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| Ptychognathus sakaii Hsu, Shih & Li, 2022 |
Abstract
The brackish-water crabs of the genus Ptychognathus Stimpson, 1858, the most diverse genus in the family Varunidae, inhabit the estuaries or seashores influenced by freshwater. Ptychognathus sakaii, a new species from Kenting, southern Taiwan, is described in this study, with a comprehensive key to the ten species of this genus from Taiwan. This new species is similar to its congeners, but can be distinguished mainly by the features of the carapace, ambulatory legs, and male first gonopods.
Keywords: Decapoda; morphology; Ptychognathus sakaii; species diversity; taxonomy
Family Varunidae H. Milne Edwards, 1853
Subfamily Varuninae H. Milne Edwards, 1853
Genus Ptychognathus Stimpson, 1858
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| Ptychognathus sakaii sp. nov. A, B, E, holotype male (CW 6.7 mm; NCHUZOOL 17047). C, D, F, paratype female (CW 5.9 mm; NCHUZOOL 16503). E, F, color in life. |
Ptychognathus sakaii sp. nov.
Etymology. This species is named for the Japanese carcinologist Tune Sakai, who studied the crab fauna from Taiwan (e.g., Sakai, 1939) and described two new species of Ptychognathus from Taiwan (P. ishii from Lanyu Island; P. takahasii from Danshuei).
Distribution. Only known from Kenting, southern Taiwan.
Habitat. This species inhabits the intertidal area, with sediment composed of coral sand and pebbles. Individuals always hide under pebbles and were sometimes sympatric with Ptychognathus aff. barbatus, P. hachijoensis, and Pseudograpsus albus Stimpson, 1858 in Dingtanzih, Kenting, southern Taiwan.
Jhih-Wei Hsu, Hsi-Te Shih and Jheng-Jhang Li. 2022. Description of A New Species of Brackish-water Crab of the Genus Ptychognathus Stimpson, 1858 (Crustacea: Brachyura: Varunidae) from southern Taiwan. Nauplius. 30 • DOI: 10.1590/2358-2936e2022002
