Distribution patterns of Syllidae (Annelida: Polychaeta) from seagrass (&lt;i&gt;Zostera marina&lt;/i&gt; and &lt;i&gt;Z. noltei&lt;/i&gt;) meadows in the Ensenada de O Grove (Galicia, NW Spain)

Patricia Quintas,Juan Moreira,Jesús S Troncoso

doi:10.3989/scimar.03770.26a

Abstract

This paper describes the distribution and composition of the syllid fauna inhabiting seagrass meadows in the Ensenada de O Grove (NW Spain). Samples were collected on muddy sediments colonized by either Zostera marina L., Zostera noltei Hornemann or by a mixed meadow with both species. Syllids were dominant (13340 individuals; 37% of total polychaete abundance), including 22 species (12 genera). The mixed meadows housed the highest number of species and the Z. noltei meadow had practically no syllids. The dominant species were Exogone naidina, Parapionosyllis elegans, Parexogone hebes and Prosphaerosyllis campoyi ( > 80% of total abundance). Carnivores (mainly species of Parapionosyllis, Amblyosyllis , and Streptosyllis ) were dominant, especially in muddy sand with either Z. marina or Z. noltei and sandy mud with a mixed meadow. The most important abiotic variables for explaining the composition and distribution of the syllid fauna were bottom water salinity, sorting coefficient and carbonate content. The highest number of species was recorded at sites with a high salinity and carbonate content and the lowest at sites with a high sorting coefficient.

Highlights

Seagrass meadows are of great ecological importance in shallow-water environments, as their structures increase the habitat complexity
As part of a broader project devoted to characterizing the soft-bottom benthic fauna of the Ensenada de O Grove (NW Spain) (Project XUGA30101A98), the main objective of this paper is to describe the syllid fauna inhabiting the seagrass meadows of the inlet in terms of composition, abundance, number of species and trophic structure
The Ensenada de O Grove is located in the inner part of the Ría de Arousa (Galicia, NW Spain) between 42o41’N-42o28’N and 9o01’W-8o44’W (Fig. 1)

Summary

Introduction

Seagrass meadows are of great ecological importance in shallow-water environments, as their structures (leaves, rhizomes and roots) increase the habitat complexity. They harbour numerous epiphytic and epifaunal taxa (Orth and Heck 1980, Webster et al 1998, Attrill et al 2000), providing shelter and protection from predators (Heck and Thoman 1981) and a variety of food resources (e.g. seagrass, detritus and epiphytes) (Kitting et al 1984, Hily et al 2004, Fredriksen et al 2005) to the associated faunal assemblages. Some species are epifaunal while others (especially among the Exogoninae and Eusyllinae) are infaunal (Çinar 2003, López and Gallego 2006)

Objectives

Methods

Results

Discussion

Conclusion