I _,... ___ CC..'CCCC~---------- MOLLUSCS OF NORTH CAROLINA A Check-list of Marine and Brackish Species · · with No~es on Geographic and Ecological­ Dis tr i bu ti on Douglas Wolfe . CENTER FOR ESTUARINE AND MENHADEN RESEARCH U.S. Bureau of·Commercial Fisheries and Nancy Wolfe Published jointly with the REGIONAL MA.RINE SCIENCE PROJECT Carteret County Public Schools ·Beaufort, N. C. 28516 September, 1970: 200 To Cynthy. Nicky, and Cathy ACKMOWLEDGMENT The autho~s thank Will Hon, Director of the Carteret County Marine Science Progrn~. for suggesting that this list be compiled. for exped1t1ng its pr•paration through the vartous stages of pub11cattan, for making editorial suggestions, and for prepar1nn the illustrations. CONTENTS Paae fJ.vnbcr .... ~~ _,,."'-,..,.... ,._..,..._.... -...- Pref a co 5 Introduction 6 Annotated Chock-1tst 9 Amph1neura 11 Gastropoda 11 Scaphopoda 29 Ceph:lopoda 42 Amphineura - Scaphopoda - Cephalopoda 44 Gastropoda 57 Ref erenct:s 67 PREFACE The coastal waters of North Carolina harbor a very rich and diverse assemblage of mo11uscs. Amateur shell-collectors and.profess1ona1 malaco1ag1sts alike regard North Carolina as a producttve source of mator1al .for pleasure and study. Although we began ·collecting and studying Horth Carolina molluscs only in 1964, we have collac~ed about 300 species from the brackish rivers. sounds~ and beaches of the state and f~om the shallow ccnt1nenta1 shelf offshore. This listing of molluscs is corapiled from our own co11ec­ ttons and from published actounts of other 1nvesttgators. The 11st 1s not complete; additional species lie unreported In various collections, and others remain to be discoveted especta11y in the deepef .water offshore Where tntensiv~ collecting effort has begun only recently. We believe, however,-that the ltst provides helpful information for collectors ·on the distribution and variety of molluscs to be found in North Carolin~ waters. -5- INTRODUCTION Coastal th Caro11na is characterized by its flatness. Here rivers and stredMs flaw sluggishly fta~ the continent into broad, extensivet ~nd shaliow estuar1ti• bay• and sauhds. Beyond the barrier islands. or oute~ bihk1~ the floor of the ocean slopas drad~ally to depths of 150 to 200 feet some 30 to 50 m1les from the·shore. Th1s broad expanse of relatively flat bottom. both inshore and offshore, consists principally of sand and shell sediments. but.the habitat 1s diversified by siltation near the mouths ·of rtvers) by occasional rock o~t­ croppings offshorei and by mnn's construction of jetties and pilings. A rich molluscan fa~na is supported in these various ha bi ta ts .. Cape Hatteras has long been desig~ated as the boundary between the warming 1nfl~ence of Gulf Stream waters and the coal northern currents wht~h flow southward along the coast of New Jersey and Virginia. This unique situation plays an impor­ tant role 1n determining molluscan d1strJbut1on3 and allows the molluscan fauna tn North Carolina to be c~tegorized ~nto three fairly distinct assemblages, ~ach with 1ts own geographical limits .. !n addi.tio.n, ,di.ff_erent molluscs live tri.different types of substrates and some are limited to waters of a characteristic salt tontenti or s~11n1ty. Knowing where a mollusc lives by no means assures the collector of a specimen, but h1s chances are much improved 1f he hunts within-the general geograph~cal range of the species! in or near waters of the proper salt content, and on the best available substrate suited to the adaptations of the species sought. -6- A provfnce is a large Qeograph1c 'rea throughout wh1ch the compos1tton of 11v1ng organisms is about the same. The boundaries of such areas are u~~a11y not obvious and do not represent strict limits an th~ distribution Df the organisms within. Oceanic circulation patterns and climate 1nteract, however~ to produce detectab1e.discontinuitfes in the distri­ bution of marine molluscs in th$.wo~ld oceatis. North Carolina is somewhat unusual tn that three distihct molluscan assem- blages occur along her coast. These assemblages represent the VIRGINIAN, CAROLINIAN, and CARIBBEAN provinces, whose approximate extents are shown in figure 1. Cape Hatteras might be con- s1dered the landmark between th& northern temperate molluscs (V1rg1n1an) and the more southern sub-tropical forms (Carolinian). The Caribbean fauna tn North Carolina are restricted to the offshore edges of the Gulf Stream south of Hatteras. Not all species o~ molluscs conform to the distributional pattern of the three provinces. Cape Hatteras is not a strict range limit for all speciesl and varying degrees of overlap occur between the provinces. Northern species like~- arenaria a n d Mn 1 1u ~ e d u 1i s_ o c cu r s o u th of the ca pe d u r i n g wi n t er a n d early spr1ng~ and other northern species have permanent ranges extending into south Carolina. Some southern spec1es occur also in V1rgin1a. A few ~pec1es, like Nucula oroxima) occur all along the east coast and tnto the Caribbean; this range ts called TRANSATLANTIC. Although many species do not conform to the three provinces, collectors in North Carolina will benefit from knowing whether to expect a particular species north or south of Cape Hatteras~ along the coasts or whether the iV\OtLUSCAN PRDVJNCES ~ V1RG1NIAN . CAR OLfNiAN CAR.JBBEAN Pamlico oaea~ sh s our.a and th "' "' nt ow.Virgin.la e •djacent . e.r. "( se.e .t.e"'t-~J "' • chara.cte.,.,.... ... Sf:J.CS. species occurs only in the Car1bbean Province offshore. (For further discuss1on of molluscan provinces, see references 5 and n ,, ) Si!J>J>tr.~~ Af.fin.JJie~. ·rhe coastal plaH1 of North Can::liina and the adjacent shallow ocean floor are composed mainly ot sand. Many molluscs! including most filter-feeding bivalves and gastropod groups such as 011vidae and N1t1c1d1e 1 are well adapted to life in this type of bottom. ·In some locations, particularly in channels at the mowths of rivers, silt gathers~ forming a muddy sand bottom. Here the molluscs may be adapted to feed on the surface deposits of m1croorgan1sms and decaying organic matter. A great variety of North Carolina molluscs are found. however, not in sand or mud, but on a solid substrate. Hard substrates are relatively rare and include such habitats as rocks (mostly on jetties, but also on a few outcroppings along the continental shelf offshore), pilings. hard corals. and the Since certaH1 bivalve species burrow deeply 1nto rock, coral. or .shells~ supic1ous hol~~ should be checked carefully for molluscs. Shipworms {Tered1nidae) wtll be found deeply fmbedded in hole- ridd1ed wood, a·lcrng with species of Martes·la. Oth~r Pho1adidae burrow into peat, clay~ ar hard mud. Finally> many small species wtll be found crawling on seaweeds~ algae$ eelgrass, and other plants; and egg shells and f1am1ngo tongues (Ovul1dae) live exclusively on the soft sea fans or whip corals. Salinit~ Preference. The distribution of some molluscs is restr1cted by the salinity tolerance of either the adult argan1sm or of some larval form. A few species are restr1cted to lhe low salinity areas at the mouths of rivers o~ at the up- stream limits of the estuary, where the salt-marsh grass §...2.!ftir'..L~.1ti11,rnilli.!:_i!_ 1~ absent. Mowever, most estuarine molluscs are able, as 1s ~eartin~~ to tolerate wide ranges of Ocean1c organisms, on the other hand, are not sub- jected to saltn1ty fluctuations. and generally the range of variation th can tolerate is much narrower. Some predominantly ocean-dwelling molluscs are found~ however~ in the sounds near inlets where the salinity may occas1anal1y drop to less than fullstrength sea-water (35 to 36 parts per thousand lilt content). Other species occur on~y in tha ocean proper, although salinity may not be the dom1n1nt factor controlling the1r d1stribution there. The salinity ranges used in the checklist are arbi~ trary disttnct1onss which are not intended to represent the actual salinity tolerance of any particular species but only to serve as a guide far locating different species. ANNOTATED CHECKLIST The taxonomic listing of spec1es follows the order of T1y1or and Sohl (2Cal for Gastropoda and that of Vokes (2Cb) for Bivalv1a. Literature referencess indicated by numbers, are listed tn the bibliography. Unreferenced 11sttngs have been collected or observed by the authors. Explanation of symbols used in checklist: Province v Virginian c Caro1·iirian T Transa tl ant·i c G Caribbean {Gu'!f -9~ Substrate S Sandi sand~shei1 M Mud~ mud-sand C C1ay, peat A Attached or crawling on shells& rocks, pilings, etc. R Burrowing 1n rocks, coral, shells W Burrowing in wood G On whip or fan coral . P On plants (algae, widgen-grass, eelgrass, etc.) 0 On other organisms (parasitic or commensal) .c F ree-sw1mm1ng;~ .. peiag1c-flt .: 1 Fresh to brackish {0··10 o/oo) 2 Estuatine (5-30 o/oc) 3 lower estuarine to oceantc (25-35 o/oo) 4 Oceanic (35-36 o/oo) a Intertida1 ~10- \"' [) i',1 V L U M rv1 Q ' i II c· C f\ I fl I ,, l! L L ., .;) t~ I ! I WV) 0:: w.J :::>U 1-·Z <(I.I..! 0:: cc. Lt.I w.J I ,..... !J,.. CLASS AMPHINEURA 1~~······----- ORDER CIH TON l DA Family lschnoch1ton1dae ! l I Chaetopleura apiculata Say 3-4 j 1 ~9 ,9a ,2·i I CLASS GASTROPODA SUBCLASS STREPTONEURA ORDER ARCHAEOGASTROPOOA Famtly Sc1ssurellidae Scissurella crJspata Fleming 4 Scissurella proxima Dall Family Haliotidae Haiiotls pourtalesi Dall Family fissurellidae Emarginula phr1xoides Dall RJmuJa frenula Dall Diodora fluvJana Da11 Lucapina sutfusa Reeve t 1 5 rucapine11a llmatuld Reeve 4 I 1 Fam11y Trochidae ] Lisah~ala ottoi Ph11ippi 4 s~1aziella lamellosa Verrill I Smith I 1 I 1 , 1 s Salariella lacunella Dall ! -11- Hicrcgaza zotella Dall Calliostoma baizdi Verrill & Smith Calllostoma balrdi psyche Da11 Calltostoma euglyptum A.