Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Fragilariforma rakiuriensis C.Kilroy & K.Sabbe

Fragilariforma rakiuriensis

Type slide

Deceit Peaks, Stewart Island, New Zealand, M. Charteris, 10 November 1997. CHR 565732.

Isotypes: BM 101033; BRM Zu 5/44; CAS 221054; NIWA diatom collection,
Christchurch, New Zealand (#A6/426).

Institution holding the type material


Known distribution

New Zealand

Stewart Island: Deceit Peaks, open rocky stream at 500 m, pH 5; Table Hill, flowing and standing water, pH 5.2-5.6, EC 100 µS/cm.


Tasmania: Western Lakes, e.g. Sappho Lake, pH c. 6.1, EC 16 µS/cm.


Meaning "from Rakiura", one of the Māori names for Stewart Island.


Valves 11-55 µm long, (5.5-)6.5-9 µm wide. Girdle view: narrowly rectangular. Colonies linear. Open girdle bands 2-4, with rows of poroids on edges facing epitheca. Valve view: lanceolate, constricted centrally, with distinctly protracted apices, to rhombic with narrow protracted apices. Constricted-rhombic transition at 22.5-29 µm long. Striae 11-14 in 10 µm, fine, continuous across valve and mantle, approx. parallel but usually irregular, axial break only occasional; areolae not visible in LM. Marginal spines simple tapering hollow tubes on interstriae, absent at apices. Mantle plaques usually absent.

NOTE: abridged to satisfy the publisher's copyright requirements.


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


Kilroy C, Sabbe K, Bergey EA, Vyverman W, Lowe R 2003. New species of Fragilariforma (Bacillariophyceae) in New Zealand and Australia. New Zealand Journal of Botany 41: 535-554.