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Marine Habitat Classification

Description of biotope or habitat type

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   Hediste diversicolor and Corophium volutator in littoral gravelly sandy mud

Physical habitat description

Salinity Variable (18-35 ppt)
Wave exposure Extremely sheltered
Tidal streams
Substratum Gravelly sandy mud
Depth Band Lower shore, Mid shore, Upper shore
Other Features

Download comparative physical and biological data. The comparative tables enable a rapid comparison of the species composition and principal physical characteristics between a given set of biotopes.

Distribution of habitat LS.LMx.GvMu.HedMx.Cvol <I>Hediste diversicolor</I> and <I>Corophium volutator</I> in littoral gravelly sandy mud

  • Records used to define the biotope (core records)
  • Other records assigned to this biotope, marked as 'certain'
  • Other records assigned to this biotope, marked as 'uncertain'

Point data based on records in the UK Marine Recorder Snapshot.


Extremely sheltered gravelly sandy mud, subject to variable or reduced salinity. The infaunal community consists of the ragworm Hediste diversicolor, Streblospio shrubsolii, Capitella capitata and Manayunkia aestuarina. Oligochaetes and Corophium volutator are abundant. Given the low sample numbers for this biotope, more records are needed to confirm the characterising species list.


It is probable that there are broad transition areas between this biotope and the corresponding muddy sediment biotope Hed.Cvol. The boundaries may be very indistinct, with HedMx.Cvol present in patches of gravelly mud on areas of mudflat, where the main biotope is Hed.Cvol.

Temporal variation

Not known.

Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale Typical abundance - (count per m2) % of core records where taxon was recorded
Corophium volutator 27 Frequent 9057 61-80%
Baltidrilus costatus 21 Abundant 14311 81-100%
Hediste diversicolor 13 Super abundant 1542 81-100%
Tubificoides pseudogaster 11 Abundant 5291 61-80%
Enchytraeidae 8 Abundant 2469 41-60%
Tubificoides benedii 8 Abundant 4791 61-80%
Manayunkia aestuarina 7 Common 4769 81-100%
Capitella capitata 2 Abundant 1089 41-60%
Streblospio shrubsolii 2 Common 2576 41-60%

Similar biotopes or habitat types

Occurs in estuarine muds, without a gravel fraction. The infauna is dominated by similar species.

Occurs in gravelly mud under less saline and slightly less sheltered conditions. The main differences in the infaunal assemblage are the abundance of M. balthica, and Peringia ulvae, the absence of oligochaetes and a range of polychaetes, and lower abundances of C. volutator.

Occurs in gravelly mud, higher up on the shore. The polychaete fauna is similar, but there are fewer oligochaetes. The bivalve infauna is more diverse, with abundant Scrobicularia plana.

Occurs in similar physical conditions. The main differences in the infaunal assemblage are fewer oligochaetes, a higher frequency of occurrence of S. shrubsolii, and the presence of occasional S. plana.

Occurs in less sheltered gravelly sandy mud. The principal differences in the infaunal assemblage are the abundance of Tharyx killariensis and the absence of C. volutator.

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