Hymerhabdia typica

Topsent, 1892b

Species Overview

Hymerhabdia typica Topsent, 1892b is a thin yellow or orange, hispid crust, recognizable only after microscopic examination. It occurs in souther deep water.

Taxonomic Description

Colour: Yellow or dark orange.
Shape, size, surface and consistency: Thinly encrusting with bumpy and slightly hispid surface. Size 2 x 1.5 x 1 cm. No apparent oscules.
Spicules: (Hymerhabdia typica spics) Tylostyles, smooth, straight, with well-developed heads: 500-800 x 3-13 µm. Rhabdostyles and centrotylote oxeas, smooth, strongly recurved and spirally twisted: 120-300 x 4-5 µm.
Skeleton: The tylostyles are erect on the substrate, with their heads embedded in a layer of rhabdostyles and curved oxeotes.
Ecology: Deep water, from 15 m downwards.
Distribution: Mediterranean, Azores, Roscoff.
Etymology: Typicus (Greek)= conformable, referring to the thin shape following the contour of the substrate.
Type specimen information: The type is in the Monaco Museum, with a slide in the Paris Museum.

Remarks

This species differs from its congener H . intermedia in the smaller rhabdostyles and the possession of centrotylote oxeas in stead of strongyles. The latter are less strongly curved.
Source: Carballo and Garcia-Gómez, 1994