Morphological and molecular characterization of Teleaulax gracilis sp. nov. and T. minuta sp. nov. (Cryptophyceae)

Abstract

Laza-Martinez A., Arluzea J., Miguel I. and Orive E. 2012. Morphological and molecular characterization of Teleaulax gracilis sp. nov. and T. minuta sp. nov. (Cryptophyceae). Phycologia 51: 649–661. DOI: 10.2216/11-044.1

Teleaulax is a genus of delicate cryptophytes that are common and sometimes abundant in marine samples. Previous to this study, only three species (Teleaulax acuta, T. amphioxeia and T. merimbula) were known in the genus. Here, two new species were described from strains isolated from plankton samples collected at the seaward end of the Nervioi-Ibaizabal River estuary (south-eastern Bay of Biscay). They were examined by light microscopy and scanning and transmission electron microscopy, and the nuclear 18S rDNA was sequenced to infer the molecular phylogeny. The species of this genus have been distinguished by size, shape (especially of the cell anterior and posterior), swimming behaviour, morphology of the posterior band and the relative extension of the furrow. The most characteristic traits of Teleaulax gracilis sp. nov. were the cell anterior, that was only slightly rostrate, and the shape of the cell posterior, which tapered off gradually in form of a wedge and finished in a pointed antapex sustained by a V-shaped band. Teleaulax minuta sp. nov., with a length of 5–6.8 μm, is the smallest within the genus and lacks a posterior band. Common features shared with other congeners are, among others, the long furrows, the more or less rostrate cell anteriors and tapered posteriors, a sheet-like internal periplast component thinner than the plasma membrane and the thylakoids arranged in stacks of three.

Key Words::

• Cryptophyceae
• Cryptophytes
• Flagellates
• Furrow
• Nucleomorph
• Periplast
• Taxonomy
• Teleaulax

ACKNOWLEDGEMENTS

This research was funded by the Basque Government (projects GIC07/111-417-07 and K_EGOKITZEN) and the Bilbao-Biscay Water Consortium. A grant from the Spanish Ministry of Education and a fellowship for PhD researchers awarded by the UPV/EHU to A.L.-M. also supported this study. The authors wish to thank Gianfranco Novarino for the advice and hospitality during the stay of A.L.-M. at the Natural History Museum of London where some of the Teleaulax strains were initially analysed; we also thank Ibai Olariaga for the assistance with the ICNB and Alex Martínez (Department of Classic Studies, UPV/EHU) for the assistance with the translations of the diagnoses to Latin.