Cell morphology and PSP-toxin profiles of Alexandrium minutum in the Marlborough Sounds, New Zealand

Abstract

Thecal plate morphology and paralytic shellfish poisoning (PSP) toxin spectra produced by three strains of a small Alexandrium species isolated from the Marlborough Sounds, New Zealand were examined. Although these cells displayed minor morphological features described in the literature as characteristic of both A. minutum and A. lusitanicum, the former designation was adopted. High performance liquid chromatography (HPLC) analysis of culture extracts showed the toxin profiles to consist predominantly of various proportions of the carbamate toxins GTX1, GTX2, GTX4, neoSTX, and STX. These toxin profiles were similar to those observed in other New Zealand isolates of A. minutum. They were however rather different from those observed in this species elsewhere in the world though the specific toxicity of these cells (1.8–2.2 pg STX equivalents per cell) was similarly low. © 1997, Copyright Taylor & Francis Group, LLC.