I. V. Stonik

Toxicity, morphology and distribution of Pseudo-nitzschia calliantha, P. multistriata and P. multiseries (Bacillariophyta) from the northwestern Sea of Japan

Toxicity, morphology and distribution patterns of three bloom-forming species of the diatom genus Pseudo-nitzschia (potential producers of the neurotoxin domoic acid and causative organisms of amne ...

Diversity of Pseudo-nitzschia H. Peragallo from the western North Pacific

A survey focusing on species belonging to the diatom genus Pseudo-nitzschia was conducted in the western North Pacific (the northwestern Sea of Japan and the Sea of Okhotsk). Light and electron microscopic examination of 314 phytoplankton field samples collected from 1995 to 2006 revealed the presence of 11 Pseudo-nitzschia species: P. americana, P. cf. caciantha, P. calliantha, P. delicatissima/arenysensis, P. fraudulenta, P. cf. heimii, P. multiseries, P. multistriata, P. obtusa, P. pungens and P. seriata. Detailed morphological descriptions and illustrations as well as distributional data are provided for all 11 Pseudo-nitzschia taxa. The study presents a taxonomical baseline investigation of Pseudo-nitzschia from the western North Pacific and provides distributional data from an area otherwise not thoroughly examined earlier. Morphological deviation from the current description of P. cf. heimii, P. obtusa and P. caciantha is presented. It is established that P. calliantha, P. multistriata, P. multiseries and P. pungens occur in bloom proportions and are widely distributed in the Sea of Japan and the Sea of Okhotsk. In the literature, P. seriata is characterized as being restricted to the northern hemisphere where it occurs in the North Atlantic Ocean exclusively. The current study, however, documents that P. seriata is found in the North Pacific and hence is widespread in the northern hemisphere. One species, P. cf. caciantha, is a new record for the western North Pacific, whereas two others, P. cf. heimii and P. multistriata, are new records for the Sea of Okhotsk. The geographical distribution of P. cf. caciantha, P. multistriata and P. obtusa in the North Pacific is expanded by the current study.

Species Composition and Seasonal Dynamics of Density and Biomass of Euglenoids in Peter the Great Bay, Sea of Japan

The species composition and seasonal dynamics of density and biomass of euglenoids in the plankton of Peter the Great Bay were examined. Ten species of euglenoids were found. Of these, Eutreptiella braarudiiThrondsen and Eutreptiella eupharyngeaMoestrup et Norris are new records for the Far Eastern seas of Russia. Sharply pronounced peaks of euglenoid density and biomass occurred in the spring and summer. Increased density and biomass of species of the genera EuglenaEhr. and EutreptiaPerty were observed in polluted waters near sewage outlets.

Morphology and Ecology of the Species of the Genus Pseudo-nitzschia (Bacillariophyta) from Peter the Great Bay, Sea of Japan

Phytoplankton studies in Peter the Great Bay (Sea of Japan) revealed three species of the genus Pseudo-nitzschia H. Perag. in H. et M. Peragallo, namely, P. pungens (Grun. ex Cl.) Hasle; P. multiseries (Grun.) Hasle, and P. pseudodelicatissima Hasle. Mass blooms of P. pungens and P. multiseries were registered in Amurskii Bay in June 1992. The maximum density (11 million cell/liter) was registered at the water surface after heavy rainfall. A short-term outburst of the density of P. pseudodelicatissima (2.7 million cells/liter) was registered in Amurskii Bay in November 1997. We present morphological descriptions of all the species from the results of light and electron microscopy and discuss possible reasons favoring their mass development in Peter the Great Bay.

Flora of planktonic microalgae of Amursky Bay, Sea of Japan

Long-term studies of the species composition of phytoplankton in Amursky Bay (Sea of Japan) carried out during the period from 1991 to 2006 revealed a total of 357 species of planktonic microalgae from eight divisions: Cyanophyta (8 species), Chrysophyta (8), Bacillariophyta (157), Cryptophyta (5), Dinophyta (143), Raphidophyta (3), Euglenophyta (11), and Chlorophyta (22 species). An annotated checklist of species is presented. In comparison with the late 1960s and early 1970s, the species richness of phytoplankton increased markedly; a greater number of bloom-forming species was recorded.

Attheya ussurensis sp. nov. (Bacillariophyta)—a new marine diatom from the coastal waters of the Sea of Japan and a reappraisal of the genus

I.V. Stonik, T.Yu. Orlova and R.M. Crawford. 2006. Attheya ussurensis sp. nov. (Bacillariophyta)—a new marine diatom from the coastal waters of the Sea of Japan and a reappraisal of the genus. Phycologia 45: 141–147. DOI: 10.2216/04-48.1 A new species of the mainly sand-dwelling marine diatom genus Attheya is described from the Sea of Japan. Of the seven species of the genus, Attheya ussurensis most closely resembles Attheya decora in its valve and girdle structure and in its plastid form and number, but it also possesses features found in one or other of the remaining species (presence of a rimoportula, pores in the girdle bands and horn morphology). Keys are provided to aid ide.gification of all known Attheya species.

Phytoplankton of the Coastal Waters off Vladivostok (the Northwestern Part of the East Sea) under Eutrophic Conditions

The qualitative and quantitative composition of the phytoplankton of the coastal waters off Vladivostok during the period 1991-1994 was studied. The following trends in the phytoplankton composition with decreasing distance from the source of eutrophication were revealed: 1) total density and bio-mass increased; 2) the density of the diatom Skeletonema costatum, which reflects a decrease in the Shannon-Weaver species diversity index during the summer microalgal bloom, increased significantly; and 3) the density of the non-diatom component of the phytoplankton increased.

Species of the genusEutreptiella (Euglenophyceae) from Russian waters of East/Japan Sea

The paper reviews data available on euglenophycean algae of the genusEutreptiella from the Russian waters of East/ Japan Sea. Five species (such asE. braarudii, E. eupharyngea,E. gymnastica, E. cf.marina, andE. pascheri) were identified in our study.E. cf.marina andE. pascheri were found for the first time in the far eastern seas of Russia (including East/Japan Sea, Bering and Okhotsk seas). Morphological descriptions of species are based on light and electron microscopical studies and supplied with information on ecology and distribution. Original micrographs of these species obtained by light and electron microscopy are presented. It was established thatE. eupharyngea, E. gymnastica, andE. pascheri cause water “blooms” in spring and summer in eutrophic coastal areas of Peter the Great Bay (East/Japan Sea), where their cell concentrations at these periods exceed 1 × 106 cells l-1.

Species Structure of Plankton Microalgae on the Coast of the Sea of Okhotsk on Sakhalin Island

The results of long-term studies of the species structure of microalgae plankton of the coast of the Sea of Okhotsk of Sakhalin Island were summarized. There were 227 species and 4 intraspecific taxa attributed to 8 divisions. The greatest number of species was represented by the divisions Bacillariophyta (112 species and 3 intraspecific taxa) and Dinophyta (96 and 1 respectively). For the first time 5 diatom, 4 dinoflagellate, and 1 euglenophyte species were recorded for the Sea of Okhotsk.

Potentially toxic diatomsPseudo-nitzschia fraudulenta andP. calliantha from russian waters of East/Japan Sea and Sea of Okhotsk

Potentially toxic diatomsPseudo- nitzschia calliantha andP. fraudulenta were found in bottle samples of phytoplankton collected in Amurskii Bay (East/Japan Sea) and in the coastal waters of Sakhalin Island (East/Japan Sea and Sea of Okhotsk) in different seasons during 2002-2006. The mass development of these species occurred in October and November 2002 at water temperatures of 6-16°C and salinities of 28.8-33.5 PSU. The highest concentrations ofP. calliantha andP. fraudulenta were about 2x105 cells L1 and 1.5x105 cells L-1, respectively.P . fraudulenta was found for the first time in the Russian waters of the East/Japan Sea. Morphological descriptions of these species based on observation with light and electron microscopy and information on their ecology are presented. Data on the geographical distribution of these species are supplemented.