“The taxonomic assignment of Prorocentrum species is based on morphological characteristics; however, morphological variability has been found for several taxa isolated from different geographical regions. In this study, we evaluated species boundaries of Prorocentrum hoffmannianum and Prorocentrum belizeanum based on morphological and molecular data. A detailed morphological analysis was done, concentrating on the periflagellar
beta-catenin inhibitor architecture. Molecular analyses were performed on partial Small Sub-Unit (SSU) rDNA, partial Large Sub-Unit (LSU) rDNA, complete Internal Transcribed Spacer Regions (ITS1-5.8S-ITS2), and partial cytochrome b (cob) sequences. We concatenated the SSU-ITS-LSU fragments and constructed a phylogenetic tree using Bayesian Inference (BI) and Maximum Likelihood (ML) methods. Morphological analyses indicated that the main characters, such as cell size and number of depressions per valve, normally used to distinguish P. hoffmannianum from P. belizeanum, overlapped. No clear differences were found in the periflagellar area architecture. P. hoffmannianum and P. belizeanum were a highly supported monophyletic clade separated into three
sub-clades, which broadly corresponded to the sample collection regions. Subtle morphological overlaps found in cell shape, size, and ornamentation lead us to conclude that P. hoffmanianum and P. belizeanum might be considered conspecific. The molecular data analyzes did not separate P. hoffmannianum MCE and P. belizeanum into two morphospecies, and thus, we considered them FK506 research buy to be the Prorocentrum hoffmannianum species complex because their clades are separated by their geographic origin. These geographic and genetically distinct clades could be referred to as ribotypes: (A) Belize, (B) Florida-Cuba, (C1) India, and (C2) Australia. This article is protected by copyright. All rights reserved. “
“A new photosynthetic planktonic marine dinoflagellate, Azadinium dexteroporum sp. nov., is described from the Gulf of Naples (South Tyrrhenian Sea, Mediterranean Sea). The plate formula of the species, Po, cp, X, 4′, 3a, 6″, 6C,
5?S, 6‴ and 2″″, is typical for this recently described genus. Azadinium dexteroporum is the smallest rep-resentative of the genus (8.5 μm average length, 6.2 μm average width) and shares the presence of a small antapical spine with the type species A. spinosum and with A. polongum. However, it differs from all other Azadinium species for the markedly asymmetrical Po plate and the position of the ventral pore, which is located at the right posterior end of the Po plate. Another peculiarity of A. dexteroporum is the pronounced concavity of the second intercalary plate (2a), which appears collapsed with respect to the other plates. Phylogenetic analyses based on the large subunit 28S rDNA (D1/D2) and the internal transcribed spacer (ITS rDNA) support the attribution of A.