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) anusakdiisp. nov. and Aricidea (Aricidea) thammapinanaesp. 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) anusakdiisp. 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) thammapinanaesp. 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 All data have been archived and are freely available from the Dryad Digital Repository (https://doi.org/10.5061/dryad.hqbzkh1cn).

Three new species of Levinsenia Mesnil, 1897 (Annelida: Paraonidae) from shallow and deep waters of Southwestern Atlantic Ocean

“…Neuropodia with two types of chaetae, capillary chaetae and modified neuropodial spines ( Figs 7H, 7I and 8C), starting on chaetiger 14 (12)(13)(14)(15). Neuropodia of first five chaetigers with 12 capillary chaetae each, arranged in two rows; on chaetigers 6-12, neuropodia with 8 capillary chaetae each, arranged in two rows; from segment 14 to end of body, neuropodia each with 3-6 modified stout spines, strongly curved, with expanded shaft and distinct fringe on convex side, arranged in a single row (Fig 7H-7J), and 3 accompanying capillary chaetae slenderer than capillary chaetae of preceding regions.…”

“…The family Paraonidae currently includes about 155 described species, with a worldwide distribution [8,9]. Due to the utilization of finer (0.5 mm mesh) sieves and the numerous projects focused on diversity in deep-sea environments [10], several new species have been described recently [11][12][13].…”