Lissodendoryx isodictyalis

(Carter, 1882b)

Species Overview

Lissodendoryx isodictyalis (Carter, 1882b) is a thinly encrusting brownish-greenish soft sponge. It was originally described from the Caribbean, and the conspecificity of European specimens similar in spiculation to the Caribbean specimens remains to be demonstrated. It has been recorded mostly from the Mediterranean, but there is a single record from NW Spain.

Taxonomic Description

Colour: Brownish-greenish.
Shape, size, surface and consistency: Persistently thinly encrusting with irregular surface (the Caribbean specimens are mostly massive and may reach considerable size). The surface may be easily detached in flakes. Consistency soft.
Spicules: (Lissodendoryx isodictyalis sp) Megascleres : Ectosomal tylotes, smooth, with very pronounced heads: 180-310 x 2-6 µm; choanosomal styles, slightly constricted underneath the head, points abruptly ended or mucronate: 150-280 x 3-6 µm.
Microscleres : Arcuate isochelae in a single size class (the Caribbean specimens have two size classes): 14-33 µm; sigmas in a single size class (the Caribbean specimens have two size classes): 25-35 µm.
Skeleton: Tylotes form perpendicular bundles at the surface which fan out to become tangential; styles are loosely arranged in a paucispicular isodictyal reticulation.
Ecology: Encrusting on other sessile organisms, shallow water.
Distribution: ?NW Spain; ?Mediterranean, Caribbean.
Etymology: Isodictyalis (Latin) = with equal meshes, referring to the regular skeletal reticulation.
Type specimen information: The type is in the Natural History Museum, London: BNMH 1939.3.24.13 (dry + slide), schizotype.

Remarks

There are sufficient discrepancies between the Caribbean specimens of L . isodictyalis and the European descriptions. Eventually, European material will have to be described as a new species.
Source: Topsent, 1925a