Leuconia bulbosa

(Hanitsch, 1895)

Species Overview

Leuconia bulbosa (Hanitsch, 1895) is a white bulbous (hollow) calcareous sponge. Surface corrugated and somewhat hispid. It can only be reliably distinguished from other similar Leuconia species when spicules are examined. It is a southern species known only from a single record off the coast of Portugal.

Taxonomic Description

Colour: White or yellowish grey in alcohol.
Shape, size, surface and consistency: Solitary, sessile, of bulb-like or sometimes irregular shape, tapering upwards to a terminal osculum, which is provided with a very small oscular fringe. Surface somewhat corrugated and hispid. The larger and more regular specimens measuring about 22 mm in diameter and 20 mm in height. Width of osculum 2.5 mm.
Spicules: Calcareous. Ectosomal triactines, basal ray: 200 x 18 µm, lateral rays: 170 x 18 µm; triactines of the chamber layer, basal ray: 400 x 22 µm, lateral rays: 340 x 22 µm.
Atrial tetractines with apical ray: 100 x 10 µm, basal ray: 170-270 x 10 µm, lateral rays: 390-450 x 10 µm
Ectosomal oxeas: 1400 x 7.5 µm; club-shaped oxeas: 450-750 x 50 µm; microxeas: 70 x 2 µm. Oscular rhabds: 420 x 1.3 µm.
Skeleton: Apical rays of the atrial tetractines project at right angles into the gastral cavity. Ectosomal oxeas radially arranged and projecting.
Ecology: No data.
Distribution: West coast of Portugal.
Type specimen information: No type material in BMNH.

Remarks

This species is ill-known, since no images of it have so far been published. Several Leuconia species are apparently closely related. The specific distinctness is derived from the possession of four oxea sizes and shapes.
Source: Burton, 1963.