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

Abstract

A new species of semi-terrestrial sesarmid crab of the genus Geosesarma De Man, 1892, is described from central Taiwan. Geosesarmamirumsp. nov. is distinct in possessing a strong transverse crest on the inner surface of the male chela and a diagnostic male first gonopod which is relatively long and stout, with the distal chitinous part broad and spatuliform. Like most Geosesarma species, G.mirumsp. nov. has large eggs and direct development, contrasting with the only other species known from Taiwan, G.hednon Ng, Liu and Schubart, 2004, which has small eggs and planktotrophic larvae.

Gene Arrangement and Adaptive Evolution in the Mitochondrial Genomes of Terrestrial Sesarmid Crabs Geosesarma faustum and Geosesarma penangensis

“…This is the first phylogenomic analysis that placed Geosesarma as the sister group to the [(C. dehaani + C. neglectum) + (Chiromantes haematocheir + S. sinensis)] clade. This result confirmed that Geosesarma belongs to Grapsoidea, Sesarmidae, congruent with the morphological assignments (Ng et al, 2008;Ng, 2017;Ng and Wowor, 2019;Shy and Ng, 2019). All Sesarmidae species cluster into a clade consisting of two sister groups, which was consistent with previous findings (Wang et al, 2019;Li et al, 2020;Lu et al, 2020; Sesarmidae species are most closely related to Gecacinidae, constituting part of the Grapsoidea group, which is in accordance with the results of the studies by Chen et al (2019), Wang et al (2019), Lu et al (2020), and.…”

“…The genus Geosesarma De Man, 1892, belonging to the Sesarmidae family, is represented by 67 species at present. The genus is distributed in Malaysia, Indonesia, Philippines, Thailand, Papua New Guinea, and the Andamans (Ng et al, 2008;Ng and Wowor, 2019;Shy and Ng, 2019;Naruse and Ng, 2020). Geosesarma species are commonly known as vampire crabs due to the bright yellow eyes of some species (Ng et al, 2015).…”

“…Nevertheless, genomic and genetic resources are lacking for the genus Geosesarma. Previous studies have assigned Geosesarma to Sesarmidae based on morphology (Ng et al, 2008;Ng, 2017;Ng and Wowor, 2019;Shy and Ng, 2019); nevertheless, no genetic analysis has been performed to show the position of Geosesarma within Sesarmidae. In this study, the complete mitogenomes of G. faustum and G. penangensis were analyzed and compared with other Brachyura mitogenomes.…”

Geosesarma sodalis, a new species of vampire crab (Crustacea, Brachyura, Sesarmidae) from a limestone cave in central Sarawak, Malaysia

“…Geosesarma are often called vampire crabs because many species have bright yellow eyes in life (see Ng et al 2015;Ng 2017). Geosesarma is a large genus, with 67 species known from Southeast and East Asia, the Andaman Islands, Papua New Guinea, and the Solomon Islands (Ng et al 2008;Ng and Wowor 2019;Shy and Ng 2019;Naruse and Ng 2020).…”