Description of two new species of Paraonidae (Annelida) from the Gulf of Thailand, Western Pacific

Abstract

Two new species of Aricidea Webster, 1879 ( Paraonidae ), Aricidea ( Acmira ) anusakdii sp. nov. and Aricidea ( Aricidea ) thammapinanae sp. nov. were collected from 10–26.5 m depth, in soft bottoms with mud mixed with sand and shells at Songkhla Sea, the Gulf of Thailand between 2011–2018. Aricidea ( Acmira ) anusakdii sp. nov. is clearly distinguished from other species of the subgenus Acmira by having a rounded bilobed prostomium divided by a slight notch on the anterior margin; red pigments on the subdistal to the tip of each branchia (new character); two prebranchial chaetigers; 48–68 pairs of branchiae; and modified neurochaetae as strong curved spines with blunt shafts surrounded by pubescence from chaetigers 19–44. On the other hand, Aricidea ( Aricidea ) thammapinanae sp. nov. can be separated from other members of the subgenus Aricidea by the presence of a biarticulated median antenna; distinctive notopodial lobes as broad triangular with short distal protuberances on chaetiger 3, 4–8 pairs of branchiae; and modified neurochaetae as bidentate neurochaetae with a long pubescent subterminal arista on the concave side. All data have been archived and are freely available from the Dryad Digital Repository ( https://doi.org/10.5061/dryad.hqbzkh1cn).