Experimental Studies on Hatching Conditions of the Resting Eggs of Marine Cladocerans and Their Seasonal Variation in Onagawa Bay

eladoceransOnagawa Bayseasonal successionresting eggshatchabilit

Euphausiid distribution, abundance and succession in North Atlantic warm-core ring 82B

Author Posting. © The Authors, 2004. This is the author's version of the work. It is posted here by permission of Oxford University Press for personal use, not for redistribution. The definitive version was published in Journal of Plankton Research 27 (2005): 175-188, doi:10.1093/plankt/fbh170.Zooplankton collections were made with a Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS) both day and night in warm-core ring 82B in the North Atlantic Ocean and at night in the Slope Water between March and August 1982. Species succession of euphausiids in 82B was presented during the lifespan of this warm-core ring, aiming at providing basic information on possible response of North Atlantic marine ecosystem to global warming. Species succession of euphausiids (32 species) in this long-lived warm-core ring was investigated. Major physical changes of 82B occurred in March-April by convective mixing and thermostad cooling, in April/May by stratification of the surface waters, and in August by the interaction with Gulf Stream. Substantial changes in species composition were observed that corresponded to these physical changes. Four different patterns were found in temporal change in abundance of warm-water species. There were species that decreased in number from March to August, species that decreased from March to June, but increased in August, species that increased from Match to August, and species that showed no systematic trend. These differences may be attributable to a species tolerance to the thermostad temperature decrease and their vertical distribution. There was also a large change from April to June with ascendance of the transition species, Thysanoessa gregaria. Cold-water species had variable patterns of abundance in 82B and occurred more abundantly in the Slope Water than in the ring. The monthly percentage decrease in the abundance of warm-water species in 82B was high compared with that of cold-water species in cold-core rings as a result of the more rapid changes in the physical structure and the shorter lifetimes of warm-core rings in the Western North Atlantic.This work was partially supported by grants from The Sumitomo Foundation and from The Asahi Glass Foundation given to Y.E. and by grants from the National Science Foundation (OCE8012748, OCE8508350, and OCE879962) to P.H.W. for collection of the samples and from the WHOI Adams Chair and NOAA Grant NA17RJ1223 for support during the manuscript preparation

Temporal changes in euphausiid distribution and abundance in North Atlantic cold-core rings in relation to the surrounding waters

Author Posting. © Elsevier B.V., 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 54 (2007): 181-202, doi:10.1016/j.dsr.2006.10.008.The species composition of euphausiids was investigated in relationship to the hydrographic conditions in the North Atlantic cold-core rings (CCR) and adjacent waters to elucidate species succession in evolving water masses. Using data, dating back to the 1970’s, from as many CCRs as possible and selecting typical cases where no major physical perturbations occurred, a general pattern of euphausiid succession and change in vertical distribution in rings with time was obtained. This pattern was related to the general distribution of euphausiids in the northwestern North Atlantic Ocean, aiming at providing basic information on probable response of North Atlantic marine ecosystem to global warming. Of the 34 euphausiid species identified, 5 were cold-water species, 17 were warm-water species, 6 were wide-ranging warm-water species, 1 was transitional, 4 were cosmopolitan and the remaining was Thysanoessa parva. Among cold-water species, Euphausia krohni and Nematoscelis megalops were dominant in CCRs. E. krohni became rare in rings older than 6 months, whereas N. megalops survived longer, being abundant in some rings of 9 months or older, by staying within its preferred temperature range as the CCR elevated isotherms sank to depths where they are normally found in the Sargasso Sea and because it is an omnivore-carnivore. Among warm-water species, epipelagic species appeared first in rings, corresponding to the physical change occurring most rapidly in the surface layers. Mesopelagic species appeared later. Cold-water species made up 65-85% of the total euphausiid population in number in younger rings (1-5 months old), while warm-water species contributed only 2-7%. Wide-ranging warm-water species made up about up to one fourth of the total in rings 5 and 7 months old. Warm-water species, mainly E. brevis, increased in older rings (9 months old or older) and made up 50% of the total in the oldest ring. The contribution of cold-water species decreased to 14% in older rings. T. parva made up 26-38% of the total in rings 6 months or older. CCR populations can be characterized by high species number, but intermediate evenness between the Slope Water and northern Sargasso Sea. In CCRs, only a limited number of species were dominant even if there were more species present in rings as old as 9-12 months than in the northern Sargasso Sea. In rings older than 9 months, euphausiids showed two peaks in their vertical distribution: a shallow daytime peak at about 400 m and a nighttime peak in the upper 100 m consisting of warm-water species (mainly E. brevis) and a deeper persistent peak at 800 m or deeper consisting of the species N. megalops and T. parva. This shallow peak in CCRs is shallower than that in the surrounding northern Sargasso Sea, and the deep peak is rarely observed in these waters.This work was partially supported by a grant from The Asahi Glass Foundation given to Y.E. and by grants from the National Science Foundation (OCE8012748, OCE8508350, and OCE879962) to P.H.W. for collection of the samples and from the WHOI Adams Chair and NOAA Grant NA17RJ1223 for support during the manuscript preparation

Contributions of heterotrophic and autotrophic prey to the diet of euphausiid, Euphausia pacifica in the coastal waters off northeastern Japan

The contributions of heterotrophic and autotrophic prey to the diet of Euphausia pacifica were examined in coastal waters off northeastern Japan in May and October 1999. The autotrophic contribution was estimated from gut pigment contents, and the heterotrophic contribution from the volume of each taxonomic group in the stomach. Our observations suggest that heterotrophic prey, especially copepods, were more important than autotrophic prey in both seasons. The contributions of heterotrophic prey items in adult E. pacifica ranged from 57-79% in May and from 27-93% of the total ingested carbon in October. The contribution of copepods was largest, ranging from 54-77% in May and from 27-93% in October. We discuss the contribution of athecate ciliates, another possible heterotrophic prey of importance, to the diet of E. pacifica

Biological characteristics of euphausiids preyed upon by Adelie penguin, Pygoscelis adeliae, breeding at Hukuro Cove, Lutzow-Holm bay in 1995/1996

Adelie penguins were used as a biological sampler from late December 1995 to late January 1996 to study biological characteristics of euphausiids in Lutzow-Holm Bay, which is generally covered with fast sea-ice even in summer. Stomach contents and diving behavior of the penguins were examined. Euphausiids accounted for 73% of total wet weight of stomach contents, and fish 27%. Among euphausiids, Euphausia superba occupied 83%, and E. crystallorophias 17%. Females occupied 96% of the total number of E. superba, males only 4%. E. crystallorophias consisted of 73% females, 10% males and 17% juveniles. Adelie penguins might eat nutritionally superior female euphausiids selectively, and/or they could not catch male euphausiids which can swim faster. It was suggested that those individuals which dived deeper ate more euphausiids than fish, and larger E. superba

Life cycle of the suctorian ciliate Ephelota plana attached to the krill Euphausia pacifica

© The Author(s), 2016. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Journal of Experimental Marine Biology and Ecology 486 (2017): 368-372, doi:10.1016/j.jembe.2016.11.003.The hypothesis that life cycle of an epibiotic suctorian ciliate Ephelota plana is adapted to the molt cycle of the krill Euphausia pacifica collected in Saanich Inlet, Canada was evaluated. The infestation prevalence of E. plana and the number of individuals attached increased from postmolt stage to premolt stage of E. pacifica, and concurrently cell growth of E. plana was observed. Budding individuals of E. plana first appeared at early premolt stage and increased to 21% at late premolt stage. Thus the life cycle of E. plana seems to be adapted to the molt cycle of E. pacifica

Morphological, Developmental, and Ecological Characteristics of the Suctorian Ciliate Ephelota gigantea (Ciliophora, Phyllopharyngea, Ephelotidae) Found on Cultured Wakame Seaweed in Northeastern Japan

Wakame seaweed is an important aquatic resource in Iwate Prefecture. However, a suctorian Ephelota gigantea sometimes causes great damage to wakame culture. Since little is known about the biological characteristics of E. gigantea, its detailed morphology and temporal change of biological characteristics during the 2010 culture season were investigated. Scanning electron microscope observations showed that E. gigantea had different striation patterns on the stalk; there was a swell made of cement by which the stalk was attached to wakame firmly; and the buds had cilia arranged in concentric circles about a ring in the center of the ventral side. A suctorian parasite was found to infect E. gigantea, and the infection seemed to have decreased drastically the attached density of E. gigantea on wakame. Cell size of parasite-infected E. gigantea individuals was larger than that of uninfected individuals, probably because larger E. gigantea has larger surface area for attachment of the parasite. Cyst formation or conjugating individuals were not observed

Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release

Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed

Sardine procalcitonin amino-terminal cleavage peptide has a different action from calcitonin and promotes osteoblastic activity in the scales of goldfish

The nucleotide sequence of a sardine preprocalcitonin precursor has been determined from their ultimobranchial glands in the present study. From our analysis of this sequence, we found that sardine procalcitonin was composed of procalcitonin amino-terminal cleavage peptide (N-proCT) (53 amino acids), CT (32 amino acids), and procalcitonin carboxyl-terminal cleavage peptide (C-proCT) (18 amino acids). As compared with C-proCT, N-proCT has been highly conserved among teleosts, reptiles, and birds, which suggests that N-proCT has some bioactivities. Therefore, both sardine N-proCT and sardine CT were synthesized, and their bioactivities for osteoblasts and osteoclasts were examined using our assay system with goldfish scales that consisted of osteoblasts and osteoclasts. As a result, sardine N-proCT (10− 7 M) activated osteoblastic marker enzyme activity, while sardine CT did not change. On the other hand, sardine CT (10− 9 to 10− 7 M) suppressed osteoclastic marker enzyme activity, although sardine N-proCT did not influence enzyme activity. Furthermore, the mRNA expressions of osteoblastic markers such as type 1 collagen and osteocalcin were also promoted by sardine N-proCT (10− 7 M) treatment; however, sardine CT did not influence their expressions. The osteoblastic effects of N-proCT lack agreement. In the present study, we can evaluate exactly the action for osteoblasts because our scale assay system is very sensitive and it is a co-culture system for osteoblasts and osteoclasts with calcified bone matrix. Both CT and N-proCT seem to influence osteoblasts and osteoclasts and promote bone formation by different actions in teleosts. © 2017 Elsevier Inc.Embargo Period 12 month