Ectyodoryx foliatus

(Fristedt, 1887)

Species Overview

Ectyodoryx foliatus (Fristedt, 1887) is a small leaf-shaped sponge with smooth surface and soft, fragile consistency. Its live colour is unknown. It is an ill-known deep water species.

Taxonomic Description

Colour: Grey in alcohol.
Shape, size, surface and consistency: Leaf-shaped. Height up to 3.5 cm, thickness 3 mm. Surface even and smooth. Oscules numerous, small. Consistency fragile, soft.
Spicules: Megascleres : Ectosomal tornotes, tylote-like with unequal mucronated heads: 200 µm; acanthostyles possibly in two size classes, entirely but weakly spined: 130-300 µm.
Microscleres : Arcuate isochelae, strongly but evenly curved: 35 µm; sigmas: 20 µm.
Skeleton: Not recorded. Presumably, tornotes form brushes at the surface; choanosomal skeleton should be a reticulation of bundles of acanthostyles.
Ecology: Deep water, 70-1948 m.
Distribution: Norway; North Atlantic, Arctic; also recorded from South Africa.
Etymology: The name refers to the leaf-shaped habit.
Type specimen information: No data.

Remarks

The skeleton of this species is not properly known. We could only use Lundbeck's (1909) interpretation of the type as a basis for the description.
The two other sympatric Ectyodoryx , E . atlanticus and E . multiformis , differ substantially in shape (thinly encrusting inE. atlanticus ) and spicule sizes and categories (megascleres twice as long in E . atlanticus ; several categories of microscleres in E . multiformis ).
Source: Arndt, 1935