Morphology, genetics and toxin profile of Prorocentrum texanum (Dinophyceae) from Argentinian marine coastal waters

Abstract

Two strains of Prorocentrum texanum (LPCc020 and LPCc032) were established from coastal waters of the Province of Buenos Aires, Argentina. Field and cultured materials were examined using light and scanning electron microscopy, and the planktonic species Prorocentrum texanum, a known okadaic acid producer, was identified. We compared morphology, genetics and toxin profile of P. texanum based on material from Argentina in relation to strains from the Gulf of México. Our specimens and those described in the protologue of P. texanum var. texanum had similar shape, thecal ornamentation distribution patterns of large and small pores, and morphology of wings supported by platelets 1 and 4, respectively. Morphometric differences occurred in the ranges of length, depth and diameter of thecal plate pores. Morphology of the periflagellar area was described from Argentinean strains. SSU, ITS and LSU rDNA-based phylogenies of strains LPCc020 and LPCc032 placed them with other sequences of P. texanum. ITS rDNA showed that the most closely species, in order, are P. micans, P. steidingerae, P. mexicanum/P. rhathymum, and P. koreanum. The ability of the Argentinian strains to produce marine biotoxins was assessed, but, no toxins were detected. This is the first report of P. texanum outside the Gulf of México.