Diversity and Distribution of Sabellida (Annelida) under Protection Regimes

Luigi Musco,Adriana Giangrande,Margherita Licciano

doi:10.3390/w13111491

Abstract

Sabellida are widespread, diverse and abundant in marine benthic habitats. Their distribution patterns on hard-bottom substrates are poorly studied so far. Little is known about the factors influencing their distribution, including the protection regimes that are known to affect assemblage diversity. We analyzed hard-bottom Sabellida at 1.5 and 5 m depths at the Torre Guaceto Marine Protected Area (MPA) (SE Italy) to describe diversity and distribution patterns, and to identify potential factors influencing their distribution. The Sabellida diversity varied significantly among stations and was higher at 5 m depth. No relation with the protection regime was found. Among environmental variables, only sedimentation appeared related, suggesting that local trophic features might have influenced the observed pattern. Among habitat formers, only the macroalga Halimeda tuna significantly explained part of the observed variation, probably due to its role as a basibiont for some Sabellida taxa. Other predictor variables of Sabellida distribution were the abundances of some invertebrate taxa, especially Syllidae and some filter feeders such as Sabellariida and Cirripedia, probably due to shared ecological requirements, rather than a direct effect on Sabellida distribution. The relation with the Syllidae remains obscure so far, albeit some kind of interaction (including predator/prey interactions) between these two taxa cannot be excluded. Sabellida should be taken into account when analyzing patterns of biodiversity of hard-bottom environments.

Highlights

Sabellida (Annelida), known as fanworms, are diverse and widespread sedentary polychaetes, including about 1200 benthic species living from the intertidal to deep-sea habitats, from the tropical to Arctic and Antarctic regions [1].Sabellida include Sabellidae Latreille, 1825, Fabriciidae Rioja, 1923, and SerpulidaeRafinesque, 1815, mostly represented by small-sized species, except for some Sabellidae [1].The impressive review on the past and present knowledge on phylogeny, distribution and taxonomy by Capa et al [1] evidences the poorly existing information on the ecology of its species, which are abundant in a large array of environments, being among the dominant taxa [2]
The study area mostly overlaps the Torre Guaceto Marine Protected Area (MPA), corresponding to about 8 km in the Apulian region (South East Italy) (Figure 1), a low-lying coastline including clay cliffs to the south, a rocky shore in the central part and sandy beaches to the north that alternate with rocky coves and rocky plateaus further north
Contrary to the surrounding areas, the MPA has been protected from anthropogenic impacts, including overfishing, harvesting and mass tourism [28]

Summary

Introduction

Sabellida (Annelida), known as fanworms, are diverse and widespread sedentary polychaetes, including about 1200 benthic species living from the intertidal to deep-sea habitats, from the tropical to Arctic and Antarctic regions [1].Sabellida include Sabellidae Latreille, 1825, Fabriciidae Rioja, 1923, and SerpulidaeRafinesque, 1815, mostly represented by small-sized species, except for some Sabellidae [1].The impressive review on the past and present knowledge on phylogeny, distribution and taxonomy by Capa et al [1] evidences the poorly existing information on the ecology of its species, which are abundant in a large array of environments, being among the dominant taxa [2]. Most species inhabit littoral hard substrates, living among algae, associated to sponges, mollusks, and ascidians, or among coral crevices, but they occur in acidified areas, hydrothermal vents and deep Antarctic areas [5,6,7]. They are typical foulers in marinas, harbors and/or other sheltered areas, where they can reach very high densities [6,8,9,10,11,12]. Several species have been unintentionally introduced through ships’ hulls, ballast waters or with maricultured species, even becoming non-indigenous species generating local negative ecological and economic impacts [6,12,13,14,15]

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Conclusion