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THE NAUTILUS

Volume 117, Number 1 April 28. 2003 ISSN 0028-1344

A cjuartcrhj devoted to malacology.

EDITOR-IN-CHIEF

Dr. Jose H. Leal

The Bailev-Mattliews Slicll Miiscuin 3075 Sanibel-Captiva Road Sanibel.FL 33957

MANAGING EDITOR

Christina Petrikas

The Bailey-Matthews Shell Museum 3075 Sanibel-Captiva Road Sanibel,FL 33957

EDITOR EMERITUS

Dr. M. G. Harase\v\'ch Department of Invertebrate Zoologv' National Museum of

Natural Iliston Smithsonian Institution Washington, DC 20560

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Dr. Arthur E. Bogan

North Carolina State Museum of

Natin"al Sciences Raleigh, NC 27626

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Invertebres Marins et Malacologie Mu.seum NatioiuJ d'Histoire Naturelle 55, rue Buffon Paris, 7.5005 France

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Center for Conser\ation Research

and Training Uni\crsit\ of I la\v;iii 30.50 Malic Wav, (iihnore 409 Honolulu. HI 96822

i:)r Robert T. Dillon, J r Department (jl Biology College of C;liarleston Charleston, SC 29424

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Dr. Charles Lydeard Biodi\'ersitv and Svstematics Department of Biological Sciences University of Alabama Tuscaloosa, AL 35487

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Florida Museum of Natural Histon- University of Florida C;aine.svirie, FL 3261 1-2035

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Dr. G. Thomas Walters Aquatic Ecolog\' Laboratory- 1314 Kinnear Road Columbus, OH 4.3212-1194

Dr. John B. Wise

Houston Museum of Natural Science Houston, TX 770.30-1799

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TH Et7NAUTI LUS

\'(>liiiiic 117. Xiiiiihcr 1

April 2H. 2003

CNTKXTS ISSN 0028-1344

Fred E. ^^'ells E(.'(ilii<j;i(al scpaiatidii (il tlir iniulwliclks nrcliidliii sulcntu

(Born, 177S) ami T. scniistiiatd (Moirli, lS52i ((^astmpnila: Potainiilidac) trniii luirtlierii Australia 1

Dici;<) (;. Zola\a Two new species (il Arn/c/j/u/i Moiiteins.ito. 1 S75 i l^i\ al\"ia:

Christian Iliiarle Nenleptoiiiilaei lioiii South Cedi^ia Islands. Soutli Atlantic

( )eeau fi

Gai'A' W. Sclimelz \ new speiies (il Mrtitld (Ciastropoda: ( lolnhraiiidae! Irom

Rojjer W. Portell the Liiwcr Mincetie ('liipola Fiirniatinu el l'"liiiida 12

Ciiido Pastorino A new species ol Ancillariinae (Clastropnda: ()Ii\idae' liciui

the southwestern Atlantic Ocean 15

Hicliarcl C. ^^'illan On the publication date, authorship, and tApe species of

H()l)erl Burn I'liiliriiciiliiin and 'DjIinliHa (Oastropoda: Opistliohrancliia:

Fn liidiuoidea): a rejoinder 23

Book Re> icw 29

Notice 30

U'-:',T,u.-, Sii

MAY 5 2003

^^'ooc's hvjie, W.A 02543

tulion

Sponsored in part by the State of Florida, Department of State, Division of Cultural Affairs, tfie Florida Arts Council and the National Endowment for the Arts.

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THE NAUTILUS 117(l):l-5, 2003

Pirn- 1

Ecological separation ol the nuidwhelks Tcrcbralia sulcata (Born, 1778) and T. sciiiisfriafa (Morch, 1(S52) (CTastropoda: Potaniididae) from northern Australia

Fred E. \\ells

Wcstciii Aiistialiiiii MiiM'iiiii I'ciih (iODO, Wcslriu \iislr.ilia AUSTHM.IA WfllslC'i'iiiuscuiii.wa.iliA.au

ABSTRACT

Until R'fciitK. t\M) species were reen'^iii/ed m llir |)i>l,iiiii(li(l s;eiiiis Tii'ilinilhi T jinhistris (L.iniiaens, ITliT' and / siilcntn (lioiii. ITTS' I Iduliriek (1991) separated /' \(iiii-,l liiitii (M()relr 1 Soi i hdni /' \iiliiilir ha.seil cm a detailed e\aiiiiiiatiiiii ol shells, radnlae, an.iti jiii\, and t^eniirapliieal ilistril)utinns. The present paper pniMdes ei iniparati\ e data i m '4eii^i aplneal dis- tliliutiiin alcin;^ the Anstialiau coast, liahitat, si/e lre(|nenc\ characteristics, and densities of tlie two species, w Inch provides further confirmation that separate specific status is warranted.

Adililioinil kill iiiii'd.s (a'nthioKk'a. uiantjioxes, ta\onoui\. ecolo<r\.

IXlHODlt riox

Tile Pdtainididae is one of tlie (li)nnnanl families of hkiI- iiisks in in,in'j;rn\es in tlie liulo-West Pacific region. In particular, iiiiidw lielks cjf the m'lieia I'lnhniliii and 7r/- csr(>j)iiiiii are aniiiiig the largest and luosl visihleol niaii- gr()\e inollusks, and are ke\' components ol the ecos\s- tem (McNae. I9fi7; IVjaS; Plazait, 1977; 1984; Wells and l„illi. ill press! ill a series of studies in the Ba\ of f-iest. iioithwestern .Aiislrali.i, and in IIoiil!; Kong. Wells ( 19S0, f9S:l f9S4a, 19S4li. 19SH. 1990) demonstrated the im- portance of Tcrchralin (the Ba\ of Best population was identified in tlu' piipcrs as T. sulcald hut is now consid- ered to lie 7! sciiiisthtltd). For example, rcichniliii sfin- istlidtil comprised 55'^ of the hioniass ol ail inxerte- hrates in the Alicciiiiia /one ol the iiiaiigro\es iii the Bay ol Best, Both 7' jxilusfris and T s<inistniit(i can attain signilic.inf densities (often al)o\i' 100 in -i within mangroM's. hiil populations reach to the edge ol the At - icciiiiid pnenmatophores and no tnrtlier (Wells, 19Sfii.

Ill recent years there has been an increase in studies ol Tcri'hrnlia, inclndiiig their general hiologx (Soeiiio- dihardjo and Kastoro, 1977: Rambaliii et ,il., 19S7'. feed- ing (Nishihira, 19.S.3; Slim et ak. 1997). eark gniwlli (Bao. 193S: Hashimoto and Xishijima. I9S7), historical (k'clincs in populations ((Jligaki and K.nro/.imii, 2000),

iiini[iarati\e ecology iWells, 19S()I. ;ind I'elatioiislup to canopy i-o\er ((.royvc. 1997; Croyyc and McMalion (1997).

I'litil 1991. all ecologii-al studies recognized only fyvii species of I'cnhnilui. T. iiillii\tri\ (IJiiiKU'ils. f 7B7 ! ;md 7' \iilciitii (Born, f77S). In a m;ijor reyision of the group. Ilonlirick (1991) recognized a third species ol Tcrfhnil- iiL sep;n'atiiig 7' scmistriala (M()rch, 1852), a taxon pre- yionsK considered lo lie a syiionyiii oi 7' \ulcillil. The yyxirk y\'as based on ;i yyide comliination ol characters, including shells, ratlulai', anatoiny, and geographical dis- tributions. Wilson (1993) considered the diyisiou of 7' snJcatd into tyyd closely rekited species re<|uiretl confir- mation based on ecological separation ol the species. The pn'Sent paper compares the ecology of T. scmistria- l/i antl T. sulcald. confirming that separate specific status is yyariaiited.

MATKBI \1,S AM) .MKlllonS

Tcrchrdlid scinislrinhi .iiid V' sulrdid yyere found to occur in separate portions ol tin' same mangroye systems dur- ing ;i collecting eypeditioii iiKide to DaiAyin Harbour, Northern Territory, in |une 198(i. The ty\(i species yyere tagged for groyyth studies at Maiidorali ( 12'54' S; 13()°32' E) in .May and December 1999 respectiycK and yyere monitored ;it ;ip|)idximately six monthly iutenals. The compaiatiy e study ol the tyyii species reporti'd here was made Iroiii 21 to 2(1 M.iy 2001. on the last yisit lor till- gri i\\ ill studies.

The ty\o species yyere re;idily identified ill the field using shell chaiacters described by Hoiibrick (1991'. The shell of Tcrchrdiui sciiiislridln is larger ;m(l lieayier than 7' Milcdtd. has yyeaker sutures, is yyeakK sculptured yyith flattened spiral cords, and lacks a\ial ribs,

\ 30 111 Irausecl (ape \\;is placed peqiendiculai' to (he shoreline at the Iroiil ol the mangroyes (Tcrcbrdlin \ul- fdld'i ;m(l at the back ol the mantrroycs (7! sciiiisliidid''.

\ 1 II

ladrat

yvas si'arc

hed

eyery z m ironi

(he

\yard or Jandyyard Iriuge ol the mangroyes until the limit

Piige 2

THE NAUTILUS. \V)1. 117. NO.

-^^

Figures 1, 2. .Shell ol Ycnhvitlui siilcdin \\ ' .mil /' Mini- slriala (2) from the niangrove.s at .\l,iii(l(ir.ili, Daiwin M.uixiiir. Nortlieni Tcrriton'. Scale liar = M) iiiiii.

creek. Fitt\ animals were coiiiilcd in each lial)itat. To he eonsiderecl to l)e on the nuuiiiroxc. llie snail had to ha\e the sliell apex oil the f^ronnd: animals Kin'j; on the mud snrlaee with thi'lr loot attached to a inan'.ir()\'e were con- sidered lo !)e on the sediment.

Shore lieiiihts ol llie populations were determiued on the alternoon ol 22 Ma\ 2001. The time when the lower portion ol the Tcrchrtilia siilcala population hecame co\- ered on the lisiuii; tide was noted, and the tide followed up the shoreline. Shore heights were determined hv com[)arison with the .\ustrahan National Tide Tahles (Department ol Deleuce, 2000) lor Dan\'in Ifarhonr Tides in the harhour are predominantK semidinrnal witli a Tuaximuiii ramie during the vcar ol 7.S m. '{"lie mean neap tidal range is 1.9 m. while springs axerage 5.5 m.

Data on geographic distrihutions ol the two species were ohtained l)\ examining specimens in the .Australian Museum, S\(lne\ i.WIS). The Natural IlistoiA Museum. London (HMNTli. National .Museum ol Natmal iliston. Smithsonian luslitntioii lU'SNNL'; Western .Australian Must'um i\\'.\.\l). ,iud the Zoological .Museum, (^opeii- haw'n (/..MC),

ol the snail popuialious. Ail snails encountered were counted and measured lo the neanvsl I nun willi cali- pers. FoiU' transects were made at ~> m interxals along tiie slioreline lor T siilcnlu ,iiid at 3 m inlei'\als Im- T. scmisfriafa.

The hal)itals occupied li\ the snails were also noted wlien searcliing the transects. .Additional snails were col- lected in the area to ohtain 500 measni-ements lor Tir- I'hralia si'iiiistriata and as man\ as possilile lor 7' .siilcal/i. a.s there were insullicii'ut T sulciilii in the area (o mea- sure 500 individuals. Total shell length was mcasui'ed to the nearest 1 mm with calipers. \n inllated outer lip is lormed when the animals mature, alter which no lurther IncrciLse in shell length occurs illoiihrick. 1991 >. I'osi- tioiis ol I', siilcatd on niangrovc's or sediment snrlaee were mea.snrcd to the ca.st and west ol a small tidal

RESULTS

Populations ol tiic two species (Figures 1. 2^ were clearK' separated in the mangroxcs at Mandorah. Tcrchralia sitl- cdlii oeciipies the seaward /one ol the mangroxes at a mid-tidal level ol 4.9 to 5.3 in (Tahle ll. Tiie site is near .1 channel hehind an intertidal sand heai'h. and is occu- pied li\ a mixed mangrove assemhlage. including txvo Luge Aiicciiiiiii iniiriiui trees, one ol which is ajiproxi- niatelv (i III high, sin, ill i <2 iiO ('criojis iiiisl rails, and isolated trees ol liliizopliora sli/losa. Tin' mangroves vai"\' in size Irom small sa|)lings a lew centimeters higli to lull grown li slifloMi The eh.innel h.mk slopes steeplv up to the mangrove /one. where the shore levels oil. The uiiiddv sand is then relativelv Hat. with shore height in- creasing hv 0.4 III over a hori/.outai ilislauee ol ai)out 25 111. This ilat area is occuiiicd hv T. sulcata. Shoreward

Table 1. (loiiiparisoii el the iiMi(l\\lielks I'cichidlid siiliiilii ,niil 7' sciiiislriiilii In the iii,iii<iriives ,it M.iiKldr.ili. l)aiA\in ll.irliour, Nortlieni lerrilorv. The ilillerenee helweeii hahit.its (leeiipied tn tin' east ,iii(l v\est (il the tidal ereek was sl,itislie,illv si^iiKieailt (x^ = l9.fS. p < ().().5!.

( li.ir.ielerislic

r<iil)i(ili(i sididUi

Iriihidliii \nnistriiitii

Position ill iiiani;rovcs .Shore liciglil liahitat

neiisitv

Si/e Ireiniencv eli.iraeleristies

Other pol.ntiiilids picsiiil

Seaward inargin

•1.9-5.3 ill

On sediiiieiit surl.iee; also elinilis iiMiinrove

trees, slirnhs and piieuiiialijpli(ires to a

lieiijlit ol ii]i to W) em Mean 0.4 i 0.1 in -. Sm.ill. Mean length ol pojMilatioii 2S..5 ± 0,'

mm 111 ^ I9(ii. rangi' 13—14 mm. .Adults:

Mi'an Ic'iigtli 33.7 ± 0.4 iiiiii in = S2'.

range 2(>— 13 iiiin. None

Shoreward margin (i. 1 -(l(i in

On sediment snrlaee: never elinihs up iiiail- grovi's

Mean 1 ,3 ± O.-i iii -.

I..ir'j,e. Mean leiiglli ol popnlalion 411,.") ± (I.S

mm II ^ 49S1. range 1.3-(')9 mm. Vdiilts:

Mean length tiO.ti ± 0.3 miii ui = 113).

range .51-69 mm. Tcrchniliii j>(ilii\lris. TclcsC(>i>iitiii Iclcscujiiiiiii.

Ccrilliidcd hif't-lliciii

F. E. Wells. 2003

■atic

Tahio 2. ( !ciiii])arisi}ii dl I'l nhniliii siilcalu (in llic nniil siirlarc :iikI on iiuiii<;r(>\i's to tlir cast and west iil the small tidal rrcrk at Maiidorali. Oanxiii Harliniir Xortlicni IViriton

		\ Itlllliel ol
	Kast ol	snails west ol
llaliital	tidal creek	tidal creek	Total
( )ri sand siiiiacc	11	.').'>	II
( )ii iiiail'j;rn\rs	39	IT	5(-i
Total	50	5(1	10(1

(lie niaiiiiioM' lieeiiines a nu iik ispetific Idlest (il lai^c R s/(//ri\r;

Tn'chnilid siilciili: nci'iii' Imtli mi the sciliiiiciit suiiaee ami on the l()\\er tiiinks and leaM's ol the inaii'^iiAcs to a heiij;ht: ol (iO em. thoiitili most oeeiir at less tliaii ■')() em Iroiii the smiaee iil tlii' mnd. \ (lillerenee was loniid hetweeii loeatiuns ol T siilrtild on iiuin<;ro\es to the cast and west ol .i shallow tidal creek. The creek is approxi- iiiateK 20 ill wide at hii^h tiile, Init oiiK' 5 in at low tide. Till' eastern side, where the Ixiiik is steep, contains a small, monospecific stand ot (Vr/o^is diisfnilis. Se\t'nt\- eiij;ht percent ot the 7'. sidaita were on the trees when sur\p\ed at low tide (Table 2). The animals secrete mn- I.IIS. which hinds them to the iiiaii'j;ro\i'. It the imdei-- kiu^ surtace is Hat, the nineiis can loriii a complete seal and fuiiftioii as an epiphraij;ni. More lommonK', the tnti- cus act.s to attach oiiK the inner pai't of tlie sliell aper- ture to thi' maiit!;ro\c. Botli adults and jn\eniles are found on the mnd surface and on tlii' manifroxes: how- ever there is a tendenc\ tor jineiiiles to predominate on the niangrtnes anil adults on the mud surface.

To the we.st of the small tidal creek, where the tran- sects were made, Tcrchmliii snicala were most common on the mud snrlaee. with fifi^i oeciirrin<; on the mud. The difference between hal)itats occupied to the east and we.st of the tidal creek was statisticalK' significant. While no quantitative measui'ements weri' made, T. siil- fdlii under Ar/rciiiiiii iiuihiui were Iar'j;eK on the sedi- ment surface, while those in lihizoplnini slijlusd or CVr- iops inislralis tended to he on the mangroves.

In contrast to Terchralia sulcata, the population ol 7' scinistiidtii occurs at tlie landward Irinsie of the iiian- t^roves, approximatek 10(1 m to the iioi-thwest, Tlie hab- itat is a sand surface with a mixture ol iiiaiit;;ro\e species, iucludinii; jiredominantK Rliiztipluna sli/lDsa and Aviccii- iiia marina, at a tidal hei'Jit ot (S. 1 to R.tS m. .\ii iipjier inteitidal sand beach commenci's at a shore heiiihl of H.6 m. torniini4 the upper limit ot the population of 7' scmistriatd. While some individuals of 7' scitiisthata oc- cur amonnst the H \ti/li<\(i. most are on the open mud surface anionic the .\, inariiia piieimiatophores. The lo- cations ot the snails clian'j;e soniev\lial over a txvo-week tidal cvcle as thev seek protection from desiccation amonij; the maiiiirove roots duriii'j; the neap tides, llow- I'ver, thev never climb the mangroves as ociairs in 7' sulaiia. I'Aposed Hat roi'ks in the centre ol the man-

ijroves limit the seaward exteni ol the T. sciitisl riala pop- ulation.

Separation ol ihe two liviii'^ populations is complete. \ total ot 744 Tirchiiilia miIcuUi were measured during; tlie tasiiiiui; experiments: no living individuals ol T. sciii- istiiata were loiind in tli<' I' sulcata population. .A total of 2270 r sduislriala were measureil: oulv a sin'Jc livinsj; /. sulcata was lound in the T. sciiiisli'iala pojinlation.

There are also dilferences in the densities ot the two populations ot Terchralia I'criliralia sulcata has a vcn low deiisilv ol oiilv 0.4 ± 0,1 m ' and did not co-occur with other potamidid species. The mean densitv ol 7' sciiiistriata was \ .3 ± 0.3 in -. 'i'hree other potamidids occiiri'ed in the transects with T. scuii.slriata. Tirchralia jialustris and Dlcsccpiuju tclcsccpiutn (Limiai'us. 17oS) had mean d<'iisities ot (i, I ± 1,2 iii ' and l.K ± O.Ci m - respect ivclv. A single specimen ot C'critliidca lariu-llici-fi (Philippi. 1S49I was also found.

There is a clear diifei'ence in tlu' size trei|iieiKv char- acteristics ot Terchralia sulcata an<l T. .scndstriata at Xhuidorah (Table 1: FiL^nre 3). The mean size of adult 7" sulcata is 33.7 ± 0.4 mm, with a mLLximum size of 43 mm. In contrast, the ineaii size of adult T. scniistriata is fSO.rs ± O.) mm. with a maximnm of 69 mm. Tims the smallest adult T snuistriata was S mm lari^er than the larijest adult 7' sulcata.

Exaniiiiation ot specimens in museiuns shows that the ,\iistralian distributional data provided for Terchralia sul- cata bv Ilonbritk (1991) are inacctirate. Essentiallv Iloubrick assume<I tlie hvo species had tlie same geo- graphical range on the north coast of Australia: from Shark Bav, Westeiii .\ustnilia, to southeiTi Queenslaiul. Terchralia snuistriafa is in fact widi'lv distributed along the north coast ol tlie continent fiom Sliai'k Bav, West- ern .Austialia, to Keppel Bav on the east coast of (,)ueensland (F'igure 4). Terchralia sulcata also extends south to Keppel Bav, Queensland, but it is restrii'ted to the Kimbei'lev, from Broomi- northwai'd. in Western .Australia. In the text of liis paper. Ilonbrick (1991) refers to specimens of T sulcata tiom more southerly localities in Westei-n Australia: Rowlev Slioals (USNM 847084) and Bav of Best. Xorth West Cape (USNM SOlfiOfi). Specimens ol both lots were re-examined for the present papei-. The label for USNM 847084 clearly states the specimens ot 7. sulcata were collected in Broome In the H<iwlev Shoals pApedition. Limited collecting was done in Broome before sailing tor the Bovviev Shoals. The shoals are open ocean i-oral leid atolls and no Terciiralia occur there (Wells and Slack-Smith, 19S(i). Thi' speci- men from the Bav of Best (USNM S()1606) was ajipar- entlv first lonsidered to bi' T. sulcata bv Ilonbric'k, lie later changed his iniiKl and included the spetimen in T .scmi.sthata in the Smithsonian collection, but appai'i'utlv neglected to change his wiitteii notes. That specimen and all others collected in the Bav of Rest are in fact T. seutistriatiL

DISCUSSION

The present paper demonstrates Terchralia scinistriata ,111(1 7 sulcata are clearlv separ.ited ecolo^icallv. There

Page 4

THE NAUTILUS, Vol. 117. No. 1

E 'o

* .-

o. 4U

Terebralia sulcata

500 km I

DAdults □ Juveniles

Shell length (mm)

Figure 4. (^Miijrapliiial (listriliiitidii ol icrchidlui suhiilii and T. snni.slriiitii in iiortlicin \iislralia.

Terebralia sermstriata

120 '

DAdults

^ □ Juveniles

specimens

i-j

Urn

£ 0-

—L^

—

Shell length (mm)

I'igiirf .'{. Si/c li'c'(|iicnr\ liisto^iaiiis ol rmliniliii miIhiUi (upper) and T sfiiiislriiita (lowcrt i-ollcclcd ni llic niaii'.iii>\i's at .Mandoraii, l)an\iii llarhour. Xiirllicrn Inrildn Ikjiii 21 t<i 2(i Ma\ 2001.

inan<j;n)\e .sxsttMiis, liiit tlic\ occiipx' separate areas of the inangro\es. W'lu-ic the two species li\c in tiie sanu' iiian- tir()\(', 7' siilcala li\es in tlie st'award. nntl-inteitidal por- tions ol tile inan<4i()\cs, while i siniistridid li\es in the shoreward, npper portions ol the nian<j;ro\es. Terebralia .slllcilhl Ii\es liolli on llie niiid snilaee and also elilllbs lip to do em up ihe nKuiii;ro\es: in eontrasl. I', sfiiiistridta aie alwa\s on the scdnnent surlaee and iie\i'r I'liinh up the inany;i'o\cs. .Shells of T. sciiiistritila are siij;nifieantl\' lankier than those ol T. sulcata Ironi the same inaiigr()\("s. Inlonnalion on the se^reiialion ol llie Iw'o species at .\iandoiah was eolleeled iucideiitalK to a major tasjging |iro<4rain coiulneleil lo stiiiK growth in all thri'c species ol 'TcrchralKL lApedltioiian siincvs ol inolhisks in tlie Kimlieiiex region ol Western .\iistialia and near (a)\c in llie Northern icrritorx iWells. impulilisiieih have lonnd a niinilier ol man<i;r()\es when' similar se<4rey;ation occin's lielween po|)iilatioiis of 7'. sidcatu and 7' sciiiisl riala. Be- iMiise ol the eonsiderahli' expense ol working in remote areas, onl\ llie \landorali po|)iilalions eoiild he exam- ined in detail.

are substantial (lillerences in their ^eoii;ra|iliieal dislri- i)uti()ns. Moiilirick (1991) examined numerous speci- mens of T. sulcata from a wide rantie m the wcslein Pacific Ocean. iuclii(liii<4 -\jala\sia. \ ietnani. Indonesia. Papua New (aiinea. Philip|)ines. ( .liina, l\Mik\ii Islands. and the (Caroline Islands, lii eontrasl T. sciiiistritita is iimitetl to the north coast ol Australia and southern New (aiinea.

In northern .\iistialia. Tcrcliralin siilcnln is limilcil lo tlie coast lH■t^\(■en Broome. Western \iislialia .iiid Kep- pel Bav, Queensland. Terebralia seinislriala oci'iirs in the entire range occupied 1)\ 7' sulcata in norlhern .\ustralia l)ut is also common in ihe lai'^i' slrelch ol eoasi lielwci'ii Shark Bav and Broome Western .\iislialia In llie region between Broome and Keppel Bav. ihe two species ol Terebralia are svnipalric in ihal lliev inli.ilnl llie same

\(KN()Wi.i:n(:\iiNTs

|)i |. 11. ll.inlrv llieii III llic Northern Territoi"v Mu- seum, picivided detailed km ivv Ie(l',j;e ol Danvin Harbour ill iiiv earlv expeditious lo the area and exleiisivelv dis- cussed Tii-ebralia with me. .\1\ sniiseijiieut research on lliis •j,enus has benefited greallv Iroiii these disi-ussions. 1 lliank die |)ublieaiis awA slall ol llic M.iiidoiali Beach 1 lot el III! iheir wai 111 lios|)italitv dm iii'j, iiiv v isils lo .Man- doraii l)i \l (i 1 larase\A\cll kiiidlv airanged access to llie molliisk (.■olleclions of the Smithsonian Instiliitiou; Ms. Kalliie Wav lo those of the BMNll; and Dr. Jorgen Knndscn In tin- /.i iiilo'j;ieal Miisenm, ( openliagen. Mr. Ian 1 ,oeli and I )i W iiislon I'ondei ^eneiousK' |)r()\ided distribulioiial mloinialiou Iroiii llie .\uslialian Museum. Svdnev. Mr. (.'lav Brvceaiid Mi (oiev \\ liisson provid-

Wells. 200

Pasie

I'd Iccliiiical siippoil III llic [)ii'[i:ii;lI|(iii iiI llir iiiaiiii- script.

LITERATURE CITED

( JDwc. T. 1' \'rl':)7. The ilistnliiitKJii nl I'ln Imiliii iiiilnslii-, \\illi respi'et t(i iiiierolialiital in iiiaii'j,iii\e lnresls ul l)ai"\Mii Harbour. I: Descriptieii's el palhiiis In ll.nile\ | |{.. (;. Caswell, n. .Megerian ami 1 1 K l,.irsnn cds ! Tlie Marine Flora ami Fauna of DaiAMii llarliiini Xoillurn \iislralia. Nortlieru TerritoiT Mnsenni, IJan\iij. and llir \usliali,iii Marine .Sciences Association, pp. 425 — 13.'>.

Cnme. 1', V. and R. F. McMalion, 1^)97, Tlie thslrihution ol' I) iihniliti pahistris with respecl to niitrohaliilat in uian- '4ro\e lorests of l^aiwin flarlioiii, II: F.\peiiiiieiital e\al- iiation ol l)eha\iour. In: IIanle\, |. 1\.. (;. Caswell, 1). Meg- eriau and If. k. Larson (eds.) The marine Flora and Fau- na of Danvin llarhoiir. Northern .Australia. Northern Ter- riton .Museum. I).u^\iii. and the \iislialiaii M.uiiie Sciences .Association, pp. 435 — f44.

Department of Defence. 2000. .Australian Nalioii.il fide 'fables 2000. .Vustraliau Ilsdrographic Publication 1 1 \uslralian (Ancnmieiit Publishinsj Senice. (,'anberra

1 1.Lshiinotn. 'f. .iud S Nishijinia. 1987. I^ist lanal dexelopmeiit and growth ol rcnbralia sulcata iBorn' idastropoda: Po- (.uiiididae). Hioloijiciil Magiizine of Okinawa 25: 53-.56.

Ilonbncf, l\ S. 1991. Systematic re\ie\\ and Imietiorial iiior- plioloiH. of the niansjrove siuiils rciihinlni ,iiid Tclcscojii- iim ( Potaimdidae: Prosobrancliia! M;ilaeol(i'j;ia '^S. 2S9- 33S.

McNae, W. 1967. Zonation within mangroves associated witii estuaries in north (Queensland. In: LaulT. C. H. (ed.) Es- tuaries. American Association lor die \d\,mcenieiit of Sci- ence Publication S3, pp. 419-124

McNae, W. 196S. A general account of the tauna and flora of mangrove swamps and forests in the Indo-Wesl Pacific region. .Advances in Marine Biolog\ 6: 74-270.

Nishihira. M. 19S3. Grazing of tlie maugnne litters bv Tcrc- Iniiliii piiliistris (Gastropoda: Potamididaei in the Okina- w.iii mangal: Preliminar\ report. (lalaxea 2: 45-58.

Oligaki. S.-f. and T Kurozuiui. 2000. Historical decline of the mudwhelks Tclcsctipiiiin and Terehnilia m the l\\nk\u Is- lands and Taiwan: Evidence from shell inoiinds. .Asian Ma- rine Biologv 17: 125-135.

Plazait, ].-C. 1977. Les cerithides tropicau.x et leur poKnuiqih- isine lie a I'ecologie littorale des mangroves. Malacologia K-i: .3.5-44

Pla/iiil. |,-<!, 19S4, .Miilliisk tlistribulioii m t\\r inaii'j;ro\e. In for, I'", D. and f. Dor (eds.) Hvdrobiologv of the .Mangal. f)r W, jimk. 4lie Hague, pp. 111-143,

K.imbabii, A \ S., B. \'. Prasad, and M. Balaparameswara Kao. 19S7. Hesponse of the mangro\e mndsnail 'rcrchnilid juil-

iistiis I Linnaeus li Pidsobianehia: Polainididae i to different substrata. |oiirual of the Marine Biological .Association of India 29: i 10 I t.5

Kao, II. S. 1938. Obserxations on the urouth and habits ol the gastropod mollusk. I'l/mziis imliislris (Linne!, in the .\n- tlamaus. Heeords of the Indian Museum 40: 19.3-200

Slim. F. ].. M. ,A. Ileimninga. and G. \an der Wide. 1997. Leaf litter reino\al b\ the snail Icrfhrnlid i)tilii\lri\ (Linnaeus) and sesaiinid crabs in an east .Alruan iiiani;ro\c forest (Gazi Ba\. Kenva). |ouriial of Exjierimeiilal .Marine l5iol- ogv and I'.cologx 215: 35.

Soeiiiodihardjo, S. and W. kasloro. 1977, Notes on Ti':rlinilirj palmtri.s ((iastropoda) from the coral islands in the Jakarta Bay area. Marine Research in Indonesia 18: 131-I4S.

Wells. F. F. 1980. A comparative stiuK of distribution of die nmdwlielks TcrciiniUii siilriila and T jviltifitris in a man- grow swamp in norlliwrstei ii Australia. .Malacolo'^ical Re- view 13: f-5.

Wells. F. E. f983. .An anaKsis of marine invertebrate distri- butions in a luangrove swamp in northwesteni \iistralia. Bulletin of Marine Science 33: 736-744.

Wells, I' l\. 19S4a. (.'omparative distribution of uiacromollusks and macrocrnstaceaus in a North-western .Australian man- grove svstem. Australian |ournal of .Marine ami Fresh- water Research 35: 591-596.

Wells, F F, I9S4li, The I'otamididae (Mollusca: Gastropoda) of llong Kong, with an examination of habitat segregation in a sniiill nuuigrove svstiin. In: Morton. B, S, and D Dudgeon (eds.) Proceedings of the Second International Workshop on the .Molluscs of Hong Kong and Southern China 1 Ioiil; Kong l'ni\ersit\ Press, Hong Kong, pp. 139- 154.

Wells. F, E. 1986. Distribution of molluscs across a pneumat- ophore boundan in a small ba\ in .Northwestern .Australia.

.il of .M(

Studies 52: 8.3-90.

Wells. F. F. 1990. Distribution of marine invertebrates in a Hong Kong mangrove, with emphasis on molluscs. In: Morton, B. S. (ed.iTlie .Manue Flora and Fauna of Hong Kong and Southern ('hiua II. Hong Kong Univei'sitx Press, Hong Kong, pp. 78.3-793.

Wells, F. E. and C. .M. Lalli. In press. .Aspects of the ecologv of the mudwhelks Ten'bralUi pdlustri.s and T. sonistriatd in northwesteni Austr;dia. In: Wells. F. E., D. I. Walker, and D. S. [ones (eds.) The Mamie Flora and Faiiiia of Dampier, Western Australia, Western Australian Museum, Perth,

Wells, V. E. and S. M. Slack-Smith. 1986. Part I\'. Molluscs. In: Bern.-. P. H". (ed.) F'aunal Survev of the Rovvlev Shoals and Scott Reef Western .Australia. Records of the West- ern .Aiistraliaii Mnsenni Supplement 25. pp. 41-58,

Wilson. H R. 199:!. Australian Marine SIk'Hs. \oluiiie f ( )d- vssev Publishing. Kallaroo. lOS p]i.

THE NAUTILUS 117(1):6-11. 2003

Pa^e 6

Two new species ol Xcoleptoii Monterosato, 1875 (BivaKia: Neoleptonidae) from South Georgia Islands, South Atlantic Ocean

Diego G. Zela>a Crislian Ituartc

Division ol lii\i.'rtcl)ratc Zoolo<j;\

Musco lie La Plata

1900 La Plata, Bucrios Aires

ARGENTINA

dzelavaCa iiiiisco.lriix iii.iMil|i.c(ln.ar

ABSTRACT

Two new neoleptoiiid species from South CJeorijia Islands are described, ^'colcpton iivorgiainim iie\\ species is characteri/ed by a medium si/.e shell, smooth shell surface, and o\ate shell ontline, slisjlitK' pointed at anterior end. \colcj>ton holiuhcn:,! new species is a small size species, sculptured \\ ith well-marked and regularly spaced cominanj^iual ribs. Moreover, the record of S'mlcpliin pinrcHi Irom South Cieorijia Islands is brought into (juestion.

Addilioiiril kfi/ nords: Svsteniaties, South Mi.iulic ( )ceau.

LNTHODLCTIOX

Nrolcploii Miiiilciiisatd. 1S75. is a sli.illnw -water wdihl- wide genus ol small Ncoleiitniiulac liivaKes. HeeentK. Sala.s ami Colas (199S) provided a eonipi'diensivf svs- teiiiatie revision ol tlie lieniis. ineludinti; a detailed ana- toinieai description ol the tvpe species, Xi'olijilnii stil- caluliiin (|elfre\s, IS59I.

F\\i' Scolcptoii species are known lioni (lie .\la<i('llaii- ic Region: ycolvpton cohhi (Cooper and Preston. 1910), Neolcj)li>n hcinicHi (Preston, I9I2>. Xcolcptaii coticcu- tricum (Preston. 1912), Xcolcplun Impci Sool-Rvcn, 1957. and Ncolcpton falkhindicuiii Dell, I9ft4. None of these species have lieen rejiorted from South (Jeorgia Islands (Bernard. 19S:5; Salas and Colas. I99S: \aldovi- nos-Zarges. 1999 i.

Dell (19641 described Xcaliploii pan (Hi Inim \lae- (juarie Island and allocated specinii'us Irom South (a'or- gia Islands to that species clespite slight differences in shell outline and hinge details hefween the two localities. In tlie same paper, Dell i 19(i4) niisidentilied neoleptonid specimens Irom Shag Roc-ks, near Simlli (ieorgia Is- lands, as Srolcploii pdmsilinnn (Dall, IS76i, a sjieeies belonging in the geinis Waldo Nieol, 19(Sfi (Xieol. 1966) and excluded Irom the Neoleptonidae (Salas and Colas. 199S; Zelava and Ituarle. 2002).

In the present papei' twii new neoleptonid species from South Georgia Islands are described.

M.\TERIALS .VXD .MLTIIODS

The studied luaterial was collected In the RA' Edl.vhix) L. lloLMBERc; from the Institute) Nacional de Investi- gacii'ni V Desarrollo Pesquero (INTDEP^ during the .\pril 1996 cruise to South Georgia Islands arranged bv the Instituto .\ntartico Argentine) (Figure 1). Samples were taken with a drag net, fi.\ed in 109^ bnllered lor- m.iiin and transported to the laboratorv where bivalves were sorted Irom sediments using a stereosco|iie micro- scope and pres(>n(>d in etbanol.

The studied species were Inllv described lUid illus- ti'aled using scanning electron microscope (SEM) pho-

I'igiire 1. Lmalioii map showing the tvpe localitv (°) tor \i i>li-pUiii i^(Oi)ii(iiiiiiii new species and .V. hohnhcivi new spe- cies.

D. (;. Zi-la\a and C. Itiiarti', 20(13

Paw

Figures 2-9. Scolcpton i^cor'^iannm new specifs. 2. lIolot\pe, MLP 6733-1. latt-ral \ie\\ of the riglit \al\e. 3-9. Parahpes. Ml.P (i7o.)-2. .3. Posterior \ie\v. 4. Detail of the protoeoncli. 5. Shell siirfaee sculpture. 6. Inner view of a left \aKc. 7. Inner view of a nght \aKc, 8. Left \al\e, di'tail of liin^e 9. I'viulit x.Axr detail ol liin<j;e. Scale bars- Finnres 2 3 fi-9 = 1 iinir Figures 4, 5 = 100 \^.lu.

Page 8

THE NAUTILUS, Vol. 117. NO. I

Figure 10. Xmli-jiloii <j,i'i>r'^iiiiniin new spcc-ics, \ partialK (lissccti'il spcciineii (i, = 3.3 nun) .slitiwinij tletails ol solt parts anatomy, f: loot; g: inland cells of (lie mantle edge; id: inner (lemihraneli: ad: onter ilcmiliranel].

tograplu'. Hinge teetli tcnninologx Inllows Beniarcl (1895. 1898) and Salas and (;otas 0998). Shell niea- surenuMits were recorded aeeording to the Following cri- teria: .shell length (L): nuLxinunn anteroposterior dis- tance; siiell height iTlV nuLxiinniii dorsoventral distance, peipendicnlar to length; shell width (W); inaximnni dis- tance across \al\es. .Moqihornetric ratios II/L and \\7H were calcnlated. In the text, nunihei' of specimens mea- sured (n), mean, and standard deviation are gi\i'n. \oncher specimens wove deposited in Museo de La Pla- t.i. La I'lata iMLP), Mnseo .\rgentino de (aencias Na- tnrales "Bernardino Hi\ada\ia," l^nenos .Aires (MA(;N) and .Museum xNational d' Histoire Natnrelli', Paris (MNHN).

For comparatix'e purposes, txpes of Xcolcplon Jiiipi'i h'om the Swedish Mnseuni ol Natnnil lliston. Stoek- Iiolm (S.MMIl, ;in(l photographs ol the hololxpe of .\', powclli Iroiii the Natural llislon .Museum, London (NHM) w^ere used.

SVSTL.M.YIICS

Xcoli'plmi Hforffdnum new spei-ies F'igures 2-10

Descnplion: Shell delie;ile. medium sized (maximmu L = 3.4 ium>. nol inllated n.itio W II = 0.54 ± O.O.'l n = 12), shell onlline ovate, some\\h;il elongate, high ii;ilio H/L = 0.83 ± 0.02, n = 12). somewhat ineiiuilateral. posterior end larger and wider than anlerioi' one. which is slightK' |ioiuted; anterior and poslerioi' li;iir of dors;il margin only slightly cnned, \'entral maigin cxcnK and wideK arcuate: anterior margin short, acute, jiosferior margin wideK- and eveuK eurveil. He;iks \ei\ sui.lII. shaipK' triangular. slightK drspl.ieed rorw;ii(l. ele.irk oiil- .stariding Irom shell surface ;m(l well \isil)le aliove dors.il margin I'roloconc-li well-marked, smooth, not nmch in- flated, aliout .300 |jLni long. Shell surlaee lirilliant. |ier- iostracum pinkish, laintK- sculptuicd with \ci-\ low. ii- regulark' spaced, eonunarginal lihs.

Hinge plate strong, narrowing moderately below the beaks. Left \al\e: cardinal 2a relatiwK- short, straight, greatl\- enlarged at posterior hall, cardinal 2b relatixclv long, forming a hook with 2a, posterior lateral PII shori, strong and well outstanding from dorsal margin, iiight valve: cardiiKil 1 high, with distal c-usp and short ba.se nearK perpenilicular to anteroposterior axis: 3a slender and low, 31) quite short and \er\ thin, PI well de\cloped, elongate, with distal cusp.

Innei' and outer demibranchs jircsent; the oult'r de- mibnnieh. shorter, represents approximateK' the half Of the iiuK'r one. Branchial filaments of outer and imier demibranchs sloping toward the anterior end. Inhalant ;iperture and exh;ilaul siphon bordered bv a single row ol short tentacles. Large glandular cells of the mantle edge at both sides of the pedal aperture were present and well \isible li\ tnmsparence.

T\pe Material: I lolot\pe. MLP 6733-1; Paratxpes: 20 MLP fi7.3.3-2. 10 \IA(:N .35289; 10 MNHN nmnnn- bei'ed; ;ill Irom the l\pe li)e;ilit\. HA' F,m\IU)() L. Iloi Aiiiiiic, 8 April 1996.

Oilier Material Examined: >60 specimens from the t\pe loe;ilit\ (MLP 67.33-:5, M.\(:N .35290).

Type Locality: 54°18' S. 35° 30' W, South Ceorgia Iskmtls. 94 111.

Distribution: The species is onK known from tin' t\pe loealit\.

ElymoIog\: The species is named ;ilter the South (;eorgi;i Isl.iiiils. the t\pe loealitv.

Heniarks: Xrchploii <ic(iriii(niuiti new species resem- bk's \ct>lfj>t(>ii liiipci in shell oiitliiie. dillering h\ its smaller, higher, .md more iueijuikiteral shell. Hinge teeth. p.irlieiilarK the cardinal 1, are more delicate in .V. il(i>riii<niuiii than in .V. Iiupri. The color of periostraeum. pinkish in .V. (^cor^iaiium and whitish in .V. Iiupci is also a distiuctiw character, \colcpton gcorgiV/iH/i/i is also sim- ilar to Xc(fl('j]toii hoiinhenjj new speeitvs, from which it dillers in li;i\iiig ;i less inlkited shell, shi'll outline with a pointed anterior end, and smooth shell surlac-e. Both s[)ecies are cliaraeterized In tluir pinkish perioslraeum. Xcolcplon <icor<iiaiiiiiii dillers Irom .V. cohhi. X. Bcu- iictfi. and V r()iirciilri<iiin l)\ its r|uite o\ ate sh(>ll outline ;ukI siiioiitli shell siuiace: the more ine(|uilateral slu'll .mil the lower and not jironiiiient beaks clearK" separate \ gcorg/r/ii/n/i Irom .\'. fdlkldiidicitin. Xcolcplon gcor- 'j^idimiii also dillers Irom .\'. jionclli in iKixing ;i iiiorc^ o\ate shell outline, a consisteiilK more acute anterior cud and more cnned dorsal and \(>ntral margins. .Wo- Icjiloii jiniiclli w.is described Irom Maciinarie Island; in the same p;q)ei I )ell i 1 96 1 ) ;ilso relerred se\('r:ll S|ie(i- iiiens Irom Sonlh ( le(ir<j;i;i Iskmds to this sp<'(ies. Tlking into account the narrow distribution ranges that char- acterize main Xcolcplon species, as iiilerred Irom the generic- revision b\ Salas and (^olas i 1998*. it is not nii- likeK tli;il tile specimens Irom S(}iith (ieor^i;! Iskmds

D. C. Zcla\a and C. Ituartc. 2()():3

Page 9

Figures 11-l.S. An )/,/)/<>/( linlinlicn^i new spci-ics. 11. Hdlolxpc iMLF (iT34-l i; lateral \ic\\ iiltlie Icit \aKr. 12-l.S. rarat\pcs (MLP 6734-2). 12. Po.sterinr view, l:J. IJetail ol' the protdc-oucli. 14. Slull siiilarr Miilptmc 1.5. Iiiiht \ic\\ ol a Irit \al\c. Hi. Inner \ie\v ofa rit;lit valve. 17. l.elt \;ilve. detail of hinge. 18. Right \aKv. detail ot Iniige. Scali- l)ais: Kii^nres 11. 12. 13-lS = 1 nnii; Fignres 1.3, 14 = KHI |a.in.

Page 10

THK NAUTILUS. \ol. 117, Xc

Figui'f 19. W'olcploii luilinh('riS.i new species. A paitiallv ili.s- sected .specimen (L = 2.7 mm) showing details ol solt parts anatoniv. f: foot: g: gland ceils of tjie mantle edge; id: imier deniibranch; od: outer deniilirancli.

reported l>\ Dell (1964) a.s A'. powcUi. would represent a dillercnt \c(ilcj)t(>ii species. pDssiliK ,V, i^cdr^iiiiiiiin.

Neolcpldit liolinhcrni new species (Figures 11-lSi

Description: Shell delicate, small sized {nuLxiniinii L = 2.S mm), somewhat inflated (ratio W'/ll = 0.66 ± 0.03, n = 14), .shell outline cnate, somewhat elongate, high (ratio II/L = 0.85 ± 0.02, n = 14), somewhat inecjui- lateral, posterior end exjianded, larger than anterior one; dorsal margin extended in a wide cune, tending to be -Straight at posterior half: posterior margin cuned, ven- tral margin e\enlv arcuate, anterior margin short and ciuAe. Beaks subcentral. usually eroded. Protoconch vvell-markeil, smooth, not inflated, al)out 300 |xm long. Shell sm-face dull shining or silk\, sculptured with well- marked conunargiual ribs, e\enly spaced; periostracum pinkish.

Hinge plate solid, narrowing moderatcK' below the beaks and at posterior hall. Left \al\e: cardinal 2a rela- ti\'eK' long, slender, enlarged at posterior end; cardinal 2b solid; posterior kiteral PII elongated, liardK' discern- ible tioin doisal m;iigin. I{ight \;il\c; cardinal 1 high, with sliarpK triangular tlistal cusp and large base; 3a slender, long anil low. .'51) (juite short, weak, PI well de- \elo|)ed, elongate, with (lisl;il cusp.

iimt'r and outer deinibrauchs present: the outer imicli shorter. sli^htK oxerlappiug the nnier one ;iu(l repi"e- senting about the third of its length. I''ilaments ol outer demibrauch uearK horizontal. Inhalant aperture ;md e\- lialant siphon bordered bv a single row ol sliorl leula- cli'S. (Glandular cells of the numtle edge preseiil al liolli sides ol the peiLil ;ipertnre.

Tvpe \I:itiTi:il: iiolot\pe, MLP6734- i; paral\pes: 20 \iLP 6734-2. 10 .\IACX 35291, 10 \IMI\ unumn- bered; all Irom the t\pe locality, 8 April 1996, HA' Kd- f MUX) I .. ll<)i.\iBi;iu;.

Other Material E.vamined >60 specimens liom the t\pc locaht) iMLP 6734-3, .MACN 35292).

Type Locality; 54°18' S, 35°3()' W South Georgia Is- huids. 91 III.

Distrihiilioii: The species is ouK known from tlii' t\pe loeiililv.

EtMiiologN: The species is named after the RA' Er)- iAi;i)() 1,. lloi.MBFRG, aboard of which this species was collected.

Remarks: The general shell outline and the shell sur- face sculpture of well-marked commarginal regularly spaced ribs are chagnostic features of Ncolepton Iwlm- b('r<ii \w\\ species. Ncolepton holmhrn^i is most similar to Ncolepton georgianutn new species, differing in hav- ing a more inflated shell, not much inflated protoconch antl slu'll surface with stronger and regularlv spaced commarginal ribs. The more triangular shell outline with nearly equally arcuate anterior and posterior ends is also distinctive for .V. holmhergi. The hinge in N. Iiobubcrgi differs in ha\ing a high carihnal 1, with a wider base and triangular distal cusp.

W'olcpton hnpci. another similar species, clearK dif- fers from A'. Iiohnbcrgi bv its larger size, smooth shell surface, stronger hinge teeth and whitish periostracum.

Ncolepton hobnhcrgi differs from Ncolepton falklan- dieiun bv its well-marked shell surface sculpture and not prominent beaks. N. hobnbcrgi differs from the other Magellanic Ncolepton species (A', cobbi, N. concentriaim and A', beunctti) in being smaller, ha\ing a relativek' low- er and markedh' ovate shell outline.

.\(:kno\\ledg\ients

The authors wish to tliank A. Waren and K. Sindeinark (SMNII) for allowing the stuck- of tvpes of Neolcj)ton linpii. .uul Iv. Way and \. C'ampbell (XH.M) for sending photographs of the holot\pe of .V. powclli. D. Nahabe- dian kinilK made availabli' the specimens collected by the RA' EDr.AKDo L. Holnhikiu;. The authors are mem- ln'rs of the Consejo Naciouiil de In\estigaciones C'ienti- ficas V Tecnicas (CONICET). This work was pai-ti;illy sup- ported b\ a grant fVoin Finuhicirin .\ntorchas to D. Z.

LITERATURE CITED

Hern, 11(1 K 1S9.3,