, 

the offspring of the fall spawning 

stock develop to the postlarval stage, 

overwinter buried in nearshore sediments, and then emerge and maintain a 

relatively slow, even growth through 

the spring and summer. The cohort 

produced by the spring spawning stock 

develops and grows rapidly. Recruitment of the two cohorts to the fishery 

may nearly coincide, with the result 

that growth sampl ing might easily be 

misinterpreted as representative of a 

single, widely variable stock. The 

outlined scenario is, as yet, largely 

speculative but seems a plausible 

explanation of several areas poorly 

known in brown shrimp biology. 

In light of the above scenario, 

the relative value of various es timates 

of mortality will not be discussed 

beyond the following brief listing: 

Weekly Z6s7 Source 

0.27 Klima (1964) 

0.99-1.24 McCoy (1968) 

0.57 McCoy (1972) 

0.26-0.46 Purvis & McCoy 

(1974) 

0.31-0.76 Laney & Copeland 

(1981) 

5 LGL Ecological Research Associates, 

Bryan, Texas. 

6 Adapted from Laney and Copeland 

(1981). 

/ Z = instantaneous total mortality coefficient. 
For discussion of the effects of 

the brown shrimp fishery on other 

aquatic resources (e.g., other shrimp, 

demersal finfish), see Van Lopik et al. 

(1979) and Gulf of Mexico Fishery 

Management Council (GMFMC 1981). 

ECOLOGICAL ROLE 

All actively feeding stages of the 

brown shrimp are omnivorous. Larvae 

are reported by Van Lopik et al. (1979) 

to feed in the water column on both 

phyto- and zooplankton. After moving 

into estuarine nursery areas, postlarvae become demersal and feed at the 

vegetation (marsh grass, mangrove, or 

seagrass) -water interface. Jones (1973, 

cited by White and Boudreaux 1977) reported that postlarvae from 25 to 44 mm 

indiscriminately ingested the top 1 ayer 

of sediment, which contained detritus 

(comprised primarily of Spartina), 

a1 gae, and microorganisms, and termed 

them "omivorous encounter feeders. " 

In this same study, Jones found 

that 45- to 65-mm juveniles "selected 

the organic fraction of the sediment" 

and termed them "opportunistic omnivores." Those over 65 mm began to 

disperse to deeper waters and became 

more predaceous, but occasional 1 y ingested both detritus and algae and 

were termed "omnivorous predators. " 

Prey- i tems included polychaetes, amphipods, nematodes, chi ronomid larvae, and 

ostracods. Based on 1 aboratory feedin 

experiments, 0gl e and Price (19763 

suggested that mysids may also serve 

as food for juveniles in northeastern 

gulf coast estuaries. Darnel1 (1958) 

described feeding habits for 91- to 

142-m brown shrimp from Lake Pontchartrain, Louisiana, similar to the findings of Jones (1973) for brown shrimp 

over 65 mm. 

Several species of Penaeus are 

prey to a host of fish spemunter 

1945; Darnel1 1958, 1961) and larger 

crustaceans (Hunt et al. 1980). Enormous numbers of many of the fish species are captured and discarded as 

by-catch by commercial shrimp trawlers 

(GMFMC 1981). No quantitative studies 

of the role of brown shrimp in estuarine trophic dynamics were found in the 

1 i tera ture. 

It has been suggested that temporal and spatial shifts which represent 

the major differences between the three 

major commercial shrimp species (brown, 

white, and pink) may have evolved as a 

mechanism to avoid direct competition 

(Gunter and McGraw 1973; Van Lopik 

et a1 . 1979). 

ENVIRONMENTAL RECUIREMENTS 

Temperature 

Brown shrimp have been collected 

at water temperatures as low as 2°C 

(36"F), but few are normally taken 

below 10°C (50°F), with highest catches 

taken above 20°C (68°F) (Swingle 1971; 

Christmas and Langl ey 1973). Temperatures of 4.4"C (40°F) or less may cause 

mass narcosis and mortality (Gunter 

and Hi1 debrand 1951). Kutkuhn (1966) 

reported that shrimp taken in waters of 

greater than 32.2"C (90°F) "are usually 

fl acid and highly sensitive to stresses 

induced by handling." This is consistent with the observations of ZeinEldin and Aldrich (1965) that growth 

and survival were both reduced above 

32.2"C (90°F) with a suggested maximum 

to1 erable temperature for postl arvae of 

just over 35°C (95°F). 

Optimum temperature for 1 arval 

development has been reported as 28" to 

30°C (82" to 86°F) (Cook 1965). Estuarine recruitment of postl arval penaeids 

was recorded by Christmas et a1 . (1966) 

only at temperatures of greater than 

12°C (54°F). Post1 arval growth was 

reported by Zein-El din and A1 drich 

(1965) to begin between 11" and 18°C 
(52" and 64"F), increase rapidly between 18" and 25°C (64" and 77"F), and 

peak at 32°C (90°F). No growth was seen 

by St. Amant et al. (1965) when water 

temperature dropped be1 ow 16°C (61°F). 

Venkataramaiah et al. (1972) found maximum growth, survival , and efficiency 

of food utilization at 26°C (79°F) (vs. 

21" and 31°C [70° and 88"FI). They a1 so 

found that with a rapid change in temperature (direct transfer from 26" to 

21°C [79" to 70°F]), postlarvae and 

juveniles became inactive, often convulsed, and in some cases developed 

muscul ar paralysis. Direct transfers 

between salinities varying from 8.5 to 

34 ppt had no adverse effects. 

Salinity 

Post1 arval brown shrimp have been 

captured in sal ini ties from essential ly 

fresh (Swingle 1971) to 69 ppt (Simmons 

1957), but few have been taken in waters of less than 5 ppt (Loesch 1976; 

Christmas and Langl ey 1973). Venkataramaiah et a1 . (1972) successfully 

reared brown shrimp at 1.7 ppt, but had 

no survival at 0.5 ppt. These findings 

coincide closely with those of Gunter 

et a1 . (1964), who suggested a minimum 

salinity of 0.8 ppt. Tagging studies 

by White and Boudreaux (1977) indicated 

that heavy freshwater introduction into 

marsh nursery areas may cause juveniles 

to migrate to deeper water or laterally 

towards offshore shallows (i e., to 

higher sal inity habitats) earl ier than 

under normal hydrographic conditions . White and Boudreaux also discussed the 

fishery imp1 ications of such early 

migration. The field observations of 

Barrett and Gillespie (1973) led them 

to suggest a salinity optimum of 19 ppt 

for brown shrimp. 

Temperature-Sal ini ty Interaction 

A wide range of temperaturesalinity combinations seems to be 

to1 erated by brown shrimp, with interactive effects becoming most evident at 

the extremes of the respective to1 erance ranges. Venkataramaiah et a1 . (1972) observed highest growth rates 

and survival at temperature-sal ini ty 

combinations of 26°C or 79°F (vs. 21" 

and 31°C [70° and 88"FI) and 8.5 or 

17 ppt (vs. 25.5 and 34 ppt). A wider 

range of salinities was tolerated at 

26°C (79°F) than at the higher or lower 

temperatures. An increased range of 

sal ini ty to1 erance at temperatures 

above 21°C is consistent with the findings of others (Copeland and Bechtel 

1974 ; Loesch 1976). A1 though i nconsistent with the findings of Venkataramaiah et a1 . (1372), a similar increase 

in the range of temperature tolerance 

at higher salinities has also been 

observed (Zein-El din and A1 drich 1965). 

The combination of low salinity and low 

temperature has repeatedly been shown 

to be damaging to brown shrimp (ZeinEldin and Aldrich 1965; St. Amant 

et a1 . 1966; Venkataramaiah et al. 

1972). 

Van Lopi k et a1 . (1979) summarized 

the relation of brown shrimp harvest to 

temperature and sal ini ty by stating 

that a "good brown shrimp year" can be 

expected after a warm, relatively high 

sal ini ty spring in coastal nursery 

areas. Mean temperature and sal ini ty 

threshold values (i.., above which 

harvest was good and below which harvest was poor) of 20°C (68°F) and 

10 ppt during the primary recruitment 

and growth period were suggested by 

Hunt et al. (1980) for brown shrimp 

a1 ong the North Carol i na coast. These 

same values appear to be consistent 

with data from Louisiana resented by 

Barrett and Ralph (1977y in their 

figures 5 and 6. 

Substrate and System Features 

Fie1 d observations have repeatedly suggested that post1 arval brown 

shrimp recruit in greatest abundance 

to soft bottom, shallow areas of estuaries in or near marshes or seagrass 
beds (Christmas et al. 1966). Williams 

(1958) experimental ly demonstrated a 

significant preference by settling 

postlarvae for softer, muddier substrates with decaying vegetation. Apparently, field-observed recruitment 

patterns, in this case, accurately 

reflect a specific preference rather 

than a misinterpretation of the result 

of several related processes (e. g., 

random recrui tment combined with differential mortal i ty rates between 

available habitats to give the resultant impression of apparent habitat 

selection). If this is indeed the 

case, the maintenance of such interface 

habitats is critical in the species' 

life history and to the continuity of 

normal devel opment . Possible reasons 

for this association with vegetationwater interfaces have been discussed in 

previous sections. Adults are taken in 

, greatest abundance on mud or silt bottoms, but are also taken on mud-sand, 

sand, or she1 1 bottoms (Perez-Farfante 

1969; Van Lopik et al. 1979). 

The importance of the surrounding 

vegetational system has been emphasized 

by Turner (1977), who found total 

shrimp yield to be directly proportional to marsh acreage in Louisiana, 

and to acreage of marsh plus seagrass 

in the northeastern Gulf of Mexico. He 

found no significant relationship of 

shrimp yield with water surface area, 

mean water depth, or volume of the 

estuaries investigated. Experimental 

perturbations (blocking off wetlands 

with levees and bulkheads) have been 

shown to decrease postlarval and adult 

densities (Mock 1967). Van Lopik 

et al. (1979) provided the following 

list of "alterations" which remove area 

suitable as shrimp habitat: 

1. Impoundments that prevent 

influx of shrimp 

2. Bul kheading that removes 

the critical marsh-water or 

mangrove-water interface 

3. A1 terations in freshwater 

discharge that create an 

unfavorable salinity regime 

4. Stimulation of saltwater intrus ion 

5. Continuing encroachment of 

pol luted waters on the estuari ne waters 

Other Environmental Requirements 

The following quote from Kutkuhn 

(1966) with regard to turbidity is 

apparently sti 11 appl icable today: "No 

successful studies have been conducted 

to relate turbidity with shrimp occurrence and density, but gross observation suggests that those bays which are 

consistently the most roi ly general ly 

harbor per unit area and, in season, 

the largest concentrations of young 

shrimp. Whether this reflects more the 

nutritive potential of the detrital 

material in suspension, or protection 

of transient shrimp from predation by 

fishes, birds, and other animals remains a moot question." Answers to 

questions on the effects of increased 

turbidity may lie largely in understanding its effects upon, and the 

relative importance of phytoplankton 

based versus rooted vegetati on/detrital based productivity and remineral - 

ization. The former would seem to be 

more directly affected by increased 

turbidity. For a review of questions 

re1 ati ng to estuarine productivity see 

Nixon (1981). 

Trent et al. (1976) attributed 

decreased brown shrimp abundance at 

altered marsh sites in West Bay, Texas, 

to low dissolved oxygen conditions 

(below 3.0 ml/l, from May 20 to August 

12). Detailed laboratory studies of 

oxygen consu~ption by brown shrimp and 

the interaction of oxygen consumption 

with temperature, sal ini ty, and body 

size are presented by Bishop et al. 

(1980). 
Couch (1979) reviewed the litera- both among them and with environmental 

ture on the effects of various pol- conditions for several penaeid shrimps. 

lutants (petroleum and non-petroleum Information on their known diseases 

organic chemicals, heavy metals), and parasites is also reviewed. 

biological agents, the interactions 
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Am. 48:80. 

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

King. 1949. The shrimp fishery 

of the Southern United States. 

Comm. Fish. Rev. 11:l-7. 

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

1973. Primary factors which influence commercial shrimp production 

in coastal Louisiana. La. Dep. 

Wildl. Fish. Tech. Bull. 9. 

Barrett, B.B., and E.J. Ralph. 1977. 

1977 environmental conditions 

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in coastal Louisiana along with 

shrimp catch data for the Gulf 

of Mexico. La. Dep. Wildl. Fish. 

Tech. Bull. 26. 

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

Seasonal occurrence and size 

distribution of postlarval brown 

and white shrimp near Gal veston, 

Texas, with notes on species 

identification. Fish. Bull., U.S. 

66: 149-158. 

Bishop, J.M., J.G. Gosselink, and J.H. 

Stone. 1980. Oxygen consumption 

and hemolymph osmolal i ty of brown 

shrimp, Penaeus aztecus. Fish. 

Bull., U.S. 78:741-757. 

Louisiana State University, Baton 

Rouge. 

Christmas, J.Y., and W. Langley. 1973. 

Estuarine invertebrates, Mississippi. Pages 255-317 J.Y. 

Christmas, ed. Cooperative Gulf 

of Mexico estuarine inventory and 

study, Mississippi. Gulf Coast Research Laboratory, Ocean Springs, 

Miss. 

Christmas, J.Y., G. Gunter, and P. 

Musgrave. 1966. Studies on 

annual abundance of postlarval 

penaeid shrirnp in the estuarine 

waters of Mississippi as related 

to subsequent commercial catches. 

Gulf Res. Rep. 2(2) :117-212. 

Christmas, J.Y., W. Langley, and T. 

Van Gevender. 1976. Investigations of commercially important 

penaeid shrimp in Mississippi. 

Gulf Coast Research Laboratory, 

Ocean Springs, Miss. 

Clark, S.H., and C.W. Caillouet. 1975. 

Die1 fluctuations in catches of 

juvenile brown shrimp and white 

shrimp in a Texas estuarine 

canal. Contrib. Mar. Sci. 19: 

119-124. 

Cook, H.L. 1965. Rearing and identifying shrimp larvae. U.S. 

Fish Wildl. Serv. Circ. 230: 

11- 13. 

Blackmon, J.H., Jr. 1974. Observation Copeland, B.J. 1965. Fauna of the 

on the migration of the brown Aransas Pass Inlet, Texas. I. 

shrimp, Penaeus aztecus, through Emigration as shown by tide trap 

a tidal pass in the Caminada Bay, collections. Publ. Inst. Mar. 

Louisiana area. M.S. Thesis. Sci. Univ. Tex. 10:9-21. 
Copeland, B.J., and T.J. Bechtel. 1974. 

Some environmental limits of six 

gulf coast estuarine organisms . Contrib. Mar. Sci. 18: 169-204. 

Couch, J.A. 1979. Diseases, parasites, 

and toxic responses of commercial 

penaeid shrimps of the Gulf of 

Mexico and South Atlantic coasts 

of North America. Fish. Bull., 

U.S. 76:l-44. 

Darnell, R.M. 1958. Food habits of 

fishes and larger invertebrates 

of Lake Pontchartrain, Louisiana, 

an estuarine community. Publ. 

Inst. Mar. Sci. Univ. Tex. 5:535- 

416. 

Darnell, R.M. 1961. Trophic spectrum 

of an estuarine community, based 

on studies of Lake Pontchartrain, 

Louisiana. Ecology 42(3) :353-568. 

Fontaine, C.T., and R.A. Neal. 1971. 

Length-weight relations for three 

comnercially important penaeid 

shrimp of the Gulf of Mexico. 

Trans. Am. Fish. Soc. 100:584-586. 

Gaidry, W.J., 111, and C.J. White. 

1973. Investigations of commercial ly important penaeid shrimp 

in Louisiana estuaries. La. 

Wildl. Fish. Comm. Tech. Bull. 8. 

Gulf Coast Research Laboratory. 1976. 

'The biology (life cycle) of 

penaeid shrimp in Mississippi 

waters. Gulf Coast Research 

Laboratory, Marine Education 

Center. Marine Educational Leaflet 8. 

Gulf of Mexico Fishery Management Council (GMFMC). 1981. Draft fishery 

management plan environmental 

impact statement and regulatory 

analysis for groundfish in the 

Gulf of Mexico. Gulf of Kexico 

Fishery Management Counci 1, Tampa, 

Fl a. 

Gunter, G. 1945. Studies on marine 

fishes of Texas. Publ. Inst. Mar. 

Sci. Univ. Tex. 1:l-190. 

Gunter, G., and H.H. Hildebrand. 1951. 

Destruction of fishes and other 

organisms on the south Texas coast 

by the cold wave of January 28- 

February 3, 1951. Ecology 32(4): 

731-736. 

Gunter, G., and K. McGraw. 1973. Some 

analyses of twentieth century 

landing statistics of marine 

shrimp of the South Atlantic and 

Gulf States of the United States. 

Gulf Res. Rep. 4(2):191-204. 

Gunter, G., J.Y. Christmas, and R. 

Ki 1 lebrew. 1964. Some relations 

of salinity to population distributions of motile estuarine organisms with special reference to 

penaeid shrimp. Ecology 45(1): 

181-185. 

Hunt, J.H., R.J. Carroll, V. Chinchilli, and D. Frankenberg. 1980. 

Relationship between environmental 

factors and brown shrimp production in Pamlico Sound, North 

Carolina. N.C. Dep. Nat. Resour. 

and Commer. Dev., Div. Mar. Fish., 

Spec. Sci. Rep. 33. 

Jones, R.R., Jr. 1973. Utilization of 

Louisiana estuarine sediments as a 

source of nutrition for the brown 

shrimp, Penaeus aztecus. Ph. D. 

Dissertation. Louisiana State 

University, Baton Rouge. 

Joyce, E.A., Jr. 1965. The commercial 

shrimps of the northeast coast of 

Florida. Fla. Board Conserv. Mar. 

Lab. Prof. Pap. Ser. 6. 

Kl ima, E. F. 1964. Mark-recapture 

experiments with brown and white 

shrimp in the northern Gulf of 

Mexico. Proc. Gulf Caribb. Fish. 

Inst. 17:52-64. 
Klima, E.F., and J.A. Benigno. 1965. 

Mark-recapture experiments. U .S. 

Fish Wildl. Serv. Circ. 230. 

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resources. Pages 16-36 in R.F. 

Smith, A.H. Swartz, and W.H. 

Massmann, eds. A symposium on 

estuarine fisheries. Am. Fish. 

Soc. Spec. Publ. 3. 

Laney, R.W., and B.J. Copeland. 1981. 

Population dynamics of penaeid 

shrimp in two North Carolina tidal 

creeks. Rep. 81/1, Carolina Power 

& Light Co., Raleigh, N.C. 

Loesch, H.C. 1976. Penaeid shrimp 

distributions in Mobile Bay, 

Alabama including low salinity 

records. Gulf Res. Rep. 5(2): 

43-45. 

McCoy, E.G. 1968. Migration, growth 

and mortal i ty of North Carol ina 

pink and brown penaeid shrimps. 

N.C. Dep. Conserv. Dev., Div. 

Commer. Sports Fish., Spec. Sci. 

Rep. 5. 

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Resour., Div. Commer. Sports 

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Mock, C.R. 1967. Natural and altered 

estuarine habitats of penaeid 

shrimp. Proc. Gulf Caribb. Fish. 

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31-57 in R.D. Cross and D.L. 

Williams, eds. Proceedings of the 

national symposium on freshwater 

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and Wildlife Service, Office of 

Biological Services. FWS/OBS 

81/04. 

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of the shrimp, Penaeus aztecus, 

fed a diet of live tqysidmtacea: Mysidacea). Gulf Res. 

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histories of some American Penaeidae, chiefly the commercial 

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Atlantic shrimps of the qenus 

Penaeus. ~ish. Bull., -u.s. 

67061-591. 

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species identification sheets for 

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Atlantic (Fishing Area 31), Vol. 

VI. FAO, Rome. 

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stages of Gulf of Mexico brown 

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183: 94-98. 

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Wildl. Serv. Circ. 230:13-17. 

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U.S. Fish Wildl. Serv. Circ. 

230: 68-70. 

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Bull. Mar. Sci. Gulf Caribb. 18: 

1- 16. 

St. Amant, L.S., M.J. Lindner, G.W. 

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Gulf of Mexico estuarine inventory. Ala. Mar. Resour. Bull. 5. 

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Seasonal distribution and relative 

abundance of planktonic-stage 

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river flood waters on brown shrimp 

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22. 

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129(1) : 199-216. 
10272 -101 

. . I I 

4. Title and Subtitle 

Species Profi les: Life Histories and Environmental Requirements 

(Gulf of Mexico) -- Brown Shrimp 

REPORT DOCUMENTATION 3. Recipient's Accession NO. 

PAGE 

5. Report Date 

February 1983 

6. 

-. 

7. Author(s) 

Dennis R. Lassuy 

9. Performing Organization Name and Address 

U.S. Fish and Wild1 ife Service 

Division of Biological Services 

National Coastal Ecosystems Team 

1010 Gause Boulevard 

S1 idel 1 . LA 70458 

16. Abstract (Limit: 2W words) 

Species profiles are 1 iterature summaries on the taxonomy, morphology, range, 1 i fe history, 

and environmental requirements of coastal aquatic species. They are designed to assist in 

environmental impact assessment. The brown shrimp, Penaeus aztecus, is the major species 

in the Gulf of Mexico shrimp fishery, the most valu-302 million in 1980) commercial 

fishery in the United States. It is heavily preyed on by many fishes. Spawning occurs 

offshore from about September to May and most postlarvae move into estuaries from February 

through April. Within the estuary they occupy shallow water near marshes with soft 

substrate. Juveniles emigrate from estuaries to offshore areas from May through August. 

They grow as fast as 3.3 mm per day in estuaries. Adults concentrate around the 55-m contou 

offshore. Postlarval and juvenile shrimp are normal 1 y taken in water temperatures above 

10°C and rapid growth occurs above 18'~. Few shrimp are collected below 5 ppt salinity. 

Brown shrimp are benthic feeders and prefer soft substrates. High populatiorls are 

associated with coastal marshes. 

8. Performing Orgpnlzation Rept. No. 

10. Project/Task/Work Unit No. 

11. Contract(C) or Grant(G) NO. 

(c) 

(G ) 

12. S~nsoring OrEanization Name and Address 

National Coastal Ecosystems Team U.S. Army Corps of Engineers 

Fish and Wildlife Service Waterways Experiment Statior 

US Department of the Interior P.O. Box 631 

Washington, DC 20240 Vicksburg, MS 39180 -- 

17. Document Analysis a. Descriptors 

'. 

FWS/OBS-82/11. l* 

13. Type of Report & ~eriodxvered 

14. 

Estuaries 

Fishes 

Growth 

Feeding 

2. 

IS. Supplementary Notes 

*U.S. Army Corps of Engineers report No. TR EL-82-4. 

Unl imi ted 

b. Identifien/Opcn-Ended Terms 

Brown Shrimp Life history 

Penaeus aztecus Spawning 

Salinity requirements 

Temperature requirements 

~abi tat requirements c. COSATI Field/Croup 

~ 20. Security Class Unclassified CThis Page) /A-

22. Price 

Unclassified ee ANSI-239.18) OPTIONAL FORM 272 (4-77 

(Formerly NTIS-35) 

Department of Commerce 

16. Availability Statement 19. Security Class CThis Report) 21. No. of Pases 
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