<documentID-CLB-Dataset="22013"ID-DOI="http://dx.doi.org/10.3897/zookeys.934.49359"ID-GBIF-Dataset="99c6eb43-dc87-4106-82ed-1325f4df7b26"ID-PMC="PMC7250940"ID-Pensoft-Pub="1313-2970-934-25"ID-Pensoft-UUID="598339B5A93C5551BC575CD4048FC8D3"ID-PubMed="32508494"ID-ZooBank="B9F2C8D8C0314191B6F51E78D4D6881E"ModsDocID="1313-2970-934-25"checkinTime="1589939917447"checkinUser="pensoft"docAuthor="Smith, Rachel R. & Short, Andrew Edward Z."docDate="2020"docId="220F1134F685576EB449C842D3699397"docLanguage="en"docName="ZooKeys 934: 25-79"docOrigin="ZooKeys 934"docSource="http://dx.doi.org/10.3897/zookeys.934.49359"docTitle="Chasmogenus ligulatus Smith & Short 2020, sp. nov."docType="treatment"docUuid="F863DFA5-50EB-43C5-86DD-0F05DDD797C8"docUuidSource="ZooBank"docVersion="6"id="598339B5A93C5551BC575CD4048FC8D3"lastPageNumber="25"masterDocId="598339B5A93C5551BC575CD4048FC8D3"masterDocTitle="Review of the genus Chasmogenus Sharp, 1882 of northeastern South America with an emphasis on Venezuela, Suriname, and Guyana (Coleoptera, Hydrophilidae, Acidocerinae)"masterLastPageNumber="79"masterPageNumber="25"pageNumber="25"updateTime="1732684861311"updateUser="ExternalLinkService">
<mods:titleid="FBF3012826C6D22D662D9DEEFB0D8427">Review of the genus Chasmogenus Sharp, 1882 of northeastern South America with an emphasis on Venezuela, Suriname, and Guyana (Coleoptera, Hydrophilidae, Acidocerinae)</mods:title>
<mods:affiliationid="308ABB07A02D3FCE16C7490FC5FC1798">Department of Ecology & Evolutionary Biology, and Division of Entomology, Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA</mods:affiliation>
<mods:namePartid="2ECBBE914BFFF2E72C6844EC19DF85EE">Short, Andrew Edward Z.</mods:namePart>
<mods:affiliationid="ABAEAF7ED5CC48575127A91B804089E1">Department of Ecology & Evolutionary Biology, and Division of Entomology, Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA</mods:affiliation>
<taxonomicNameid="0D9710D4AD642198A081F1A9B673EE17"ID-CoL="8XGFZ"LSID="220F1134-F685-576E-B449-C842D3699397"authority="Smith & Short, 2020"authorityName="Smith & Short"authorityYear="2020"class="Insecta"family="Hydrophilidae"genus="Chasmogenus"higherTaxonomySource="CoL"kingdom="Animalia"lsidName="Chasmogenus ligulatus"order="Coleoptera"pageId="0"pageNumber="25"phylum="Arthropoda"rank="species"species="ligulatus"status="sp. nov.">Chasmogenus ligulatus</taxonomicName>
<figureCitationid="FBFC1CD4F471BAFBAD0B5FCE5419423E"captionStart="Figure 10"captionStartId="F10"captionText="Figure 10. Dorsal view of heads of Chasmogenus spp. from Suriname and Guyana A C. brownsbergensis B C. ligulatus C C. guianensis D C. pandus."figureDoi="10.3897/zookeys.934.49359.figure10"httpUri="https://binary.pensoft.net/fig/411765"pageId="0"pageNumber="25">Figures 10B</figureCitation>
<figureCitationid="35274A9EDA9FF451065C81F0C8AB1923"captionStart="Figure 15"captionStartId="F15"captionText="Figure 15. Aedeagi of Chasmogenus spp. A-D C. pandus A dorsal view (Suriname) B side view (Suriname) C specimen from French Guiana D specimen from Brazil E C. ligulatus F C. sinnamarensis G C. undulatus H, I C. acuminatus H specimen from Suriname I specimen from Guyana. Scale bars: 0.25 mm."figureDoi="10.3897/zookeys.934.49359.figure15"httpUri="https://binary.pensoft.net/fig/411770"pageId="0"pageNumber="25">, 15E</figureCitation>
<figureCitationid="4122029E4F3B386EF2AE8A2425A56231"captionStart="Figure 17"captionStartId="F17"captionText="Figure 17. Distribution of Chasmogenus spp."figureDoi="10.3897/zookeys.934.49359.figure17"httpUri="https://binary.pensoft.net/fig/411772"pageId="0"pageNumber="25">, 17</figureCitation>
<figureCitationid="E6280C09969EEAD49A326BC04FEEEF85"captionStart="Figure 21"captionStartId="F21"captionText="Figure 21. Habitat of Chasmogenus spp in Suriname. A Type locality and habitat for C. brownsbergensis, Brownsberg Nature Park (collecting event SR 12 - 0804 - 03 A) B type locality and habitat for C. ligulatus, near Mt. Kasikasima (collecting event SR 12 - 0320 - 02 A) C type locality and habitat for C. tafelbergensis, summit of Tafelberg tepui (collecting event SR 13 - 0817 - 01 A) D type locality and habitat for C. schmits, S of Kwamala along the Kutari River (collecting event SR 10 - 0316 - 01 B) E habitat for C. acuminatus, Central Suriname Nature Reserve, Raleighvallen (collecting event SR 16 - 0316 - 01 B) F habitat for C. guianensis, upper Palumeu River, (collecting event SR 12 - 0311 - 01 A)."figureDoi="10.3897/zookeys.934.49359.figure21"httpUri="https://binary.pensoft.net/fig/411776"pageId="0"pageNumber="25">, 21B</figureCitation>
<taxonomicNameid="D65302C7FBA81DB375162CD7AB605205"authorityName="Smith & Short"authorityYear="2020"class="Insecta"family="Hydrophilidae"genus="Chasmogenus"higherTaxonomySource="CoL"kingdom="Animalia"lsidName="ligulatus"order="Coleoptera"pageId="0"pageNumber="25"phylum="Arthropoda"rank="species"species="ligulatus">ligulatus</taxonomicName>
: same data as holotype except: 20.iii.2012, sandy stream on trail to METS camp, SR12-0320-02A (4 exs., SEMC, including DNA Voucher SLE474); same data as holotype except: 20-25.iii.2012, detrital pools along trail to METS camp, SR12-0320-03A (1 ex., SEMC).
<figureCitationid="28AF643852EF845197AA3708B093024D"captionStart="Figure 10"captionStartId="F10"captionText="Figure 10. Dorsal view of heads of Chasmogenus spp. from Suriname and Guyana A C. brownsbergensis B C. ligulatus C C. guianensis D C. pandus."figureDoi="10.3897/zookeys.934.49359.figure10"httpUri="https://binary.pensoft.net/fig/411765"pageId="0"pageNumber="25">10B</figureCitation>
Total body length 3.2-3.5 mm. Body form elongate oval with slightly curved lateral margins. Dorsum of head multi-colored, frons dark brown, clypeus slightly paler, labrum distinctly paler (Fig.
<figureCitationid="A4B774DF8558618D5C8F30B414C5DD7E"captionStart="Figure 10"captionStartId="F10"captionText="Figure 10. Dorsal view of heads of Chasmogenus spp. from Suriname and Guyana A C. brownsbergensis B C. ligulatus C C. guianensis D C. pandus."figureDoi="10.3897/zookeys.934.49359.figure10"httpUri="https://binary.pensoft.net/fig/411765"pageId="0"pageNumber="25">10C</figureCitation>
). Pronotum dark orange-brown, slightly paler marginally. Elytra uniformly dark orange-brown to dark brown. Venter orange-brown mesally, dark brown marginally.
Ground punctation on head fine to moderately dense. Clypeus with anteromedial emargination which exposes a shallowly rounded gap between the labrum and the clypeus (Fig.
<figureCitationid="6ACB1D4EC8DCB5C90585B7B1E1CA9614"captionStart="Figure 10"captionStartId="F10"captionText="Figure 10. Dorsal view of heads of Chasmogenus spp. from Suriname and Guyana A C. brownsbergensis B C. ligulatus C C. guianensis D C. pandus."figureDoi="10.3897/zookeys.934.49359.figure10"httpUri="https://binary.pensoft.net/fig/411765"pageId="0"pageNumber="25">10C</figureCitation>
). Mentum strongly depressed in anterior two-thirds with triangular notch. Maxillary palps long, longer than width of head immediately posterior to eyes.
Ground punctation on pronotum fine. Prosternum very weakly tectiform. Mesoventrite with weak elevation forming a posteromedial longitudinal carina. Metafemora densely and uniformly pubescent in basal nine-tenths.
<figureCitationid="960167C63EBBBD8FD6707FB5D74D86DE"captionStart="Figure 15"captionStartId="F15"captionText="Figure 15. Aedeagi of Chasmogenus spp. A-D C. pandus A dorsal view (Suriname) B side view (Suriname) C specimen from French Guiana D specimen from Brazil E C. ligulatus F C. sinnamarensis G C. undulatus H, I C. acuminatus H specimen from Suriname I specimen from Guyana. Scale bars: 0.25 mm."figureDoi="10.3897/zookeys.934.49359.figure15"httpUri="https://binary.pensoft.net/fig/411770"pageId="0"pageNumber="25">15E</figureCitation>
) with median lobe nearly parallel-sided but curved slightly to the left; apex bluntly rounded, distinctly extending beyond the apex of the parameres. Sclerite of the median lobe expanded and developed into a long, narrow crescent. Gonopore situated near the base of the median lobe. Parameres symmetrical, with outer margins strongly sinuate; the basal half of the parameres parallel sided with apical half appearing greatly expanded, then tapering to a blunt apex. Basal piece short, ca. one-third the length of the parameres.
<figureCitationid="6744ACDECF19D26D5B9941B8AF164C36"captionStart="Figure 17"captionStartId="F17"captionText="Figure 17. Distribution of Chasmogenus spp."figureDoi="10.3897/zookeys.934.49359.figure17"httpUri="https://binary.pensoft.net/fig/411772"pageId="0"pageNumber="25">17</figureCitation>
<figureCitationid="88A25A3F636ADF92100135C08B6C351A"captionStart="Figure 21"captionStartId="F21"captionText="Figure 21. Habitat of Chasmogenus spp in Suriname. A Type locality and habitat for C. brownsbergensis, Brownsberg Nature Park (collecting event SR 12 - 0804 - 03 A) B type locality and habitat for C. ligulatus, near Mt. Kasikasima (collecting event SR 12 - 0320 - 02 A) C type locality and habitat for C. tafelbergensis, summit of Tafelberg tepui (collecting event SR 13 - 0817 - 01 A) D type locality and habitat for C. schmits, S of Kwamala along the Kutari River (collecting event SR 10 - 0316 - 01 B) E habitat for C. acuminatus, Central Suriname Nature Reserve, Raleighvallen (collecting event SR 16 - 0316 - 01 B) F habitat for C. guianensis, upper Palumeu River, (collecting event SR 12 - 0311 - 01 A)."figureDoi="10.3897/zookeys.934.49359.figure21"httpUri="https://binary.pensoft.net/fig/411776"pageId="0"pageNumber="25">21B</figureCitation>
