<strong>Sabellariidae from Lizard Island, Great Barrier Reef, including a new species of <em>Lygdamis</em> and notes on external morphology of the median organ</strong>

MARÍA CAPA; LARISSE FARONI-PEREZ; PAT HUTCHINGS

doi:10.11646/zootaxa.4019.1.10

Issue: Vol. 4019 No. 1: 18 Sept. 2015

Type: Article

Published: 2015-09-18

DOI: 10.11646/zootaxa.4019.1.10

Page range: 184–206

Abstract views: 62

PDF downloaded: 36

**Sabellariidae from Lizard Island, Great Barrier Reef, including a new species of Lygdamis and notes on external morphology of the median organ**

MARÍA CAPA⁺⁻
LARISSE FARONI-PEREZ⁺⁻
PAT HUTCHINGS⁺⁻

NTNU University Museum, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway. Australian Museum Research Institute, Australian Museum, 6 College Street, Sydney, 2010 NSW, Australia.

PPGECO, Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Campus Universitário, s/n, CCB, Córrego Grande, Florianópolis, SC, 88010-970, Brazil.

Australian Museum Research Institute, Australian Museum, 6 College Street, Sydney, 2010 NSW, Australia.

Annelida Australia median ridge Sabellaria lungula Gesaia larva Lygdamis nasutus n. sp.

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Abstract

We document herein the occurrence of three species of Sabellariidae at Lizard Island, Great Barrier Reef, including a new Lygdamis species. Sabellaria lungalla, described from Northern Territory, is reported for Queensland for the first time. The genus Gesaia, represented by a planktonic larva collected in shallow waters of the Archipelago, is a new record for Australia. Lygdamis nasutus n. sp. is characterised by one of the most conspicuous median organ described in the family (cylindrical, distally pigmented and is provided with a flattened, teardrop corona), its paleae morphology (with straight paleae, outer ones with asymmetrical pointed tips and subtle thecal sculpture and inner paleae with blunt tips and smooth surface), three lateral lobes on chaetiger 2, abdominal chaetigers with two type of neurochaetae, and notopodial uncini with 1–4 longitudinal rows of teeth. Comparison of the external morphology of the medial organ and median ridge of several species has been undertaken. Even though its function remains uncertain, the median organ morphology seems species specific and may provide relevant information about the evolutionary history and adaptations of sabellariids.