Fine-structural characterization and phylogeny of Peridinium polonicum, type species of the recently described genus Naiadinium (Dinophyceae)

TY - JOUR

T1 - Fine-structural characterization and phylogeny of Peridinium polonicum, type species of the recently described genus Naiadinium (Dinophyceae)

AU - Craveiro, Sandra C.

AU - Daugbjerg, Niels

AU - Moestrup, Øjvind

AU - Calado, Antonio J.

PY - 2015/8/1

Y1 - 2015/8/1

N2 - Peridinium polonicum is a freshwater peridinioid with an unusual tabulation that includes one or two anterior intercalary plates in the mid-dorsal axis, and in such a low position that it seems inset in precingular Plate 4. Although the species has been classified in both Peridinium and Peridiniopsis, evidence from nucleotide sequences consistently shows that its closest relatives are within the Scrippsiella group. The genus Naiadinium Carty has been recently described with P. polonicum as its type species. However, Naiadinium was separated from other peridinioids only on the basis of shape and plate arrangements and these characters do not allow reliable determination of its closest phylogenetic relatives. Serial section fine-structural analysis revealed the presence of a small peduncle supported by a conspicuous microtubular basket that extended far into the cell, a complex pusular system that included a collecting chamber from which about 70 pusular tubes radiated; a flagellar apparatus with general peridinioid characters but with an unusually large distance of nearly 700. nm between basal bodies. An ITS1-5.8S-ITS2 rDNA-based phylogenetic analysis grouped, with high statistical support, Naiadinium polonicum with three species currently placed in Scrippsiella, viz. S. irregularis, S. precaria and S. ramonii.

AB - Peridinium polonicum is a freshwater peridinioid with an unusual tabulation that includes one or two anterior intercalary plates in the mid-dorsal axis, and in such a low position that it seems inset in precingular Plate 4. Although the species has been classified in both Peridinium and Peridiniopsis, evidence from nucleotide sequences consistently shows that its closest relatives are within the Scrippsiella group. The genus Naiadinium Carty has been recently described with P. polonicum as its type species. However, Naiadinium was separated from other peridinioids only on the basis of shape and plate arrangements and these characters do not allow reliable determination of its closest phylogenetic relatives. Serial section fine-structural analysis revealed the presence of a small peduncle supported by a conspicuous microtubular basket that extended far into the cell, a complex pusular system that included a collecting chamber from which about 70 pusular tubes radiated; a flagellar apparatus with general peridinioid characters but with an unusually large distance of nearly 700. nm between basal bodies. An ITS1-5.8S-ITS2 rDNA-based phylogenetic analysis grouped, with high statistical support, Naiadinium polonicum with three species currently placed in Scrippsiella, viz. S. irregularis, S. precaria and S. ramonii.

U2 - 10.1016/j.ejop.2015.05.001

DO - 10.1016/j.ejop.2015.05.001

M3 - Journal article

C2 - 26094011

SN - 0932-4739

VL - 51

SP - 259

EP - 279

JO - European Journal of Protistology

JF - European Journal of Protistology

IS - 4

ER -