The First Finding of the Actinia Synandwakia hozawai in the Sea of Okhotsk

The finding of the actinia Synandwakia hozawai in the coastal waters of northern Sakhalin (Sea of Okhotsk) suggests a wider range of this species, which was previously only known to inhabit the coastal waters of eastern Japan. Data are presented on the morphology of the S. hozawai specimen from the Sea of Okhotsk and the types of its nematocysts.     

Intertidal Communities of Severnyi Bay (Northern Sakhalin Island)

The paper describes the composition, structure and vertical distribution of intertidal communities in Severnyi Bay (the northern extremity of Sakhalin Island).     

Plastid inheritance in the planktonic raphid pennate diatom Pseudo-nitzschia delicatissima (Bacillariophyceae)

Plastid inheritance was followed during sexual reproduction in the raphid pennate diatom Pseudo-nitzschia delicatissima, using rbcL haplotypes as plastid identification tools. Pseudo-nitzschia species are dioecious and show functional anisogamy with 'male' mating type+(PNd(+)) cells and 'female' PNd(-) cells. Vegetative cells possess two plastids. In P. delicatissima, meiosis results in two gametes that both contribute two plastids to the zygote. The latter initially contains four plastids, but during auxospore development two of these four seem to disappear, and the initial cell emerging from the auxospore appears to contain only two. Here we assessed if the plastids are inherited strictly unipaternally, strictly biparentally, or randomly. We traced the source of the plastids in the F(1) generation by using PNd(+) and PNd(-) parental strains with different rbcL genotypes, here denoted AA (homoplastidial, with two plastids of rbcL haplotype A) and BB (homoplastidial; two plastids of haplotype B). Results showed that 16 out of 96 strains raised each from single F(1) cells had retained two paternal (PNd(+)) plastids, 20 had two maternal (PNd(-)) plastids and the remaining 60 had one maternal and one paternal plastid. This pattern is in accordance with the hypothesis that either two of the four plastids are eliminated during auxospore formation, or that all plastids are retained in the auxospore and segregate in pairs joining at random during the first mitotic division of the initial cell. Heteroplastidic F(1)-strains retained the AB genotype throughout the vegetative phase of their life cycle. The finding that 60 out of 96 F(1) strains were heteroplastidial contrasts with an absence of such genotypes in our strains raised from single cells sampled in the Gulf of Naples.     

First Records of Dinoflagellates Alexandrium margalefi Balech, 1994 and A. tamutum Montresor, Beran et John, 2004 in the Seas of the Russian Far East

New records of two Alexandrium species are reported for the Russian seas. A. margalefi Balech was found in Peter the Great Bay (Sea of Japan), and A. tamutum Montresor, Beran et John was found in Aniva and Sakhalinskii bays (Sea of Okhotsk). Both species were observed in summer in small numbers at water temperatures of 22– 24°C and 8.6–11°C, respectively. Data on the morphology and distribution of the species is provided.Original Russian Text Copyright © 2005 by Biologiya Morya, Selina, Morozova.     

Morphological peculiarities of <Emphasis Type="Italic">Fragilidium mexicanum</Emphasis> Balech, 1988 (Dinophyta) from the Far-Eastern Seas of Russia

The vegetative cells of Fragilidium mexicanum Balech are recorded from the Far Eastern seas of Russia (Sea of Japan and Sea of Okhotsk) for the first time. Morphological study of both cultured and wild cells of F. mexicanum showed that the shape of the cell and the first (1″) and second (2″) precingular plates, the direction of the slot in plate 1″, and the shape of the anterior sulcul plate (S.a.) vary greatly. These features bear similarity to those of F. mexicanum, as well as a closely related species, F. subglobosum. The most conservative characters distinguishing the two species are the shape and size of the first and seventh postcingular plates and the shape of the posterior sulcal plate.     

Toxic Pseudo-nitzschia multistriata (Bacillariophyceae) from the Gulf of Naples: morphology,toxin analysis and phylogenetic relationships with other Pseudo-nitzschia species

The genus Pseudo-nitzschia includes several species capable of producing domoic acid, the causative agent of Amnesic Shellfish Poisoning. Some of these species have been recorded frequently in the Gulf of Naples. For one of the species, P. multistriata, which has been recurrently found in our sampling area since 1995, this is the first report for European waters. Here we provide further details on the fine structure of this species. Pseudo-nitzschia multistriata was the only one found to produce domoic acid among all the Pseudo-nitzschia species from the Gulf of Naples, and this finding raises the number of potentially toxic species in this genus to nine. Phylogenetic relationships among several Pseudo-nitzschia species were assessed using the hypervariable domains (D1–D3) of the large subunit (LSU) rDNA. The match between the phylogeny obtained and important taxonomic characters used in this genus are discussed. Results show that P. multistriata clusters with wider species lacking a central larger interspace in the raphe. Close genetic relationships were determined between P. fraudulenta and P. subfraudulenta, and between P. pungens and P. multiseries. Genetic differences among these pairs of species are comparable to those among isolates of P. pseudodelicatissima from the Gulf of Naples, indicating high intraspecific genetic diversity of Pseudo-nitzschia species in the relatively conserved LSU region. This could explain the problematic results obtained when testing a match between species-specific Pseudo-nitzschia LSU probes and our sequences.     

First Record of Ulca bolini (Pisces: Hemitripteridae) in the Southeastern Part of the Sea of Okhotsk

This paper presents data on the first record of Ulca bolini. The fish was caught at a depth of 280–300 m in the Sea of Okhotsk off the Kuril Islands (Prostor Bay, Iturup Island). It was 60 cm in fork length (FL) and 7 kg in weight.     

The ocellus of the cockroach,Periplaneta americana (Blattariae)

Summary The ocelli of Periplaneta americana were studied by light and electron microscopy. The view that the ocellus of the cockroach represents a degenerated structure can no longer be supported. All organelles necessary for function are present.The club-shaped retinular cells lie homogeneously distributed in the cupule of the ocellus. Rhabdoms are seen as sickle-, y-, x-or star-shaped structures with up to six cells in formation. Cells were found which had formed two rhabdomeres.The mass of cell organelles lies in the cytoplasm between the cell nucleus and the rhabdom. Smooth endoplasmic reticulum is wound into a spindle formation of considerable size at the origin of the axon in some cells. A cylindrical body in which 10–40 microtubules are packed, as yet unknown in insect retinular cells, is described.The receptory area of the ocellus terminates in a tapetum which contains granules, soluble in alcohol. The axon bundles of the retinular cells run through the tapetum and immediately thereafter make synaptic contact with dendrites of the ocellar nerve cells, while still within the ocellus.The authors are indebted to Mrs. Margaret Weber-Wood for her linguistic assistance     

Thermoregulatory anatomy of pronghorn (Antilocapra americana)

We have found that pronghorn (Antilocapra americana) use external heat exchange with the environment and internal heat exchange between the carotid artery rete and cavernous venous sinus blood to regulate body temperature. Now we have investigated the relationship between the histological structure of the skin, cephalic veins, and carotid rete–cavernous sinus system and the physiological mechanisms pronghorn use, and whether their thermoregulatory anatomy has adaptive advantages. We harvested tissue samples of skin, three veins (i.e., angularis oculi vein, dorsal nasal vein, and facial vein), and the carotid rete–cavernous sinus system from four pronghorn, two culled in summer and two in winter, and examined each histologically. The three veins had the typical structure of veins with large lumina and thin walls. The carotid rete consisted of small (0.1–0.5 mm) arterioles with a density of ~10/mm², intertwined with veins (~2/mm²), enclosed within the cavernous sinus; a structure ideal for heat exchange. We concluded that the main function of the dorsal nasal and facial veins is to return cold blood to the body to effect whole body cooling. The cavernous sinus is supplied with warm blood by the palatine veins in winter and cold blood by the deep facial veins in summer, an arrangement different to that in other ungulates, such as sheep, in which the angularis oculi vein supplies the cavernous sinus. Pronghorn skin is richly supplied with blood vessels that facilitate convective heat loss in summer. In winter, the number of coarse and fine hairs per square millimeter increases more than in European deer to form a thick pelage that minimizes heat loss. In summer, the pelage is shed because hair follicles involute. Unlike in other ungulates, pronghorn skin has little adipose tissue. The number of apocrine glands increases in winter rather than in summer. We concluded that the glands have a reproductive/social function rather than a thermoregulatory one. In summary, our study shows that the thermoregulatory anatomy is consistent with our physiological data and has adaptive advantages that help explain the survival of pronghorn in an arid habitat characterized by extreme temperature variation and sparse vegetation.     

Auxospore formation inLicmophora (Bacillariophyta)

InLicmophora gracilis var.anglica two auxospores are produced per pair of mother-cells, through the allogamic fusion of migratory and stationary gametes. Both active gametes are produced from the same mother-cell and hence both zygotes are formed in the other mother-cell. Pairing can occur between two stalked cells, or between a stalked cell and a detached cell; in the latter case the migratory gametes derive from the detached cell. The auxospores expand parallel to one another and to the apical axis of the donor mother-cell. Behavioural anisogamy of this kind, which may be termed thecis-type, seems to be characteristic of most araphid pennates and contrasts with thetrans-type exhibited byCymbella, Gomphonema and some other raphid taxa, where each mother-cell produces one migratory and one stationary gamete.     

The Morphology of Cysts and Motile Cells of Gyrodinium instriatum (Dinophyta), a Species New to the Seas of Russia

The germination of dinoflagellate cysts isolated from the surface sediment from Peter the Great Bay (Sea of Japan) provided motile cells of Gyrodinium instriatum. This is the first report on this species for the seas of Russia. The morphology of both collected and germinated cysts and motile cells is described, and data on the ecology and distribution of the species are provided.     

Feeding,egg production,and egg hatching success of the copepods Acartia tonsa and Temora longicornis on diets of the toxic diatom Pseudo-nitzschia multiseries and the non-toxic diatom Pseudo-nitzschia pungens

In 1987, there was an episode of shellfish poisoning in Canada with human fatalities caused by the diatom Pseudo-nitzschia multiseries, which produced the toxin domoic acid. In order to examine whether domoic acid in this diatom serves as a grazing deterrent for copepods, we compared feeding rates, egg production rates, egg hatching success and mortality of the calanoid copepods Acartia tonsa and Temora longicornis feeding on unialgal diets of the toxic diatom P. multiseries and the similarly-sized non-toxic diatom Pseudo-nitzschia pungens. Copepods were collected in summers of 1994, 1995 and 1996 from Shediac Bay, New Brunswick, Canada, near Prince Edward Island, the site of the 1987 episode of domoic acid shellfish poisoning. Rates of ingestion of the toxic versus the non-toxic diatom by A. tonsa and T. longicornis were similar, with only one significantly different pair of values obtained in 1994, for which A. tonsa had a higher mean rate of ingestion of the toxic than the non-toxic diatom. Thus, domoic acid did not appear to retard grazing. Analyses of copepods with high performance liquid chromatography (HPLC) revealed that copepods accumulated domoic acid when feeding on P. multiseries. Egg production rates of copepods when feeding on P. multiseries and P. pungens were very low, ranging from 0 to 2.79 eggs female^–1 d^–1. There did not appear to be differential egg production or egg hatching success on diets of the toxic and non-toxic diatoms. Mortality of females on the toxic diet was low, ranging from 0 to 20%, with a mean of 13%, and there was no apparent difference between mortality of copepods feeding on toxic versus non-toxic diatoms. Egg hatching success on both diets, although based on few eggs, ranged between 22% and 76%, with a mean percentage hatching of 45%. Diets of the non-toxic diatom plus natural seawater assemblages supplemented with dissolved domoic acid, revealed similar rates and percentages when compared to previous experiments. In summary, none of the variables measured indicated adverse effects on copepods feeding on the toxic compared to the non-toxic diatom.     

Genus Alexandrium Halim, 1960 (Dinophyta) from the Pacific coast of Russia: Species composition, distribution, and dynamics

At present 8 species of Alexandrium genus have been found in seas and adjacent waters of Russia: A. acatenella, A. catenella, A. insuetum, A. margalefii, A. ostenfeldii, A. pseudogonyaulax, A. tamarense, and A. tamutum. The distribution and population density of Alexandrium species varied within the surveyed area of the Pacific: in the Sea of Japan and Sea of Okhotsk, 7 species were recorded; 3 species were recorded along the Pacific coast of Kamchatka; and 2 species were found in the Bering Sea. A. tamarense was the most widespread and abundant species over the area. A. insuetum was recorded only in the Sea of Japan, and A. catenella, in the Sea of Okhotsk (Terpeniya Bay). The highest concentration of Alexandrium spp. (2–7 million cells/l) was recorded along the Pacific coast of Kamchatka and in the Bering Sea; in the Sea of Okhotsk, a rather high concentration (51000 cells/l) was registered in Aniva Bay; in the Sea of Japan, the highest concentration was recorded in Peter the Great Bay (6000 cells/l). The distribution of cysts (spores) in surface sediments of the Pacific coast of Russia as a whole reflected the pattern of distribution of vegetative cells of Alexandrium. Cysts of Alexandrium cf. tamarense prevailed all over the area, with the maximum concentration along the Pacific coast of Kamchatka. Beyond that type of cysts, insignificant numbers of cysts of Alexandrium cf. minutum were recorded in Peter the Great Bay and Aniva Bay. Analysis of seasonal dynamics revealed that cells of Alexandrium spp. occurred in Peter the Great Bay from June up to September, and along the Pacific coast of Kamchatka from April to October. In the first region, the maximum density was recorded in August; it was provided by A. pseudogonyaulax (59% of the total density of Alexandrium), A. tamarense (35%), and A. insuetum (6%). In the second region, it was recorded in July, thanks only to development of A. tamarense.     

Phylogeny of the Bacillariaceae with emphasis on the genus Pseudo-nitzschia (Bacillariophyceae) based on partial LSU rDNA

In order to elucidate the phylogeny and evolutionary history of the Bacillariaceae we conducted a phylogenetic analysis of 42 species (sequences were determined from more than two strains of many of the Pseudo-nitzschia species) based on the first 872 base pairs of nuclear-encoded large subunit (LSU) rDNA, which include some of the most variable domains. Four araphid genera were used as the outgroup in maximum likelihood, parsimony and distance analyses. The phylogenetic inferences revealed the Bacillariaceae as monophyletic (bootstrap support ≥90%). A clade comprising Pseudo-nitzschia, Fragilariopsis and Nitzschia americana (clade A) was supported by high bootstrap values (≥94%) and agreed with the morphological features revealed by electron microscopy. Data for 29 taxa indicate a subdivision of clade A, one clade comprising Pseudo-nitzschia species, a second clade consisting of Pseudo-nitzschia species and Nitzschia americana, and a third clade comprising Fragilariopsis species. Pseudo-nitzschia as presently defined is paraphyletic and emendation of the genus is probably needed. The analyses suggested that Nitzschia is not monophyletic, as expected from the great morphological diversity within the genus. A cluster characterized by possession of detailed ornamentation on the frustule is indicated. Eighteen taxa (16 within the Bacillariaceae) were tested for production of domoic acid, a neurotoxic amino acid. Only P. australis, P. multiseries and P. seriata produced domoic acid, and these clustered together in all analyses. Since Nitzschia navis-varingica also produces domoic acid, but is distantly related to the cluster comprising the Pseudo-nitzschia domoic acid producers, it is most parsimonious to suggest that the ability of species in the Bacillariaceae to produce domoic acid has evolved at least twice.     

Somatic embryogenesis in avocado (Persea americana Mill.) in vitro

A tissue culture procedure was developed for the regeneration of somatic embryos from callus cultures of the avocado,Persea americana. Immature zygotic embryos, 0.6–0.8 mm long, were used as original explants. Addition of 0.1 mg/l picloram (4-amino-3,5,6-trichloropicolinic acid) to culture medium appeared critical for callus initiation. Development of somatic embryos was accomplished in picloram concentrations of 0.01 to 0.1 ml/l. A few well developed embryos produced green shoots. Attempts to induce a higher incidence of germination were unsuccessful.Investigation was supported by funds from the California Avocado Society, the Instituto Nacional de Investigaciones Agrarias, the Fundation Juan March, the Chancellor's Patent Fund, and the Southern California Phi Beta Kappa Alumni Association. Authors thank H. Quick for the photography and J. Lippert for the illustrations.     

Parasitism and decreased response to sex pheromones in malePeriplaneta americana (Dictyoptera: Blattidae)

Parasites are known to alter the behavior of their hosts, but little is known about their effects on responses to sexual stimuli. Periplaneta americanainfected with the acanthocephalan Moniliformis moniliformiswere compared to uninfected animals in their behavioral and electroantennogram responses to a synthetic P. americanapheromone component, periplanone-B, and a pheromone mimic, bornyl acetate. In a t-maze there was no significant difference between infected animals' responses to periplanone-B and a random binomial distribution; the responses of uninfected animals were significantly nonrandom. The electroan-tennogram responses of infected and uninfected animals to bornyl acetate or periplanone-B did not differ significantly, however, indicating that the alteration probably does not occur at the peripheral level but at a central nervous system level.