Home|Search|Identify|Taxonomic tree|Quiz|About this site|Feedback
Developed by ETI BioInformatics
Characteristics, distribution and ecology
Taxonomische classification
Synonyms and common names
Literature references
Images, audio and video
Distribution map
Links to other Web sites

(Sollas, 1880)

Species Overview

Stelletta normani Sollas (1880) (also known as Dragmastra normani) is a pale yellow, globular mass of up to 20 cm diameter, with hispid surface and hard consistency. For a certain identification examination of the spicules, which include huge triaenes and oxeas, as well as asters and trichodragmas, is necessary. It is a northern deep-water species.

Taxonomic Description

Colour: Yellowish-white, but may seem darker because of encrusting organisms.
Shape, size, surface and consistency: More or less spherical in shape, becoming depressed cake-like with age. Size up to 20 cm in diameter. Surface hispid due to projecting spicules, and these also "collect" encrusting organisms (e.g. foraminiferans) and sediment. Oscules not apparent. Consistency hard.
Spicules: (Stelletta_normani_spics.jpg ) Megascleres: Oxeas, slender or fusiform, straight or slightly curved: up to 6000 x 60-100 µm; dichotriaenes: 3200 x 100 µm, with protoclads: 400 and deuteroclads: 600 µm; protriaenes: up to 5500 x 32 µm; anatriaenes: up to 5500 x 32 µm with clads: 125 µm.
Microscleres: Oxyasters: 20 µm in diameter; strongylasters / tylasters: 12 µm; trichodragmas: 50 x 20 µm.
Skeleton: Radiate. Oxeas and triaenes protruding through the cortex and the surface. Cortical region 1.5 mm in thickness. In the middle there is a layer of trichodragmas. These are also scattered throughout the choanosome.
Ecology: Deep water, 85-200 m
Distribution: Arctic, Sweden, Norway, North Atlantic including Azores.
Etymology: Named after the Rev. A.M. Norman, pincipal collector for Bowerbank, and editor of Volume IV of Bowerbank's Monographs of the British Spongiadae.
Type specimen information: The type is in the Natural History Museum, London. Type locality: Kors Fjord, Norway, coll. A.M. Norman

Remarks

This is a northern deep-water species. Among the Ancorinidae of the area it sharesthe spicule combination of triaenes, euasters and trichodragmas with Stelletta lactea Carter, but differs from that in overall spicule sizes and the possession of pro-and anatriaenes which are lacking in lactea. The presence or absence of trichodragmata is considered of specific value, not of generic value, so a separate genus Dragmastra to which this species has been assigned frequently, is superfluous.
Source: Sollas, 1880, 1888.

Stelletta normani