NEW RECORD OF THE LAND SNAIL POLYGYRA CEREOLUS (MEGERLE VON MÜHLFELD, 1818) (GASTROPODA, STYLOMMATOPHORA, POLYGYRIDAE) FOR MALACOFAUNA OF IRAQ

In this study, the specimens of land snails Polygyra cereolus (Megerle von Mühlfeldt, 1818) (Gastropoda, Stylommatophora, Polygyridae) are collected between March and April 2021 from gardens and nurseries in Baghdad province, this species was recorded as a new record to Iraq molluscan fauna. Description of the most important characteristics, measurements of the shell are presented with digital photographs, subsequently this study represents the first record of the Polygyridae in Iraq.

MOLLUSCS FROM THE UPPER MESOPHOTIC ZONE IN A SCARCELY KNOWN REEF OF THE WESTERN EQUATORIAL ATLANTIC

Despite the increasing focus on biodiversity of mesophotic coral ecosystems (MCEs) on a global scale, some biological groups, such as molluscs, are still poorly investigated. The taxonomic diversity of the molluscan fauna of a scarcely known MCE of the Western Equatorial Atlantic, Northeastern Brazil, was surveyed. Samples were collected along the shallower strata of the upper mesophotic zone (between 33-36 m depth). Twenty-one taxa (nine species of gastropods, ten species of bivalves, and two taxa of chitons) were listed, two of which (Novastoa sp. and Thylaeodus sp.) are potential endemic species. A new northern limit of distribution of Persicula moscatellii was established and seven species had new bathymetric records for living specimens (Barbatia domingensis, Barbatia cancellaria, Lamychaena hians, Leiosolenus bisulcatus, Pinctada imbricata, Hipponix incurvus, and Persicula moscatellii). Hipponix costellatus are the most representative species with 49 individuals, followed by Lima caribaea with six individuals. The present work is the first contribution to the knowledge of the molluscan fauna associated with consolidated substrates from this little-known MCE. Keywords: mesophotic coral ecosystems, tropical reef, molluscan diversity, Brazilian Province, conventional SCUBA.

Gigantic scaphopods (Mollusca) from the Permian Akasaka Limestone, central Japan

Paleozoic scaphopods are among the most poorly known mollusks because of their featureless tubular shell morphology and fragmentary preservation. An apical orifice at the posterior end of a conch is a diagnostic character of Scaphopoda that distinguishes them from other groups of animals that produce similar calcareous tubes, but this structure is rarely preserved. A rich molluscan fauna from the Permian Akasaka Limestone in central Japan includes scaphopod shells, and past studies have reported four species, all of which were based on fragmentary specimens. This study recognizes six species in the Akasaka Limestone mainly on the basis of museum/institution collections, and a new genus (Minodentalium) and three species (Prodentalium onoi, M. hayasakai, and M. okumurai) are described, two known species (P. akasakensis and P. neornatum) are redescribed in more detail, and one species (Prodentalium sp.) is described under open nomenclature. The following eight known species are allocated to the new genus Minodentalium: Plagioglypta furcata Waterhouse, 1980; Pl. girtyi Knight, 1940; Pl. subannulata Easton, 1962; Dentalium ingens De Koninck, 1843; D. meekianum Geinitz, 1866; Pl. prosseri Morningstar, 1922; Dentalium priscum Münster in Goldfuss, 1842; and D. herculeum De Koninck, 1863. All the species, except for M. hayasakai, are gigantic, reaching 200 mm or more in length. The species richness is the greatest known from a single locality/formation worldwide. UUID: http://zoobank.org/35405b9d-3ba7-40bf-87c5-3f2b550b1a6d

Terrestrial gastropods of Humaitá Forest Reserve, southwestern Brazilian Amazon

The molluscan fauna of southwestern Brazilian Amazonia is poorly known due to the lack of focused collection areas in the region since the early 20th century. The present study provides an inventory of the terrestrial gastropods from a forest fragment in the eastern Acre state, Brazil: the Humaitá Forest Reserve (“Reserva Florestal Humaitá”). Live specimens and empty shells were collected between August 2018 and January 2019. A total of 20 species were identified, distributed in 11 families. Most (13) of these species were recorded in Acre for the first time. Furthermore, we confirm the occurrence of Systrophia helicycloides (d’Orbigny, 1835) in Brazil, reiterate the synonymy of Plekocheilus pentadinus (d’Orbigny, 1835) with P. floccosus (Spix in Wagner, 1827), and synonymize Solaropsis peruviana Haas, 1951 with S. juruana Ihering, 1905.

Distribution of freshwater Mollusca in Koothaippar wetland ecosystem Tiruchirappalli District Tamil Nadu

Freshwater Mollusca form an important animal group of the wetland ecosystems. The distribution and availability in terms of number of species needs scientific attention. Present study is an attempt to document the available Molluscan forms in Koothaippar wetlands of Tiruchirappalli District. This study was carried out between summer 2013 to post-monsoon 2017. Nine species were recorded and among them 6 species belong to Gastropoda representing 2 orders, 3 families, 3 genera while 3 species were bivalves representing 1 order, 1 family and 2 genera. Bellamya bengalensis, Lamellidens marginalis and Pila globosa were the predominantly present molluscan fauna and are distributed throughout the year. Five species of Molluscan fauna (Pila virens, Pila scutata, Bellamya dissimilis, Indoplanorbis exustus and Lamellidens corrianus) are less abundant and Parreysia favidens was found to be rare species of the ecosystem. These Molluscan forms, representing different families ranging from 34% of Ampullariidae, 33% of Unionoida, 22% of Viviparoidae and 11% of Planorbidae. Percent distribution of these shelled organisms indicate that they represent 3 orders viz., 56% of Architaenioglossa, 33% of Unionoida and 11% of Hygrophila.

Are Spine-Bearing Freshwater Gastropods Better Defended?

Freshwater snails usually possess thin unadorned shells lacking structural components such as spines. Exceptions can be found on the high, well-watered islands of the South Pacific. Streams on these islands support a rich freshwater molluscan fauna with several nerite taxa (Neritimorpha: Neritidae) exhibiting extremely long dorsal spines. We sought to assess the defensive capacity of these structures for several co-occurring nerite genera on the Island of Ovalau, Fiji. Our overarching hypothesis was that spines confer a defensive advantage. We tested four predictions for eight common taxa: (i) predator “rich” habitats (the creek entrance) would be dominated by spine-bearing nerites, (ii) spine-bearing species should be smaller in size, (iii) nerites with spines would exhibit lower levels of shell damage and (iv) nerites with spines should invest less in their shells (i.e., their shells should be thinner). Most of these predictions received support. Spine-bearing species dominated the entrance to the creek and were smaller in size. Levels of shell damage were low overall, with 2 of the 3 spinose taxa exhibiting no shell damage, as did many of the nonspinose taxa. Finally, shells of spinose species were 25% thicker, demonstrating increased rather than decreased investment. Taken together, these findings suggest that the elaborate spines of Clithon spp. play a defensive role.