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Three species of dinophysoid planktonic dinoflagellates are described from the eastern Mediterranean Sea. Amphisolenia sp. aff. brevicauda was collected at 70-m depth in the Ionian Sea. This small species showed a more asymmetric midbody and a proportionally longer neck when compared to the closer relative A. brevicauda. Three individuals of Dinofurcula tricornuta sp. nov. collected at 154-m depth in the Marmara Sea are characterized by three posterior-oriented processes when compared to its congeneric species. This is the first record of the genus Dinofurcula beyond the eastern tropical Pacific Ocean. Dinophysis profunda sp. nov. collected at 500-m depth in the Ionian Sea is characterized by ovate hypotheca and a serrate crest-like left sulcal list when compared to its close relative D. alata. These findings evidence an undescribed biodiversity in the under-sampled subphotic depths. [ABSTRACT FROM AUTHOR]

Abstract: The distribution and morphology of the dinoflagellate Erythropsidinium (=Erythropsis) was studied in the vicinity of the Kuroshio and Oyashio Currents, the Philippine, Celebes, Sulu and South China Seas, western and central equatorial and southeast Pacific Ocean. Ninety-four specimens were observed, most of them collected from depths of less than 90m. The highest abundance (15cellsL−1) was recorded in the north Philippine Sea in May (32°N, 138°E, 30-m depth). Twenty-four specimens were found in a station in the offshore Perú-Chile Current (31°52′S, 91°24′W). The transition regions between open warm waters and productive currents or upwellings seem to favour the abundance of Erythropsidinium. Specimens with duplicate pistons, with two protuberant ocelloids, and specimens with a piston that attains up to 20 times the body length are illustrated for the first time. All the specimens have been ascribed to the type species, Erythropsidinium agile, until stable taxonomical criteria are established for the species diagnosis. Despite the complexity of its organelles, the ocelloid and piston, the competitiveness of Erythropsidinium in the pelagic ecosystem seems to be low. [Copyright &y& Elsevier]

Abstract: The distribution of planktonic ciliates, aloricate (naked) and loricate (tintinnid) was investigated in the open waters of the Oyashio and Kuroshio Currents, Philippine, Sulu, Celebes and South China Seas, and the western and central equatorial Pacific. The abundance of nauplii and post-naupliar copepods as potential predators was estimated. In average, the tintinnids represented 10–20% of the abundance of aloricate ciliates (50–200 cellsL−1). One hundred and two species of 37 genera of tintinnids were recorded. As a general trend, the highest species richness was found in moderate oligotrophic waters. Photographic records of some taxa of interest and unidentified specimens were reported. In the subarctic waters of the Oyashio Current, a few tintinnid species showed high abundance fluctuations that may be controlled by the copepods. During the summer the species of Parafavella with longer loricae predominated in parallel to the increase of the copepodite abundance. In warm open waters, the success of a ciliate species could depend on its anti-grazing strategy. Eutintinnus apertus attached to a spine-bearing diatom was the most ubiquitous species. Tintinnids may be subjected to lower predation pressure than aloricate ciliates. The increase of the lorica length or the association with diatoms may be an anti-grazing strategy, which determines the success of one tintinnid taxon versus other congeneric species. Although the aloricate ciliates would be less affected than tintinnids by the reduction of food availability under oligotrophic conditions, the ciliate populations as a general trend seem to be controlled by the predators (top-down) rather than by the availability of food resources (bottom-up). [Copyright &y& Elsevier]

The morphology and distribution of the diatoms Chaetoceros tetrastichon and Ch. dadayi as epiphytes on the loricae of the tintinnids Eutintinnus apertus and E. pinguis investigated in the open waters of the Pacific Ocean. The Eutintinnus–Chaetoceros consortia was encountered in 38 of the 52 sampling stations from 34°N to 33°S, and together were among represented the most wide-spread species. The abundance was low with a maximum of 32 consortia l−1 and E. apertus was often the most abundant species of the genus. The free-living Eutintinnus congeneric species showed a wider vertical distribution, whereas E. apertus–Chaetoceros tended to be near the surface. The success of E. apertus in consortium with Chaetoceros may be due to increase of the clearance rate and/or the lower susceptibility to predation. Chaetoceros modifies its morphology to adapt the epiphytic life, especially Ch. dadayi. The shorter curved setae may facilitate the transfer to the lorica of the daughter tintinnid after the cell division. The free-living Ch. tetrastichon and Ch. dadayi are very rare and Chaetoceros remained attached to empty loricae or encysted tintinnid cells. This suggests that the Eutintinnus–Chaetoceros consortium is obligate for the success of the diatom and renders the tintinnid more competitive versus congeneric species. [ABSTRACT FROM AUTHOR]

Abstract: Examples of rarely reported dinoflagellates of the family Kofoidiniaceae F.J.R. Taylor (Noctilucales) from the northwest, equatorial and southeast Pacific Ocean are described and illustrated. Kofoidinium was the most ubiquitous genus with a maximum abundance of 10cellsL−1. Specimens of this genus were identified to four species: Kofoidinium sp. that showed a pointed extension that emerges from the antero-ventral region and K. velelloides, both of which had diameters that ranged from 40 to 200μm; Kofoidinium pavillardii which showed a rounded epitheca and a larger size (∼300–700μm in diameter); and another species, tentatively identified as K. splendens, that contained red circular inclusions. Further research is needed to clarify the characteristics that separate K. splendens from the other species. This study is the first to record the genus Spatulodinium in tropical waters and in the southern hemisphere. S. cf. pseudonoctiluca was found in the southeast Pacific Ocean, as well as other smaller specimens with a different shape or disposition of the tentacle that may belong to two other species. In the northwest and equatorial Pacific, specimens of Spatulodinium showed a green pigmentation that suggested the existence of the first species known in the order Noctilucales to contain its own chloroplasts. Immature stages of kofoidiniaceans, some containing symbiotic microalgae, are illustrated, as well as mature stages related to Pomatodinium and to unknown genera of kofoidiniaceans. Kofoidiniaceans are shown to be common and widely distributed in the Pacific, and are probably also frequent in other oceans, but are rarely recognised. [Copyright &y& Elsevier]

The distribution of the dinoflagellate Histioneis was studied in the vicinity of the Kuroshio Current, the Philippine, Celebes, Sulu and South China Seas and the western and central equatorial Pacific Ocean. A total of 65 specimens, assigned to 17 species, was observed. For the first time, photomicrographs of several species are reported. Histioneis cymbalaria and H. longicollis were the most common. Nearly all specimens were recorded from 0–70 m depth, and the highest abundance was recorded in the Philippine Sea in July (32°N, 138°E, 30 m depth) with a maximum of 32 individuals per litre. [ABSTRACT FROM AUTHOR]