ISSN 2755-3531
Variation in spatial structure and abundance of clausiliids (Mollusca: Clausiliidae) in the nature reserve Dębno Nad Wartą (W Poland) during wintering
Szybiak, K., Błoszyk, J., Koralewska-Batura, E. and Gołdyn, B.
Abstract
Studies on the distribution and abundance of Cochlodina laminata, Ruthenica filograna and Clausilia bidentata in wintering conditions were based on a network of four permanent monitoring plots. Of the three clausiliids present, C. laminata was the most widely distributed, while the occurrence of R. filograna was limited to one plot. The small distribution area of the snail was compensated for by its high abundance. The distribution of clausiliids was found to depend significantly on the soil humidity and temperature, these factors were, however, dependent on the litter composition which much better explains the observed variation. Canonical analysis (CCA) showed that R. filograna and C. bidentata preferred places with a sparse herb layer and a considerable proportion of litter of hornbeam (Carpinus betulus) and ash (Fraxinus excelsior). C. laminata was more tolerant with respect to the herb layer proportion, and the optimum of its occurrence was associated with alder litter (Alnus glutinosa). All three clausiliid species avoided litter of oak (Quercus), sycamore (Acer pseudo-platanus) and aspen (Populus tremula).
Key words: Permanent monitoring plots, Clausiliidae, microhabitats, snail distribution, wintering.
High resolution PDF (1.3mb)An allometric analysis of juvenile fluted giant clam shells (Tridacna squamosa L.)
Chan, K. R., Todd, P. A. and Chou, L. M.
Abstract
To explore potential allometric relationships in juvenile giant clams, Tridacna squamosa, log-transformed shell dimensions were regressed against the logarithm of shell length. Results indicate that shell height and vertical shell height are negatively allometric; possibly a strategy to enhance stability in high water energy environments. Anterior length also exhibits negative allometry; in this case growth may be constrained by contact with the substrate. Shell width, right-valve width, posterior length, scute length and scute width show positive allometry, and could contribute to increased survival as both greater overall width and larger scutes are known to reduce predation.
Key words: Allometry, Giant clam, Morphometrics, Tridacna.
Abstract
Charpentaria ornata is a SE-Alpine species which reaches the extreme north-east of its range in isolated populations in the Czech Republic and the extreme south-west of Poland, where it is known from this study only from eight abandoned limestone quarries in the western part of the Krowiarki range (Lower Silesia, region of Kłodzko). It is a red-listed species in the Polish fauna. These quarries harbour a total of 39 gastropod species, a mixture of open-country, tolerant and specifically forest species. Ch. ornata associates with open country species, and its density declines as tree cover increases. At this edge of its range, it appears unable to survive in full forest cover, although this is the natural climax vegetation of the region. Comparison with the more southerly populations in the Czech Republic shows that in warmer conditions it can survive full canopy cover, and is part of a rich, natural clausiliid fauna. It seems most likely that the species spread north from Czech sites in the mid-Holocene climatic optimum, and survived later as a result of early forest clearance exposing limestone crags to more xerothermic conditions. Later reafforestation was offset in these few sites by quarrying. Thus, in contrast to most threatened species of land gastropod, effective conservation requires the maintenance of highly disturbed habitats in an early stage of succession.
Key words: Charpentieria ornata, Clausiliidae, ecology, endangered species, succession, pioneer species.
The genus Callumbonella (Gastropoda: Trochacea) with the description of a new species from Namibia
Rolán, E., Gonzalez-Porto, M. and De Matos-Pita, S. S.
Abstract
The Recent species of the genus Callumbonella from the Mediterranean and east Atlantic are studied and comparison is made with a similar species found in deep water off Namibia. The species Callumbonella gorgonarum from the Cape Verde Archipelago is considered valid. It is concluded that the Namibian species is different and it is described as such in the present work. Comparison is made of the morphological characters of the shell, soft parts, operculum and radula. The placement of this genus is discussed due to the differences of anatomical and radular characters when compared with the subfamilies in Trochidae.
Key words: Gastropoda, Trochacea, Callumbonella, new species, Namibia.
On the identity of Strombus coniformis Sowerby II, 1842 (Gastropoda: Strombidae), with additional notes on its distribution
Kronenberg, G. C., Liverani, V. and Dekker, H.
Abstract
Based on shell characters, Strombus (Conomurex) coniformis Sowerby II, 1842 can be distinguished from S. (C.) decorus (Röding, 1798). The distribution range of both forms is partly overlapping, without intermediates being known. Therefore both have to be considered valid species. As the type specimens of S. (C.) coniformis are considered lost, a neotype for this species is designated. S. (C.) decorus masirensis Moolenbeek & Dekker, 1993 is a junior objective synonym of S. (C.) coniformis. Conomurex is considered a genus, rather then a subgenus of Strombus. New locality data for Conomurex coniformis are provided, forming a range extension for this species from Iran southwards to Eastern Africa.
Key words: Strombidae, Conomurex, neotype, range extension, Indian Ocean.
Koreamya arcuata (A. Adams, 1856) gen. nov. (Galeommatoidea: Montacutidae), a commensal bivalve associated with the inarticulate brachiopod Lingula anatina
Lützen, J., Hong, J.-S. and Yamashita, H.
Abstract
We describe the shell, soft anatomy, and reproduction of the montacutid bivalve, Koreamya arcuata (A. Adams, 1856) gen. nov. Contrary to most montacutids the outer demibranch has been preserved, although in a reduced state. The species is a protandrous consecutive hermaphrodite which stores sperm in a groove-shaped ctenidial seminal receptacle. The particular type of sperm receptacle and the presence of a lithodesma in Koreamya indicate an affinity to Montacutona Yamamoto & Habe, 1959, but the shells of the two differ widely in shape and proportions. The species is a commensal, and lives permanently attached to the valves near the shell gape of Lingula anatina at several Korean intertidal flats. It is also known from the Philippines, SE India and W Australia.
Key words: Koreamya arcuata, Galeommatoidea, morphology, systematics, commensalism, distribution.
First British record of the shipworm Uperotus (Bivalvia: Teredinidae) from driftwood on the Llyn peninsula, Wales
Oliver, P. G., Wood, H. and Holmes, A. M.
Abstract
The shipworm genus Uperotus is recorded for the first time from British shores. The name U. lieberkindi (Roch, 1931) is adopted rather than U. panamensis (Bartsch, 1922). The pallets and shell are illustrated.
Key words: Uperotus lieberkindi, new record, British Isles.
Systematic position and anatomy of Drepanostomella tucma Hylton Scott, 1948 (Stylommatophora: Scolodontidae)
Cuezzo, M. G. and Miranda, M. J.
Abstract
We redescribe Drepanostomella tucma Hylton Scott, 1948 and discuss the possible affinities of the genus. This is the first published report on the anatomy of a species of the genus Drepanostomella Bourguignat, 1889 since this taxon was previously known only on the basis of its shell morphology and radula. Drepanostomella was traditionally classified within Systrophiidae (now Scolodontidae), a widely distributed family in the Neotropical region. D. tucma is characterized by its deep sunken spire in a nautiloid shell, smooth protoconch, nacreous periostracum and an acute incision at parietal angle of the aperture. The animal has a holopod foot, while most of the other genera components of the family have an aulacopod foot. The radula has a central small tooth with the first lateral tooth smaller than the second one. Noteworthy is the presence of papilla regularly arranged with slightly recurved corneous hooks over the inner penis wall. Similar protuberances with corneous hooks have been already described in a Hirtudiscus Hylton Scott, 1948. Drepanostomella shows shell similarities mainly with Hirtudiscus and Guestieria Crosse, 1872. On the base of its radula morphology, its condition of “egg retainer” and the course of the right ommatophoral retractor passing between penis and vagina, Drepanostomella should be classified within the Scolodontinae (sensu Tillier, 1980). Differences and similarities of Drepanostomella with Happia Bourguignat, 1889, Systrophia Pfeiffer, 1855, Entodina Ancey, 1887 and Systrophiella, Baker, 1925, the rest of the Scolodontinae genera (sensu Tillier, 1980), are discussed. However, more anatomical studies and a cladistic analysis are necessary to further test these proposed affinities.
Key words: South America, Scolodontidae, Systrophiidae, radula, genitalia.
Oestophora prietoi n. sp., O. mariae n. sp. and O. ebria (Corbella, 2004), three Oestophora Hesse species (Stylommatophora: Trissexodontidae) from the Iberian peninsula
Ruiz, A., Arrebola, J. R. and Puente, A. I.
Abstract
Oestophora prietoi n. sp. and O. mariae n. sp. are described from Andalusia in southern Iberia, and Suboestophora ebria Corbella, 2004 is assigned to the genus Oestophora Hesse. These three species are compared with all known Oestophora species from the Iberian Peninsula, along with other related species from north Africa that are cited in the older literature. Future anatomical (north African species), molecular (in general) and biogeographical studies are required to improve the knowledge about the phylogeny of this and other related genera.
Key words: Taxonomy, new species, Andalusia, Oestophora, prietoi, mariae, ebria.
Idas lamellosus Verrill, 1882 (Bivalvia: Mytiloidea) a woodfall mussel new to the fauna of the northeast Atlantic
Oliver, P. G. and Holmes, A. M.
Abstract
Idas argenteus var. lamellosus Verrill, 1882 is recorded for the first time from the northeast Atlantic. It is regarded as distinct from I. argenteus and given species rank as Idas lamellosus. The shell is described from material collected by the Triton expedition of 1882 from the Wyville-Thomson Ridge at a depth of 944 metres. The shells were extracted from sunken wood along with specimens of I. argenteus.
Key words: Idas lamellosus, woodfall, new record, NE Atlantic.
Preliminary considerations for freshwater mussel reproduction and possible application for extensive rearing in Italy
Panini, E., Sicuro, B., Daprà, F. and Forneris, G.
Abstract
The present work is aimed to investigate the physiology of reproduction of the freshwater mussel (Anodonta anatina) for future extensive farming. In this paper the knowledge of life history traits and reproductive aspects is considered as the first step for obtaining juveniles for rearing mussels in captivity. In the first part of this research 2,285 specimens of A. anatina were placed in 5 sites in the Avigliana Lakes (NW Italy) and reared for a 2 years period. A sample of 180 specimens was collected in the Lake in November 2003 and 57% of mussels were gravid. The brooding period started from late August to the next spring. Histology performed on 11 individuals collected in April and late June 2004 clearly showed either females or hermaphrodites, confirming that A. anatina sexual strategy is characterised by a high plasticity. In order to obtain juveniles in captivity, a correct assessment of glochidial maturity was necessary. In April hooks of glochidia were completely developed and the adductor muscle was clearly visible. A partial extrusion of the mantle before glochidial release can be considered a good indicator of glochidial maturity, while water temperature and glochidial snapping activity are less reliable. Four Pumpkinseed (Lepomis gibbosus), 8 Bleaks (Alburnus alburnus) and an European Perch (Perca fluviatilis), were infested with glochidia in aquarium, confirming that A. anatina is a low selective host fish species and that host fish parasitism can be easily performed in artificial conditions with fish species commonly found in Avigliana Lakes.
A case of direct development to a juvenile A. anatina without the parasitic stage on fish was also observed: a metamorphosed glochidium (juvenile) was found in the genital duct together with sub-triangular glochidia of smaller size. This is the first observation of direct development reported for an European unionid.
Freshwater mussel farming could be interesting activity for the future for bacteria filtration in integrate productions and as alternative feedstuffs for farmed fish nutrition. This preliminary work is the first step for larval rearing and potential future of European freshwater mussel farming.
Key words: Freshwater bivalves, mussels farming, unionids, Anodonta anatina.
Taxonomical notes on Euro-Siberian freshwater molluscs*: 2. Redescription of Planorbis (gyraulus) stroemi Westerlund, 1881 (Mollusca: Gastropoda: Planorbidae)
Glöer, P. and Vinarski, M. V.
This paper is dedicated to the memory of Dr. Alexander Kafanov, promiment Russian malacologist and zoogeographer, who died in April 2007.
Abstract
Gyraulus stroemi Westerlund, 1881 is a species distinct from G. acronicus (A. Férussac, 1807). It was, however, overlooked by the W-European malacologists for a long time. In this paper the shells as well as the anatomy have been studied thoroughly (including syntypes of Planorbis stroemi) and compared with morphological and anatomical features of G. acronicus. By means of scanning of museum collections and the literature, a distribution map was constructed which reveals that G. stroemi is a species that lives predominantly in the Artic and Subarctic.
Note*: The first part of the serial has been published in Ruthenica (Moscow), vol. 17(1-2) 55-63, 2007.
Redescription of Planorbis moquini Requien, 1848 (Gastropoda: Planorbidae)
Glöer, P. and Zettler, M. L.
Abstract
The conchological and anatomical characters of the topotypes of Planorbis moquini Requien, 1848 have been studied in detail. Comparisons with Planorbis agraulus Bourguignat, 1864 from Algeria revealed that these species are distinct from each other. In addition we examined additional Planorbis spp. from Sardinia and Crete showing that neither species are conspecific with P. moquini and P. agraulus. The question remains as to which Planorbis spp. live in the Mediterranean in addition to P. moquini and P. agraulus.
Key words: Planorbis moquini, redescription, anatomy, topotype.
Yoldiella and Portlandia (Bivalvia) from the Faroe Shetland Channel and Rockall Trough, northeast Atlantic
Killeen, I. J. and Turner J. A.
Abstract
Benthic environmental assessments associated with oil and gas explorations along the UK Atlantic Margin have revealed deficiencies in the taxonomy of many deep-water taxa. Amongst the Bivalvia the protobranch genera Yoldiella and Portlandia are particularly complex. This study presents tabular keys, shell and gut loop descriptions for those taxa living on the continental slope and abyssal areas of the Atlantic Margin west and north of Scotland.
The study is based primarily on samples collected in three surveys under the direction of the Atlantic Frontier Environmental Network (AFEN) between 1996 and 2000, with additional material from museum collections. Specimens were found at 239 stations from depths ranging from 98m on the outer continental shelf to 2046 m in Rockall Trough. One species of Portlandia and eight species of Yoldiella were recognized in the AFEN material P. intermedia, Y. annenkovae, Y. curta, Y. jeffreysi, Y. lucida, Y. nana, Y. philippiana, Y. propinqua and Y. valorousae nom. nov.
Yoldiella annenkovae is recorded for the first time in British or Irish waters.
Yoldiella valorousae nom. nov. is a replacement name for Y. lata sensu Allen, Sanders & Hannah 1995).
A further 8 species that occur in parts of the NE Atlantic adjacent to the AFEN study area are included. Y. biscayensis, Y. fabula, Y. frigida, Y. incala, Y. insculpta, Y. lenticula, Y. solidula, Y. thaerella sp. nov.
Y. thaerella sp. nov. is Y. inconspicua inconspicua sensu Allen, Sanders & Hannah 1995 non Y. inconspicua Verrill & Bush, 1898.
Y. incala is a taxon raised to species rank from Y. obesa incala Allen, Sanders & Hannah 1995).
Key words: Yoldiella, Portlandia, protobranch, taxonomy, Atlantic Margin, Atlantic Frontier Environmental Network.
Short Communication
Two further UK sites for Caecum armoricum, De Folin, 1869, formerly known only in the Fleet, Dorset, as a member of the interstitial ‘springs’ community
Pain, C., Wilkinson, S. and Light, J.
Book Review
Land and Freshwater Molluscs of Brazil by L. R. L. Simone published by EGB, Fundação de Amparo à Pesquisa do Estado de São Paulo, Brazil 2006. 390pp A4 Hardback, ISBN 85-906670-0-6. Price c.£90.
Topley, P.
Spiny Oysters: A Revision of the Living Spondylus Species of the World by Kevin Lamprell privately published by Mrs Jean Lamprell (PO Box 933, Morayfield, Queensland, Australia, 4506) in a limited edition of 500 numbered copies. ISBN 1.921.054611, 119 page A4 Hardback. $50 Australian (approx. £34).
Brown, K.
Seashells of the Egyptian Red Sea by Mary Lyn Rusmore-Villaume. Published by The American University in Cairo Press 2008. ISBN 978-977-416-096-7. XII+308pp. Price £17.95 Hardback.
Brown, K.