Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Gyrosigma sterrenburgii

S.R.Stidolph

Gyrosigma sterrenburgii

Type slide

Westshore, Napier, New Zealand; in salt marsh. Stidolph Collection BW-201/10.


Institution holding the type material

Publication

Known distribution

New Zealand; Kapiti Island: Okupe Lagoon, Lat. 40°50'S, Long. 174°56'E; Napier: Westshore, Lat. 39°28'S, Long. 176°52'E; Purimu Creek, Lat. 39°30'S, Long. 176°52'E; Miranda: Lat. 37°10'S, Long. 175°19'E.

Etymology

After F.A.S. Sterrenburg, diatomist.

Description

Valve sides parallel up to about a third of the distance from apex, then moderately sigmoid and gradually attenuate to narrowly rounded apices. Valve face convex, length 238-368 µm, width 25.4-30.4 µm. Axial area narrow, central area rotated to convex side of axial rib, rib of double curvature, conspicuous and slightly eccentric towards convex valve margin. Raphe angle –2/+2°. Helictoglossa conspicuous, terminal areas funnel shaped, conspicuous and laterally displaced to concave side of axial rib. Striae transverse and longitudinal. Longitudinal striae 11 in 10 µm and slightly more conspicuous than transverse striae, 12 in 10 µm. Colour by standardised darkfield: gold.

Notes

Funding from TFBIS (Terrestrial and Freshwater Biodiversity Information System), administered by the New Zealand Department of Conservation, is gratefully acknowledged.

Reference

Stidolph SR 1992. Observations and remarks on the morphology and taxonomy of the diatom genera Gyrosigma Hassall and Pleurosigma W. Smith III. Gyrosigma sterrenburgii sp. nov., and Pleurosigma amara sp. nov. Diatom Research 7: 345-366.