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Marine Habitat Classification

Description of biotope or habitat type

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   Hygrosoma petersii, Benthothuria funebris and Oneirophanta assemblage on Atlantic upper abyssal mud

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure
Tidal streams
Substratum Mud - pelagic ooze
Zone Atlantic upper abyssal
Depth Band Biotope depth range 2100 - 3100 m; assemblage recorded from 2900 m
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 M.AtUA.Mu.HolCom.HygPet <i>Hygrosoma petersii</i>, Benthothuria funebris and Oneirophanta assemblage on Atlantic upper abyssal 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'
  • Predicted extent of the level 3 (for sublittoral rock & deep sea) or 4 (for sublittoral sediment) habitat

Point data based on records in the UK Marine Recorder Snapshot. Predicted habitat extent is from UKSeaMap.


This biotope consists of assemblages dominated by holothurians Benthothuria funebris and Oneirophanta with echinoderm Hygrosoma petersii on mud. Gage (1986) describes this assemblage from his deepest station in the southern Rockall Trough at 2900m on pelagic ooze. No other detail are available on this assemblage and it is possible that it may represent a transitional assemblage between the Acanella arbuscula assemblage (found shallower) and the abyssal Psychropotes longicauda and Oneirophanta mutabilis assemblage found deeper. This assemblage has been described based on literature only.


No situation data available.

Temporal variation

No temporal variation data available.

Characterising species

Taxon % of core records where taxon was recorded
Hygrosoma petersii
Benthothuria funebris

Similar biotopes or habitat types

Occurs deeper in the mid abyssal. Dominant holuthrians are Psycropotes longicauda and Oneirophanta mutabilis mutabilis mutabiliss.

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