Abstract
A new species and a new record species of xanthid crabs collected from shallow subtidal hard bottoms of Taiwanese waters are described in the present study. Garthasia ludaoensis n. sp. represents the second species for the genus and can be readily distinguished from the type species, G. americana (Garth, 1939), by having: 1) smaller width to length ratio of the carapace; 2) larger width to length ratio of the third maxilliped; 3) smaller width to length ratio of merus of the third maxilliped; 4) no distinct longitudinal keel on surfaces of sternites 1 and 2; 5) smaller length to width ratio of merus of the last ambulatory leg; 6) smaller width to length ratio of pleonite 2 of the male abdomen; 7) pleonite 2 in semicircular-shaped; 8) a tuft of long setae near distal opening of G1; and 9) distal end of basal segment without upright protrusion of G2. This genus is reported for the first time from Taiwan, as well as from the West Pacific. The second xanthid crab specimen examined in the present study has live colour pattern of the carapace and morphological characters similar to that of Zosimus maculatus (de Man, 1887) described from Ambon, Indonesia (about 3.7° S). The present finding extends the northern distribution range of this species to near 22° N and represents a new record of this species for Taiwan.
References
Alcock, A. (1898) Material for a carcinological fauna of India. No. 3. The Brachyura Cyclometopa. Part I. The Family Xanthidae. The Journal of the Asiatic Society of Bengal, 67 (2), No. 1, 67–233.
Dana, J.D. (1852) Conspectus Crustaceorum, etc. Conspectus of the Crustacea of the Exploring Expedition under Capt Wilkes, U.S.N., including the Crustacea Cancroidea Corystoidea. Proceedings of the Academy of Natural Sciences of Philadelphia, 6, 73–86.
Davie, P.J.F., Guinot, D. & Ng, P.K.L. (2015) Systematics and classification of Brachyura. In: Castro, P., Davie, P.J.F., Guinot, D., Schram, F. & von Vaupel Klein, C. (Eds.), Treatise on Zoology—Anatomy, Taxonomy, Biology—The Crustacea. Vol. 9. Part C. Brill, Leiden, pp. 1049–1130.
https://doi.org/10.1163/9789004190832_021
Desmarest, A.G. (1823) Malacostracés. In: Dictionnaire des sciences naturelles, dans lequel on traite méthodiquement des différens êtres de la nature, considérés soit en eux-mêmes, d´après l´état actuel de nos connoissances, soit relativement à l´utilité qu´en peuvent retirer la médecine, l´agriculture, le commerce et les artes. Suivi d´une biographie des plus célèbres naturalistes ... Strasbourg, Paris, 28, 138–425.
Garth, J.S. (1939) New brachyuran crabs from the Galapagos Islands. Allan Hancock Pacific expeditions, 5 (2), 9–29, pls. 1–10.
Guinot, D. (1967) Recherches préliminaires sur les groupements naturels chez les Crustacés Décapods Brachyoures. III. A propos des affinités des Genres Dairoides Stebbing et Daira de Haan. Bulletin du Muséum National d’ Histoire Naturelle, Paris, Séries 2, 39 (3), 540–563.
MacLeay, W.S. (1838) On the Brachyurous Decapod Crustacea. Brought from the Cape by Dr. Smith. In: Smith, A. (Ed.), Illustrations of the Zoology of South Africa; consisting chiefly of Figures and Descriptions of the Objects of Natural History Collected during an Expedition into the Interior of South Africa, in the Years 1834, 1835, and 1836; fitted out by “The Cape of Good Hope Association for Exploring Central Africa”. Published under the Authority of the Lords Commissioners of Her Majesty’s Treasury, London, pp. 53–71, pls. 2 + 3.
Man, J.G. de (1887) Bericht über die von Herrn Dr. J. Brock im indischen Archipel gesammelten Decapoden und Stomatopoden. Archiv für Naturgeschichte, 53 (2), 215–288, pls. 7–10.
https://doi.org/10.5962/bhl.part.4747
Ng, P.K.L. (1993) Kraussiinae, a new subfamily for the genera Kraussia Dana, 1852, Palapedia, new genus, and Garthasia, new genus (Crustacea: Decapoda: Brachyura: Xanthidae), with descriptions of two new species from Singapore and the Philippines. The Raffles Bulletin of Zoology, 41 (1), 133–157.
Ng, P.K.L., Guinot, D. & Davie, P.J.F. (2008) Systema Brachyurorum: Part I. An annotated checklist of extant brachyuran crabs of the world. The Raffles Bulletin of Zoology, 17, 1–208.
Ng, P.K.L., Shih, H.-T., Ho, P.-H. & Wang, C.-H. (2017) An updated annotated checklist of brachyuran crabs from Taiwan (Crustacea: Decapoda). Journal of the National Taiwan Museum, 70 (3–4), 1010–1683.