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© SociedadEspañola deMalacología Iberus, 23 (2): 1-6, 2005 A new species ofLodderena (Gastropoda: Skeneidae) from the Bahamas Una nueva especie de Lodderena (Gastropoda: Skeneidae) de las Bahamas Colin REDFERN* and Emilio ROLAN** Recibidoel26-1-2005.Aceptadoel30-VI-2005 ABSTRACT A new species in the genus lodderena (Gastropoda: Skeneidae) is described from the Bahamas. The new species is compared to í. ornato (Oisson and McGinty, 1958). RESUMEN Se describe una nueva especie del género Lodderena (Gastropoda: Skeneidae) de las Bahamas. La nueva especie se compara con L ornato (Oisson and McGinty, 1958). KEYWORDS: Skeneidae,Lodderena, Bahamas, newspecies. PALABRAS CLAVE: Skeneidae,Lodderena, Bahamas, nuevaespecie. INTRODUCTION Olsson and McGinty (1958) one new species, L. janetmayae from described Pachystremiscus as a subgenus Abaco,Bahamas. of Cyclostremiscus Pilsbry and Oisson, In recent years the sénior author has 1945. Included were two new species continued to examine sediment samples described from the Caribbean coast of from the Bahamas. One of these con- Panamá: C. ornatus and C. pulchellus, the tained examples of the three known type species of Pachystremiscus. Kay Caribbean species together with exam- (1979) figured two species from the ples of what appeared to be a fourth, Pacific. MooLENBEEK (1996) discussed undescribed species. The study of this the genus Lodderena ¡rédale, 1924, which material is the subject of this paper, is considered the correctgenusñame for which includes the description of a new this group of species, mentioning most species that is morphologically cióse to of the existing taxa and describing two L. ornata. newspecies. Rubio, Rolan and Redfern (1998) studied species ofLodderena occurringin MATERIALAND METHODS the Caribbean, including some speci- mens from other áreas that suggested a This study is based on a 0.4 liter wider distribution. They also described sample ofsedimentcollected at a depth *7475 EstrellaCirde, BocaRatón, Fl33433, USA. ** Mixseo de Historia Natural, Campus Universitario Sur. 15782 Santiago de Compostela. e-mail: emilioro- [email protected] Iberus, 23 (2), 2005 of 6 m at Lynyard Cay, Abaco, Ba- BMSM Bailey-Matthews Shell Museum, hamas. Sanibel,Florida,USA MNCN Museo Nacional de Ciencias Abbreviations: Naturales,Madrid AMNH American Museum of Natural MNHN Museum Nationale d'Histoire History,NewYork Naturelle,Paris ANSP Academy of Natural Sciences, ZMBZoologischesMuseum, Berlin Philadelphia CCR Collection of Colin Redfern, Boca BMNH The Natural History Museum, Ratón,Florida,USA London CERCollectionofEmilioRolan,Vigo RESULTS FamilySkeneidae Clark, 1851 Genus Lodderena Iredale, 1924 Lodderena bunnellin. sp. (Figs. 1-9) Typematerial:Holotype(Figs.1,9),0.56mm,depositedatANSP.Oneparatypedepositedineach ofthefollowingcollections:MNCN(15.05/46685) (Figs.2,8),0.64mm;MNHN(Fig.3),0.56mm; AMNH(Figs.4,7),0.58mm;BMNH(Fig.5),0.56mm;ZMB(Fig.6),0.60mm;BMSM.3paratypes inCERand21inCCR.Alltypematerialconsistsofemptyshellscollectedfromthetypelocalityin August,2004. Typelocality:LynyardCay,Abaco,Bahamasin6m. Etymology:NamedforRodgerR.Bunnell,whocollectedthesedimentsamplethatcontainedthe typematerial. Description: Shell (Figs. 1-6) very ovoid or rectangular shapes (Fig. 7). small, rounded, dorsally planispiral, After the first half of the whorl this whitish. Protoconch (Figs. 8, 9) approxi- pattern is replaced by spiral threads, mately 200 pm in diameter, with about one of which is a little stronger and one whorl, nucleus rounded, surface sometimes forms a peripheral angula- roughened, with 1-2 spiral lines ofirreg- tion. Ventrally the sculpture is very ular granules. Separationfromthe teleo- similar, but with the addition of short, conch is rather well defined. Teleoconch widely-spaced axial riblets adjacent to with only one whorl, sometimes a little the lower peripheral cord. Occasional less. Sculpture is formed dorsally by shells have a spiral row ofnodules cióse irregular undulating axial ribs that are tothesuture. well separated initially but become nar- Aperture regularly rounded, with a rower, more numerous and crowded as doubleperistome. the whorl develops. The beginning of Microsculpture: Under high magnifi- the peripheral curvature is marked by a cation, small granules canbe seen inthe narrow spiralcord, abovewhicha series peripheral área (Fig. 7), with very fine of fine spiral threads starts to form axiallineselsewhere. whenthewhorlis abouthalfdeveloped. Dimensions: the holotype is 0.56 mm The strengthening spiral sculpture, sub- in máximum diameter, and the largest sequently consisting of up to 9-10 specimenstudiedis0.64mm. threads, causes the axial ribs to shorten, Distribution: Lodderena ornata and L. but they lengthen againjust behind the pulchella are widely distributed in the aperture. Sculpture on the rounded Caribbean área and it is likely that L. periphery of the shell initially consists bunnelli n. sp. has a comparable range, ofthreeweak, irregular spiral cords that as indicated by the similarity of a shell are connectedbyaxial threads ofsimilar from the U. S. Virgin Islands figured as strength to form a net-like pattern of Lodderena sp. by Rubio etal. (1998, fig. Redfernand RoláN: Anewspecies oíLodderena from the Bahamas mm Figures 1-9. Lodderena hunnelli n. sp., from Abaco, Bahamas (CCR). 1: holotype, 0.56 (ANSP); 2: paratype, 0.64 mm (MNCN); 3: paratype, 0.56 mm (MNHN); 4-6: paratypes, 0.58, 0.56, 0.60 mm (AMNH, BMNH, ZMB); 7: microsculpture, paratype (AMNH); 8: protoconch, paratype (MNCN); 9: protoconch, holotype (ANSP). Figuras 1-9. Lodderenabunnelli, n. sp., deAbaco, Bahamas(CCR). 1:holotipo, 0,56mm (ANSP);2: paratipo, 0,64mm (MNCN);3:paratipo, 0,56mm (MNHN); 4-6:paratipos, 0,58, 0,56, 0,60mm (AMNH, BMNH, ZMB); 7: microescultura,paratipo (AMNH); 8:protoconcha,paratipo (MNCN); protoconcha, holotipo (ANSP). Iberus, 23 (2), 2005 TableI. DifferencesbetweenLodderenaornataandLodderenabunnellin. sp. TablaI. DiferenciasentreLodderenaornataj)/Lodderenabunnelli n. sp. iornato Lbunnellii\.s\i. largordiom.between0.66-0.92mníi smallerdiam.between0.56-0.64mm Dimensions n=10median=0.78mníi n=10median=0.58mm shelldorsallyplonispiral;peripherymeets shelldorsallyplonispiral;periphery Spire aperturenearthecentre meetsaperturenearupperdorsalborder Teleoconch 1 whod+Vs 1 whorloralittleless 3veryprominentnodulose Usuallynonodulosecords;occasionally Spirolsculpture cordsoneachside osmalloneventrallyciósetothesuture Spiralsculptureattheperiphery threeprominentcords;sometimoswith threeweak, irregularcordsconnectedby (nearbeginningofteleoconchwhorl) axialthreadsformingirregularrectangles axialthreadsformingovoidorrectangularshapes Spiralsculptureoítheperiphery threeprominent,laterallynodulosecords; rarelywithcords;numerousspiral (towardsendofteleoconchwhorl) intermediótespimlthreadsonlyattheend linesonaconvexcurvature thicker,aboutathirdof thinner,aboutaquarterof Thicknessofouterlip thediameteroftheaperture thediameteroftheapertura Nucleusoftheprotoconch slightlyovoid raunded Microsculptureoftheprotoconch irregular,mainlyneartheperiphery someirregulargranulesspirallyaligned Microsculptureoftheteleoconch nearthesuture fine : finer 41). The existence of L. bunnelli n. sp. lackofanyintergradationbetweenthese mayhavebeen overlooked elsewhere in two sympatric species. Comparison of the Caribbean due to its small size and the two species showed us a number of possibleconfusiónwithL. ornata. differences,assummarizedinTableI. Remarks: The sediment sample that Another similar species is Lodderena contained thetypematerialofL. bunnelli striata (Kay, 1979) from Hawaii, but this n. sp. also yielded 12 examples of L. species is larger (up to 1 mm), and the janetmayae, 20 of L. pulchella and 486 of periphery ot the last whorl has only L. ornata. Study of this material clearly spiral striae, lacking the net-like pattern showedthattherewasnointergradation thatischaracteristicofL. bunnellin. sp. betweenthefourspecies. Records of L. ornata in Rubio etal. Mayr (1963) stated that when two (1998) from the Bahamas, Cuba, Cape different morphs are found sympatri- VerdeandSaoTomé,togetherwiththose cally without any intergradation in the present work from the Bahamas, between them, they represent two dif- Sao Tomé and Easter Island, show that ferent species. Problems for the taxono- this species probablyhas a wide distrib- mist occur when two different morphs ution in tropical seas, and that the mor- share similar main characters. In the phologicalcharactersoftheshell,includ- present case the distinction between ing features of the protoconch, remain Lodderena bunnelli n. sp. and L. ornata surprisingly constant throughout its (Figs. 10-14), the closest species, was range. L. emeryi (Ladd, 1966) is a taxon based on several different characters, very similar to L. ornata and could even andimportancewas also attached to the beconspecific(Moolenbeek, 1996). Redfernand RoláN: Anewspecies oíLodderenafrom the Bahamas Figures 10, 11. Lodderena ornata, 0.78 mm, Abaco, Bahamas (CCR). 10: shell; 11: protoconch. Figure 12. Lodderena ornata^ 0.75 mm, SaoTomé, WestÁfrica (CER). Figures 13, 14. Lodderena ornata, 0.80mm, EasterIsland (CER). 13: shell; 14: protoconch. Figuras 10, IL Lodderena ornata, 0,78 mm. Abaco, Bahamas (CCR). 10: concha; 11:protoconcha. Figura 12. Lodderena ornata, 0,75 mm, Santo Tomé, África occidental(CER). Figuras 13, 14. Lod- derenaornata, 0,80mm. IsladePascua (CER). 13:concha; 14:protoconcha. It is surprising that one species such human intervention, such as the dis- as L. ornata could be present in such charge of ballast water from ships. widely separated áreas, especially con- Alternatively, this could be a case of sidering thattheprotoconchispaucispi- reproductive isolation involving more ral and does not have a long plank- than one species. Identification from totrophic period that would allow wide widely separated geographic áreas has distribution. We think thatthere are two been based solely on shell similarities, possible explanations, the first ofwhich and the biology, ecology and soft parts is that dispersal could be attributable to aremostlyunknown. Iberus, 23 (2), 2005 ACKNOWLEDGEMENTS We thank Rodger R. Bunnell, of this study. We also thankJesús Méndez Sanibel, Florida, for providing the sedi- oftheCACTI,UniversityofVigo,forthe ment sample that formed the basis of scanningelectrónmicrography. BIBLIOGRAPHY Kay, E. a., 1979. HawaiianMarineShells. Reef Olsson,a. a. andMcGinty,T. L., 1958. Re- and Shore Fauna of Hawaii, sect. 4: Mol- cent marine mollusks from the Caribbean lusca. B. P. Bishop Museum Special Publica- coastofPanamáwiththedescriptionofsome tion,64(4),653pp. newgeneraandspecies.BulletinsofAmerican Mayr, E., 1963. Animal Species and Evolution. Paleontology,39(177): 1-58. BelknapPress,Cambridge.797pp.(6thEd., Rubio,F.,Rolan,E.andRedfern,C,1998.TTie 1979). genus Lodderena Iredale, 1924 (Achaeogas- MooLENBEEK, R. G., 1996. New skeneiform tropoda, Skeneidae) in the Caribbean. Ar- speciesofthegenusLodderenaIredale,1924 gonauta,11 (2):39-48. from the Sultanate of Ornan (Gastropoda: Skeneidae). VitaMarina,44(1-2):21-28.