Temporal variation of the algae-associated molluscan assemblage of artificial substrata in Bay of Tunis (Tunisia)

Abstract

The molluscan assemblage inhabiting photophilous algae from artificial rocky shores in the Bay of Tunis) was studied from February 2009 to February 2010. Five monthly replicates were taken with a quadrate of 25 × 25 cm. A total of 16105 individuals of molluscs, belonging to 93 species, were collected. Gastropods were the most species-rich group, with 66 species (70.96%), followed by bivalves with 26 species (27.95%). Gastropods were also the most abundant with 11529 individuals (71.60%), followed by bivalves with 4575 individuals (28.41%). Nevertheless, Mytilaster minimus was the dominant species overall during the studied period (15.6% of total abundance), followed by Tricolia miniata (11.6%), Bittium reticulatum (11.5%), Gibbula racketti (10.4%) and Rissoa similis (9.8%). The high abundance of juveniles of soft (e.g. Venerupis aurea, Nassarius corniculum) and hard bottom species (e.g. M. minimus, Fissurella nubecula) highlight the important role played by this habitat as a nursery for species from nearby habitats. The presence of the alien molluscs Mitrella psilla (2.5% dominance) and Arcuatula senhousia stresses the importance of algae as a vehicle and/or receptor habitat for alien species. Species richness and abundance displayed significant seasonal changes, with maxima in winter 2009, but the Shannon-Wiener diversity index showed similar values throughout the year. Multivariate analyses also indicated the presence of significant seasonal differences for this molluscan assemblage.

Mollusc fauna associated with the Cystoseira algal associations in the Gulf of Trieste (Northern Adriatic Sea)

“…The majority of the species collected were characterized by a short life cycle (1-2 years) and with larval stages developing inside eggs (Gambi & Morri, 2008). As was first hypothesised by Pérès (1967) and confirmed by following studies (Poulicek, 1985;Antit et al, 2013), photophilic algae represent a preferential habitat for egg deposition and larval settlements. The high number of juveniles collected resulted in a bias in species determination, because juveniles could resemble adults of different species, which could lead to a potential underestimation of species number.…”

“…Cystoseira species are widespread in the Mediterranean infralittoral belts, and represent the final stage of the succession of photophilic algal communities on hard bottoms (Pérès & Picard, 1964). These communities also play a role of habitat former (Giaccone & Bruni, 1971) since they display a three-dimensional structure that provides habitat and shelter for a large number of algae and invertebrates (Mann, 1973;Antit et al, 2013). The importance of these associations for fish (Lipej et al, 2009;Orlando-Bonaca & Lipej, 2005;Fiorin et al, 2008;Orlando-Bonaca et al, 2008a;Vergés et al, 2009;Cheminée et al, 2013) and invertebrate communities (Milazzo et al, 2000;Costa & Ávila, 2001;Chemello & Milazzo, 2002;Gozler et al, 2010;Urra et al, 2013) has already been the subject of investigation in different areas of the Mediterranean Sea.…”

Seasonality and trophic diversity in molluscan assemblages from the Bay of Tunis (southern Mediterranean Sea)

“…The soft bottoms of La Goulette (Bay of Tunis) harbour a high biodiversity of molluscs, with 147 species identified so far, which represents a higher species richness than that found in adjacent photophilous algal stands (Antit et al, 2013). This contrasts with observations made in other regions when comparing neighbouring bottoms with and without vegetation (Currás et al, 1993;Connoll, 1994;Turner & Kendall, 1999).…”

ReefMedMol: Mollusca from the infralittoral rocky shores - the biocoenosis of photophilic algae - in the Mediterranean Sea

“…2012, Antit M. et al 2013, Antoniadou and Chintiroglou 2007, Antoniadou et al 2006, Antoniadou et al 2005, Badalamenti et al 2002, Bellan-Santini 1969, Huelin and J. 1984, Kasemi et al 2008, Kocataş 1978, Milazzo et al 2000, Miloslavich et al 2013, Pitacco et al 2014, Poulicek 1985, Sanchez-Moyano et al 2000, Simboura et al 1995, Terlizzi et al 2005, Terlizzi et al 2003, Trono 2006, Villari 1993, Russo 1998, Chemello and Milazzo 2002).…”

“…2012, Antit M. et al 2013, Antoniadou and Chintiroglou 2007, Antoniadou et al 2006, Antoniadou et al 2005, Badalamenti et al 2002, Chemello and Milazzo 2002, Kasemi et al 2008, Milazzo et al 2000, Miloslavich et al 2013, Pitacco et al 2014, Sanchez-Moyano et al 2000, Terlizzi et al 2005, Terlizzi et al 2003). The increased research effort on these habitats along with the initiative of the NAGISA project, addresses the need for a better understanding of the role of this important in the coastal marine environment which is under continuus pressures and threats (EEA 2015).…”