Marine Species Identification Portal : Amphiute paulini

Hanitsch, 1894a

Species Overview

Amphiute paulini Hanitsch, 1894a is a whitish group of calcareous tubes, originating from a common stolon-like base. Occasionally a solitary tube is found. Consistency fragile. It is similar to several other tubiform calcareous sponges, and may be only reliably identified from microscopical examination. Its main diagnostic feature are huge longitudinally arranged oxeas. It is a southern species reported from the west coasts of France, Spain and Portugal.

Taxonomic description

Colour: White.
Shape, size, surface and consistency: Tubiform, solitary or in groups growing from a stolon-like basis. Length of tubes several cms. Surface slightly rough due to projecting oxeas, but otherwise smooth. Oscules apical, surrounded by a short fringe. Consistency fragile.
Spicules: (Amphiute paulini Borojevic) Calcareous. Triactines, tetractines and oxeas. Triactines in two distinct categories: equal-rayed, subregular, with rays of 100-300 x 9-13 µm; and pseudosagittal, with paired rays 80-180 x 8-18 µm and basal rays 100-300 x 9-15 µm. Tetractines regular, with rays of the basal triradiate system 128-165 x 4-8 µm and the apical rays 30-80 x 3-10 µm. Oxeas in two distinct categories: microxeas 200-800 x 2-10 µm, and giant oxeas 400-2700 x 5-120 µm.
Skeleton: (Amphiute paulini skeleton) The cortical (ectosomal) and atrial skeleton are strengthened by longitudinally arranged giant oxeas. (Amphiute paulini skel) The ectosomal skeleton is a thin layer of equal-rayed triactines carried by the paired rays of subectosomal parasagittal triactines, at the outside there are perpendicular microxeas protruding beyond the surface. The atrial skeleton is a layer of tetractines carried by the paired rays of choanosomal parasagittal triactines. The intermediate choanosomal skeleton is built of perpendicularly arranged basal rays of subectosomal and choanosomal parasagittal triactines.
Reproduction: June-November.
Ecology: On vertical rock walls in the sublittoral.
Distribution: It is a southern species reported from the west coasts of France, Spain and Portugal.
Etymology: Named after the collector, Professor Paulino de Oliveira of Coimbra, Portugal.
Type specimen information: The type is in the Museu de Zoologia de Coimbra (Borojevic, 1966a).

Remarks

This species may be superficially similar to Sycon spp. and some Leuconia, e.g. L. caespitosa. Microscopical examination is ultimately necessary to make a certain identification.
Source: Burton, 1963.

Amphiute paulini