Content uploaded by Thor Seng Liew
Author content
All content in this area was uploaded by Thor Seng Liew on Jun 27, 2015
Content may be subject to copyright.
A preview of the PDF is not available
The slugs and semislugs of Sabah, Malaysian Borneo (Gastropoda, Pulmonata: Veronicellidae, Rathouisiidae, Ariophantidae, Limacidae, Philomycidae)
Abstract and Figures
As a part of an inventory of the terrestrial malacofauna of the Malaysian state of Sabah (northern Borneo), the slugs and semislugs were given particular attention. Except for several exotic and presumed exotic species, slugs and semislugs are generally rare and infrequently encountered , mostly at high altitudes, where several short-range endemics appear to exist. We describe one new species, viz: Ibycus rachelae nov. spec. (Ariophantidae). We furthermore present new records and characters for identification of other species, namely: the veronicellids Laevicaulis alte (Férussac, 1821), Valiguna flava (Heynemann, 1885), and Semperula wallacei (Issel, 1874), the rathouisiid Atopos punctata Collinge, 1902, the ariophantids Microparmarion pollonerai Collinge & Godwin Austen, 1895, M. simrothi Collinge & Godwin Austen, 1895, Parmarion martensi Simroth, 1893, and Philippinella möllendorffi (Collinge, 1899), the limacid Deroceras retic-ulatum (Müller, 1774), and the philomycids Meghimatium striatum (Van Hasselt, 1824), M. uni-forme Laidlaw, 1937, and M. pictum (Stoliczka, 1872). For the genus Meghimatium, our taxono-my is based on a molecular phylogenetic reconstruction, which we present. Finally, we provide reports and illustrations on several species for which the available material is currently insufficient for formal identification, namely, an unidentified Atopos (Rathouisiidae), for which only juveniles (preying on Opisthostoma) were found, a second unidentified Atopos (Rathouisiidae) and an unidentified Microparmarion (Ariophantidae) for each of which only a single adult was available, as well as an unidentified Parmarion (Ariophantidae) known only from a photograph .
Figures - uploaded by Thor Seng Liew
Author content
All figure content in this area was uploaded by Thor Seng Liew
Content may be subject to copyright.
... Shell visible through a left-lateral, crescent-shaped lumen in the mantle; mantle-edge on the right side with a large circular lobe. Schilthuizen & Liew 2008 ( fig. 102a-d, 106a, map 20f) Schilthuizen & Liew 2008: 296;Liew et al. 2010: Online Supporting Information, Appendix S1. -Type from Malaysia, Sabah, mount Kinabalu. ...
... Note. Because of molecular and anatomical data, Schilthuizen & Liew (2008) suspect that Meghimatium pictum is a compound entity in the present delimitation. Cross diagnosis. ...
... a-d. Ibycus rachelaeSchilthuizen & Liew, 2008, a. Juvenile animal, reconstructed from specimen preserved in alcohol, right lateral view, animal 19 mm long, b. Dorsal view, c. ...
... Becoming a slug through the reduction of the shell has occurred multiple times among the stylommatophoran land snails; this has occurred particularly frequently within the limacoid snail families Ariophantidae Godwin-Austen, 1883, Helicarionidae Bourguignat, 1877, and Urocyclidae Simroth, 1889(Solem 1966Hausdorf 1998;Hyman et al. 2007;Hyman and Köhler 2020). This process, so-called 'limacization', has also produced intermediate forms between slugs and snails, known as 'semislugs', which are characterized by the presence of an external shell with a reduced number of whorls, and a loss of the ability to completely withdraw its body under the protective shell (Collinge 1902;Blanford and Godwin-Austen 1908;Solem 1966;Barker 2001;Schileyko 2003;Schilthuizen and Liew 2008;Hyman and Köhler 2020). In addition, semislugs tend to show extensive development of the mantle lobes that can completely cover its shell, providing an increased surface area for gaseous exchange (Tillier 1983;Barker 2001). ...
... Convergence in shell characters has been demonstrated in Australian helicarionids (Hyman and Köhler 2020). The lack of reproductive information has created a profound inaccuracy in their recognition and delimitation (e.g., Blanford and Godwin-Austen 1908;Solem 1966;Schilthuizen and Liew 2008;Hyman and Ponder 2010;Hyman and Köhler 2020). At present, anatomy-based approaches or those integrating molecular analyses are likely to more successfully resolve these taxonomic problems. ...
Knowledge of Thai semislugs remains scarce, especially the dancing semislug genus Cryptosemelus. Prior to the present study, only a single species has been recognized with little available information. To address this knowledge gap, we surveyed for semislugs in western and southern Thailand, which yielded three species belonging to the genus Cryptosemelus . The little-known type species C. gracilis is redescribed herein, including a comparison with the type specimens. Two additional species, C. betarmon sp. nov. and C. tigrinus sp. nov. , are described as new to science. All three species are characterized by differences in their genital anatomy, especially with respect to anatomical details of the penis, epiphallus, and spermatophore. In addition, C. tigrinus sp. nov. differs from C. gracilis and C. betarmon sp. nov. in the mantle color pattern.
... Rathouisiidae Heude, 1885 is a family of terrestrial slugs. Although available information on this family remains insufficient at present, there are three recognized genera: (1) Rathouisia Heude, 1884; (2) Atopos Simroth, 1891; and (3) Granulilimax Minato, 1989(Wu et al. 2006Schilthuizen & Liew 2008;. Rathouisiid slugs are found in Australia, Papua New Guinea, Indonesia, Singapore, Malaysia, Philippines, Vietnam, Laos, Thailand, Myanmar, India, China, and Japan (Barker, 2001;Schilthuizen & Liew, 2008;Tan & Chan, 2009;Minato, 2015;Tripathy et al., 2018;Inkhavilay et al., 2019). ...
... Although available information on this family remains insufficient at present, there are three recognized genera: (1) Rathouisia Heude, 1884; (2) Atopos Simroth, 1891; and (3) Granulilimax Minato, 1989(Wu et al. 2006Schilthuizen & Liew 2008;. Rathouisiid slugs are found in Australia, Papua New Guinea, Indonesia, Singapore, Malaysia, Philippines, Vietnam, Laos, Thailand, Myanmar, India, China, and Japan (Barker, 2001;Schilthuizen & Liew, 2008;Tan & Chan, 2009;Minato, 2015;Tripathy et al., 2018;Inkhavilay et al., 2019). In this family, only several species have so far been described (e.g., Wu et al., 2006;Minato, 2015). ...
Rathouisiidae Heude, 1885 is a family of terrestrial slugs. Although only several species has
so far been described in this family, rathouisiids are estimated to be highly diversified. In the
present study, we report the presence of the slug of Rathouisiidae in South Korea and its DNA barcode for the first time.
... The genus Meghimatium comprised phenotypically highly variable, shell-less slugs and is widely distributed in East and South Asia (Azuma, 1995;Schilthuizen and Liew, 2008;Tsai et al., 2011;Tsai and Wu, 2008;Wiktor et al., 2000). In Japan, three species of this genus have been described based on body colour, jaw, radula, and genital morphology: M. bilineatum (Benson, 1842), M. fruhstorferi (Collinge, 1901), and M. ninosawaensis Azuma, Azuma and Okamura, 2001 (Table 1). ...
East Asia, specifically the Japanese Archipelago, is a biodiversity hotspot of both vertebrates and invertebrates. Mollusks represent a burst of species diversity in this region due to the effects of biotic and abiotic factors on their morphological traits, such as shell shape and size. However, the evolutionary history of terrestrial slugs in East Asia remains unknown. In the present study, we investigated the molecular phylogeny of terrestrial slugs of the genus Meghimatium. This genus includes three described and eight undescribed species, and our study used all except for two. Based on phylogeny and the species delimitation tests, the genus Meghimatium was split into many putative species, suggesting higher species diversity than previously thought based on morphological and anatomical studies and that almost undescribed species may be inappropriate. Therefore, morphological traits, such as body size and colour, conventionally considered for classification may easily vary or be similar across geographic region. Moreover, the divergence time of this genus is almost concordant with the geographical time scale of the formation of the Japanese mainland. Our findings suggest that molecular phylogenetics helps classify Japanese Meghimatium slugs, but comprehensive taxonomic revisions using multi-locus analyses are needed.
... About 30 named species from South-East Asia to New Guinea and northern Australia are attributed to Atopos (lists of Atopos species are given by: Heynemann, 1906: 37-38;Collinge, 1908: 119;Hoffmann, 1926: 26-27; another species, overlooked in these lists, needs to be added: Atopos gravelyi Ghosh, 1915). MolluscaBase (2021) reports 23 species (although one, A. heynemanni (Simroth, 1891), as taxon inquirendum), but as stressed by De Wilde (1984), Wiktor (2003), Schilthuizen & Liew (2008) and Tan & Chan (2009), a modern revision of Atopos speciography is still lacking. Despite many detailed studies on their anatomy, most earlier contributions did not consider gross genital morphology, often dealing more with the histological structure of the organs (Simroth, 1891;Sarasin & Sarasin, 1899;Collinge, 1902aCollinge, , 1903Ghosh, 1912Ghosh, , 1913Ghosh, , 1914Ghosh, , 1915Odhner, 1917;Laidlaw, 1940;De Wilde, 1984;Wiktor, 2003). ...
A small slug found in the tropical greenhouse of the Science Museum (MUSE) of Trento (Italy) turned out to be a species of the little-known systellommatophoran family Rathouisiidae. We undertook detailed comparative anatomical and molecular studies using specimens of the MUSE slug, Rathouisia sinensis, and sequences of other systellommatophoran species deposited in GenBank to conduct a systematic and phylogenetic assessment. Analysis of the genitalia of the MUSE slug and R. sinensis revealed an unusual triaulic tritrematic structure: two separate female ducts – one for egg release (oviduct), the other for intake of allosperm (vagina) – and a separate male duct for autosperm release. Analysis of the nucleotide sequences of several mitochondrial (COI, 16S rDNA) and nuclear (18S rDNA, ITS2 flanked by 5.8S and 28S rDNA fragments, H3) gene fragments supported assignation of the MUSE slug to Rathouisiidae, but also its distinction from the other rathouisiid genera Atopos, Granulilimax, Rathouisia and an undescribed genus from the Ryukyu Islands (Japan). Therefore, we decided to describe the MUSE slug as a new species in a new genus: Barkeriella museensis gen. et sp. nov. The species is certainly an alien introduced into the tropical greenhouse of MUSE, but its origin is unknown and calls for further investigation.
... The species has been found in the rather temperate and mountainous eastern Indian states of Mizoram and Manipur, about 1000 km east of Fansipan (Surya Rao et al. 2004, Surya Rao et al. 2007), but is also claimed to be rather common in Karnataka, southern India (Jayashankar et al. 2012, NA Aravind personal communication 2020), though based on external characters only and still to be confirmed). It is further known from modified highland habitats of Sri Lanka (Naggs et al. 2003) and Malaysian Borneo (though based on external characters only: Schilthuizen and Liew 2008), from Taiwan (Tsai and Wu 2008), Japan (National Institute for Environmental Studies, Japan 2020; https://www.nies.go.jp/biodiversity/invasive/resources/listen_moll uscs.html, accessed 23.08.2020), ...
Several individuals of the terrestrial slug Deroceras laeve were collected in 2018 in the Hoàng Liên Son mountain range of northern Vietnam. The three specimens which were investigated anatomically were aphallic or hemiphallic. A partial COI sequence verified the species identity. This is the first discovery of D. laeve and also of the slug family Agriolimacidae on the Indochinese Peninsula. The collecting site is situated near a cable-car station and below a tourist complex on Fansipan mountain, both of which had just been built by a Swiss-Austrian company between 2013 and 2016. This and the fact that the species had not been found elsewhere in the surrounding area, although searched for thoroughly, indicate that D. laeve is most probably a recent introduction, potentially with building material from Austria or Switzerland.
... In addition, for some semislugs in the resting stage, we found them near their fecal matter (Fig. 3A), which might suggest this animal has homing behavior, and they will return to sleep in the same position every day. According to Schilthuizen and Liew (2008) a semislug is defined as snails with a partially visible shell that, due to their rather small shell, cannot withdraw its body into its shell. Muangnua is a slug-like semislug possessing a reduced shell having only one remnant coil that is always covered by a mantle lobe. ...
Muangnua arborea Tumpeesuwan & Tumpeesuwan, sp. nov. , is described, based on specimens deposited in the land snail collection of Mahasarakham University, Thailand. This species is the second described in the genus Muangnua , for which colour pictures of the living semislug in natural habitats, scanning electron microscope photos of the radula, and anatomy of the mature specimens were studied and presented for the first time for this genus. Keys to genera of Southeast Asian slug-like semislugs and species of Muangnua are provided.
... Laevicaulis alte was originally described by Férussac (1822) as resembling a leech found in France and is generally recognized by its dark gray or almost black body with a thin pale median dorsal line (Schilthuizen and Liew 2008). Veronicella cubensis ranges from almost white (possibly albino) through olive tan to darker brown, usually also with a pale median line on its dorsal surface and sometimes darker dots that can fuse to form two lateral bands Fischer [1868 (as Vaginu lus plebeius)] was based on a drawing sent to him; it was brief and noted that the body was Kim and M. San Jose.) brown with indistinct darker longitudinal lines and paler mantle edges. ...
The Veronicellidae include some of the most widespread and agriculturally damaging invasive slugs. However, they are difficult to distinguish and identify accurately based on external morphology because of their great intraspecific variability, especially in body color and pigmentation pattern. Based on the published accounts, museum collections, and recent surveys, four species had been recorded previously from the Hawaiian Islands: Diplosolenodes occidentalis, Laevicaulis alte, Sarasinula plebeia, and Veronicella cubensis; and the latter three plus an additional species, Semperula wallacei, were known from the Samoan Islands. We reexamined these identifications using external morphology, internal anatomy, and/or DNA sequences. Both L. alte and V. cubensis are present on all six of the largest Hawaiian Islands. Sarasinula plebeia, although recorded previously, was not present in the museum collections and was found in only one of our recent survey samples, on O'ahu. It may in fact never have been present in the Islands previously, the earlier records being misidentifications; or it may have been present but highly localized and was not collected and deposited in the Bishop Museum (Honolulu). Unfortunately, the single Diplosolenodes occidentalis specimen was not found in the usnm collections. Molecular analyses of specimens from American Samoa, previously identified as L. alte and S. plebeia, showed them to be primarily V. cubensis, with a few Semperula wallacei and Laevicaulis sp., and a single L. alte and S. plebeia, and all specimens sequenced from independent Samoa were S. wallacei.
This study presents a list of land snails and slugs found on limestone hills in the District of Bau, the state of Sarawak in Malaysian Borneo. Systematic and random sampling for land snails was conducted at eight limestone outcrops, namely, Gunung Stulang, Padang Pan, Gunung Kapor, Gunung Lobang Angin, Gunung Doya, Gunung Batu, Bukit Sekunyit and Gunung Sebayat. A total of 122 land snail species was documented with photographs of each species. Of the 122 species collected, 13 are new to science, namely, Acmella bauensis sp. nov. , Japonia bauensis sp. nov. , Plectostoma margaretchanae sp. nov. , Microcystina arabii sp. nov. , Microcystina atoni sp. nov. , Microcystina paripari sp. nov. , Microcystina lirata sp. nov. , Microcystina oswaldbrakeni sp. nov. , Microcystina kilat sp. nov. , Philalanka jambusanensis sp. nov. , Everettia microrhytida sp. nov. , Everettia minuta sp. nov. , and Paralaoma sarawakensis sp. nov.
Cybertaxonomy and portable DNA sequencing now make it possible for citizen scientists to be engaged in the discovery and description of new taxa. We here provide a proof of principle. A new semi-slug, Microparmarion exquadratus n. sp. (Ariophantidae) was discovered during a field course in tropical biology in Borneo for citizen scientists. The new species is the first lowland representative of its genus. It differs from other (high-elevation) Microparmarion species by its size, pigmentation on head and tail, and shape of dart sac and receptaculum. As part of the course programme, the participants prepared a taxonomic description and illustrations, and used the mobile genomic laboratory of the course to obtain DNA barcodes. As far as we are aware, this is the first time a new invertebrate species has been described both morphologically and genetically from the field.
We redescribe and figure Valiguna flava, an almost unknown Southeast-Asian land slug. Detailed morphology, radula, jaw and living specimens of Valiguna flava were studied for the first time, based on material recently collected in Borneo and on the holotype. Vl. flava is also compared with Valiguna siamensis, the only other species of the genus, which is for the first time recorded in China.
This paper gives an overview of a number of ecological, demographic, and behavioural characteristics of a group of closely related species (here referred to as O. (P.) concinnum) of the diplommatinid snail subgenus Plectostoma. Some of the members of this species complex are endemic to limestone outcrops in the Kinabatangan. This information will be an essential basis for further studies of their evolution and conservation. Our data show that Plectostoma populations are very dense and very large, with tens of millions of adults on less than a square kilometre being no exception. Adults make up the largest part of the population, and also are overrepresented among the dead shells on the forest floor. This indicates that most individuals survive to adulthood and/or adult lifespan is long compared to the time spent as juveniles. At least one-third of adults die due to predation, and probably more, since some predators do not leave marks on the shell. Mating behaviour appears to involve a " shell-mounting " phase, followed by " face-to-face " copulation. Males are characterised by a bright red shell apex, but otherwise no
We present the known diversity and distribution of Veronicellidae in the Oriental and Australian biogeographical regions. Material from several museums was used (Gomes & Thorné, 2001). The 13 species identified are: Filicaulis bleekeri (Keferstein, 1865), Laevicaulis alte (Férussac, 1821), Sarasinula plebeia (Fischer, 1868), Semperula birmanica (Theobald, 1864), Se. carusi (Simroth, 1893), Se. insularis Thorné (1983), Se. maculata (Templeton, 1858), Se. parva (Heynemann, 1885), Se. tailandensis Thorné et al., 1994, Se. wallacei (Issel, 1874), Valiguna flava (Heynemam, 1885), VI. siamensis (Martens, 1867) and Veronicella cubensis (Pfeiffer, 1840). Semperula is mainly concentrated in the Australian region. Se. maculata, Se. parva and Se. wallacei are found in the Australian region, close to the Wallace line, with the exception of the latter which can also be found on the island of Upolu, much further to the east. Se. insularis is only recorded in the Christmas islands (Australia). L. alte and Sa. plebeia have the widest distribution, being found in both the Oriental and Australian regions. F. bleekeri and V. flava are restricted to a few Indonesian islands, near the Wallace line, while there are records of VI. siamensis in Thailand and Sri Lanka. Ve. cubensis is recorded only in Hawaii and Guam, in the Australian region.
