Geosesarma spectrum, a new species of semiterrestrial vampire crab (Crustacea: Decapoda: Brachyura: Sesarmidae) from Brunei Darussalam, Borneo

Abstract

A new semiterrestrial vampire crab from the family Sesarmidae, Geosesarma spectrum n. sp., is described from Brunei Darussalam (Borneo). The new species is characterised by its colouration in life, relatively large size, and form of the carapace, ambulatory legs and gonopods. The new species is compared to its closest congeners from Borneo. This description brings the number of Geosesarma species to 60.

Geosesarma mirum, a new species of semi-terrestrial sesarmid crab (Crustacea, Decapoda, Brachyura) from central Taiwan

“…At the moment, 64 species have been recorded, with the majority from Indonesia (Ng et al 2008; Ng 2015, 2017; Ng et al 2015; Manuel-Santos et al 2016; Ng and Grinang 2018; Ng and Wowor 2019; Ng and Ng 2019). Thus far, the most northerly record of the genus is Taiwan and Luzon in the Philippines, with two known species: G.vicentense (Rathbun, 1914) and G.hednon Ng, Liu & Schubart, 2004 (Ng et al 2004; Ng and Lemaitre 2017). Both species, however, are atypical members of Geosesarma as they have small eggs and planktotrophic larvae (see Ng et al 2004; Ng and Lemaitre 2017).…”

“…Thus far, the most northerly record of the genus is Taiwan and Luzon in the Philippines, with two known species: G.vicentense (Rathbun, 1914) and G.hednon Ng, Liu & Schubart, 2004 (Ng et al 2004; Ng and Lemaitre 2017). Both species, however, are atypical members of Geosesarma as they have small eggs and planktotrophic larvae (see Ng et al 2004; Ng and Lemaitre 2017). Most species of Geosesarma (when egg sizes are known) (over 90%) have large eggs and direct development.…”

Terrestrial crustaceans (Arthropoda, Crustacea): taxonomic diversity, terrestrial adaptations, and ecological functions

“…Jamaican snail crab Sesarma jarvisi breeds inside water-filled shells of the land snail of the genus Pleurodonte and provides parental care for larvae ( Diesel and Horst 1995 ; Diesel and Schubart 2000 ). Vampire crab Geosesarma notophorum and some other species of the genus from high-altitude forests of Sumatra exhibit a completely abbreviated development and unusual brooding behavior in which the female carries her offspring on the dorsal surface of the carapace for approximately 2–3 days after hatching ( Ng and Tan 1995 ; Ng et al 2015b ; Ng and Ng 2019 ). The most interesting case of parental care is described in the Jamaican crab Metopaulias depressus , which includes the long-term maintenance of optimal levels of appropriate conditions (oxygen, pH, and calcium (Ca+)) for larval development ( Diesel 1989 ; Diesel and Schuh 1993 ).…”

Deterioration of Coastal Ecosystem: A Case Study of the Banana Bay Ecological Reserve in Taiwan

“…Most land crabs studies on Banana Bay focus on species classification and characteristics [36], newly published species [37][38][39], comparison of regional differences in species [40]; as well as population and reproduction of a single species [41]. However, the study of life cycles has gained importance recently [42][43][44].…”

“…The relative stability of the physical and chemical environment in the oceans is good for the spread of larvae over long distances [77], so most land crab larvae can make connections in vast tropical islands. A study has compiled the distribution of six species of land crabs in India and the Western Pacific [60], while the new species of land crabs on the Hengchun Peninsula have a highly correlated geo-relationship with the Philippines and Indonesia [39].…”