A new mud lobster of the genus Thalassina Latreille, 1806 (Crustacea: Decapoda: Gebiidea: Thalassinidae) from marine seagrass beds in Dongsha (Pratas) Island, South China Sea Author Lin, Feng-Jiau Author Komai, Tomoyuki Author Chan, Tin-Yam text Raffles Bulletin of Zoology 2016 2016-05-20 64 98 104 journal article 10.5281/zenodo.4504421 2345-7600 4504421 B436FB7A-5442-47B8-AD97-065DB9062B72 Key to the extant species of Thalassina 1. Rostrum with blunt tip; posterodorsal median process of carapace long or short; sternites of pleomeres 2–5 each with median or lateral tubercles........................................................................2 – Rostrum with acute or subacute tip; posterodorsal median process of carapace short; sternites of pleomeres 2–5 only with lateral tubercles on either side of midline ..............................5 2. Lateral margin of rostrum and dorsolateral carina of pereopod 1 palm with conspicuous tubercles.........................................3 – Lateral margin of rostrum and dorsolateral carina of pereopod 1 palm without conspicuous tubercles or at most with obsolescent tubercles [posterodorsal median process of carapace long; tergites of pleomeres 2–5 each with median tubercles]........... .................................................................................. T. krempfi 3. Posterodorsal median process of carapace long; dorsolateral carina of pereopod 1 palm extending over entire length.......4 – Posterodorsal median process of carapace small; dorsolateral carina of pereopod 1 palm extending to half or proximal threefourths length...........................................................................6 4. Cervical groove of carapace unarmed or bordered with a few tubercles; merus of pereopod 3 with minute spines on dorsal margin in limited extent......................................... T. anomala – Cervical groove of carapace bordered with spines at least laterally; merus of pereopod 3 with row of conspicuous spines on dorsal margin over entire length .......................................5 5. Postcervical carapace covered with numerous spines; cervical groove bordered by row of spines entirely ............. T. spinosa – Postcervical carapace only armed with a few spines adjacent to linea thalassinica; cervical groove bordered by spines only laterally................................................. T. pratas , new species 6. Postrostral median groove extending beyond posterior ends of rostral lateral carinae; male gonopod 1 generally slender with 3 or 4 conspicuous teeth on lateral margin proximally........... ................................................................................ T. kelanang – Postrostral median groove not reaching posterior ends of rostral lateral carinae; male gonopod 1 generally broad, unarmed on lateral margin..................................................... T. squiamifera 7. Lateral margins of rostrum with tubercles only.....................8 – Lateral margins of rostrum and anterolateral margins of carapace with tubercles and spines [pereopod 1 merus with large spines on ventral margin proximally, palm with dorsolateral carina extending almost over entire length, lateral ventral carina with spiniform tubercles and spines; sternites of pleomeres 2–5 with lateral tubercles only in males, no lateral tubercles in females] .......................................................... T. spinirostris 8. Pereopod 1 merus with large spines on ventral margin proximally, palm with dorsolateral carina extending nearly over entire length; sternites of pleomeres 2–5 with faint lateral tubercles in males, no lateral tubercles in females .................. .................................................................................. T. gracilis – Pereopod 1 merus without large spines on ventral margin proximally, palm with dorsolateral carina extending to about midlength; sternites of pleomeres 2–5 with lateral tubercles and often numerous anterior tubercles ...................................9 9. Pereopod 1 palm with covering of granules on space between dorsolateral and dorsomesial carinae, latter carina with 14–16 spiniform tubercles.............................................. T. saetichelis – Pereopod 1 palm without covering of granules on space between dorsolateral and dorsomesial carinae, latter carina with 18–23 blunt tubercles.................................................. T. australiensis