Cienc. Tecnol. Mar, 29 (1): 59-70, 2006
THALASSIONEMA BACILLARE (HEIDEN) KOLBE (THALASSIONEMATACEAE, BACILLARIOPHYCEAE): A SPECIES FROM CHILEAN WATERS NEARLY UNKNOWN UNTIL NOW BUT COMMON IN NORTHERN COASTAL PHYTOPLANKTON
PATRICIO RIVERA 1 FABIOLA CRUCES 1 SERGIO AVARIA 2
1 Departamento de Botánica, Universidad de Concepción, Casilla 160-C, Concepción. E-mail: privera@udec.cl 2 Facultad de Ciencias del Mar y de Recursos Naturales, Universidad de Valparaíso, Casilla 5080 - Reñaca, Viña del Mar.
Recepción: 15 de diciembre de 2004 - Versión corregida aceptada: 21 de marzo de 2006.
ABSTRACT
Species of the genus Thalassionema present in 88 samples of marine phytoplankton from Chile, deposited in the Diatom Collection, University of Concepcion-Chile, were studied. T. bacillare (Heiden) Kolbe, a nearly unknown species from Chilean waters, was found in 29 samples, and was frequent in the material collected between 18o 16’ S (Arica region) and 33o 02’ S (Valparaíso Bay) and scarce at 36o 42’ S (Concepción Bay). The valve morphology was studied using light and scanning electron microscopy. A taxon diagnosis and photographs of the principal morphological features are provided and compared with those present in the other two Chilean Thalassionema species: T. nitzschioides (Grunow) Mereschkowsky and T. pseudonitzschioides (Schuette & Schrader) Hasle. The analysis of many diatom samples previously studied by Chilean scientists permits the confirmation that in several opportunities T. bacillare was misidentified with the long cells of T. nitzschioides, and more frequently with T. frauenfeldii (Grunow) Hallegraeff, a taxon not found in the numerous samples analyzed in the present study. The paper concludes with comments on the ecology and Chilean distribution of the Thalassionema species found in this study.
Key words: Thalassionema, T. bacillare, morphology, distribution, Chile.