treatments-xml/data/F1/95/6C/F1956C94AA834E13883896A779048B27.xml
2024-06-21 12:57:21 +02:00

340 lines
42 KiB
XML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<document ID-DOI="http://dx.doi.org/10.3897/zookeys.393.6717" ID-GBIF-Dataset="ca1977b6-7464-4c67-999d-761e0faa67ab" ID-PMC="PMC3974427" ID-Pensoft-Pub="1313-2970-393-1" ID-PubMed="24715783" ID-ZBK="5B035E76BBD14A44A5D8C2140E6168F1" ModsDocAuthor="" ModsDocDate="2014" ModsDocID="1313-2970-393-1" ModsDocOrigin="ZooKeys 393" ModsDocTitle="A cybertaxonomic revision of the micro-landsnail genus Plectostoma Adam (Mollusca, Caenogastropoda, Diplommatinidae), from Peninsular Malaysia, Sumatra and Indochina" checkinTime="1451246065565" checkinUser="pensoft" docAuthor="Liew, Thor-Seng, Vermeulen, Jaap Jan, Marzuki, Mohammad Effendi bin &amp; Schilthuizen, Menno" docDate="2014" docId="F1956C94AA834E13883896A779048B27" docLanguage="en" docName="ZooKeys 393: 1-107" docOrigin="ZooKeys 393" docSource="http://dx.doi.org/10.3897/zookeys.393.6717" docTitle="Plectostoma" docType="treatment" docVersion="3" lastPageNumber="30" masterDocId="A935FFF6FFE56726FFC5FFA8FFCE7A2A" masterDocTitle="A cybertaxonomic revision of the micro-landsnail genus Plectostoma Adam (Mollusca, Caenogastropoda, Diplommatinidae), from Peninsular Malaysia, Sumatra and Indochina" masterLastPageNumber="107" masterPageNumber="1" pageNumber="28" updateTime="1668158106070" updateUser="ExternalLinkService">
<mods:mods xmlns:mods="http://www.loc.gov/mods/v3">
<mods:titleInfo>
<mods:title>A cybertaxonomic revision of the micro-landsnail genus Plectostoma Adam (Mollusca, Caenogastropoda, Diplommatinidae), from Peninsular Malaysia, Sumatra and Indochina</mods:title>
</mods:titleInfo>
<mods:name type="personal">
<mods:role>
<mods:roleTerm>Author</mods:roleTerm>
</mods:role>
<mods:namePart>Liew, Thor-Seng</mods:namePart>
</mods:name>
<mods:name type="personal">
<mods:role>
<mods:roleTerm>Author</mods:roleTerm>
</mods:role>
<mods:namePart>Vermeulen, Jaap Jan</mods:namePart>
</mods:name>
<mods:name type="personal">
<mods:role>
<mods:roleTerm>Author</mods:roleTerm>
</mods:role>
<mods:namePart>Marzuki, Mohammad Effendi bin</mods:namePart>
</mods:name>
<mods:name type="personal">
<mods:role>
<mods:roleTerm>Author</mods:roleTerm>
</mods:role>
<mods:namePart>Schilthuizen, Menno</mods:namePart>
</mods:name>
<mods:typeOfResource>text</mods:typeOfResource>
<mods:relatedItem type="host">
<mods:titleInfo>
<mods:title>ZooKeys</mods:title>
</mods:titleInfo>
<mods:part>
<mods:date>2014</mods:date>
<mods:detail type="volume">
<mods:number>393</mods:number>
</mods:detail>
<mods:extent unit="page">
<mods:start>1</mods:start>
<mods:end>107</mods:end>
</mods:extent>
</mods:part>
</mods:relatedItem>
<mods:location>
<mods:url>http://dx.doi.org/10.3897/zookeys.393.6717</mods:url>
</mods:location>
<mods:classification>journal article</mods:classification>
<mods:identifier type="DOI">http://dx.doi.org/10.3897/zookeys.393.6717</mods:identifier>
<mods:identifier type="Pensoft-Pub">1313-2970-393-1</mods:identifier>
<mods:identifier type="ZBK">5B035E76BBD14A44A5D8C2140E6168F1</mods:identifier>
<mods:identifier type="ZooBank">5B035E76BBD14A44A5D8C2140E6168F1</mods:identifier>
</mods:mods>
<treatment ID-GBIF-Taxon="152052218" LSID="urn:lsid:plazi:treatment:F1956C94AA834E13883896A779048B27" httpUri="http://treatment.plazi.org/id/F1956C94AA834E13883896A779048B27" lastPageId="29" lastPageNumber="30" pageId="27" pageNumber="28">
<subSubSection pageId="27" pageNumber="28" type="nomenclature">
<paragraph pageId="27" pageNumber="28">
Genus
<taxonomicName LSID="http://species-id.net/wiki/Plectostoma" class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
</paragraph>
</subSubSection>
<subSubSection pageId="27" pageNumber="28" type="reference_group">
<paragraph pageId="27" pageNumber="28">
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
Adam 1865: 177. Type species:
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Plectostoma DeCrespignii</taxonomicName>
(by original designation)
</paragraph>
<paragraph pageId="27" pageNumber="28">
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Geothauma" higherTaxonomySource="GBIF" kingdom="Animalia" lsidName="Geothauma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Geothauma</taxonomicName>
<bibRefCitation author="Crosse, H" journalOrPublisher="Journal de Conchyliologie" pageId="74" pageNumber="75" pagination="279 - 292" title="Etudes malacologiques sur les genres nouveaux ou peu connus." url="http://www.biodiversitylibrary.org/page/25234590page/292/mode/1up" volume="32" year="1892">Crosse 1892</bibRefCitation>
: 282. Type species (by original designation):
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma grandispinosum" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="species" species="grandispinosum">Plectostoma grandispinosum</taxonomicName>
(Godwin-Austen, 1889).
</paragraph>
</subSubSection>
<subSubSection pageId="27" pageNumber="28" type="generic classification dispute">
<paragraph pageId="27" pageNumber="28">Generic classification dispute.</paragraph>
<paragraph pageId="27" pageNumber="28">
The genus
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
was described by
<bibRefCitation author="Blanford, WT" journalOrPublisher="Journal of the Asiatic Society of Bengal" pageId="73" pageNumber="74" pagination="117 - 127" title="Contributions to Indian Malacology." url="http://www.biodiversitylibrary.org/item/124448page/141/mode/1up" volume="29" year="1860">Blanford and Blanford (1860)</bibRefCitation>
based on one
<normalizedToken originalValue="species">species-</normalizedToken>
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma nilgiricum" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="species" species="nilgiricum">Opisthostoma nilgiricum</taxonomicName>
from India.
<bibRefCitation author="Adam, H" journalOrPublisher="Proceedings of the Zoological Society of London" pageId="72" pageNumber="73" pagination="753 - 755" title="Descriptions of a new genus and some new species of mollusks." url="http://www.biodiversitylibrary.org/item/90954page/543/mode/1up" volume="1865" year="1865 b">Adam (1865b)</bibRefCitation>
described a second species of
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
, namely,
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma decrespignyi" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="species" species="decrespignyi">Opisthostoma decrespignyi</taxonomicName>
, which he previously described under the new genus
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
(
<bibRefCitation author="Adam, H" journalOrPublisher="The Annals and Magazine of Natural History, including Zoology, Botany and Geology" pageId="72" pageNumber="73" pagination=": 177" title="Description of a new genus of land-shells from the Island of Labuan, Borneo." url="http://www.biodiversitylibrary.org/item/90412page/859/mode/1up" volume="3" year="1865 a">Adam 1865a</bibRefCitation>
). Nevertheless,
<bibRefCitation author="Blanford, WT" journalOrPublisher="The Annals and Magazine of Natural History, including Zoology, Botany and Geology" pageId="73" pageNumber="74" pagination="305 - 307" title="On the Genus Plectostoma H. Adam, and the animal of Diplommatina Benson." url="http://www.biodiversitylibrary.org/item/72153319" volume="3" year="1867">Blanford (1867)</bibRefCitation>
concluded that the conchological differences between these two taxa were not enough to create a different genus. Instead, he suggested these could be two different subgenera. Next, another two
<normalizedToken originalValue="subgenera">subgenera-</normalizedToken>
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Gyrostropha" higherTaxonomySource="GBIF" kingdom="Animalia" lsidName="Gyrostropha" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Gyrostropha</taxonomicName>
Ancey, 1887 and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Geothauma" higherTaxonomySource="GBIF" kingdom="Animalia" lsidName="Geothauma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Geothauma</taxonomicName>
Crosse, 1892, were proposed for different forms of
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
. However,
<bibRefCitation author="Smith, EA" journalOrPublisher="The Annals and Magazine of Natural History, including Zoology, Botany and Geology" pageId="78" pageNumber="79" pagination="284 - 285" title="Note on the Genera Geothauma and Gyrostropha." url="http://www.biodiversitylibrary.org/page/24344618page/332/mode/1up" volume="6" year="1893 a">Smith (1893a)</bibRefCitation>
suggested that this subgeneric classification was not necessary until more data other than shell morphology were available. Since then, a classification into three subgenera within the genus
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
, namely,
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Geothauma" higherTaxonomySource="GBIF" kingdom="Animalia" lsidName="Geothauma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Geothauma</taxonomicName>
,
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
, and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
has generally been accepted (e.g.
<bibRefCitation author="von Martens, E" journalOrPublisher="Mitteilungen aus dem Zoologischen Museum in Berlin" pageId="76" pageNumber="77" pagination="251 - 294" title="Beschreibung einiger im oestlichen Borneo von Martin Schmidt gesammelten Land und Suesswasser-Conchylien." url="http://www.biodiversitylibrary.org/item/44411page/272/mode/1up" volume="4" year="1908">von Martens and Thiele 1908</bibRefCitation>
,
<bibRefCitation author="van Benthem Jutting, WSS" journalOrPublisher="Journal of Conchology" pageId="72" pageNumber="73" pagination="196 - 210" title="Notes on land Mollusca of the Malay Archipelago." volume="19" year="1932">van Benthem Jutting 1932</bibRefCitation>
,
<bibRefCitation author="van Benthem Jutting, WSS" journalOrPublisher="The Bulletin of the Raffles Museum" pageId="72" pageNumber="73" pagination="5 - 61" title="The Malayan species of Opisthostoma (Gastropoda, Prosobranchia, Cyclophoridae), with a catalogue of all the species hitherto described." url="http://rmbr.nus.edu.sg/rbz/biblio/24/24brm005-062.pdf" volume="24" year="1952">van Benthem Jutting 1952</bibRefCitation>
), until, in a recent review of the genus
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
,
<bibRefCitation author="Vermeulen, JJ" journalOrPublisher="Basteria" pageId="79" pageNumber="80" pagination="139 - 163" title="Notes on the non-marine molluscs of the island of Borneo 2. The genus Opisthostoma (Gastropoda Prosobranchia: Diplommatinidae), part 1." volume="55" year="1991">Vermeulen (1991</bibRefCitation>
,
<bibRefCitation author="Vermeulen, JJ" journalOrPublisher="Basteria" pageId="79" pageNumber="80" pagination="73 - 191" title="Notes on the non-marine molluscs of the island of Borneo. 6. The genus Opisthostoma (Gastropoda Prosobranchia: Diplommatinidae), part 2." volume="58" year="1994">1994</bibRefCitation>
) followed a classification into only two subgenera, namely,
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="27" pageNumber="28" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
.
</paragraph>
</subSubSection>
<subSubSection lastPageId="28" lastPageNumber="29" pageId="27" pageNumber="28" type="diagnosis">
<paragraph pageId="27" pageNumber="28">Diagnosis.</paragraph>
<paragraph lastPageId="28" lastPageNumber="29" pageId="27" pageNumber="28">
Despite the distinct ecological niche differences (see
<normalizedToken originalValue="belowDistribution">below-Distribution</normalizedToken>
and habitat) between
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">
<pageBreakToken pageId="28" pageNumber="29" start="start">Opisthostoma</pageBreakToken>
</taxonomicName>
and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
, it is not feasible to use this criterion in the genus identification, because information about the ecology is usually not available as most collections are made by soil sampling. After 150 years of work on
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
, it is still difficult to identify reliable apomorphic character states that can be used to distinguish between
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
(
<bibRefCitation author="Vermeulen, JJ" journalOrPublisher="Basteria" pageId="79" pageNumber="80" pagination="139 - 163" title="Notes on the non-marine molluscs of the island of Borneo 2. The genus Opisthostoma (Gastropoda Prosobranchia: Diplommatinidae), part 1." volume="55" year="1991">Vermeulen 1991</bibRefCitation>
,
<bibRefCitation author="Vermeulen, JJ" journalOrPublisher="Basteria" pageId="79" pageNumber="80" pagination="73 - 191" title="Notes on the non-marine molluscs of the island of Borneo. 6. The genus Opisthostoma (Gastropoda Prosobranchia: Diplommatinidae), part 2." volume="58" year="1994">1994</bibRefCitation>
). Both share the character state of the constriction, which is a slight shrinkage in the whorl towards the end of the spire. When the animal retracts into its shell, its operculum rests at the constriction (
<bibRefCitation author="Vermeulen, JJ" journalOrPublisher="Basteria" pageId="79" pageNumber="80" pagination="139 - 163" title="Notes on the non-marine molluscs of the island of Borneo 2. The genus Opisthostoma (Gastropoda Prosobranchia: Diplommatinidae), part 1." volume="55" year="1991">Vermeulen 1991</bibRefCitation>
). It is, however, possible to make a morphological distinction between
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
on the basic of the shell colouration in a fully grown adult, which is orange or pinkish in
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
and white or pale yellowish in
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
. The colour differences between these two genera are very clear when comparing the living snails or freshly dead shell material (Figure 17, and Appendix 18). Some
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
species have a regularly coiled tuba, and a shell form that is similar to
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Arinia" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Arinia" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Arinia</taxonomicName>
. However,
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Arinia" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Arinia" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Arinia</taxonomicName>
can be easily distinguished by shell colour differences. The shell colour in
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Arinia" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Arinia" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Arinia</taxonomicName>
is similar to that in
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
.
</paragraph>
<caption pageId="28" pageNumber="29">
<paragraph pageId="28" pageNumber="29">
Figures 17. Photographs of 17 living
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
species. A
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma salpidomon" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="salpidomon">Plectostoma salpidomon</taxonomicName>
(van Benthem Jutting, 1952), BOR 5569 B
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma umbilicatum" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="umbilicatum">Plectostoma umbilicatum</taxonomicName>
(van Benthem Jutting, 1952), BOR 5503 C
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma palinhelix" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="palinhelix">Plectostoma palinhelix</taxonomicName>
(van Benthem Jutting, 1952), BOR 5520 D
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma kakiense" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="kakiense">Plectostoma kakiense</taxonomicName>
(Tomlin, 1948), BOR 5516 E
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma mengaburensis" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="mengaburensis">Plectostoma mengaburensis</taxonomicName>
sp. n., BOR 5574 F
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma kubuensis" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="kubuensis">Plectostoma kubuensis</taxonomicName>
sp. n., BOR 5518 G
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma whitteni" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="whitteni">Plectostoma whitteni</taxonomicName>
sp. n., BOR 5536 H
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma senex" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="senex">Plectostoma senex</taxonomicName>
(van Benthem Jutting, 1952), BOR 5631 I
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma crassipupa" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="crassipupa">Plectostoma crassipupa</taxonomicName>
(van Benthem Jutting, 1952), BOR 5515 J
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma ikanensis" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="ikanensis">Plectostoma ikanensis</taxonomicName>
sp. n. Form BOR 5507, BOR 5507 K
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma ikanensis" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="ikanensis">Plectostoma ikanensis</taxonomicName>
sp. n. Form BOR 5504, BOR 5504 L
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma sinyumensis" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="sinyumensis">Plectostoma sinyumensis</taxonomicName>
(Maassen, 2001), BOR 5537 M
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma crassipupa" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="crassipupa">Plectostoma crassipupa</taxonomicName>
(van Benthem Jutting, 1952), BOR 5512 N
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma siphonostomum" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="siphonostomum">Plectostoma siphonostomum</taxonomicName>
(van Benthem Jutting, 1952), BOR 5557 O
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma laidlawi" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="laidlawi">Plectostoma laidlawi</taxonomicName>
(Sykes, 1902) Form BOR 5510, BOR 5510 P
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma relauensis" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="relauensis">Plectostoma relauensis</taxonomicName>
sp. n., BOR 5511 Q
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma christae" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="christae">Plectostoma christae</taxonomicName>
(Maassen, 2001), BOR 5505 R
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma retrovertens" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="retrovertens">Plectostoma retrovertens</taxonomicName>
(Tomlin, 1938), BOR 5559 S
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma tohchinyawi" order="Architaenioglossa" pageId="28" pageNumber="29" phylum="Mollusca" rank="species" species="tohchinyawi">Plectostoma tohchinyawi</taxonomicName>
sp. n., BOR 5533.
</paragraph>
</caption>
</subSubSection>
<subSubSection pageId="28" pageNumber="29" type="description">
<paragraph pageId="28" pageNumber="29">Description.</paragraph>
<paragraph pageId="28" pageNumber="29">Apex. Protoconch is either slightly, moderately or distinctly convex (Figure 3).</paragraph>
<paragraph pageId="28" pageNumber="29">
Spire. Height: 1.0
<normalizedToken originalValue="mm">mm-</normalizedToken>
3.7 mm. Width: 0.85
<normalizedToken originalValue="mm">mm-</normalizedToken>
2.60 mm (Figure 11). Number of whorls between 2 3/4-71/4. Apical spire shape: oblong or depressed conical (Figure 4). Basal spire shape: conical, ovoid or ellipsoid (Figure 5). Whorl periphery: flat, slightly, moderately or distinctly convex. Umbilicus: open, partially closed, or totally closed.
</paragraph>
<paragraph pageId="28" pageNumber="29">Constriction. Parietal teeth: parietal side of inner constriction whorl (Figure 2) with two long lamellae (Figure 6A), two ridges with a knob at each end (Figure 6B), one ridge with a knob at one end (Figure 6C), or no teeth (Figure 6D). Basal teeth: basal side of inner constriction whorl (Figure 2) with no teeth (Figure 7B), one ridge running parallel with the whorl growing direction, one ridge with a knob at one end running perpendicular to the whorl growing direction, or a combination of the latter two types (Figure 7A).</paragraph>
<paragraph pageId="28" pageNumber="29">Tuba. Coiling direction: regular coiling (type 1, Figure 8A) or distorted (Type 2, or 3) (Figure 8B and C). Tuba whorl length in proportion to spire last whorl: ca. 3/8-1 1/2. Proportion of tuba that attaches to spire: whole to none.</paragraph>
<paragraph pageId="28" pageNumber="29">Aperture and peristome. Peristome: simple aperture without outer peristome (Figure 10B), or double peristome (Figure 10C and 10D). Shape of outer peristome (Figure 10A): same as inner peristome and uniformly round, or highly projected or slightly projected at either a particular side or at a several sides of anterior, poteriorior, left and right laterial (Figure 9 and 10A).</paragraph>
<paragraph pageId="28" pageNumber="29">Spiral lines. Either thick or thin, or only thin lines present (Figure 12).</paragraph>
<paragraph pageId="28" pageNumber="29">
Radial ribs. Rib density: 4-32 per mm on the
<normalizedToken originalValue="spires">spire's</normalizedToken>
last whorl in right lateral view (Figure 13A). Intensity: thick or thin (Figure 13B). Shape: straight, slightly curved, distinctly curved, single humped, single looped or double looped and the shape remaining the same or changing between between the spire and the tuba (Figure 13C, but single-looped, and double-humped not shown). Inclination: from orthoclin to prosoclin.
</paragraph>
</subSubSection>
<subSubSection lastPageId="29" lastPageNumber="30" pageId="28" pageNumber="29" type="distribution and habitat">
<paragraph pageId="28" pageNumber="29">Distribution and habitat.</paragraph>
<paragraph lastPageId="29" lastPageNumber="30" pageId="28" pageNumber="29">
The distribution range of
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">
<pageBreakToken pageId="29" pageNumber="30" start="start">Plectostoma</pageBreakToken>
</taxonomicName>
is about 4.6 million square kilometres within the extent limited by 11°N, 97°E and 5°S, 120°E. However probably less than 5% of this large area is covered by limestone outcrops where suitable habitat may exist for obligate karst taxa like
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
. The genus counts 79 species and occurs in Vietnam (1 species), Thailand (1), Peninsular Malaysia (28), Sumatra (1), and Borneo (48). Peninsular Malaysia, Sumatra and Borneo are part of the biogeographical region called Sundaland (
<bibRefCitation author="Johnson, DS" journalOrPublisher="Malayan Nature Journal" pageId="75" pageNumber="76" pagination="68 - 69" title="A question of nomenclature." volume="18" year="1964">Johnson 1964</bibRefCitation>
).
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
is found on most limestone hills. However, the genus is conspicuously absent on the limestone hills to the west of the central mountain ranges, such as the hills in the States of Perak and Kedah in Peninsular Malaysia, and in the northwestern half of Sumatra (Figure 18). No species have been recorded from the east coast of Sumatra, where hardly any limestone outcrops exist.
</paragraph>
<caption pageId="29" pageNumber="30">
<paragraph pageId="29" pageNumber="30">
Figures 18. Distributional records of
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
species.
<normalizedToken originalValue="AD">A-D</normalizedToken>
distribution records for each of 31
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
species.
</paragraph>
</caption>
<paragraph pageId="29" pageNumber="30">
Based on collection data and our field experience, there is a distinct ecological divergence between
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
. This was already observed in the 19th century (
<bibRefCitation author="Blanford, WT" journalOrPublisher="Journal of the Asiatic Society of Bengal" pageId="73" pageNumber="74" pagination="117 - 127" title="Contributions to Indian Malacology." url="http://www.biodiversitylibrary.org/item/124448page/141/mode/1up" volume="29" year="1860">Blanford and Blanford 1860</bibRefCitation>
,
<bibRefCitation author="de Crespigny, CC" journalOrPublisher="The Natural History Review" pageId="73" pageNumber="74" pagination=": 599" title="Note on a shell from Labuan." url="http://www.biodiversitylibrary.org/page/9749440page/609/mode/1up" volume="5" year="1865">de Crespigny 1865</bibRefCitation>
,
<bibRefCitation author="Blanford, WT" journalOrPublisher="Proceedings of the Zoological Society of London" pageId="73" pageNumber="74" pagination="447 - 451" title="On Opisthostoma, H. Blanford, with description of a new species from the neighbourhood of Bombay, and of the animal and operculum." url="http://www.biodiversitylibrary.org/item/90954page/545/mode/1up" volume="1866" year="1866">Blanford 1866</bibRefCitation>
), and also by
<bibRefCitation author="Berry, AJ" journalOrPublisher="The Bulletin of the National Museum" pageId="72" pageNumber="73" pagination="101 - 105" title="The habitats of some minute cyclophorids, hydrocenids and vertiginids on a Malayan limestone hill." url="http://rmbr.nus.edu.sg/rbz/biblio/30/30bnm101-105.pdf" volume="30" year="1961">Berry (1961)</bibRefCitation>
.
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
can only be found in limestone outcrops, where the rock face is its major habitat, although a few individuals can occasionally be found on vegetation debris below the limestone rock face.
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
, on the other hand, is a soil dweller, living in leaf litter on the forest floor. They are mostly but not exclusively found in forest over limestone bedrock (
<bibRefCitation author="Schilthuizen, M" journalOrPublisher="Raffles Bulletin of Zoology" pageId="78" pageNumber="79" pagination="35 - 42" title="Abundance and diversity of land-snails (Mollusca: Gastropoda) on limestone hills in Borneo." url="http://rmbr.nus.edu.sg/rbz/biblio/51/51rbz035-042.pdf" volume="51" year="2003 b">Schilthuizen et al. 2003b</bibRefCitation>
).
</paragraph>
</subSubSection>
<subSubSection pageId="29" pageNumber="30" type="phylogenetic relationships">
<paragraph pageId="29" pageNumber="30">Phylogenetic relationships.</paragraph>
<paragraph pageId="29" pageNumber="30">
Our molecular phylogenetic analysis reveals that
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
,
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
, and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Arinia" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Arinia" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Arinia</taxonomicName>
are phylogenetically closely related (Figure 16). It is important to point out that the phylogenetic relationships among
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
,
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
(except
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma vermiculum" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="species" species="vermiculum">Opisthostoma vermiculum</taxonomicName>
),
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma vermiculum" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="species" species="vermiculum">Opisthostoma vermiculum</taxonomicName>
, and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Arinia" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Arinia" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Arinia</taxonomicName>
are unresolved. Figure 16 shows representative shell morphologies of the taxa that were included in the phylogenetic analysis, and it is clear that it is rather difficult to find shared derived characteristics (synapomorphies) in size, spire shape, or tuba coiling regime, for either
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
or
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
.
</paragraph>
<paragraph pageId="29" pageNumber="30">
Nonetheless, we treat
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Plectostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Plectostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Plectostoma</taxonomicName>
and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Opisthostoma</taxonomicName>
as two separate genera based on their ecological divergence and differences in adult shell colouration. Similarly, we propose that
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma vermiculum" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="species" species="vermiculum">Opisthostoma vermiculum</taxonomicName>
and
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Arinia" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Arinia" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Arinia</taxonomicName>
should be considered as two separate genera. However, this hypothesis needs further testing with more genetic data from
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma vermiculum" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="species" species="vermiculum">Opisthostoma vermiculum</taxonomicName>
Clements &amp; Vermeulen, 2008 (in Clements et al. 2008), the conchologically similar
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Opisthostoma" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Opisthostoma gittenbergeri" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="species" species="gittenbergeri">Opisthostoma gittenbergeri</taxonomicName>
Vermeulen &amp; Clements, 2008 and further
<taxonomicName class="Gastropoda" family="Diplommatinidae" genus="Arinia" higherTaxonomySource="CoL" kingdom="Animalia" lsidName="Arinia" order="Architaenioglossa" pageId="29" pageNumber="30" phylum="Mollusca" rank="genus">Arinia</taxonomicName>
species.
</paragraph>
</subSubSection>
</treatment>
</document>