Leuconia ananas

(Montagu, 1818)

Species Overview

Leuconia ananas (Montagu, 1818) is an egg-shaped calcareous sponge with villose surface and apical oscule. Its colour is whitish and it is rather firm. It is a northern species.

Taxonomic Description

Colour: White or grey (alcohol).
Shape, size, surface and consistency: Ovate, cylindrical or curved cucumber-like, occasionally stalked. Size up to 35 mm high, up to 16 mm in diameter. Surface villose, with blunt papilla bearing a brush of long oxeas; papillae 1 mm high, spaced about 1 mm apart. Wide-spaced internal cavity ending in a vent of 2-3 mm diameter. Consistency firm.
Spicules: (Leuconia ananas spics) Calcareous. Ectosomal triactines, regular: 180 x 8-10 µm; choanosomal triactines subregular: 200-300 x 15-25 µm.
Choanosomal and atrial tetractines, sagittal, with paired rays: 180 x 15-25 µm, basal rays: 200-300 x 15-25 µm, and apical rays: 120 x 15-25 µm.
Oxeas: 1000-2000 x 20-30 µm.
Skeleton: Leuconoid organization. Ectosomal skeleton a tangential layer of triactines, with oxeas projecting outwards singly or in brushes. Choanosomal skeleton a mass of irregular triactines. Atrial skeleton a layer of sagittal tetractines with their long apical rays projecting into the atrial cavity.
Ecology: On hydroids and stones, in muddy environment, 6-120 m.
Distribution: Faroes, Norway.
Etymology: The name refers to the shape.
Type specimen information: No type material in BMNH.

Remarks

This species stands out among the Leuconia species by its villous, papillate surface. It is close in shape to L . aspera but differs in being less hard and having smaller spicules.
Source: Arndt, 1935.