Discovery of Neonrosellavitiata (Darwin) and Newmanellaspinosus Chan & Cheang (Balanomorpha, Tetraclitidae) from the Andaman Sea, eastern Indian Ocean.

Woranop Sukparangsi,Chinnakit Wongkunanusorn,Ashitapol Pochai,Salinee Khachonpisitsak

doi:10.3897/zookeys.833.30689

Abstract

In this present study, distantly related acorn barnacle species in the subfamily Newmanellinae (Cirripedia, Thoracica, Tetraclitidae), including Neonrosellavitiata (Darwin, 1854) and Newmanellaspinosus Chan & Cheang, 2016, were discovered in the Andaman Sea of Thailand. Neo.vitiata can be readily distinguished from other newmanellids by shell plate and operculum morphology (external shell, tergum geometry, and pattern of parietal tube) and arthropodal characters (presence of basi-dorsal point at base of penis and triangular spines on cirri, setal type, and mouth parts). Both species were found to share overlapping territories on rocks at the rockweed zone, an area submerged under seawater most of the time throughout the year. This study highlights the first discovery of Neonrosella in the eastern Indian Ocean, whose ultrastructure compared to Newmanella is redescribed and illustrated here based on scanning electron microscopy.

Highlights

The genus Neonrosella Jones, 2010 contains only one species, Neonrosella vitiata (Darwin, 1854)
A recent examination of acorn barnacle specimens from the Andaman Sea, southern Thailand, recognized two morphologically similar newmanellin species from the same area of the Na-Tai rocky shore (Phang-Nga Province); Neonrosella vitiata is new to Thailand and Newmanella spinosus is found next to Neo. vitiata at lowest low tide point
The present study represents the first discovery of Neonrosella vitiata, sharing overlapping habitat with Newmanella spinosus in the Andaman Sea, eastern Indian Ocean

Summary

Introduction

The genus Neonrosella Jones, 2010 contains only one species, Neonrosella vitiata (Darwin, 1854). A recent examination of acorn barnacle specimens from the Andaman Sea, southern Thailand, recognized two morphologically similar newmanellin species from the same area of the Na-Tai rocky shore (Phang-Nga Province); Neonrosella vitiata is new to Thailand and Newmanella spinosus is found next to Neo. vitiata at lowest low tide point. Both species are redescribed based on shell plate morphology and arthropodal characters using scanning electron microscopy (SEM). Both species are compared with the detailed redescription of New. radiata provided by Chan and Cheang (2016)

Materials and methods

Equal rami