The Shrimp and the Shrimp Fishery of the Southern United States
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THE SHRIMP AND THE SHRIMP FISHERY OF THE SOUTHERN UNITED STATES UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE BUREAU OF COMMERCIAL FISHERIES Fishery Leaflet 589 THE SHRIMP AND THE SHRIMP FISHERY OF TH E SOUTHERN UNITED STATES By WILLIAM W . ANDERSON Fishery Biologist (Research) Bureau o f Commercial Fisheries Biological Laboratory Brunswick, Georgia 'he s h r imp f i s hery of t he United States i s shrimp valued at about $69 million to t he tered primar ily in the e ight South Atlant ic fishermen we r e taken in 1963. It ranks first Gulf States (No r t h Carolina to Texas), in value of all t he fisheries of the United re about 2 16 m illion pounds of heads -on States. Figure l.--Gulf of Mexico medium sized shrimp trawler. ~h ree s p e cies of shrimp, all members of Atlantic production (la r gely in Nort h Caro fam ily (Penaeidae), are of t he greatest lina). nme-rc i a l im port ance. Separation of the Two other s h r imps are of minor importance. ch by species in rec ent years indicates The sea bob (Xiphopeneus kroye ri), is taken t t he common or white shrimp (Penaeus mainly in Louisiana and compr ises only about iferus) i s no longer t he dom inant species 1 percent of the catch . Exploratory fishing the c atches; in 1963 it contr ibuted about 36 by the U.S. Fish and Wildlife Service, Bureau 'cent of t h e catch in the G ulf of Mexico of Commercial Fisheries, has indicated com I about 4 8 pe rcent along the South Atlantic, mercial concentrations of another species, the !reas t he brown shr imp (Penaeus aztecus) royal red shrimp (Hyrnenopenaeus robustus), npri sed about 44 percent of t he cat ch in in deep waters off t he Continental Shelf in the Gulf and about 48 pe rcent along the Gulf and South Atlantic regions. These royal Ith Atlantic. T he pink or brown-spotted red shrimp occur from about 175 to 300 'imp (Penaeus d u orarum) yielded about 19 fathoms and have not as yet been fished 'cent of the G u lf c atc h (largely in the extensively, although a few vessels are work rtugas area) and 4 percent of the South ing the g rounds to a limited extent. Figure 2.--Catch of royal red shrimp from about 175 fathoms off east coast of Florida, on deck of Bureau's 1--1 / V Silve r Bay. (Photo by Exploratory Fishing and Gear Research Station, Brunswick, Ga.) YOUNG~ OCEAN I ~-- OEBO / ADULT EGGS Figure 3.--Diagram of the life cycle of white shrimp (after Ander son and Lunz 1965). 2 :he sea bob t he last t wo pairs of walking to a narrow coastal belt not more than 8 to , a re slender and much elongated. It was 10 miles off t he coast (less than 10 fathoms). n t he se four elong ate legs and the antennae T he preadults inhabit brackish water and a t :eele rs t hat the name " sea bob" apparently times are found In water tha t is almost derived. Sea bob is a c orruption of the fresh. nch " s ix barbes" or s ix beards, t he name ~n to t hi s shrimp by the Louisiana f ishe r- Spawning 1 of French descent. T h e sea bob does not in nearly t he s ize of the other commercial T he whit e shrimp, unlike the crab and cies . c r ayf ish, does not carry the egg s attached to 11 of these species of s h rimp have t he appendage s on t he ventr al surface of t he t t h ree pairs of thoracic or w a lking legs abdomen but lays t hem directly into t he wate r. which there are f ive pairs in all) ending The eggs i ssue from t he bases of the third , chelae or p incers, but can be distinguished walking leg s o f the female and are apparently var ious differences. The white, brown, fe rtilized on emission by sperm contained in pink s h r imp h ave teeth both above and a caps ule called a spermat ophore. This cap ,won the rostrum or head spine , whereas sule is transferred to the female by the sea bob and royal red s h r imp have teeth and, apparently with t he aid of the petasma, . on t he upper surface. T he brown and a ttached bet ween the last several pairs of : s hrimp can be distingui s hed from t he walking leg s . A female produces from 500,000 :e by t he presence of grooves on eit her to 1,000,000 eggs in a single spawning , and ~ of t he rostrum which extend to the back it is probable t hat some females at least rgin of t he carapace or head s hell; in t he spawn more t han once. Most, if not all, te shrimp t he se gro oves do not extend spawning takes place at sea and not in t he re t han half the length of the carapace . estuarine inland waters, and occurs mainly , brown and pink s h rimp are not so readily from lat e March or early April to t he end of arated; t he best field character is the September. t h of the groove s along e ac h s ide of the ridge on t he s ixt h tail segment- - in the Eggs and larvae wn shrimp t his is wide open (permitting ry of a f inge rnail in fai r-s ized specimens), The eggs are spherical, about 1/ 75 of an :reas in the pink s h r imp it is almost closed. inch in diameter, and sink to t he bottom. T he 'he males can be distinguished from t he larval development apparently covers at least ales by t he presence of a structure called 10 distinct stage s excluding t he egg. These petasma, which appears as a projection consist o f f ive nauplair, t hree protozoeal, he inner side of t he f irst pai r of swimming and two mysis stages (technical terms for l (underneath first tail segment). stage s of growth) . f e know more about t he white shrimp t han T h e larval development of the white shrimp of the othe rs. A brief outline of it s life requires from 2 to 3 weeks. Some 20 to 24 :o ry is given here as an example ofpenae id hours after the egg is spawned the young imp development. shrimp, called nauplius and resembling a tiny mite, breaks t he egg membrane and emerges. Thi s minute organism (about 1/ 75 LIFE HISTORY OF THE COMMON OR of an inch long) i s to a great extent at the WroTE SHRIMP me rcy of t he prevailing currents . During t he next 24 to 36 hours t he nauplius undergoes litat five successive molts to become a protozoea about 1/ 25 of an inch long . It now has seven 'he white shri mp i s most abundant in areas pairs of appendages, a pair of compound eyes , c are characterized by an inland, brackish and a complete alimentary tract. Prior to t his rsh c onnected by p asses wit h an adjacent stage the food of the nauplius has been the llow , offsh ore area of relat ively high yolk material carried over from the egg. inity and mud or clay bottom. The o ffshore This food supply is now exhausted, and hence .racteristics s e em to be required by adults forth t he protozoea must capture its own food . perhaps also by the larvae, and t he inland to survive . T his transitional period is without rshe s appear to be requi red by t he post doubt a critical one . After s everal more val preadult. T h e adults are rarely found in molts and stages the organism ends it s larval ndance in the Gulf of Mexico in d epths phase and assumes the general proportions of ate r t h an 30 fathom s ; along t he South a miniature adult . At t he end of two postlarval ~ntic coast the distribution appears limited stages and 15 to 20 days after hat ching, t he 3 young shrimp is only about 1/5 of an inch 7 mch s (173 mm.) by May 1; they ar long and is still planktonic . During this period about I year old, mature , and WIll spa of early development the young shrimp have durmg this sprmg s ason. Because the spa moved from t he saline o ffs hore spawning area ing season covers a period of about 6 mont t o the brackish in s ide marshes, bays, and any number of c ombinations of growth a estuaries . Upon reaching t he s e "nursery possible, dependmg on the month of spawni g rounds " t hey adopt for t he first tlme (it IS believed) a benthIc or bottom existence . Migrations The white s hrimp has very definite patter Young s hrimp of movements, but they vary in dlffere Young shrimp about I 3 of an inc h long areas . are found during the sprmg and summe r In In one r sp C' • f movements are s imll the brackIsh mSlde areas whIch serve as in all locahtles -- afte r he young shrimp ftr t heIr nurse ry grounds .