Gyrosigma euhippus F.A.S.Sterrenburg & R.Ross 1992

Publication Details
Gyrosigma euhippus F.A.S.Sterrenburg & R.Ross 1992: 139

Published in: Sterrenburg, F.A.S. (1992). Studies on the genera Gyrosigma and Pleurosigma (Bacillariophyceae). The type of the genus Gyrosigma and the other attenuati sensu Peragallo. Diatom Research 7(1): 137-155.

Request PDF

Type Species
The type species (holotype) of the genus Gyrosigma is Gyrosigma hippocampus Hassall.

Status of Name
This name is of an entity that is currently accepted taxonomically.

Type Information
Type locality: Type: BM; BM 23713, BM 23715, BM 23716 (syntypes, all from the same material)

Description
Valve moderately sigmoid, slender lanceolate, sometimes with a (freely variable!) kink, gradually tapering with acutely rounded ends and markedly vaulted, 120-250µm long, 22-27µm wide. Raphe sternum with single curvature, raphe angle +6 to +9°, middle portion nearly straight, nearly central throughout. Central raphe fissures clear, projecting far into the central area, ending as rounded hooks and dimorphic (oppositely deflected to either the convexity or concavity of their raphe branch on the two valves of a frustule). Central area slender, oval, symmetric. Terminal areas unilaterally dilated funnels in semilateral position. On the convex side of the apical raphe sternum the areolae run for some distance along the apex, paralleled at the periphery by an apical row of minute foramina in a narrow hyaline zone, just visible in the LM. Transverse striae 14-17 in 10µm, the central dozen or so somewhat radiate, longitudinal striae clearly coarser, 10-12 in 10µm medially, abruptly closer near the margin.

Habitat
Marine littoral species, personally observed (Sterrenburg) on Dutch, British and German North Sea coasts.

Key Characteristics
Differentiation from G. scalprum: much coarser longitudinal striae, central raphe fissures projecting much further into the central area, totally different apical micropore segment.

Created: 26 April 2002 by M.D. Guiry.

Last updated: 09 July 2011

Verification of Data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.

Linking to this page: https://www.algaebase.org/search/species/detail/?species_id=43972

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 09 July 2011. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 24 April 2024

Currently in AlgaeBase: