A NEW SPECIES OF RUNCINELLA ODHNER, 1924 (GASTROPODA: OPISTHOBRANCHIA) FROM THE GALAPAGOS ISLANDS

Runcinella thompsoni new species (Gastropoda: Opisthobranchia)is described on the basis of material collected in the GalapagosIslands. This new species differs from R. zelandica Odhner,1924, both in colour, reddish in the former, dark green withwhite freckles in the latter, and radular tooth morphology,mainly the first lateral teeth. The species is also comparedwith other red runcinids both from Atlantic and Pacific localities. (Received 28 October 1991; accepted 4 January 1993)     

HYDROBIIDAE (GASTROPODA: HYDROBIOIDEA) FROM THE RIBEIRA VALLEY, S.E. BRAZIL, WITH DESCRIPTIONS OF TWO NEW CAVERNICOLOUS SPECIES

Potamolithus karsticus n. sp. and Potamolithus troglo-bius n.sp., two Brazilian aquatic cavesnails (Gastropoda: Hydrobiidae),are described. P. troglobius is blind and depigmented, and isthe first stygobiontic snail to be described from Brazil Additionally, specimens of Potamolithus ribeirensis Pilsbry,1911 were collected near the type locality for comparison withthe new cave species (Received 2 December 1993; accepted 20 June 1994)     

MORPHOLOGICAL STUDIES OF LYMNAEID SNAILS FROM THE HUMAN FASCIOLIASIS ENDEMIC ZONE OF BOLIVIA

The taxonomic position of the Lymnaeidae from the BolivianAltiplano has been unclear. On the basis of conchological characters,some authors reported two species from this area, Lymnaea viatrix andL. cubensis while others, considering also anatomical characters,considered L. viatrix as a synonym of L. cubensis. More recentstudies demonstrated genetic identity between the Bolivian lymnaeidsand L. truncatula from the Iberian Peninsula. Populations recognizedas L. cubensis correspond to a distinct genetic group, but geneticinformation was not available for L. viatrix. In the light ofthese genetic results, a morphometric study of both the shell (usingRaupian parameters) and male reproductive system was carried outof L. cubensis from Cuba (type locality), Dominican Republic,Guadeloupe and Venezuela, and of L. truncatula from Bolivia,France, Portugal, Spain and Morocco. Syntypes of L. viatrixfrom Argentina (var. A. ventricosa) and specimens of L. viatrix(var. B. elongata) from the type locality, Peru, were also studied(conchological characters only). The conchological study showedthe presence of a large amount of variability between populations.This variability was not congruent with genetic results. Alarge amount of variability was also found using anatomicalcharacters of the male reproductive system and all of them clearlyseparate L. cubensis from L. truncatula independently from geographicalorigin. Thus anatomical characters, unlike conchological parameters,do differentiate taxonomic species inferred from genetic studies. (Received 11 September 1997; accepted 5 March 1999)     

SOME OBSERVATIONS ON THE DIET AND DISTRIBUTION OF NUDIBRANCHS AT SIGNY ISLAND, ANTARCTICA

Observations were made on the diet and distribution of eightspecies of nudibranchs found in Borge Bay, Signy Island, Antarctica.Specimens from seven sites were examined in situ on four separateoccasions during 1992 and 1993 using SCUBA. A small collectionfor identification was also made Six of the eight species presentwere identified, and the first ecological data for at leastone species (Charcotia granulosa) were recorded. Notaeolidiagigas was feeding principally on hydroids of the genus Tubulariaover the entire depth range surveyed (3–36 m), and wasmost abundant in shallow water, whereas Truomella belli wasonly found at deeper sites, mostly on an octocoral of the genusAscolepis. Charcoaa granulosa and Pseudotritoma gracilidensappeared to be specialist bryozoan feeders and, as has beenfound at other locations, Austrodoris kerguelenesis specialisedon the demosponge Dendnlla antarcnca. Two unidentified aeolidspecies occurred almost entirely on particular hydroids andthe prey of Tritonia antarctica was not apparent. The physicalsize of Antarctic nudibranchs may have important implicationsto the type of prey and feeding strategy used by different species. (Received 11 May 1995; accepted 3 December 1995)     

A NEW SPECIES OF THE AEOLID GENUS FLABELLINA (NUDIBRANCHIA) FROM THE STRAIT OF GIBRALTAR

A new species of nudibranch, Flabellina insolita, is describedfrom specimens from the Strait of Gibraltar. The new speciesis assigned to the genus Flabellina on the basis of the jaws,radula and reproductive system, despite the shape of the rhinophoresand oral tentacles and the presence of small papillae flankingthe pericardium and small laminar enlargements on the dorsalsurface of the body. These features separate this species fromother aeolids. (Received 14 June 1988; accepted 19 August 1988)     

NORTH ATLANTIC NUDIBRANCHS OF THE CHROMODORTS CLENCHI COLOUR GROUP (OPISTHOBRANCHIA: CHROMODORIDIDAE)

The correct identity of three chromodorid nudibranch species,Chromodoris clenchi, C. neona and C. binza is established onthe basis of material from the Caribbean Sea. These three speciesare compared with C. britoi, from the northeastern Atlanticand the Mediterranean Sea. All four species have a colour patternof cream with red (or yellow) lines and blue spots. (Received 30 March 1993; accepted 20 November 1993)     

FOUR NEW SPECIES OF TAMBJA BURN, 1962 (NUDIBRANCHIA: POLYCERIDAE) FROM THE INDO-PACIFIC

The genus Tambja previously included 24 described species. Fournew species, T. tentaculata n. sp., T. gabrielae n. sp., T.zulu n. sp. and Tambja victoriae n. sp., from the Indo-Pacificare described. Tambja tentaculata n. sp., from Guam, is theonly known species in the genus with well developed, dorsolaterallygrooved, oral tentacles. Its inner lateral teeth have a bifidinner cusp with two long, sharp denticles. The oral tentaclesof T. tentaculata are more typical of Roboastra species, whilethe shape of the inner lateral teeth is more typical of Tambja.Nevertheless, the arrangement of the two cusps of the innerlateral teeth and the presence of a rachidian tooth withoutdenticles and with a central notch at the anterior edge, typicalof the species of the genus Tambja, suggest the placement withinthis genus. Tambja gabrielae n. sp., from Indonesia and PapuaNew Guinea, has dark green to dark brown ground colour withbright yellow patches scattered on the body. Tambja zulu n.sp. from Durban, South Africa, is characterized by a black groundcolour with slender yellow longitudinal lines. Tambja victoriaen. sp. is a new species from Papua New Guinea and Australiathat has frequently been misidentified as Roboastra arika, characterizedby its blue body colour and yellow lines. The four species aredistinguishable based on differences in body coloration, ofcharacters of the radula and of the reproductive system. Anoverview on distinguishing features of all known Indo-PacificTambja species is presented. (Received 21 June 2004; accepted 20 January 2005)     

CONASSIMINEA, A NEW GENUS OF THE ASSIMINEIDAE (CAENOGASTROPODA: RISSOOIDEA) FROM SOUTHEASTERN AUSTRALIA

A new genus of Assimineidae, Conassiminea, is described fromestuarine habitats in southeastern Australia (New South Wales,Tasmania and Victoria). Two new species, C. studderti and C.zheni, are included in the genus, the former being the typespecies. Conassiminea is distinct from all other assimineidgenera in two autapomorphies in the female reproductive system:the seminal receptacle has two ducts and the bursal duct isextremely wide. The phylogenetic relationships of the new genuswere examined using a morphological dataset. (Received 26 February 2005; accepted 22 April 2005)     

Molecular Phylogeography of Oncomelania Lindoensis (Gastropoda: Pomatiopsidae), the Intermediate Host of Schistosoma Japonicum in Sulawesi

Oncomelania lindoensis from Lake Lindu, Sulawesi, was characterizedfor genetic variation at 21 allozyme loci and compared withO. hupensis (China) and O. quadrasi (Philippines). Geneticdistances and interpopulation patterns of allele-sharing pointto a closer relationship between Sulawesi and the Philippines(Nei's unbiased genetic distances (D) averaged 0.50) than betweenSulawesi and China (D= 0.79). These data, coupled with a considerationof the geographic distribution of the genus, support the hypothesisthat the Sulawesi Oncomelaniaoriginated by avian-facilitated colonizationfrom the Philippines about two million years ago. Oncomelania from Sulawesi were originally described as subspecificallydistinct: Oncomelania hupensis lindoensis. However, the allopatricdistribution, unique alleles at five loci, and significant geneticdistances from congeners in Mindanao and elsewhere in the Philippinessuggest that this taxon should be distinguished as a full specieswithin the Oncomelania hupensis species group, namely: O. lindoensisDavis & Carney 1973. Comparison with published data on variationwithin quadrasi and in three Chinese subspecies of hupensisshowed that D values increase with taxonomic level in this speciesgroup. D averaged 0.15 (0–0.26) within Chinese subspeciesand 0.04 (0–0.13) within the Philippines, but was 0.30(0.20–0.45) between Chinese subspecies, and 0.48–0.80between the three species (hupensis, quadrasi and lindoensis).The genotypic cluster species concept and these multilocus geneticdistances can be used to help define species and subspeciesin these medically important snails. (Received 14 May 1997; accepted 20 April 1998)     

DESCRIPTION OF A NEW SPECIES OF PHYLLIDIOPSIS BERGH (NUDIBRANCHIA: DORIDOIDEA: PHYLLIDIIDAE) FROM THE TROPICAL WESTERN PACIFIC, WITH COMMENTS ON THE ATLANTIC SPECIES

A new species of phyllidiid nudibranch, Phyllidiopsis shireenae,is described. The new species has a middorsal crest insteadof being flattened dorso-ventrally like most phyllidiids. Itsbody is a very pale shade of pink with black bands, and itsrhinophores are salmon pink. The anatomy of the alimentary systemand reproductive system are described. Characters originallyused by Bergh (1875) to differentiate the genus are supportedby this new species. Phyllidiopsis shi-reenae is presently knownfrom coral reef habitats in the extreme western Pacific Ocean.A review of the taxonomic status of the Atlantic specis of Phyllidiopsisis required. ^*Present address: Australian Biological and Environmental Survey.Australian National Parks and Wildlife Service, GPO Box 1383,Canberra. ACT 2601. Australia. (Received 15 August 1989; accepted 8 January 1990)     

THE IMPORTANCE OF MUCUS AS A DEFENCE AGAINST CARABID BEETLES BY THE SLUGS ARION FASCIATUS AND DEROCERAS RETICULATUM

The effect of mucus exudation on the survival of Arion fasciatusand Deroceras reticulatum was studied by exposing mechanicallystimulated and control slugs to Carabidae beetles for 24 hours.A light stimulation, lasting three minutes, exhausted the copiousflow of mucus for one day. A generalist, Pterostichus niger,significantly preferred stressed D. reticulatum over controlones. Similarly, P. niger exclusively ate stressed individualsof A. fasciatus. Two beetles which specialize in gastropods,Cychrus caraboides and Carabus violaceus, consumed an equalnumber of stressed and control D. reticulatum and A. fasciatus.The susceptibility of the slug species to predation was different:for each beetle species, the proportion of available D. reticulatumpreyed upon was significantly higher than that of A. fasciatus.The differences in the behaviour of A. fasciatus and D. reticulatumin defending themselves against attacks is described. The mainreason why specialist beetles are able to hunt slugs successfullyis their ability to prevent the slugs from exuding large amountsof mucus. This may succeed by different means: C. violaceustargeted their killing strokes against the posterior part ofthe mantle while C. caraboides hit the head of the slug. Inboth case the strokes seemed to paralyze the slugs. (Received 31 March 1993; accepted 1 October 1993)     

THE GENUS HAMINOEA (GASTROPODA: CEPHALASPIDEA) IN PORTUGAL, WITH A REVIEW OF THE EUROPEAN SPECIES

The study of specimens of Haminoea collected on the coast ofPortugal, together with the re-evaluation of historical specimensused by Nobre (1938–40) in his main work on the Portuguesemolluscs, recognized the presence of two species, Haminoea navicula(da Costa, 1778) and H. orbignyana (Férussac, 1822),and confirmed the misidentification of H. orbignyana as H. elegans(Gray, 1825). Anatomical analysis found intraspecific variabilityin the radula of H. navicula and H. orbignyana and in the seminalduct of the latter. The systematic value of taxonomic featuresincluding the shell, external morphology, animal coloration,radula, jaws, gizzard plates, prostate gland, seminal duct,penis and egg-masses is discussed. For all European speciesbut H. orbignyana, identification is only possible when anatomicaldata are considered, and the most relevant character is themale reproductive system. SEM images of the penis and prostateof H. navicula and H. orbignyana are given for the first time.A synoptic table for the recognition of the European speciesis provided. (Received 21 January 2005; accepted 17 June 2005)     

TWO NEW SPECIES OF THE GENUS ISLAMIA RADOMAN, 1973 FROM ITALIAN ISLANDS (PROSOBRANCHIA, HYDROBIIDAE)

Two new Italian species of the genus Islamia (Prosobranchia:Hydrobiidae), one living in eastern Sicily (I. cianensis), andone on Elba Island (Tuscan Archipelago, Italy) (I. gaiteri)are described. The two species are distinguished on the basisof shell and anatomical characters, mainly those of the malegenitalia. I. cianesis n. sp. is characterized by a valvatoidshell and a penial lobe with internal band of glandular tissuenot distinct in its lower portion from the penis body but bulgingapically as a small knob. I. gaiteri n. sp. is characterizedby a planispiral shell and a small lateral penial lobe withoutinternal glandular tissue. (Received 20 December 1993; accepted 27 June 1994)     

THE BIOLOGY OF THE NORTHEASTERN PACIFIC TURRIDAE II. OENOPOTA

The habitat, diet, some reproductive and mortality factors forseveral shallow-water species of the boreal turrid genus Oenopotafrom the Puget Sound region were determined. All fed exclusivelyon tubicolous polychaetes. Oenopota fidicula was a dietary andhabitat generalise Oenopota elegans eats Schistocomus hiltoniand lives in areas of shell fragments. Oenopota excunata eatsTharyx multifilis and is a habitat generalist. Oenopota tabulataappears to be a dietary generalist, but lives only on or nearrocks. The widely-distributed species, O. levidensis, eats spionidpolychaetes, primarily Polydora species, or Owenia fusiformis,and is a habitat generalist. Feeding frequencies are low asare population densities; although O. levidensis sometimes exceeds15 animals m^–2. Crabs are major predators upon turridsin some areas, but mortality causes are generally obscure. Spawningwas observed in four species, but only O. elegans and O. levidensishad viable larvae. Development takes 13–15 weeks, 6–7weeks in a capsule and 6–7 weeks as planktonic veligers.There are no nurse eggs. Settling was not observed. ^*Present mailing address: Bamfield Marine Station Bamfield,B.C. VOR 1B0 CANADA (Received 30 May 1982;     

ALLOZYME VARIATION IN SOME POPULATIONS OF THE FRESHWATER SNAILS LYMNAEA PEREGRA, L. AURICULARIA AND L. STAGNALIS (GASTROPODA: PULMONATA)

Three species of the genus Lymnaea (Gastropoda, Pulmonata, Basommatophora)were examined for genetic variation at 11 enzymatic loci insamples collected in Brittany (North-Western France). Variabilitywas greatest in L. percgra, but the limited area of samplingdid not allow specific inferences. The UPGMA clustering of unbiasedgenetic distances (Nei, 1978) isolated first L. auriculariasamples, and secondly the single L. stagnalis sample from theL. peregra set. This scheme of relationships was opposed tothe identification of alleles shared by the three species atthe studied loci Analysis of L. peregra population structure by F-statistics(Weir & Cockerham, 1984) suggested high inbreeding and raisedthe possible role of self-fertilization. The contradiction betweenhigh variability and high homozygosity is discussed. Furthermore,population differentiation was rather weak (although statisticallysignificant), despite some remarkable differences among loci.Nm estimates using Wright's (1951) and Slatkin's (1985) methodsrevealed a gene flow unable to prevent the effect of geneticdrift among populations. The relative homogeneity of populationswith weak genetic exchange is discussed (Received 24 May 1993; accepted 21 March 1994)     

PATTERNS OF REPRODUCTION IN THREE SANDY BEACH WHELKS OF THE GENUS BULLIA GRIFFITH

The breeding cycles of two species of sandy beach whelk (Bulliadigitalis and B. pura) are presented and compared with a thirdspecies (B. rhodostoma). In all three species, egg maturationand copulation occur in spring while summer marks the depositionand spawning of egg capsules. B. digitalis and B. pura migrateoffshore to lay their eggs, the juveniles of both species restrictingthemselves to beyond the breaker zone. Newly hatched snailsof B. rhodostoma appear in the intertidal towards late summer.The discovery of a penis-like structure on females of B. rhodostomais investigated. The pseudopenis was also found on B. pura butnever on B. digitalis. The possibility of a sex-change was eliminatedon the histological investigation of the gonads of a range ofsnails and the examination of sex-ratios over a period of fivemonths. General trends in reproductive behaviour are also discussed. (Received 18 March 1984;     

A NEW SPECIES OF BERTHELLA BLAINVILLE, 1824 (OPISTHOBRANCHIA: NOTASPIDEA) FROM THE CANARY ISLANDS (EASTERN ATLANTIC OCEAN), WITH A RE-EXAMINATION OF THE PHYLOGENETIC RELATIONSHIPS OF THE NOTASPIDEA

Berthella canariensis is described from Canary Islands. Themantle is smooth and its ground colour is grey, with black andopaque white spots scattered regularly all over the dorsal surface.White spots are less abundant than black ones. The posterior halfof the mantle has areas of with a paler ground colour that are variablein size. Berthella canariensis has several features that distinguishit from other described members of Berthella. It had a broadradula with numerous teeth per half-row. However, other aspectsof its anatomy, such as the absence of a medial buccal glandand the presence of a tuberculate gill, distinguish it fromother species with a broad radula. As the present species has two features found in some speciesof Pleurobranchus and several new higher taxa have been describedrecently, Willan's (1987) phylogenetic hypothesis was re-analysed.This analysis largely supports the hypothesis presented by Willan. The sister-group relationship of B. Canariensis with B. californiais supported by two synapomorphies. The relationship of thesetwo species to other species of Berthella is poorly resolvedin the present analysis and requires additional study of allmembers of the genus. Similarly, questions of the monophylyof Bathyberthella, Polictenidia, Parabathyberthella, Tomthompsoniaand Berthella require the consideration of additional speciesand comparison with other member of Berthella and Berthellina. Despite the need for further study, the mohophyly of the cladecontaining Bathyberthella, Polictenidia, Parabathyberthellais well supported. Similarly, numerous synapomorphic featuresconfirm the monophyly of the clade containing Bathyberthella,Polictenidia, Parabathyberthella, Tomthompsonia, Berthellinaand Berthella, and its sister-group relationship with the Pleurobranchus. The present study reveals that the Notaspidea have three distinctconfigurations of triaulic reproductive systems, not previouslydifferentiated. (Received 19 January 1998; accepted 15 November 1999)