Myxilla cf. rosacea 

Order : POECILOSCLERIDA

Family : Myxillidae

Form: Massive-lobate, sometimes with 'tassels', very irregular.

Colour: Grey/white to pink/pale orange.

Smell: None.

Consistency: Very soft and slimy ("wet brain").

Surface: The surface is irregular, almost conulate, being raised into many bumps. There is a thin transparent surface membrane. Typical Myxillid pores are absent. There are denser white patches where spicules are more abundant.

Apertures: Oscules are scattered, and somewhat irregular in shape. They are large but not numerous or conspicuous, with raised transparent edges.

Contraction: The surface collapses on removal from water, but there is no true contraction.

Internal characters

Skeleton: The principal skeleton consists of a regular reticulation of acanthostyles. Tornotes are present in the surface. Chelae and sigmata are present throughout.

Spicules: Acanthostyles (a) 170-(195)-210µm, more densely spined than those of M. rosacea, tornotes (b) 170-(180)-210µm, with microspined ends. Chelae (c) are about 35-40µm and 15-20µm; abundant sigmata (d), ca.25µm and 15µm, are present.

Habitat: Found in sheltered areas with reasonable current (1/2-1 knot) on Modiolus modiolus; almost free on mud; on hydroids and rock.

Distribution: So far known only from Strangford Lough between 20 and 30m.

Distribution Map from NBN: Grid map (fast) : Interactive map (slower, requires login to view records) : National Biodiversity Network mapping facility, data for UK.

Identity: Appearance is quite unlike other Myxillids. Spiculation is similar to M. rosacea (q.v.) but the acanthostyles are larger and more densely spined.

Voucher: BELUM : Mc229. Strangford Lough, Down.

Editors: D. Moss, B.E. Picton.