Sundathelphusa


Sundathelphusa is a genus of freshwater crabs in the family Gecarcinucidae, endemic to the Philippines and parts of Indonesia, including Sulawesi. These crabs exhibit remarkable adaptations to diverse freshwater habitats, including caves and montane streams.

Ecology and habitat

Habitat preferences

  • Surface-dwelling species: Found in rivers, streams, and swamps.
  • Despite being a cave-adapted species: Troglobitic forms like S. spelaeophila do not exhibit reduced eyes and pigmentation.
  • Montane species: S. cagayana inhabits high-elevation streams in northeastern Luzon.

Ecological roles

Behavior

  • Nocturnal activity: Most species forage at night to avoid predators.
  • Burrowing: Construct burrows in muddy banks for shelter and reproduction.
  • Reproduction: Direct development ; females carry eggs under the abdomen.
  • Cave adaptations: Troglobitic species rely on special adaptations due to reduced vision.

Taxonomy and species

Distinction from ''Parathelphusa''

  • Morphology: Sundathelphusa has elongate ambulatory legs compared to Parathelphusa.
  • Distribution: Sundathelphusa is restricted to the Philippines and Sulawesi, while Parathelphusa occurs in mainland Southeast Asia.

Species

Sundathelphusa currently has the following species:Sundathelphusa angelito Ng & Mendoza, 2020Sundathelphusa antipoloensis Sundathelphusa aruana Sundathelphusa boex Ng & Sket, 1996Sundathelphusa cagayana Mendoza & Naruse, 2010Sundathelphusa cassiope Sundathelphusa cavernicola Sundathelphusa cebu Husana & Ng, 2019Sundathelphusa celer Sundathelphusa danae Husana, Yamamuro & Ng, 2014Sundathelphusa grapsoides Sundathelphusa hades Takeda & Ng, 2001Sundathelphusa halmaherensis Sundathelphusa holthuisi Ng, 2010Sundathelphusa jagori Sundathelphusa lobo Husana, Naruse & Kase, 2009Sundathelphusa longipes Sundathelphusa miguelito Mendoza & Sy, 2017Sundathelphusa minahassae Sundathelphusa mistio Sundathelphusa molluscivora Schubart & Ng, 2008Sundathelphusa montana Sundathelphusa montanoanus Sundathelphusa niwangtiil Husana, Kase & Mendoza, 2015Sundathelphusa orsoni Husana, Kase & Mendoza, 2015Sundathelphusa philippina Sundathelphusa picta Sundathelphusa prosperidad Husana, 2020Sundathelphusa quirino Husana & Ng, 2019Sundathelphusa roberti Ng & Mendoza, 2024Sundathelphusa rubra Sundathelphusa sottoae Ng & Sket, 1996Sundathelphusa subquadratus Sundathelphusa sutteri Sundathelphusa tuerkayi Ng & Anker, 2016Sundathelphusa urichi Ng & Sket, 1996Sundathelphusa uva Ng & Mendoza, 2020Sundathelphusa vedeniki Ng & Sket, 1996Sundathelphusa vienae Husana, Yamamuro & Ng, 2014Sundathelphusa waray Husana, Naruse & Kase, 2009Sundathelphusa wolterecki Sundathelphusa aspera Ng & Stuebing, 1989 synonymous to Borneosa aspera Sundathelphusa brachyphallus Ng, 2015 synonymous to Borneosa brachyphallus Sundathelphusa spelaeophila Stasolla, Abbarchi & Innocenti, 2015 synonymous to Sundathelphusa philippina Sundathelphusa tenebrosa Holthuis, 1979 synonymous to Borneosa tenebrosa Holthuis, 1979

Conservation

Threats