MB5-236 - Fabulina fabula et Magelona mirabilis avec bivalves vénéridés et amphipodes dans du sable fin envasé compact de l'infralittoral en Atlantique (EUNIS 2022)

MB5-236 - Fabulina fabula et Magelona mirabilis avec bivalves vénéridés et amphipodes dans du sable fin envasé compact de l'infralittoral en Atlantique

Fabulina fabula and Magelona mirabilis with venerid bivalves and amphipods in Atlantic infralittoral compacted fine muddy sand

MB5-235 - Echinocardium cordatum et Ensis spp. dans du sable fin légèrement vaseux de l'infralittoral en Atlantique

MB5-237 - Arenicola marina in Atlantic infralittoral fine sand or muddy sand

Classification des habitats EUNIS 2022

Descriptif de l'habitat

In stable, fine, compacted sands and slightly muddy sands in the infralittoral and littoral fringe, communities occur that are dominated by venerid bivalves such as Chamelea gallina. This biotope may be characterised by a prevalence of Fabulina fabula and Magelona mirabilis or other species of Magelona (e.g. M. filiformis). Other taxa, including the amphipod Bathyporeia spp. and polychaetes such as Chaetozone setosa, Spiophanes bombyx and Nephtys spp. are also commonly recorded. In some areas the bivalve Spisula elliptica may also occur in this biotope in low numbers. The community is relatively stable in its species composition, however, numbers of Magelona and F. Fabulina tend to fluctuate. Around the Scilly Isles numbers of F. fabulina in this biotope are uncommonly low whilst these taxa are often found in higher abundances in muddier communities (presumably due to the higher organic content). Consequently it may be better to revise this biotope on the basis of less ubiquitous taxa such as key amphipod species (E.I.S. Rees pers. comm. 2002) although more data is required to test this. MB5-236 and MB3-233 are collectively considered to be the 'shallow Venus community' or 'boreal off-shore sand association' of previous workers (see Petersen 1918; Jones 1950; Thorson 1957). These communities have been shown to correlate well with particular levels of current induced 'bed-stress' (Warwick & Uncles 1980). The 'Arctic Venus Community' and 'Mediterranean Venus Community' described to the north and south of the UK (Thorson 1957) probably occur in the same habitat and appears to be the same biotope described as the Ophelia borealis community in northern France and the central North Sea (Künitzer et al. 1992). Sites with this biotope may undergo transitions in community composition. The epibiotic biotopes MB5-235 and MB5-237 may also overlay this biotope in some areas.

Bibliographie

European Topic Centre on Biological Diversity 2022. EUNIS marine habitat classification 2022 including crosswalks. Table Excel. (Source)