PHYLOGENY OF THE GENUS ROSTANGA (NUDIBRANCHIA), WITH DESCRIPTIONS OF THREE NEW SPECIES FROM SOUTH AFRICA

Rostanga elandsia sp. nov., Rostanga aureamala sp. nov. andRostanga phepha sp. nov. are characterized by having the radulawith slender innermost lateral teeth, which lack denticles onthe inner side of the cusp and have a single denticle on theouter side. The outermost lateral teeth of these three speciesare elongate, but shorter than in other species of the genus.In addition, R. aureamala is the only species of the genus withrachidian teeth and R. phepha is unique within the genus Rostanga byvirtue of its white coloration with dark spots. A phylogenetic analysis shows that the three new species fromSouth Africa and Rostanga setidens (Odhner, 1939) are the sistergroup of the rest of the genus. The species from Japan and MarshallIslands (North Pacific Ocean) are basal in the sister cladecontaining the other species of Rostanga Bergh, 1879. The tropicalIndo-Pacific species of Rostanga are not monophyletic. The Atlanticand Eastern Pacific species form a monophyletic, derived clade,being the sister group of Rostanga australis Rudman & Avern,1989, which has a narrow range restricted to south eastern Australia.The widespread Indo-Pacific species Rostanga bifurcata Rudman& Avern, 1989, is the sister group of Rostanga dentacus Rudman& Avern, 1989, also widesprad in the tropical western Pacific. This phylogeny suggest s a viariant origin of the Sourth African, Atlantic-EasternPacific, and probably North Pacific species, whereas in thetropical Indo-Pacific most sister speceis are sympatric. (Received 16 May 1999; accepted 31 July 2000)     

CONTRIBUTIONS TO THE KNOWLEDGE OF THE GENUS AEGIRES LOVEN, 1844 (OPISTHOBRANCHIA: DORIDOIDEA: AEGIRETIDAE) IN THE NORTH ATLANTIC, WITH DESCRIPTIONS OF TWO NEW SPECIES

New information on Aegires ortizi Templado, Luque & Ortea,1987 is given, and two new species of the genus Aegires aredescribed, one from the Caribbean and one from the MediterraneanSea. A key to the North Atlantic species of Aegires is given. (Received 10 February 1989; accepted 11 July 1989)     

A Comparative Study of the Cold-Sensitivity of Pyruvate,Pi Dikinase in Flaveria Species

Pyruvate,P_i dikinase (PPDK) was isolated and purified from theleaf tissue of a number of Flaveria species and the cold labilityof the purified enzymes studied. The PPDK from F. brownii (aC₃/C₄ intermediate species) showed a high level of stabilitycompared to other Flaveria species. (Received September 7, 1989; Accepted November 22, 1989)     

Temporal and regional variation in the copepod community in the central Barents Sea during spring and early summer 1988 and 1989

In this study, we examined a 3000 km² area to the southeastof Bear Island in the central Barents Sea with respect to copepodabundance and depth distribution at nine stations in March,April and May of 1988 and 1989. In order to describe the populationdynamics of the most prominent species in the area during theperiod of study, the annual ascent and abundance of Calanusfinmarchicus, Metridia longa and Calanus glacialis are shown.Stage abundance, vertical distribution and cohort developmentdid vary between species and years at one site. The number ofspecies and the complexity of the data for the entire area studiedhave encouraged us to search for more significant and persistentpatterns by using a canonical correlation analysis (CCA). Weincluded a total of 27 species and stage categories, latitude,salinity and sigma from the nine stations in 1989 We performedthis analysis for 1989. since we only have environmental data(CTD) available from the same stations in that year The species-environmentrelationship showed that the zooplankton community could notbe grouped according to area (latitude) or environmental (sigma,salinity) conditions during March–May in 1989. This meansthat the differences in environmental conditions in the areaof study in 1989 do not mediate any consistent gradient in thezooplankton community. When comparing the copepod data for bothyears. the largest differences are associated with the depthand month vectors. The largest interannual variation is seenin the copepod community in the depth strata from 100 to 400m. and is related to a lesser degree of similarity among thespecies and stages found in this depth interval throughout thestudy. Two species were particularly responsible for the interannualdifferences: Pseudocalanus acuspes CV and females, and C glacialisCV and adults. Changes in these two species are clearly relatedto major shifts in the hydrographic conditions between the 2years, where 1988 was generally colder compared to 1989.     

PROTAEOLIDIELLA ATRA BABA, 1955 AND PLEUROLIDIA JULIAE BURN, 1966; ONE SPECIES, TWO FAMILIES (NUDIBRANCHIA)

The aeolid nudiberanch species Protaeolidiella atra Baba, 1955and Pleurolidia juliae Burn, 1966, sole species of the familiesProtaeolidiellidae and pleurolidiidae respectively, are shownto be conspecific. The apparent ‘primitive’ featuresof their morphology are re-examined and reinterpreted and itis suggested that the species is a member of the Fomily Aeolidiidae.Unlike other members of the family, which all feed on anthozoans,this species is highly specialised for feeding on the hydroidSolanderia fusca. The single species is shown to have a wideIndo-west Pacific distribution. Functional extra-ceratal lobesof the digestive gland are reported for the first time, froman aeolid without zooxanthellae symbiosis. (Received 4 October 1989; accepted 23 December 1989)     

NORTH ATLANTIC SPURILLID NUDIBRANCHS, WITH A DESCRIPTION OF A NEW SPECIES, SPURILLA COLUMBINA, FROM THE ANDALUSIAN COAST OF SPAIN

The new species Spurilla columbina differs from its Europeancongeners in coloration and the shape of its cerata. Comparativedata derived from S. norvegica (Odhner, 1939), S. coerulescens(Laurillard, 1830) and S. verrucicornis (Costa, 1864) are tabulated. ^* T. E. Thompson died in a car accident 1 January 1990 (Received 10 January 1989; accepted 4 July 1989)     

TROPHIC ROLES OF CO-OCCURRING SPECIES OF DRUPA (GASTROPODA: MURICIDAE) AT ENEWETAK ATOLL

Diets in nature differed significantly among three species ofthe gastropod genus Drupa (Muricidae: Thaidinae) on a windward,seaward reef platform at Enewetak Atoll, Marshall Islands. Nereidand eunicid polychaetes and vermetid gastropods were the mostimportant prey organisms. D. morum ate mainly Perinereis, Ceratonereisand eunicids; D. ricinus ate mainly Ceratonereis in protectedsites and Dendropoma near the exposed outer reef edge. Sizeof Drupa was correlated with that of vermetid but not polychaeteprey. The results are compared with data from studies of otherpredators on the same prey species at Enewetak, and with J.D. Taylor's data on the diets of Drupa species elsewhere inthe Indo-Pacific region. ^*Present address: Department of Zoology, University of California,Berkeley, California 94720. (Received 4 February 1989; accepted 6 March 1989)     

Armoured dinoflagellates in the NE Atlantic during the BOFS cruises, 1988-90

The armoured dinoulagellates present in 90 plankton samplescollected by the use of an Apatein closing net were enumerated.The samples were collected from various stations around the20W meridian and between 44 and 60N during the 1988, 1989and 1990 Biogeochemical Ocean Flux Study (BOFS) cruises. Atmost stations, samples were obtained from various depths, althoughin 1990 only the surface zone was sampled. A total of 126 specieswere identified, of which 49 have chloroplasts and are thoughtto be autotrophic, 47 are assumed to be heterotrophic and thenutritional type of the remainder is unknown. The samples collectedduring July 1988 were dominated by large numbers of the twophotosynthetic species Gonyaulax polygramma and Protoceratiunreticulatum (=Gonyaulax grindleyi). The much more intensivesampling of 1989 revealed several Ceratiun species, C.fusus,C.furca and C.lineazum, together with Gonyaulax polygramma,as the most common dinoflagellates. In 1990 the samples, whichwere taken during a Lagrangian survey in May-June, were alsodominated by Ceratium species. This time C.azoricwn was a majorcomponent and Protoceratium reticulatum was again present inhigh numbers as in 1988. A number of analyses were carried outon the data collected. It was found that the majority of themore frequent species were autotrophs and most were membersof the genus Ceraziwn. The effects of depth were shown to resultin reduced numbers of cells and species, but no clear associationwas found between species and depth. After the application ofDetrended Correspondence Analysis (DECORANA) to all surfacesamples, there was found to be a clear association between thespecies composition and both time of year and latitude. Watercolumn stability is also probably an important factor in speciescomposition and cell numbers. Seasonal changes in the frequencyof the main species were also noted with some, such as C.lineatum,being more important early in the summer and others, such asProtoceratium reticulatum and particularly G.polygramma, becomingdominant later. The use of Two-way Indicator Analysis (TWINSPAN)revealed some potential species associations.     

INFLUENCE OF NON-TARGET MOLLUSCS ON THE GROWTH OF BIOMPHALARIA GLABRATA INFECTED WITH SCHISTOSOMA MANSONI: CORRELATION BETWEEN GROWTH AND CERCARIAL PRODUCTION

The presence of non-target molluscs (nine species tested) resultedin a significant enhancement of the growth of Biomphalaria glabratainfected with Schistosoma mansoni. A positive significant correlationwas found between the mean final shell diameter of B. glabrataand the total cercarial production of S. mansoni. Two hypotheseson the mechanisms implied in these interactions are proposed. (Received 6 October 1989; accepted 5 December 1989)     

Circular Arrangement of Cortical F-actin around the Subapical Region of a Tip-Growing Fern Protonemal Cell

F-actin organization in the tip-growing cells of fern protonematawas investigated by rhodamine-phalloidin staining in two species:Adiantum capillus-veneris and Pteris vittata. Circular arrangementof cortical F-actin was found around the subapical region ofprotonemal cells in both species. In rhizoids, such structureswere absent and the axial filaments appeared to fan out fromthe tip. (Received May 22, 1989; Accepted September 6, 1989)     

HETEROSTOPHIC SHELLS AND PELAGIC DEVOLOPMENT IN TROCHOIDEANS: IMPLICATIONS FOR CLASSIFICATION, PHYLOGENY AND PALAEOECOLOGY

Four species of archeogastropods, presumed members of threesubfamilies of the trochidae, exhibit significant differencesin developmental modes and shell coiling. All four species havelecithotrophic development which is reflected in their inflatedpausispiral protoconchis; however, Margarites marginatus andLirularia succincta have benthic development in gelatinous masses,while Margarites pupillus and Calliostoma ligatum have pelagicembryos and swimming larvae with a potential for dispersal overa period of a week or longer. These modes cannot be deducedfrom the size of the egg, the size or shape of the protoconch,or the size or relative prominence of female pallial reproductivestructures. The protoconch of C. ligatum is orthostrophicallycoiled, but the protoconchs of the other three species are hyperstrophicallycoiled although their teleconchs are orthostrophic. These threetrochoidean species thus share with architectonicoideans, pyramidelloideans,opisthobranchs, and pulmonates the distinctive shell characterof heterostrophy, previously unreported for archaeogastropods. These observations, considered together with others reportedin the literature, show: (1) that developmental mode (pelagicor benthic) cannot be inferred from protoconch appearance ortaxonomy in major trochoidean ganera; (2) that significant dispersalpotential is present in the histories of some trochoidean archeogastropoids;and (3) that character sets (pallial reproductive structures,pairing during spawning, heterostrophic shell coiling) thoughtnot to occur below the mesogastropod level are found in theTrochoidea. These conclusions bring into question the usefulnessof these characters in defining higher gastropod taxa and raiseadditional questions concerning the ancestry of the higher gastropods. (Received 16 February 1989; accepted 25 June 1989)     

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)     

NITROGEN EXCRETION BY THE SANDY BEACH NASSARIID WHELKS BULLIA RHODOSTOMA REEVE AND B. DIGITALIS (DILLWYN)

Nitrogen excretion by two surf zone gastropods, Bullia rhodostomaReeve and Bullia digitalis (Dillwyn) was determined under laboratoryconditions. The forms of nitrogen excreted and the effects ofmass, temperature, short-term starvation and feeding on excretionrates were determined for each species. The excretion ratesof B. rhodostoma removed directly from the surf zone (within2 h of capture) were also determined at three temperatures.No significant differences in the forms of nitrogen excretedwere found between starved and fed whelks or between species.Ammonia was the major form of nitrogen excreted with amino acidsof secondary importance. Urea was not detected and a small percentageof total dissolved nitrogen (TDN) excreted was unaccounted forin both species. Mass significantly influenced the rate of ammoniaexcretion in both species. No significant difference in slopes(common b = 0.60) were found between starved B. rhodostoma andB. digitalis or between fed whelks of the two species (commonb = 0.54). Mass adjusted mean ammonia excretion rates of starvedB. rhodostoma and those removed directly from the surf zone(‘natural diet’) did not differ significantly. Adjustedmean ammonia excretion rates of fed whelks were significantlyhigher than ‘starved’ excretion rates in both species.Temperature did not significantly influence ammonia excretionrates of fed B. rhodostoma or starved and fed B. digitalis.Bullia recycle 14.45 to 23.98 g N per metre strip of surf zoneper year which constitutes less than 1% of total phytoplanktonrequirements in the surf zone. (Received 15 August 1989; accepted 16 October 1989)     

EASTERN MEDITERRANEAN OPISTHOBRANCHIA: DOTIDAE (DENDRONOTOIDEA), ARMINIDAE AND MADRELLIDAE (ARMINOIDEA)

An account is given of Doto, Armina and Madrella species collectedon diving and dredging expeditions to the Ligurian, Tyrrhenian,Adriatic, Ionian and Aegean Seas during the period 1973–1988,supplemented by material collected around Naples (southern Italy)and Banyuls (French Côte Vermeille). In all, 5 speciesof Doto, 3 of Armina and 1 of Madrella were investigated, yielding5 new records for the eastern Mediterranean Sea and one speciesnew to science, Armina tricuspidata from the Tyrrhenian Sea.The common arminid on the American coast from North Carolinato Texas is not A. tigrina as claimed by Abbott(1954) and byEyster (1981), but is a new species, for which we propose thename Armina abbotti. Consideration of world-wide records of Madrella leads to theconclusion that the senior Madrella sanguinea Angas, 1864, embracesM. ferruginosa Alder & Hancock, 1864, M. aurantiace Vayssière,1903 and M. granularis Baba, 1949 (but not the Japanese M. gloriosaBaba, 1949, which is probably distinct). ^*T.E. Thompson died in a car accident 1 January 1990. (Received 2 May 1989; accepted 4 November 1989)     

SAND-DWELLING OPISTHOBRANCHS FROM HONG KONG

Five species of interstitial opisthobranch gastropod includingone new species, Pseudovermis chinensis are reported from coarsesand in littoral and sublittoral habitats around Hong Kong andthe south China Sea. (Received 15 August 1989; accepted 4 April 1991)     

THE GENETIC RELATIONSHIPS OF THREE TAXA IN THE LITTORINA SAXATILIS SPECIES COMPLEX (PROSOBRANCHIA: LITTORINIDAE)

Three species in the Littorina saxatilis complex (the ovoviviparousL. saxatilis and the two oviparous species L. arcana and L.nigrolineata) were screened for the products of up to 22 lociusing gel elec-trophoresis. Analysis of allele frequencies andderived genetic distances showed that, with rare exceptionsin L. saxatilis and L. arcana, conspecific populations clusteredtogether. Sympatric pairs of populations showed significantdifferentiation at many polymorphic loci. The results confirmedthe biological reality of the three taxa, and did not suggestthe existence of any previously unrecognized species. The speciesare genetically closely related to each other, with Nei geneticdistances ranging from 0.035 to 0.083. (Received 24 October 1989; accepted 18 April 1990)     

Fatty Acid Composition of Phosphatidylglycerols in Relation to Chilling Sensitivity of Woody Plants

The fatty acid composition of phosphatidylglycerol (PG) wasexamined in leaves of nine species of temperate-zone evergreens,seven species of tropical evergreens and seven species of temperate-zonedeciduous plants. The sum of the levels of palmitate, stearateand trans-3-hexadecenoate, as a percentage of the total fattyacids in the PG, ranged from 55% to 62% in the temperate-zoneevergreens, from 67% to 75% in the tropical evergreens, andfrom 58% to 72% in the temperate-zone deciduous plants. Thesefindings suggest that the sum of the saturated and trans-monounsaturatedmolecular species, relative to the total fatty acids in PG,is correlated with the sensitivity of the leaves of evergreensto chilling, being consistent with the hypothesis proposed toexplain the sensitivity to chilling of leaves of herbaceousplants. (Received December 8, 1989; Accepted March 23, 1990)     

RESTRICTION ENZYME ANALYSIS OF DNA FROM SPECIES OF BULINUS (BASOMMATOPHORA: PLANORBIDAE) USING A CLONED RIBOSOMAL RNA GENE PROBE

A ribosomal RNA gene probe (pSM889) has been used to study restrictionenzyme digests of various species of Bulinus. In order to minimiseproblems of DNA shearing associated with snail tissues a methodof extracting nucleic acids from material embedded in agaroseblocks has been used. Restriction enzyme digests with Bgl IIand Bam HI hybridised to pSM889 showed clear differences betweenB. truncatus, B. wrighti, B. africanus and B. forskalii, representingthe four species groups of Bulinus. No differences were observedbetween samples of B. tropicus and B. truncatus digested withBam HI, Bgl II and Pst I. Intra-specific variation was observedbetween samples of B. forskalii from Säo Tomé andAngola digested with Bgl II and Hind III although restrictionprofiles for Bam HI, Pst I and Bst EII digests were similar.Intra-specific variation was also observed between two differentpopulation samples of B. wrighti from South Yemen using BamHI and Bgl II digested genomic DNA hybridised to pSM889. (Received 5 December 1989; accepted 19 April 1990)     

REPRODUCTIVE BIOLOGY OF THE SESSILE GASTROPOD VERMICULARIA SPIRATA (CERITHIOIDEA: TURRITELLIDAE)

The reproductive and developmental biology of the sessile gastropodVermicularia spirata (Philippi, 1836), collected from the FloridaKeys, was studied from living and preserved material. Individualsof this species attach themselves to a variety of substrata,but were mainly found embedded in the white sponge Geodia gibberosa.Pallial reproductive structures of both sexes of V. spiratawere found greatly to resemble those of Turritella communis,a free-living member of the same family. In both species, animalsof both sexes have open pallial ducts formed by two wide, recurvedlaminae. In the female of V. spirata, the laminae of the pallialoviduct serve as a capsule gland; a pair of side pockets representa fertilization pouch (possibly doubling as a copulatory bursa)and a seminal receptacle. The functional significance of theextensive, open, pallial sperm duct is not yet clear. Vermiculariaspirata is a protandrous hermaphrodite, and small males arefree-living; they become attached at about the time they undergosex reversal. Fertilization is probably brought about by malescrawling close to the apertures of the large, sessile femalesbefore releasing sperm. Egg capsules are brooded in the females'mantle cavities. Ova of about 300 µm diameter give riseto large (about 600 µm long) swimming-crawling veligerlarvae with shells of two and a half whorls. The veligers arecapable of metamorphosis at the time of hatching, but siblingsfrom one brood metamorphosed over a two-week period in the laboratory.Juvenile snails grew rapidly by filtering phytoplankton addedto their culture water. The life history of V. spirata is welladapted to assure fertilization and recruitment in a speciesotherwise committed to a sessile, filter-feeding existence. (Received 3 February 1989; accepted 19 April 1989)     

SYSTEMATICS OF POTAMACMAEA FLUVIATILIS (BLANFORD): A BRACKISH WATER PATELLOGASTROPOD (PATELLOIDINAE: LOTTIIDAE)

Potamacmaea fluviatilis (Blanford, 1867), which is known fromestuaries and tributaries that drain into the Bay of Bengal,was studied to assess available material, determine possiblerelationships between P. fluviatilis and other patellogastropodtaxa, and review the current state of our knowledge of thisenigmatic species. Radular and shell structure characters indicatethat P. fluviatilis is referable to the Patelloidinae Chapman& Gabriel, 1923. The radular tooth morphology of P. fluviatilisis similar to that of the wood-eating taxon PectinodontinaePilsbry, 1891; both taxa have multicuspid lateral teeth. Substantialhuman population increase and its accompanying habitat destructionin this region may have had deleterious effects on this uniquepatellogastropod. (Received 22 May 1989; accepted 25 July 1989)