AD-R62 637 SPECIES PROFILES LIFE HISTORIES AND ENVIROIENTAL viREQUIREMENTS OF COASTAL.. (U) MISSISSIPPI STATE UNIVMISSISSIPPI STRTE DEPT OF BIOLOGICAL S..

UNCLRSSIFIED N H LRSALLE ET AL. APR 85 FMS/OBS-82/11.31 F/G 6/3III

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MICROCOPY RESOLUTION TEST CHARTNAT O9AL. @VAE~u OF STAP40ANDS -965A

-Biological Report 82 (11. 31) TR EL-82-4

* Apri 1986AD-A162 637

Species Profiles: Life Histories andEnvironmental Requirements of Coastal Fishes.and Invertebrates (Gulf of Mexico)

JEC 26 19

COMMON RANGIAA

C.',

Coastal Ecology Group*Fish and Wildlife Service Waterways Experiment Station

U.S. Department of the Interior U.S. Army Corps of Engineers.71

- 851-9-J

Biological Report 82(11.31)TR EL-82-4April 1985 . ,.

Species Profiles: Life Histories and Environmental Requirementsof Coastal Fisheries and Invertebrates (Gulf of Mexico)

{'. -.- *% .

COMMON RANGIA

by

Mark W. LaSalleand

Armando A. de la CruzDepartment of Biological Sciences

P.O. Drawer GYMississippi State UniversityMississippi State, MS 39762

Project Officer .. - -

John ParsonsNational Coastal Ecosystems TeamU.S. Fish and Wildlife Service

1010 Gause BoulevardSlidell, LA 70458

Performed for

Coastal Ecology GroupWaterways Experiment StationU.S. Army Corps of Engineers

Vicksburg, MS 39180

and

National Coastal Ecosystems Team Cces_ YDivision of Biological Services - -

Research and Development.Fish and Wildlife Service

U.S. Department of the InteriorWashington, DC 20240

---

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- , . . • -

Corps~~~~.-o ofEgnes-R L8-.1 p

• '. -,

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This series should be referenced as follows:,,-...

U.S. Fish and Wildlife Service. 1983-19 . Species profiles: life historiesand environmental requirements of coastal fishes and invertebrates. U.S. Fish...,WildI. Serv. Biol. Rep. 82(11). U.S. Army Corps of Engineers, TR EL-82-4. D

This profile should be cited as follows: .-' ',.

LaSalle, MW., and A.A. de la Cruz. 1985. Species profiles: life histories and . ,'.,environmental requirements of coastal fishes and invertebrates (Gulf of Mexico)-- common rangia. U.S. Fish Wildl. Serv. Biol. Rep. 82(11.31). U.S. Army"""",Corps of Engineers, TR EL-82-4. 16 pp. p

- •\-"--Y-

- _ ...... ......-. ... •...-....-.-........-..-.-. ,..., ........... ....-..............-.... ..

.:.:--. .: - .,

PRE FACE

This species profile is one of a series on coastal aquatic organisms,principally fish, of sport, commercial, or ecological importance. The profilesare designed to provide coastal managers, engineers, and biologists with a briefcomprehensive sketch of the biological characteristics and environmental require-ments of the species and to describe how populations of the species may be ...-. ,.expected to react to environmental changes caused by coastal development. Eachprofile has sections on taxonomy, life history, ecological role, environmentalrequirements, and economic importance, if applicable. A three-ring binder isused for this series so that new profiles can be added as they are prepared. This -.project is jointly planned and financed by the U.S. Army Corps of Engineers and -" '-the U.S. Fish and Wildlife Service.

Suggestions or questions regarding this report should be directed to oneof the following addresses.

Information Transfer SpecialistNational Coastal Ecosystems TeamU.S. Fish and Wildlife ServiceNASA-Sl idell Computer Complex1010 Gause BoulevardSlidell, LA 70458

or

U.S. Army Engineer Waterways Experiment StationAttention: WESER-CPost Office Box 631Vicksburg, MS 39180

ii-i y

Sf

CONVERSION TABLE -

Metric to U.S . Cus toma ry . -.. -Mul tip I y By To Obtain-

mill1imeters (mm) 0.03937 inches '"--centimeters (an) 0. 3937 inches,-" ""

I,°. .. *'

m e t e r s (m ) 3 .2 8 1 fe e t , . mIl"Tki lom eters (k in) 0. 6214 ail esi. . .

#., . ... •

square mtr(m)k210.76 square feet L -square kilometers (n)0.3861 square miles 2 .hectares (h a) 2.471 acres . . ..

liters (1) 0.2642 gallons .. .cubic meters (m ) 35.31 cubic feet , ..- ;cubic meters 0. 0008110 acre- feet"- "- -

mi lligrams (mg) 0.00003527 ounces T. ..- .gram s (g) 0 .03527 ounces .. .. ..kilogram s (kg ) 2.20 5 pounds., . ..-.metric tons (t) 2205.0 pounds -'.-[metric tons 1.102 short tons

kilocalories (kcal) 3.968 British thermal units - -.

Celsius d e_.rees 1.8(C) + 32 Fahrenheit degrees''-. .

U.S. Customar to Metricinches 25.40 millimeters"""";"0.03.37 inche

inches 2.54 centimeters(0. 7c

fe t (ft) 0.3048 meters '. -

mtr (i)321feet

f a t h o n s 1 . 8 2 9 m e t e r s. --'. .•miles (mi) 1.609 kilometers

nautical miles (nmi) 1.852 kil1ometers i.square feet (ft') 0.0929 square meters

acres 0.4047 hectaressquare miles (mi) 2.590 square kilometers

gallons (gal) 3.785 literscubic feet (ft 0.02831 cubic metersacre-feet 1233.0 cubic meters00081aceft

ounces (oz) 28.35 gramspou nds (lb) .4536 kiogramsshort tons (ton) 0.9072 metric tonsBritish thermal units (Btu) 0.2520 kiIocaloriesFahrenheit degrees 0.5556(F 32) Celsius degrees

iV Cuar t"Mtrc ""*

inches 25.40-illimeters "

inche 2.54centieterfeet ft) 03048.eterfathoms.1829-metermiles ml).1.09 kilmeter

nautica mile (ml 1 . 852 kil . . • . -ometers -- ". . " o •.

IV-~~~~.-. -. * J 7-- -i

AI

CONTENTS

Page

PREFACE .................................................................11ICONVERSION FACTORS ...................................................... vACKNOWLEDGMENTS ......................................................... vi

NOMENCLATURE/TAXONOMY/RANGE ............................................. 1MORPHOLOGY/IDENTIFICATION AIDS...........................................3REASONS FOR INCLUSION IN SERIES..........................................3LIFE HISTORY ............................................................ 3

Spawning ........................................................... 3Larvae and Postlarvae...............................................4 sAdult Activity and Feeding ......................................... 4 kLife Span ......................................................... 4

GROWTH CHARACTERISTICS .................................................. 5Growth Rate ........................................................ 5

TAWSize ............................................................... 5THE FISHERY ............................................................. 6ECOLOGICAL ROLE ......................................................... 7

Trophic Level.......................................................7Predators and Parasites ............................................ 7Competitors ........................................................ 7Spatial Distribution ............................................... 7

IDensity ............................................................ 7ENVIRONMENTAL REQUIREMENTS .............................................. 9

Temperature ........................................................ 9Salinity ........................................................... 9Temperature and Salinity .......................................... 9Oxygen ............................................................ 9Substrate .......................................................... 10

U Depth ...................................... 10Effects of Pollution ............................................... 10

LITERATURE CITED ........................................................ 13

v1

- - -o

- .".. .,--- - - - - - - -

ACKNOWLEDGMENTS

We thank Dr. Courtney T. Hackney, University of North Carolina at Wilmingtonand Dr. H. Dickson Hoese, University of Southwestern Louisiana, for theircritical reviews of the manuscript; T. Dale Bishop and Darryl R. Clark forinformation and help with the literature search; Mark F. Godcharles, Jake M.Valentine, and personnel of the Alabama State Docks Department and the U.S. ArmyCorps of Engineers, Mobile District, for providing comments and unpublishedreports; Jeanne J. Hartley for her illustration of rangia; and Dr. Robert J.Muncy, Betty Muncy, and Cindy Mills for help in the preparation of themanuscript.

'

vi

L-, .. ' .

• 5° -

'° ".°- ._

Posterior .mbolateraltooth- .-

pallial Pal al periostracum -

sinus line

Fiqure 1. Common ranqia.

COMMON RANGIA ,.-.. ..-

NOMENCLATURE/TAXONOMY/RANGE New Jersey (Woodburn 1962). Before

Scientific name ................. Rangia 1956, living common rangia had not. . 'cuneata (Gr~y) (Figure 1) been collected along the Atlantic

Preferred common name ........... Common coast (Wells 1961) probably becauserangia (Andrews 1971; Fotheringham earlier sampling in brackish waterand Brunenmeister 1975) areas had been inadequate. Common

Other common names ...........Brackish rangia inhabit low salinity (0 to 18water clam, Louisiana road clam ppt) estuarine habitats (Parker 1966;

Class ............. .......... Mollusca Christmas 1973; Hopkins et al. 1973;Order ................. Eulamellibranchia Swingle and Bland 1974).

Family ........................ MactridaeGeologically, the conmon rangia

Geographic range: The common rangia is has been found in Dliocene depositsfound along the Gulf of Mexico coast in the Carolinas and 'lorida and in(Figure 2) from northwest Florida to Pleistocene deposits in Chesapeake -Laguna de Terminos, Campeche, Mexico Bay and the Potomac River, the Caro-(Dall 1894; Andrews 1971; Ruiz 1975), linas, Florida, the entire northand along the Atlantic coast as far coast of the Gulf of Mexico (Figurenorth as Maryland (Pfitzenmeyer and 2), and the north coast ot SouthDrobeck 1964; Gallagher and Wells America (Conrad 1840 Dall 1894'

1969; Hopkins and Andrews 1970) and Maury 1920; Richards 1939).

I -.-....... " • .

4,04, 1 -

00

o E

LL.. - C-

CST

--

* SIN 0IF

-A RIVER

x 0ma-

TOMB/lEE _ -~ -sail

. . .. . .. . .. .

%

MORPHOLOGY/IDENTIFICATION AIDS 1973, 1976a; Hoese 1973). In turn,

this biomass is consumed by fishes, KI. .

The following description of crustaceans, and ducks (Suttkus et al.common 1954; Darnell 1958; Gunter and Shellcommon rangia is taken from Abbott--. '

(1954) and Andrews (1971, 1981). 1958; Harmon 1962; North CarolinaAdults from 2.5 Bureau of Sport Fisheries and Wildlifelength. The valves are obliquely 1965; O'Heeron 1966; Cain 1972; Tarver

ovate, thick, and heavy (Figure 1). and Dugas 1973). The shells provideThe exterior of the shell is covered hard substrate for epifaunal attachmentwith a strong, rather smooth (Hoese 1973).

periostracum that ranges from lightbrown to grayish brown to black. The The common rangia was a food itemumbones are prominent and are near the of prehistoric Indians (Mclntire 1958)anterior end. The shell interior is anu it is still occasionally canned and

glossy white with a blue-gray tinge. eaten in New Jersey, Texas, NorthThe pallial sinus is small but Carolina, and Mexico (Singley 1893;distinct. The posterior lateral tooth Woodburn 1962; Wass and Haven 1970;is long (Figure 1). Dall (1894) U.S. Department of Commerce 1971).mentions that most of the variability Economically, common rangia is more

in form is related to the differences important as a source of shells forin the height of the umbones and the road building and in the manufacture ofshape of the posterior mar~lin of the many industrial products (Tarver and Ashell. Rangia cuneata var. nasutus Dugas 1973; Swingle and Bland 1974;

(Dall 184Tis believed to e a Arndt 1976). Much of this shellrostrate form of R. cuneata (Abbott matgrial is dredged from buried1954) and may be confused with a dep',sitF in estuaries.closely related species, the brownrangia (Rangia flexuosa [Conrad]). LIFE HISTORYThe brown rangia i s 5- 4.0 cm lonqand resembles an elongate common Spawningrangia; however, brown rangia can beeasily separated from common ranqia by The reprodu:tive cycle andthe short posterior lateral tooth and environmental conditions necessary forthe nondistinct pallial sinus. Brown spawning are well known for commo-rangia is found from Louisiana to Texas rangia. The reproductive cycle wasand Vera Cruz, Mexico (Andrews 1971), studied in Louisiana by Fairbanksbut is much less common than the common (1963), in Virginia by Cain (1975),rangia. in Florida by Olsen (1976b), and in

Campeche, Mexico by Rogers andREASONS FOR INCLUSION IN SERIES Garcia-Cubas (1981). Most rangia

spawned from March to May and from lateThe common rangia is an important summer to November in Louisiana and -

component of estuarine ecosystems from February to June and September to(Parker 1959; Odum 1967; Odum and November in Mexico. In both areas,Copeland 1969; Copeland et al. 1974) spawning may be continuous.accounting, for example, for nearly 95%of the benthic biomass in the James In Virginia, oametogenesis beqanRiver Estuary, Virginia (Cain 1975). in early April and continued throughoutIn low salinity estuarine areas common the summer; gametes were ripe from Mayrangia functions as a link between pri- through November. Gametogenesis was

* mary producers and secondary consumers. initiated when water temperatureAs a non-selective filter feeder, rose to 15°C, and spawning wasrangia transforms large quantities of initiated by a rapid increase orplant detritus and phytoplankton into decrease in salinity (Cain 1975). Inclam biomass (Darnell 1958; 9lsen 1972, upstream areas of the James River,

3

".

-. °. , . . • *

Virginia, clams required a salinity straight-hinged larvae 0.75 to 130 pm;increase of about 5 ppt associated with unbowed larvae 120 to 175 pm; andreduced freshwater output, but in down- pediveligers (metamorphosed) 160 tostream areas they required a salinity 175 pm. Pediveligers began to settle,decrease of about 10 to 15 ppt associ- lose the velum, and attain gills at 175ated with inc.'eased freshwater output. to 180 pm. Metamorphosis began after 7Spawning peaked at 5 ppt in fall. In days (Chanley 1965).Florida, ripe gametes and spawning werereported from July through November; Most settling of larvae in thespawning peaked in September. Tempera- James River, Virginia, took placeture and salinity increases were sus- between September and March when thepected of triggering spawning (Olsen animals were 230 to 500 pm long and1976b). averaged 300 pm (Cain 1975). A second

settling period occurred in midsummer.In spawning, common rangia release In Lake Pontchartrain, Louisiana,

gametes directly into the water. Sex Fairbanks (1963) collected juveniles asratios were reported to be near 1:1 in small as 375 pm while Hoese (1973)Louisiana (Fairbanks 1963) and Mexico observed several small clams (< 1 mm(Rogers and Garcia-Cubas 1981), but long) attached to a hydroid colony.females outnumbered males in Virginia(Cain 19 2). The incidence of herma- How the juvenile rangia dispersephroditism in this clam was reported to is uncertain. They may be transported . ,.be 0.1% in Mexico (Rogers and Garcia- to upstream areas in the more salineCubas 1981) and 2.1% in Florida (Olsen bottom water in an incoming tide, or by1976b). The minimum length of mature swimming during low flow or both (Cainadults in Lake Pontchartrain, 1975). Fairbanks (1963) reported thatLouisiana, was 24 mm (Fairbanks 1963). larvae were capable of selecting sub-From data on annual growth increments, strate for setting and preferred sub-Fairbanks (1963) inferred that a clam strates high in organic content.could reach minimum length in 2 to 3years. In the James River, Virginia, Adult Activity and FeedingCain (1972) reported that gonads weremature in clams as small as 14 mm, Common rangia move little afterwhich were probably clams in their settling. Fairbanks (1963) observedsecond year of life. little movement of clams in aquaria.

Sikora et al. (1981) suggested thatNo fecundity data are available on rangia are capable only of vertical

common rangia. movement in the sediment. Olsen (1973)reported that clams did not move in

Larvae and Postlarvae aquaria over a 4-month period even whengiven a choice of substrates.

The early stages of development of 0common rangia were studied in Louisiana Feeding of common rangia isby Fairbanks (1963) and in Virqinia by controlled by gill palp articulationsChanley (1965). Fairbanks reported and ciliary currents over the gillsthat the average diameter of egqs was (Olsen 1972). The animal extrudesabout 69 pm. Ciliated blastula pseudofeces from the mantle cavity,developed 9.5 hours (h) after through the inhalant siphon when thefertilization, a pelagic trochophore at valves are quickly closed.26.3 h, and a veliger at 34.3 h (93 pmin mean diameter). In Virqinia, Life Span

Chanley reported that shelled larvaeappeared within 24 h after fertiliza- The life span of the common rangiation. The length of different life has not been confirmed. If one relates ..stages were as follows: the mean length (about 40 mm) of rangia -

4

•0>'

collected in Louisiana (Table 1), to mm, 5 to 9 mm, and 4 to 5 mm,estimates of growth rate (Fairbanks respectively (Fairbanks 1963). From1963; Wolfe and Petteway 1968), the mean height data for clams collected inaverage life span is about 4 to 5 Lake Pontchartrain, Tarver and Dugasyears. A clam of the maximum expected (1973) reported as much as 7.2 mm"length of 75 mm, reported by Wolfe and growth in a 2-month period. This rapidPetteway (1968) in Chesapeake Bay, growth appeared to be related to warm .would be 10 years old. Hopkins et al. temperatures. Annual growth rates have(1973) estimated a maximum life span of been reported to range from 0 to 9.7 mm15 years. for Vermilion Bay, Louisiana (Gooch

1971) and to be 3 mm in Trinity Bay,Texas (Bedinger 1974). Wolfe and

GROWTH CHARACTERISTICS Petteway (1968) calculated thefollowing von Bertalanffy growth curvefor a common rangia population in the

Growth Rate Trent River0 . ?5h Carolina: L = 75.62(1-0.995 e- . The largest

Annual growth increments of common predicted length of 75.6 mm wouldranqia in the Gulf of Mexico are represent 10 years of growth.reported to vary from 0 to 20 mm(Fairbanks 1963; Gooch 1971; Tarver and SizeDuqas 1973). Annual growth increments,estimated for the first 3 years of life Maximum length reported was 94 mmfor two populations in Lake for a common rangia from Grand GosierPontchartrain, Louisiana, were 15 to 20 Island, Louisiana (H.D. Hoese, Univ.

Table 1. Range of lengths (mm) or heights (mm) of common rangia examined infour areas of Louisiana.

Area Length Height References

Lake Pontchartrain, LA 38-42 (adults) --- Fairbanks(1963)

1-8 (juveniles) ---

--- 28 Tarver (1972)

--- 28-44 Tarver &Dugas (1973)

Lake Maurepas, LA --- 26 Tarver (1972)

25-27 Tarver &Dugas (1973) 0

Vermilion Bay, LA 31-61

--- Gooch (1971)

Sabine Lake -

Atchafalaya Bay, LA 2q-57 --- Hoese (1973)

5-

-0 .°

Southwestern La.; pers. comm.). Me an extend from Point au Fer (Atchafalayasizes (length, anterior to posterior; Bay) west to the Texas border,height, iznbo to ventral margi n) Calcasieu and Sabine Lakes, and Lakereported from other Louisiana estuaries Pontchartrain. In Mississippi , clamsare shown in Table 1. Parker (1960) live in the Pearl River Estuary andand Hoese (1973) reported that the Mississippi Sound; in Alabama, in upperlargest clams were found in the lower Mobile Bay; and in Florida insalinity areas of estuaries, whereas, Choctawhatchee Bay, Tampa Bay, theTarver and Dugas (1973) found that clam Caloosahatchie River (Arndt 1976), andsize increased with salinity. I n the upper reaches of Charlotte HarborVirginia, Cain (1972) noted that clams (Woodburn 1962).living in sand were typically largerthan those livilrg in mud.

The Louisiana Wildlife andFisheries Commission (1968) estimated astatewide production of about 5 million

THE FISHERY cubic yards of clam shell ir 1968compared with 300,000 cubic yards

The foremost commnercial value of annually in the mid-1930's. Thecommon rangia is in the use of fossil maximum annual harvest of shell in theshells for road building material, gulf States was 21.2 million tons inoyster cultch, and as a source of 1967 compared with 468,000 tons in 1912calcium carbonate for the manufacture (Arndt 1976). Of the material dredgedof glass, chemicals, chicken and cattle in 1967, an estimated 12.2 million tonsfeed, wallboard, and agricultural lime was used in construction and the(Tarver and Dugas 1973; Swingle and remainder for road base, asphalt fill,Bland 1974; Arndt 1976). Clam shells poultry grit, cattle roughage, filterare harvested by large commercial material, and whiting (pigment).hydraulic dredges. By far the largestconcentrations of living cl ams arealong the Louisiana coast. The minimum Native Americans used commonstanding crop of clams estimated to be rangia as food, as evidenced from shellbetween the Atchafalaya River and deposits in Indian middens along theSabine Lake, Louisiana, was between 24 gulf coast (Singley 1893; Mclntirebillion and 48 billion clams (Hoese 1958). The canning of rangia in Texas1973). Because of the relatively slow under the name of "little neck clams"growth rate of rangia, Hoese (1973) by the Givens Oyster Company wassuggested that no more than 5% of the reported by Singley (1893). Rangia -

living clam population should be were also canned at Cape Mvay, Newharvested annually if current Jersey (Woodburn 1962) and in Northproduction of fossil shells is to be Carolina (U.S. Department of Commercemaintained; however, at an annual 1971). Rangia have been collected andrecruitment of 5% (Fairbanks 1963) the consumed from the Potomac Creek of theestimated shell deposits in Lake Potomac River, Maryland (PfitzenmeyerPontchartrain would be nearly exhausted and Drobeck 1964), to Mexico where Wassin 35 years; at 3% Tarver and Dugas and Haven (1970) reported that this(1973) estimated depletion in 18 years. clam was served with rice as "Paella a

valenci anna"l in restaurants. TheThe potential sources of common potential use of this clam as food,

rangia shell along the gulf coast have however, is severely limited bybeen listed by Arndt (1976). In Texas, contamination of large potentialshell occurs in the upper reaches of sources by pollution (Christmas 1973;San Antonio Bay, Nueces and Lavaca Swingle and Bland 1974). Rangia areBays, Galveston Bay, Trinity Bay, and also used as bait for blue crabsSabine Lake. In Louisiana, deposits (Godcharles and Jaap 1973).-

6

.- :. .

,-. ,- .. -. rr -.- w- ...... 1 - a ZX S pr .....-..

ECOLOGICAL ROLE larvae if coincidental with rangiaspawning. .....

Trophic Level The common rangia is parasitizedby larvae of fellodistonatid trematodes-,•-.-'oCommon rangia serve to link (Fairbanks 1963). Cercariae and

primary producers and secondary sporocysts of this parasite are foundconsumers in estuarine areas. Rangia in the gonadal tissue, giving it an P -are non-selective filter feeders orange coloration and effecting(Darnell 1958; Olsen 1976a) ingesting castration. Only large clams arelarge quantities of detritus and infected.phytoplankton. Darnell (1958) reportedthat gut contents contained 70% Competitorsunidentifiable detritus, 10% sand, 17%algae (possibly Anabaena or Potential competitors of commonMicrocystis) as well as traces of rangia may be reduced by the widediatoms, foraminifera, and vascular range of salinities tolerated by thisplant material. Olsen (1976a) reported clam (Odum 1967). Polymesoda48 species of phytoplankton from caroliniana has feeding habitsstomach contents of common rangia, identical to those of rangia (Olsenalthough a large portion of the 1973, 1976a), but is spatially

- material ingested was detritus (46 to separated from ,angia; it is found81%, depending on tidal conditions). primarily in intertidal areas or in

small numbers in the shallow nearshoresubtidal areas. In contrast, rangia

Predators and Parasites live largely in the subtidal zone.Other potential competitors areCommon rangia are preyed upon by apparently not adapted to fluctuating

fish, crustaceans, mollusks, and ducks salinities.(Table 2; Suttkus et al. 1954; Darnell1958; Gunter and Shell 1958; Harmon1962; North Carolina Bureau of Sport Spatial Distribution -...-Fisheries and Wildlife 1965; O'Heeron1966; Cain 1972; Tarver and Dugas Common rangia are primarily1973). In addition, moon shell snails restricted to low salinity (< 19 ppt)(Polinices spp.) may be predators as estuaries (Maury 1920; Pulley 1952;suggested by drill holes in rangia Parker 1955, 1956, 1960; Moore 1961;shells (Hoese 1973). Common rangia are Parker 1966; Odum 1967; Christmas 1973;abundant in the diets of blue catfish, Hoese 1973; Hopkins 1970; Hopkins etfreshwater drum, spot, black drum, al. 1973; Swingle and Bland 1974).river shrimp, and blue crab in Lake Rangia have been reported from areas asPontchartrain, Louisiana (Darnell 1958, far as 25 miles upstream in delta1961). The smaller rangia are rivers (Swingle and Bland 1974), butsubjected to the greatest predation most prefer salinities of 5 to 15 ppt.pressure. Clams as large as 40 mm Tarver and Dugas (1973) found that(length or height), however, are eaten concentrations of clams were highestby fishes such as sheepshead and black adjacent to a potential source of fresh-drum (Darnell 1958; Tarver and Duqas or salt water, which may be related to "1973). A potential group of predators the need for salinity shock required

. not mentioned by the above authors are for spawning (Cain 1973).the ctenophores (i.e., Mnemioposis) Concentrations of clams were greatestwhich sometime appear in tremendous around the periphery of Lakenumbers at certain times of the year Pontchartrain and Lake Maurepas (Tarver . .(M.W. LaSalle, pers. observ.). Cteno- 1972; Dugas et al. 1974). Dispersionphores can cause mass mortality of of adult clams is commonly clumped

7

S-

Table 2. Reported predators of adult and juvenile common rangia.

Species/common name Adults Juveniles References(<5 mm)

Aythya affinis -- lesser scaup duck X 4,5AymFya mar- a -- greater scaup duck X 5TyTya collaris -- ring-necked duck X 5Anas rubripes -- American black duck X 5p7nas platyrhynchos -- mallard X 5

Ux-yura jamaicensis -- ruddy duck X 5Uasyatis sabina -- Atlantic stingray X 2Lepisosteus productus -- spotted gar X 1,2Lepisosteus spatula -- alligator gar X 1,2Lepisosteus osseus -- northern longnose gar X 1,2Uorosoma cepedianum -- gizzard shad X 1,2Anchoa mitchi II -- southern bay anchovy X 1,2Tius felis -- sea catfish X 1,2TcTalTuriTurcatus -- blue catfish X 1,2,3Aplodinotus grunniens -- freshwater drum X 1,2Leiostomus xanthurus-- spot X 1,2Micropogonias undulatus -- Atlantic croaker X 1,2Pogonlas cromis -- black drum X 1,2 (- -Archosarqus probatocephalus -- sheepshead X X 1,2Lagodon rhomboides -- pinfish X 2Paralichthys lethostigma -- southern flounder X 1,2Cynoscion arenarius -- sand seatrout X 1

Chasmodes bosqulanus -- striped blenny X 7 -.'-Penaeus setiferus -- white shrimp X 1,2M robrachium ohione -- river shrimp X 2Callinectes sapd --- blue crab X X 1,2,7Rhithropanop-W risii -- mud crab X 7Ihais haemastoma -- oyster drill x 6linices spp. -- moon shell (possible) X 8

References: (1) Suttkus et al. (1954); (2) Darnell (1958); (3) Gunter and Shell(1958); (4) Harmon (1962); (5) North Carolina Bureau of Sport Fisheries and -Wildlife (1965); (6) O'Heeron (1966); (7) Cain (1972); (8) Hoese (1973)

whereas juveniles may be distributed 818/m2 in Lake Maurepas, Louisianmore uniformly (Fairbanks 1963). (Tarver and Dugas 1973), and 238/m_

in Vermilion Bay, Louisiana. Averagedensity of clams from shallow water

Density areas between the Atchaf,$laya River andSabige Lake was 11.1/m for adults,

The density of clams varies 14/m_ for juvenile clams > 10 mm, andgreatly (for reasons discussed later). 28/m 2 for juvenile clams < 10 mmThe highest density of adult clams was (Hoese 1973). Densities as high as

8V...............---. .

T.°% T. -vSTT

129/m 2 were reported in Texas bays greater number of size classes and

(Odum 1967). A mean density of larger clams at low salinities (0 to .250/m 2 was reported in the Nueces 2 ppt) than at higher ones in FloridaRiver, Texas (Hopkins and Andrews and suggested that this range was

1970). In Lake Pontchartrain, optimal. t -

Louisiana, mean densities ranged from2.7 to 31/m 2 for large clams and 1807 Common rangia have developed phys-

to 1888/m 2 for juveniles (Fairbanks iological responses to the frequent and W.1963). sudden salinity changes present in many

estuaries. Common rangia is anosmoconformer at salinities greater

ENVIRONMENTAL REQUIREMENTS than 10 ppt, and an osmoregulator atlower salinities (Bedford and Anderson1972a,b; Otto and Pierce 1981a,b). A

A combination of low salinity, number of amino acids (including 44,

high turbidity, and a substrate of alanine, glycine, glutamic and

sand, mud, and vegetation appears to be aspartic) are concentrated at high

the most favorable habitat for the salinities suggesting that an amino

common rangia (Tarver 1972). This clam acid pool is used for osmoregulationmay be one of the few freshwater clams (Simpson et al. 1959; Allen and Awapara

to become established in brackish water 1960; Allen 1961; Anderson and Bedford

(Ladd 1951). Conversely, Remane and 1973; Anderson 1975).Schlieper (1971) considered commonranqia as belonging to a marine group Temperature and Salinity

* that has become adapted to brackishwater. Cain (1972, 1973, 1974) tested the

combined effects of temperature (8 to32°C) and salinity (0 to 20 ppt) on .. k6..

Temperature embryos and larvae of common rangia.Embryos failed to develop at 0 ppt

Winter kills in the shallow waters salinity. The optimum conditions for .- -

of Chesapeake Bay suggest that common embryos were temperatures of 18 to 290C

ranqia had reached its limit of and salinities of 6 to 10 ppt.

temperature tolerance there (Gallagher*- and Wells 1969). Cain (1975) reported Larvae survived at all*- that water temperature was the most combinations of temperature and

" import ant f act or st imul at ingm nou salinity tested (except at 0 ppt).gamnetogenesis. He also stated that the They tolerate temperatures of 8 to 32°Cplanktonic existence of larvae is and salinities of 2 to 20 ppt. Growthgreatly extended by low temperature. of larvae was best at high salinity (10

Saiiyto 20 ppt) and high temperature (20 to32-C). Straight-hinged larvae were ."-"

Common rangia are concentrated in found to be more tolerant than embryosares wh r salnit ael cereds 18 to extremes of temperature and . ... "-.

areas where salinity seldom exceeds 18 salinity.ppt (Maury 1920; Pulley 1952; Parker :.-."

1956, 1960; Moore 1961; Parker 1966;Odum 1967; Godcharles and Jaap 1973; OxygenHoese 1973; Swingle and Bland 1974). -

- Tarver and Dugas (1973) reported a Common rangia can withstand anoxic .U:.negative correlation (r = 0.71) between conditions as reported by Chen anddensity of clams and salinity and a Awapara (1969) in studies of ". 'positive correlation (r = 0.81) between glycolysis; however, rangia are

clam height and salinity (0 to 6 ppt). intolerant of exposure to air (OlsenGodcharles and Jaap (1973) found a 1976b).

9

0'

* A-*

°o-F... . *

Substrate The substrate of some coastal Owaters is mainly shells which are often

Common rangia are found in a wide dredged commercially. For example, therange of soft substrates in the common rangia makes up much of the hardnorthern Gulf of Mexico. Tenore et substrate of Lake Pontchartrain in ..

al. (1968), who studied the effects of Louisiana. The effects of shellclay, silt, and sand substrates on the dredging on the substrate and benthoscommon rangia,found clay and silt to be are too complex and controversial tounfavorable, whereas Cain (1975) discuss in this profile. See Dugas etcommonly found clams in silty-clay al. (1974), Taylor (1978), Sikora etsediments. Parker (1966) found clams al. (1981), and Sikora and Sikoraon sand, silt, and clay sediments where (1982).these constituents did not exceed 80,30, and 65%, respectively. Few clams Depthwere collected from hard sand or claybottoms in Louisiana (Tarver 1972) or The highest concentration of clamsin Alabama (Swingle and Bland 1974). along the gulf coast has beenIn Louisiana, the numbers of common associated with shallow water areasrangia were highest in a mixture of less than 6 m deep (Tarver 1972; Hoesesand, mud, and vegetation (Tarver 1973; Godcharles and Jaap 1973; Tarver1972), whereas in Alabama, dense and Dugas 1973; Dugas et al. 1974).populations lived in compacted sandy- Tarver and Dugas (1973) observed aclay areas (Swingle and Bland 1974). general decrease in density as depthIn Florida, common rangia were increased from 2.5 to 4.6 m.collected from soft mud (Godcharlesand Jaap 1973; Woodburn 1962), but in Effects of PollutionGeorgia, clams were found in mud orsoft mud-sand combinations (Godwin Common rangia are known to -1968). concentrate chemicals such as kepone.

Lunsford (1981) reported that peakThe importance of organic matter kepone levels in common rangia during

in the sediment to common rangia is summer, in the James River Estuary,not clear. Fairbanks (1963), who found were related to increased metabolismthe largest densities of rangia in and feeding rate. The concentration ofhighly organic sediments in Lake kepone was 2 to 4 times greater inPontchartrain, Louisiana, suggested rangia than in the water columnthe large amounts of associated (Lunsford and Blem 1982). The keybacteria helped to attract and support factors affecting kepone uptake wereclams. High organic content in water temperature, dissolved oxygensediments was also favorable for rangia concentration, lipid index of clamin Vermilion Bay, Louisiana (Gooch tissue, turbidity, kepone concentration1971). However, no correlation existed in the water, and the duration ofbetween the abundance of common rangia exposure (Lunsford and Blem 1982).

and the percentage of organic matter in Kepone is adsorbed by particulatethe sediment at levels below 10% (Hoese matter, which enhances its uptake by1973). Few clams were found in filter feeders such as common rangia.sediments with more than 10% organic Uptake of oil related products such asmatter in Louisiana (Hoese 1973) and benzopyrene, naphthalenes, and variousAlabama (Swingle and Bland 1974). aromatic hydrocarbons has also beenMortality of rangia can result from reported (Cox 1974; Neff et al. 1976).shell erosion, which can be accelerated All of these compounds were accumulatedin highly aerated sediments in which primarily in the viscera and fat bodiescarbonic acids are released (Tarver and of clams under direct exposure and mostDugas 1973). were readily released when clams were

10,'.,- o .":' ' -:-s

AIL

returned to clean water. Low levels of The effects of low concentrations of .*. these contaminants, however, were contaminants on common rangia are not ...

retained by the clams in each case. known.

lip -, - . . .h . -. . . -s -

b%'. °q.'1 " "

*

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......................;::§xu~ ~~~:.;,... *.... ,'.

r~ %

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,.. . ..... -

LITERATURE CITED

Abbott, R. T. 1954. American sea- on gulf coast environments. Gulfshells. Van Nostrand, New York. Publishing Co., Houston, Tex.541 pp.

Bedford, W. B. , and J. W. Anderson.Allen, K. 1961. The effect of salin- 1972a. The physiological response

ity on the amino acid concentra- of the estuarine clam, Rangiation in Rangia cuneata (Pele- cuneata (Gray). I. Osmoregula-cypoda). Biol. Bull. (Woods Hole) tT iF Physiol. Zool. 45:255-260.121: 419-424.

Bedford, W. B. , and J. W. Anderson.Allen, K., and J. Awapara. 1960. 1972b. Adaptive mechanisms of

Metabolism of sulfur amino acids the estuarine bivalve, Ran ain Mytilus edulis and Rangia cuneata, to a salinity stressedcuneata. Biol. Bull. (Woods oe) environment. Am. Zool. 12:721.118:173-182. (Abstr.)

Anderson, J. W. 1975. The uptake and Bedinger, C. A., Jr. 1974. Seasonalincorporation of glycine by the changes in condition and ftgills of Rani cuneata (Mollusca: biochemical consituents of the -

Bivalvia) in response to varia- brackish water clam Rangia cuneatations in salinity and sodium. (Gray), 1831. Ph.D. ssertation'Pages 239-258 in F.J. Vernberg, Texas A&M University, Collegeed. Physiological ecology of Station. 179 pp.estuarine organisms. Universityof South Carolina Press, Columbia. Beyers, R. J., and R. W. Warwick.

1968. The production of carbonAnderson, J. W. , and W. B. Bedford. dioxide by angia cuneata.

1973. The physiological responses Contrib. Mar. Sci. 13:45-50.of the estuarine clam, Rangiacuneata (Gray), to salinity. II.Uptake of glycine. Biol. Bull. Cain, T. D. 1972. The reproductive(Woods Ho l .144:229- . Bucycle and larval tolerances of(Woods Hole) 144:229-247. Rangia cuneata in the James River,

Andrews, J. 1971. Sea shells of the Virginia. Ph.D. Dissertation.

Texas coast. University of Texas University of Virginia,Press, Austin. 298 pp. Charlottesville. 250 pp. ..

Andrews, J. 1981. Texas shells: a Cain, T. D. 1973. The combined

field guide. University of Texas effects of temperature andPress, Austin. 175 pp. salinity on embryos and larvae of

the clam Rangia cuneata. Mar.Arndt, R. H. 1976. The shell dredging Biol. 21:1-6.

industry of the gulf coast region.Pages 13-48 in A. Bouma, ed. Cain, T. D. 1974. Combined effects ofShell dredging--and its influence changes in temperature and

13

4m . . . . .. .° . . . .. . ° , . . . . . . . . . ° . . . . . . .% .% °° -. °.

-""' "" I"" ' """ ' """ '" ""'" "" " "" '" "" " """ ;" ,'" " , -' " '

salinity on early stages of Rangia Darnell, R. M. 1958. Food habits ofcuneata. Va. J . Sci. 25:30-31. fishes and larger invertebrates of

Lake Pontchartrain, Louisiana, anCain, T. D. 1975. Reproduction and estuarine community. Pubi. Inst.

recruitment of the brackish water Mar. Sci. Univ. Tex. 5: 353-416.clam Rangia cuneata in the JamesRiver, Vi rgi niaTi. S. Natl. Mar. Darnell, R. M. 1961. Trophic spectrumFish.' Serv. Fish. Bull, of an estuarine community based on73: 412-430. studies of Lake Pontchartrain,

Louisiana. Ecology 42:553-568.Chanley, P. 1965. Larval development

of the brackish water mactrid Dugas, R. J. , J. W. Tarver, and L. S.clam, Rangia cuneata. Chesapeake Nutwell. 1974. The mollusk -

Sdi. 6:209-213. communities of Lakes Pontchartrainand Maurepas, Louisiana. La.

Chen, C., and J . Awapara. 1969. Wildl. Fish. Comm. Tech. Bull. No.Effects of oxygen on the end- 10. 13 pp.products of glycolysis in Rangiacuneata. Comp. Biochem. Physiol. Fairbanks, L. D. 1963. Biodemographic31: 395-401. studies of the clam Rangia cuneata

Gray. Tulane Stud. L0o1. 1T-3-47.Christmas, J. Y. 1973. Cooperative

Gulf of Mexico estuarine inventory Fotheringham, N. , and S. Brunenmeister.and study. Mississippi Gulf Coast 1975. Common marine invertebratesRes. Lab. , Ocean Springs. of the northwest gulf coast. Gulf

Publishing Co., Houston, Tex.Conrad, T. A. 1840. On the Silurianisystem, with a table of the strata Gallagher, J. L., and H. W. Wells. '

and characteristic fossils: 1969. Northern range extensionobservations on the genus Gnatho- and winter mortality of Rangiadon with description of a new cuneata. Nautilus 83:22-secies. Am. J-. Sci. 38:92-93.

Godcharles, M. F., and W. C. Jaap.Copeland, B. J. , K. R. Tenore, and 0. 1973. Exploratory clam survey of

iB. Horton. 1974. Oligohaline Florida nearshore and estuarine

regime. Pages 315-35 in H. T. waters with commercial hydraulicOdum, B. J. Copeland, id E. A. dredging gear. Fla. Dep. Nat...-McMahan, eds. Coastal ecological Resour. Mar. Res. Lab. Prof. Pap.systems of the U.S., Vol. 2. The Ser. No. 21. 77 pp.Conservation Foundation, Washing-ton, D.C. Godwin, W.F. 1968. The distribution

and density of the brackish waterCox, B. A. 1974. Responses of the clam, Rangia cuneata in the

marine crustaceans Mysidopsis Altamaha River, Georgica. Ga. Fishalmyra Bowman, Penaeus aztecus Game Comm. , Mar. Fish. Div.Ives, and Penaeus sel'ifiu Contrib. Ser. No. 5:1-10.(Linn. ) to petr-oleum hydrocarbons.Ph.D. Dissertation. Texas A&M Gooch, D. M. 1971. A study of Ran iaUniversity, College Station. 182 cuneata Gray, in Vermilion Fay,PP. Tiiana. M.S. Thesis. Univer-

sity of Southwestern Louisiana,Dall, W. H. 1894. Mnrap ofte Lafayette. 48 pp.

of thebracki onwatr a tri ofas R.J JWtTreanh..e""-

genus Gnathodon Gray (Ran ia Des-moulinsa Proc. U.S. Nat. Mus. Gunter, G., and W. E. Shell, Jr. 1958.17:89-106. A study of an estuarine area with

14

,.... ....... . .

_. r W Q

water-level control in the Louisi- Lunsford, C.A. , and C. R. Blem. 1982.ana marsh. Proc. La. Acad. Sci. Annual cycle of Kepone residue . ...21:5-34. and lipid content of the estuarine

clam, Rangia cuneata. EstuariesHarmon, B. G. 1962. Mollusk as food 5:121-130. -.

of lesser scaup along the Louisi-ana coast. Trans. N. Am. Wildl. Maury, C. J. 1920. Recent mollusks ofConf. 27:132-138. the Gulf of Mexico and Pleistocene

and Pliocene species from the Gulf

Hoese, H. D. 1973. Abundance of the States. Bull. Am. Paleontol. 8:1-low salinity clam, Rangia cuneata 115.in southwestern Louisiana. Proc.Natl. Shellfish. Assoc. Mclntire, W. G. 1958. Prehistoric63:99-106. Indian settlements of the changing

Mississippi River Delta. La.Hopkins, S. H. 1970. Studies on the State Univ. Coastal Stud. Ser.

brackish water clams of the genus 1:1-128.Rangia in Texas. Proc. Natl.Shellfish. Assoc. 60:5-6. Moore, D. R. 1961. The marine and(Abstr.) brackish water mollusca of the -

state of Mississippi. Gulf Res.Hopkins, S. H., and J. D. Andrews. Rep. 1:1-58.

1970. Rangia cuneata on the eastcoast: thousand mile range Neff, J. M., B. A. Cox, D. Dixit, andextension or resurgence? Science J. W. Anderson. 1976.167:868-869. Accumulation and release of

petroleum derived aromaticHopkins, S. H., J. W. Anderson, and K. hydrocarbons by four species of ,

Horvath. 1973. The brackish marine animals. Mar. Biol.water clam Rangia cuneata as 38:279-298.indicator of ecological effects ofsalinity changes in coastal North Carolina Bureau of Sportwaters. U.S. Army Engineer Fisheries and Wildlife, NorthWaterways Exp. Stn., Vicksburg, Carolina Wildlife Resources

Miss. Contract Rep. No. Commission, and VirginiaDACW39-71-C-0007. Commission of Game and Inland

Fisheries. 1965. BackLadd, H. S. 1951. Brackish-water and Bay-Currituck Sound data report.

marine assemblages of the Texas Vol. 1. 84 pp.coast with special reference tomollusks. Publ. Inst. Mar. Sci. Odum, H. T. 1967. Biological circuits •Univ. Texas. 2:12-164. and the marine systems of Texas.

Pages 99-157 in T. A. Olsen and F.Louisiana Wildlife and Fisheries Com- J. Burgess, eds. Pollution and

mission. 1968. The history and marine ecology. John Wiley andregulation of the shell dredging Sons, New York.industry in Louisiana. La. Wildl.Fish Comm. 32 pp. Odum, H. T., and B. J. Copeland. 1969. O0

A functional classification of the

Lunsford, C. A. 1981. Kepone distri- coastal ecological systems. Pagesbution in the water column of the 9-86 in H. T. Odum, B. J.James River Estuary - 1976-78. Copelarid, and E. A. McMahan, eds.Pestic. Monit. J. 14:119-124. Coastal ecological systems of the

15. .15 • .-" . .

..................................

U S R Fed. • -. 1 . .d of . U .... . .

Control Admin. , Washington, D.C. Fish Wildi. Serv. Bur. Commer.

Fish. Circ. 246:35-36.

OHeeron, M. K. 1966. Some aspects ofthe ecology f Wania cuneata Parker, R. H. 1955. Cunes in the(Gray). M.S. Thesis. Texas AT invertebrate fauna, apparentlyUniversity, College Station. 71 attributable to salinity changes,pp. in the bays of central Texas. J.

Paleontol• 29:193-211.

Olsen, L. A. 1972. Comparativefunctional morphology of feeding Parker, R. H. 1956. Macro-mechanisms in Rangia cureata invertebrate assemblages as(Gray) and Polymesoda caroTi-nana indicators of sedimentary(Bosc). Proc. Natl. Shellfish. environments in east MississippiAssoc. 63:4. (Abstr.) delta region. Am. Assoc. Petrol.

Geol. Bull. 40:295-376.Olsen, L A. 1973. Food and feeding

in relation to the ecology of two Parker, R. H. 1959. Macro-estuarine clams, Rangia cuneata invertebrate assemblages of(Gray) and Polymesoda caroliniana central Texas coastal bays and(Bosc). M.S. Thesis. Florida Laguna Madre. Am. Assoc. Petrol.State University, Tallahassee. Geol. Bull. 43:2100-2166.102 pp.

Parker, R. H. 1960. Ecology andOlsen, L. A. 1976a. Ingested material distributional patterns of marine

in two species of estuarine bi- macro-invertebrates, northern Gulfvalves: Rangia cuneata (Gray) and of Mexico. Pages 302-337 in F. P.Polymesoda caroliniana (Bosc). Shepard, ed. Recent sediments ofProc. Natl. Shellfish Assoc, northwest Gulf of Mexico. Am.66:103-104. (Abstr.) Assoc. Petrol. Geol. Bull. Tulsa,

Okla.Olsen, L. A. 1976b. Reproductive

cycles of Polymesoda caroliniana Pfitzenmeyer, H. T., and K. G. Drobeck.(Bosc) and Rangia cuneata (Gray) 1964. The occurrence of thewith aspects of desiccation in the brackish water clam, Rangiaadults and fertilization and early cuneata, in the Potomac River,larval stages in Polymesoda caro- Maryland. Chesapeake Sci.liniana. Ph.D. Dissertation. 5:209-215.Florida State University, Talla-hassee. 116 pp. Pulley, T. E. 1952. An illustrated

check list of marine mollusks ofOtto, J. , and S. K. Pierce. 1981a. Texas. Tex. J. Sci. 4:167-199.

Water balance systems of Ran•iacuneata: ionic and amino acid Remane, A., and C. Schlieper. 1971.regulation in changing salinities. Biology of brackish water. JohnMar. Biol. 61:185-192. Wiley and Sons, New York. 372 pp.

Otto, J., and S. K. Pierce. 1981b. An Richards, H. G. 1939. Marine 0interaction of extra- and intra- Pleistocene of the gulf coastalcellular osmoregulatory mechanisms plain: Alabama, Mississippi andin the bivalve mollusc Rangia Louisiana. Am. Assoc. Petrol.cuneata. Mar. Biol. 61:192-198. Geol. Bull. 50:297-316. ..

Parker, J. C. 1966. Bottom fauna Rogers, P., and A. Garcia-Cubas. 1981.study distribution and relative Evolution gonadica a nivel

16 "."--

.~~~- .- . . .. .

0 .- •°

............................................ .... .... ....

A . .- •- . .,

6.-

histologico de Rangia cuneata Rangia cuneata Gray in coastal

(Gray, 1831) de la Laguna Pon, waters of Alabama. Ala. Mar. [...-

Campeche, Mexico (Mollusca: Resour. Bull. 10:9-16.

Bivalvia). Am. Inst. Cienc. delMar. Limnol., Univ. Nat. Auton, Tarver, J. W. 1972. Occurrence, dis-

Mexico. 8:1-20. tribution and density of Rangiacuneata in Lakes Pontchartrain and

Ruiz, H. E. 1975. Estudio ecologico Maurepas, Louisiana. La. Wildl.

preliminar de las almegas Fish. Comm. Tech. Bull. No. 1. 8

comerciales del sistema lagunar de PP.Terminos, Campeche, Rangia cuneata(Gray, 1831). Tesis professional, Tarver, J. W., and R. J. Dugas. 1973.

Univ. Nat. Auton, Mexico, 80 pp. A study of the clam Rangia

(cited in Rogers and Garcia-Cubas cuneata, in Lake Pontchartrain and 4.1981). Lake Maurepas, Louisiana. La.

Wildl. Fish. Comm. Tech. Bull. No.

Sikora, W. B., J. P. Sikora, and A. 5. 97 pp.McK. Prior. 1981. Environmentaleffects of hydraulic dredging for

clam shells in Lake Pontchartrain, Taylor, J. L. 1978. Evaluation of

Louisiana. Publ. No. LSU-CEL-81- dredging and open water disposal

18. U.S. Army Corps of Engineers, on benthic environments: Gulf

New Orleans District. Contract Intracoastal Waterway -- Apala-

Rep. No. DACW29-79-C-0099. 140 chicola Bay, Florida to Lake

pp. Borgne, Louisiana. ContractReport to U.S. Army Corps of

Sikora, W. B., and J. P. Sikora. 1932. Engineers, Mobile District,

Ecological characterizition of the Mobile, Ala. 51 pp.

benthic community of Lake Pont-

chartrain, Louisiana. Publ. No. Tenore, K. R., D. B. Horton, and T. W.

LSU-CEL-82-05. U.S. Army Corps Duke. 1968. Effects of bottom

of Engineers, New Orleans substrate on the brackish water

District. Contract Rep. No. bivalve Rangia cuneata. Chesapeake

DACW29-79-C-0099. 214 pp. Sci. 9:238-248.

Simpson, J. W., K. Allen, and J.wapara, . 1959. Fleano aids J U.S. Department of Commerce. 1971.Awapara. 1959. Fren amino acids Fishery statistics of the United

in some aquatic invertebrates. States 1968. U.S. Gov. Print.

Biol. Bull. (Woods Hole) 117:- Off., Washington, D.C. Dig. 62.

371-381. 189 pp.

Singley, J. A. 1893. Contributions to Wass, M. , and D. Haven. 1970. Marsh

the natural history of Texas. clams believed potential food

Part I. Texas mollusca. Annu. supply. Bull. Va. Inst. Mar. Sci.

Rep. Geol. Sur. Tex. 4:297-343. 2:1.

Suttkus, R. D., R. M. Darnell, and J.

H. Darnell. 1954. Biological Wells, H. W. 1961. The fauna of e -

study of Lake Pontchartrain. oyster beds, with special

(annual report 1953-54). Tulane reference to the salinity factor.

" University, New Orleans, La. 59 Ecol. Monogr. 31:239-266.

PP Wolfe, D. A., and E. N. Petteway.

Swingle, H. A., and D. G. Bland. 1974. 1968. Growth of Rangia cuneata

Distribution of the estuarir.e clam Gray. Chesapeake Sci. 9:-99-102.

17

, -- .. - . ..

;;-:. .. . . . . . . . . . . . .. . . . . . .. . . . ... ; .• %,°'. .,. ,.,.... ...-. .. . •.. . -""""'... ••." _,'.,Z''=_= ' '_ L , "-

Woodburn, K. D. 1962. Clams and vicinity. Fla. Board Conserv.oysters in Charlotte County and Mar. Lab. (FBCML) No. 62. 29 pp.

_ _i-

REPORT DOCUMENTATION 1- *91 0fI N0. Li Asle...ql ACt.,'ri NoPAGE IBiologicalReport_82(11.31) __________

4. Th awf a ILtkt es D~., ateSpecies Profiles: Life Histories and Environmental RequirementsA i185of Coastal Fishes and Invertebrates (Gulf of Mexico) -- CommonRangija

7. Aut,.()

2~ ~ ~ Mark W. Lasalle and Armando A. de la Cruz Onsito.Rp.N - .

N . Performing Orguemzeti.., Name andre s Pr"ITe Mr Unf tooN..

Department of Biological Sciencesa-P.O. Drawer GY a ottc o

Mississippi State University CMississippi State, MS 39762 C

IL Smonawng Orge..izaliof Home and Adess(G

National Coastal Ecosystems Team U.S. Army Corps of Engineers IL Ty" f111"APeid.OMl

Fish and Wildlife Service Waterways Experiment StationU.S. Department of the Interior P.O. Box 631Washington, DC 20240 Vicksburg, MS 39180 14.

IS. Supplimtary Noet"

*U.S. Army Corps of Engineers Report No. TR EL-82-4I& Ahr,rcd (Unrit: 200 .Ords)

* ~ ~ 'Species profiles are literature summaries of the taxonomy, morphology, ange, lifehistory, and environmental requirements of ooastal aquatic species. TNy are designedto assist in environmental impact assessment. The common rangiaq(R~angia cunjta is acommon inhabitant of shallow, low salinity (zero to 18 ppt) estuaries along thenorthern Gulf of Mexico. The population density of rangia may exceed 1000 clams/me.'Rangia spawn between March and November, following a sudden rise or fall of salinityof 5 to 10 ppt. Juvenile clams develop rapidly, settling after about 7 days. 2 J'.

Juveniles tolerate salinity and temperature extremes of 2 to 20 ppt and 8 to 32 C.The growth rate of clams ranges from zero to 20 mmi per year depending on conditions.Clams may live 15 years or more, attaining a maximum length of about 94 mm. Rangiaare found in a wide range of substrate from sand to soft mud. Rangia are filterfeeders, ingesting large amounts of detritus and phytoplankton, and are the prey of alarge number of fish, crustaceans, mollusks, and ducks. Deposits of fossil shellmaterial are dredged for a number of industrial purposes. .,

I?. Oec.mrent Alys,s a. Dow,ntor,

EstuariesClamsDredgingb. Idaftfiaaj0.,Cndod Term,

Common rangia Life historyRangia cuneata Trophic ecologySalinity requirements Population densitySpawning habits

* C. COSATI FslId/Group

I&Av~aiiySaeotIt. sstc."rty CI las .,s ep 21. N& at Pages

Unlimited Uncla ssi fied 1630.22. Prie

ti.. ANSI-339.28) ifTIONAL FORIA 272 (4-.77)(Formerly NITIS-35)Department of commerce

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