|Aspects of epizoobiontic mollusc assemblages on Pinna shells. II. Does the Mediterranean P. nobilis represent an isle of biodiversity?|
Cosentino, A.; Giacobbe, S. (2008). Aspects of epizoobiontic mollusc assemblages on Pinna shells. II. Does the Mediterranean P. nobilis represent an isle of biodiversity? Cah. Biol. Mar. 49(2): 161-173
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723, more
Biogeography; Diversity; Pinnidae Leach, 1819 [WoRMS]; MED, Mediterranean [Marine Regions]; Marine
|Authors|| || Top |
- Cosentino, A.
- Giacobbe, S.
Epizoic molluscs on 49 specimens of the soft-bottom megabenthic bivalve Pinna nobilis Linné, 1758 sampled in the Straits of Messina (Central Mediterranean), were investigated. Univariate indices of biodiversity, based on richness, abundance/evenness and taxonomic relatedness were calculated on mollusc taxocommunity in accordance with bathymetry and shell size of the P. nobilis. Furthermore, a multivariate composition of the characterizing epizoic taxa, and the corresponding functional role were investigated; the contribution of basibionts in increasing mollusc diversity on a small scale (soft bottom habitat/biotope), as well as a large scale (regional biogeography) was also tested. Epizoic mollusc assemblage replicates some major characteristics of hard bottom assemblages which are tied to ephemeral photophilous algae, but also displays some peculiar typological and taxonomic characteristics, probably related to the selective effect of the living substratum. Gastropod to bivalve ratio ranges from 4.0 to 5.6:1 in number of species, and from 5.6 to 12.6:1 in abundance, in accordance to shell size. Bittium reticulatum (Da Costa, 1778), Rissoella inflata Locard, 1892 and Gibbula turbinoides (Deshayes, 1835) are the prevalent species, but percentage similarity analysis and non-parametric correlation emphasize at least two multispecies subsets, which contribute to typologically and functionally characterize the mollusc taxocommunity. The recurrent occurrence of cladistically and functionally related microgastropods may suggest a possible specific redundancy or, alternatively, a functional complementarity depending on the ephemeral macrophytal epigrowth. The peculiar mollusc fauna associated with P. nobilis makes this bivalve a meaningful biodiversity reservoir both on the small and large spatial scale. Estimations of local density of Pinna populations, joined with species accumulation curves of associated taxa, allows the assessment of minimal patch of bottom surfaces which may sustain a rich network o