Preprint volume - SIBM

Pre-print Volume - Posters
Topic 2: MARINE ORGANISMS AND ECOSYSTEMS AS MODEL SYSTEMS
A. TIMPANARO 1,2 , M. SINOPOLI 3 , M. GRISTINA 4 , C. CATTANO 1 , R. CHEMELLO 1
1 Dipartimento di Ecologia, Università di Palermo, Via Archirafi, 28 – 90123 Palermo, Italia.
2 Dipartimento di Scienze Ambientali, Università di Parma, Viale G.P. Usberti, 11 – Parma, Italia.
angelatimpanaro@gmail.com
3 ISPRA Sede Tecnico Scientifica Palermo, Italia.
4 CNR – IAMC, Sez. Territoriale di Mazara del Vallo (TP), Italia.
HABITAT REQUIREMENTS FOR THE CHOICE
OF NESTING SITE IN SYMPHODUS OCELLATUS (FORSSKAL)
REQUISITI DI HABITAT PER LA SCELTA DEL SITO
DI NIDIFICAZIONE IN SYMPHODUS OCELLATUS (FORSSKAL)
Abstract – This study is aimed to assess the habitat requirements for nesting site in the fish Symphodus
ocellatus (Forsskal) (Labridae). For this reason a set of biotic and abiotic variables has been collected in
84 areas surrounding the nests during summer 2009 in a coastal area of southern Tyrrhenian Sea (Sicily).
The influence of variables on the habitat requirements of nesting site was studied by Principal Coordinate
Analysis (PCO). The result showed that presence of Dictyotales and high canopy algal forms represented
the elective requirements for the choice of nesting site.
Key-words: habitat selection, nesting, marine fish, Tyrrhenian Sea.
Introduction - The choice of nesting site is a process that can have important effects
on fitness of several animal species (Boulinier et al., 2008). Indeed, many abiotic and
biotic factors have a strong influence on reproductive success. For marine fishes that
build nest during the reproduction, the selection mechanisms of the site are quite
unknown. The knowledge of habitat requirements for nesting is the first step in order to
understand these mechanisms of selection. Several authors performed an evaluation of
the habitat requirements for marine fishes, on various life history stages, by correlating
different environmental variables with their abundance (La Mesa et al., 2002;
Letourneur et al., 2003). The aim of this work is to evaluate the habitat requirements
for the choice of nesting site in the Labridae fish Symphodus ocellatus (Forsskal) used
as a model.
Materials and methods - We performed runs of samplings during summer 2009 along
the north-west Sicilian coast (Southern Tyrrhenian Sea). Data have been collected on
84 nests using underwater observations according to a standard protocol. During
sampling the following biotic and abiotic variables have been recorded: slope of the
substrate; presence (%) of the most abundant algal taxa such as Dictyotales, Cystoseira
sp. and Jania rubens; presence of sandy substrate; depth of nest (in meters); type of
cavity used for nest building (crevice/hole); average algal canopy height surrounding
the nest. We expressed all variables in numerical ranks and the influence of these
variables on the habitat requirements of nesting site of the S. ocellatus have been
studied by PCO (Principal Coordinate Analysis).
Results - The results of the distribution patterns of the variables are plotted in Fig. 1.
The first two axes explained 41.2% of the total variance (PCO1 23.9%; PCO2 17.3%).
Presence of J. rubens, Dictyotales, Cystoseira sp. and canopy variables affect the most
the distribution of samples. The results show that samples are concentrated principally
around the Dictyotales and algal canopy variables.
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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