Journal of Conchology 43 (5), April 2020

ISSN 2755-3531


Mapping juvenile habitat for the freshwater pearl mussel (Margaritifera margaritifera)

Ian Killeen & Evelyn Moorkens

Abstract. A technique has been developed to determine the extent and condition of suitable habitat for the freshwater pearl mussel Margaritifera margaritifera in rivers supporting this species. The habitat mapping technique combines physical measurements and adult mussel counts with best expert judgement in a dense network of transects, qualified by measured categorical habitat quality data in more dispersed transects, in order to get a mapped overview of mussel populations that are accurate enough to inform conservation agencies, river managers and researchers regarding the status of the population. The study to develop the methodology was carried out in a river in north-west England. A 3 km long section of riverbed was surveyed. Data was collected from each 1 m × 1 m quadrat on transverse transects at 10 m intervals. In addition, the results of the study were validated from results of a mussel demographic study undertaken in the habitat and condition combinations identified in the mapping study. Examples are given of GIS habitat maps derived from the study, including sample variation in habitat, condition and mussel numbers within individual 100m sections, and their relationship with flow.

Key words. Freshwater pearl mussel, habitat, riverine mapping, conservation, demographic profile

Date of publication. April 2020


A revision of the genus Sumelia Neubert, 1995 (Gastropoda: Eupulmonata: Clausiliidae) with the introduction of a new genus and a subgenus

Barna Páll-Gergely & Miklós Szekeres

Abstract. Reproductive anatomy, including morphology of the inner penial wall, and shell morphology of all five species hitherto classified in Sumelia Nordsieck, 1994 have been investigated. This resulted in the recognition of a new genus, Blaeneuxina n. gen. (type species: Euxina recedens Németh & Szekeres, 1995) and a new subgenus, Sumelia (Neubertia) (type species: Strigileuxina carinata Neubert, 1993).

Key words. taxonomy, systematics, Turkey, anatomy, land snail

New taxon. Neubertia Páll-Gergely & Szekeres, 2020

Date of publication. April 2020


Kontschania tetragyra n. gen. & sp. from Laos (Gastropoda: Cyclophoroidea: Diplommatinidae)

Barna Páll-Gergely & Jozef Grego

Abstract. Kontschania tetragyra n. gen. & sp. is described from central Laos, Khammouane Province. Kontschania n. gen. differs from the probably most closely related Notharinia by the truncated cone-shaped shell, open umbilicus with all whorls visible inside and the alternating low and high teleoconch ribs.

Key words. new genus, new species, endemism

New taxa. Kontschania Páll-Gergely & Grego, 2020; Kontschania tetragyra Páll-Gergely & Grego, 2020

Date of publication. April 2020


Substrate parameters affecting propagation of juvenile freshwater pearl mussels Margaritifera margaritifera (Bivalvia: Margaritiferidae)

Louise Lavictoire, Gill Notman, Allan Pentecost, Evelyn A. Moorkens, Andrew D. Ramsey & Roger A. Sweeting

Abstract. Interstitial habitat conditions are of critical importance to species inhabiting the hyporheic zone, particularly for moderately immobile species incapable of escaping poor habitat conditions. The endangered freshwater pearl mussel (Margaritifera margaritifera Linnaeus, 1758) has seen increasing propagation effort over the last three decades, often with mixed success. This study aimed to investigate parameters with the potential to affect juvenile survival in captivity by considering a range of habitat conditions within the substrate of a previously described propagation system using different substrate size classes (0.25–1 and 1–2mm) and cleaning regimes (weekly and monthly). Juvenile survival was highest in larger substrates, likely because of higher flow through larger pore spaces. This provided higher dissolved oxygen delivery in 1–2 mm substrates cleaned weekly (8.26 ± 0.19 mg/L) and monthly (8.24 ± 0.44 mg/L), compared with 0.25–1mm substrates cleaned weekly (7.98 ± 0.44 mg/L) and monthly (6.78 ± 1.27 mg/L). The amount of organic material trapped in the substrate did not differ between treatments but the high concentrations of inorganic phosphorus liberated from ashed organic matter indicated phosphorus storage in phytoplankton. High dissolved oxygen concentrations and good water replacement between the water column and the substrate are crucial for survival in captive freshwater pearl mussels.

Key words. Interstitial, propagation, Margaritifera, dissolved oxygen, substrate

Date of publication. April 2020


Additional data on eastern Pantepui Orthalicoidea land snails (Mollusca, Gastropoda)

Abraham S.H. Breure

Abstract. Recent visits by a herpetologist to hitherto unexplored or ill–explored tepuis in the Pantepui area of Venezuela reveal three new species: Plekocheilus (P.) sanderi, P. (Eurytus) annetae, and P. (E.) timoi. This brings the total number of recognised species in the Pantepui to 27 land snails, of which 23 belong to the dominating superfamily Orthalicoidea.

Key words. Amphibulimidae, anatomy, Bulimulidae, Guyana, Venezuela

Date of publication. April 2020


A new Formosana species (Gastropoda, Stylommatophora, Clausiliidae) from Shanxi Province, North China

Zhe-Yu Chen

Abstract. A new clausiliid species Formosana jianyueae n. sp. [见玥丽管螺], collected from the Manghe Macaque National Nature Reserve, Shanxi Province, China, is described and illustrated. This is the first species of Formosana described from northern China; it is a medium-sized, dextral species characterised by the combination of a lamella superior indistinctly separated from the lamella spiralis, receding lamella subcolumellaris, lateral to dorsally ending plica principalis, and four or five strong palatal plicae. This new species represents the first clausiliid record from Shanxi Province and the northernmost natural distribution of Formosana species in China.

Key words. North China; taxonomy; dextral clausiliids; new species

New taxon. Formosana jianyueae Chen, 2020

Date of publication. April 2020


First record of the false mussel Mytilopsis sp. (Dreissenidae) from Grand Cayman, Caribbean Sea

Dan Minchin & Elizabeth J. Cottier-Cook

Abstract. The byssate false mussel Mytilopsis sp. was identified for the first time in the Cayman Islands in May 2018. It occurred in the mangrove backwaters on the northern coast of Grand Cayman in great abundance. Mytilopsis spp. are highly invasive in many semi-tropical to tropical regions globally and are almost certainly spread by vessels. Identification of Mytilopsis species is difficult, as previously used morphological identification characters are highly variable and so, here we report on its occurrence in Grand Cayman, likely further spread and discuss the difficulties in its identification.

Key words. False mussel, red mangrove, marina, spread, hull fouling

Date of publication. April 2020


A new species of Streptartemon from southeastern Brazil (Gastropoda: Streptaxidae)

Rodrigo B. Salvador & Carlo M. Cunha

Abstract. A new species of Streptartemon Kobelt, 1905 land snail from Santos, SE Brazil, is herein described as Streptartemon waukeen sp. nov., from specimens originally found in an urban garden. The new species is distributed along coastal urban areas from southern Espírito Santo state to São Paulo state. It can be diagnosed from its congeners by the following features: a comparatively small shell; the penultimate and body whorls bulging and rounded; a small and roughly circular aperture; and the lack of apertural lamellae/teeth. The new species also presents a bursa tract diverticulum, which is a plesiomorphic state in stylommatophoran snails, but absent in most streptaxid genera. Further details of the genital anatomy, as well as DNA barcoding information, are provided.

Key words. Anatomy, barcoding, COI, Eupulmonata, Streptartemon waukeen sp. nov., Stylommatophora

New taxon. Streptartemon waukeen Salvador & Cunha, 2020

Date of publication. April 2020


Redescription and ecological niche of a land snail Dicharax strangulatus (L. Pfeiffer, 1846) in the Himalaya (Gastropoda: Cyclophoroidea: Alycaeidae)

Sheikh Sajan, Barna Páll-Gergely, Basudev Tripathy, Paromit Chatterjee, Kailash Chandra & Kuppusamy Sivakumar

Abstract. The operculate land snail family, Alycaeidae is comprised of species often <10mm in diameter and most species are known to be narrow-range endemics. Most Indian alycaeid species are known to be distributed in the Eastern Himalaya and the Western Ghats, whereas only a single species, Dicharax strangulatus (L. Pfeiffer, 1846), is known to be distributed in the western Himalaya. Most of the reports on this species in India and Nepal originate from the literature published during the British India colonial period. The species remains poorly understood and no studies exist regarding its ecology or habitat. The present study redescribes Dicharax strangulatus from Great Himalayan National Park (GHNP) with high resolution photomicrographs scanning electron microscope images and projected an ecological niche model to explore the possible climatic distribution of the species.

Key words. taxonomy, systematics, redescription, India

Date of publication. April 2020


On the identity of Radix peregra (O.F. Müller) (Gastropoda: Basommatophora: Lymnaeidae) in the Azores

Katrin Schniebs, Ulrich Bössneck & Anna K. Hundsdoerfer

Abstract. Specimens of the freshwater gastropod genus Radix Montfort, 1810 were collected in March 2015 in two São Miguel Island creeks, the largest island in the Portuguese archipelago of the Azores. Based on the shape of their shells they could have been assigned to two different Radix species. Because it is now known that morpho-anatomical studies of the shells and genitalia do not allow for a reliable determination of most Radix species, DNA markers were used as the best tools for identification. Four specimens, two from each location, were subject to molecular identification. Their cyt–b and ITS-2 sequences formed one cluster with the sequences of the Radix balthica specimens used in the analysis. This is the first identification of this species, a potential intermediate host of the Fasciola hepatica Linnaeus, 1758, based on molecular genetics for the Azores.

Key words. Radix balthica, Lymnaeidae, Azores, molecular genetics, morphology

Date of publication. April 2020


New Eostrobilops Pilsbry, 1927 (Eupulmonata: Strobilopsidae) of China

Guoyi Zhang, Xuyun Qiu & Tengteng Liu

Abstract. Eostrobilops wuranicus Zhang, n. sp. is reported as a new species herein, with information on the species’ ecology. This new species can be separated from other Eostrobilops species distributed in China, Korea, Japan and other adjacent regions by the ribless shell, the four basal folds and the two lamellae. Inner shell structures, i. e., the basal fold and the lamella, of Eostrobilops distributed among China, Russia, Japan and Korea are listed.

Key words. Shandong, Korea, Russia, Far East

New species. Eostrobilops wuranicus Zhang in Zhang, Qiu & Liu, 2020

Date of publication. April 2020



Obituary — Pryce Urban Buckle — 17th April 1936–9th November 2019

Mike Weideli

Date of publication. April 2020