Features of Carotenoid Profile in Black Sea Bivalve Mollusks

Journal of Evolutionary Biochemistry and Physiology - Studies of the composition of carotenoids in the Black Sea bivalve mollusks Mytilus galoprovincialis, Crassostrea gigas, Anadara kagoshimensis,...     

Salinity Adaptations and Bathymetric Distribution of Bivalve Mollusks Portlandia arcticaand Nuculana pernula in the White Sea

We examined changes in the oxygen consumption rate, the number of active animals, rate of losses of salts, and the level of cell hydration under conditions of decreased salinity in the mollusks Portlandia arctica(Gray) and Nuculana pernula(O.F. Müller), inhabiting the White Sea in the deepest depths under high salinity (about 30) and negative temperatures of –1.3 to –1.4°C throughout the year. It has been shown that the mollusks demonstrate a relatively great tolerance of desalination at the organism level and a capability to regulate cell volume under decreased salinity of the environment. We concluded that the depletion of fauna of the White Sea in the deepest depths is not connected with the tolerance level of deep-sea animals to salinity fluctuations, but rather is due to environmental conditions (liquid silts and negative temperatures).     

Marine Vibrios Associated with Bacillary Necrosis, a Disease of Larval and Juvenile Bivalve Mollusks

The etiological agents of bacillary necrosis, a disease of larval and juvenile bivalve mollusks, are designated members of the genus Vibrio.     

Morphology of the Bivalve Mollusks Crenomytilus grayanus and Mytilus coruscus in Relation to Their Spatial Distribution in the Upper Subtidal Zone

The morphology of the shell and byssus threads was studied in two closely related mussel species Crenomytilus grayanus and Mytilus coruscus. The two species differ significantly from each other in the shell shape and in the degrees of development and deformation of byssus threads. These differences, in turn, determine (either directly or indirectly) the differences in strength of the byssal attachment and are discussed in terms of their functional morphology with respect to the spatial distribution of the mussels in marine coastal zones.     

<Emphasis Type="Italic">Pearl</Emphasis>, a Novel Family of Putative Transposable Elements in Bivalve Mollusks

Abstract While genome sequencing projects have discovered numerous types of transposable elements in diverse eukaryotes, there are many taxa of ecological and evolutionary significance that have received little attention, such as the molluscan class Bivalvia. Examination of a 0.7-MB genomic sequence database from the cupped oyster Crassostrea virginica revealed the presence of a common interspersed element, CvA. CvA possesses subterminal inverted repeats, a tandemly repeated core element, a tetranucleotide microsatellite region, and the ability to form stable secondary structures. Three other less abundant repetitive elements with a similar structure but little sequence similarity were also found in C. virginica. Ana-1, a repetitive element with similar features, was discovered in the blood ark Anadara trapezia by probing a genomic library with a dimeric repeat element contained in intron 2 of a minor globin gene in that species. All of these elements are flanked by the dinucleotide AA, a putative target-site duplication. They exhibit structural similarity to the sea urchin Tsp family and Drosophila SGM insertion sequences; in addition, they possess regions of sequence similarity to satellite DNA from several bivalve species. We suggest that the Crassostrea repetitive elements and Ana-1 are members of a new MITE-like family of nonautonomous transposable elements, named pearl. Pearl is the first putative nonautonomous DNA transposon to be identified in the phylum Mollusca.     

Taxonomy and Diversity of Freshwater Bivalve Mollusks (Bivalvia) of China (Based on Analysis of the Catalog by He and Zhuang, 2013)

The diversity of freshwater Bivalvia in China was assessed on the basis of critical analysis of original and published data on the fauna, morphology, taxonomy, and molecular genetics of this group. The taxonomic composition of the following genera has been considered in depth: Anemina Haas 1969, Cristaria Schumacher 1817, Sinanodonta Modell 1944, Lanceolaria Conrad 1853, Middendorffinaia Moskvicheva et Starobogatov 1973, Nodularia Conrad 1853, Unio Philipsson in Retzius 1788, Inversidens Haas 1911, Sphaerium Scopoli 1777, Pisidium Pfeiffer 1821, Odhneripisidium Kuiper 1962, and Euglesa Leach in Jenyns 1832 = Cyclocalyx Dall 1905. No fewer than 170 bivalve species were demonstrated to occur in the freshwater areas of China. Underestimation of the Bivalvia species abundance in previous studies, including the latest catalog of the Chinese Bivalvia (He and Zhuang, 2013), may be accounted for mostly by inadequate use of morphological methods and limited faunistic data, as well as a little number of taxonomic works supported by molecular data. Both the generic and specific compositions of the Chinese Unioniformes and Luciniformes have been significantly extended and updated. Based on a complex study of conchological characters, the following synonymy was established for three species: Sinanodonta qingyuani He et Zhuang 2013 = S. woodiana (Lea 1834) syn. n., Lanceolaria yueyingae He et Zhuang 2013 = L. eucylindrica C. Lin 1962 syn. n., Acuticosta jianghanensis He et Zhuang 2013 = Nodularia douglasiae (Griffith et Pidgeon 1833) syn. n.     

Leaf Fatty-Acid Content in Relation to Hardening and Chilling Injury

At 25?C the leaves of chill-resistant plants did not containmore unsaturated fatty acid than chill-sensitive plants. Furthermorewhen chill-sensitive plants were hardened at 12?C there wasno increase in the amount of unsaturated fatty acid or totalweight of fatty acid in the leaf. These results cast furtherdoubt on the importance of the degree of unsaturation of thefatty acids in determining the critical temperature at whichthe phase change occurs in the lipid portion of the membrane. When chill-sensitive plants are chilled (5?C) the percentageof linolenic acid and total weight of fatty acid decreases rapidlybut remains constant in chill-resistant species. Hardening mayreduce the degree of damage to the plant by slowing down detrimentalprocesses such as the decrease in the percentage of linolenicacid which occurs on chilling.     

Structural Compositions of Pelagic Communities in the River Warnow and their Changes

The phytoplankton and heterotrophic microbial communities from the Oberwarnow and Unterwarnow were analyzed from November 1987 to May 1988. The production potential of the microorganisms was quantified in laboratory experiments. On the average, phytoplankton accounted for 73 % of the total biomass in the Oberwarnow and 59 % in the Unterwarnow. The corresponding figures for bacterial biomass were 24 % and 33 %, respectively. If the nutrient supply is unlimited and phytoplankton biomass predominates, the development of primary producers in eutrophic to polytrophic waters is not regulated by metazooplankton. Top-down regulation is possible only if prevailing conditions limit the growth of the dominant phytoplankton species.     

Fatty Acid Compositions of Rice Lipid and their Changes during Storage

Fatty acid composition of lipids from polished rice was studied by gas chromatography on the separated fractions, fat-by-hydrolysis, neutral fat, free fatty acid and phospholipid. After six months storage, fatty acids were released from neutral fat in the same proportion as they were combined in the neutral fat.     

Functional Significance and Weight Properties of the Shell in Some Mollusks

Functional, morphological, and weight properties of the shell are discussed for many gastropods and bivalves living under various conditions.__________Translated from Izvestiya Akademii Nauk, Seriya Biologicheskaya, No. 4, 2005, pp. 479–505.Original Russian Text Copyright © 2005 by Alyakrinskaya.     

Food transfer between chimpanzee mothers and their infants

Food sharing among chimpanzees is known to occur particularly between mothers and infants and has been proposed to be a form of parental investment. To explore the function of food sharing, it is essential to know how and what is transferred to an infant from its mother. We investigated details of interactions leading to food transfer and characteristics of items transferred in three mother–infant (<2 years old) pairs in captivity. We gave one kind of fruit or vegetable to a mother and observed interactions between the mother and her infant. Tested items consisted of familiar and novel foods for infants. Two patterns of direct food transfer, so-called sharing, were recognized: (1) infant-initiated sharing in which the infant attempted to take food and the mother did not resist, and (2) mother-initiated sharing in which the mother spontaneously offered a part of her food without the infants attempts to take it. There were clear differences in the characteristics of items transferred in these two patterns of sharing. In infant-initiated sharing, palatable parts of the same food that the mother was eating were transferred. In contrast, in mother-initiated sharing, only unpalatable parts of food in the mothers possession were transferred. Mothers seemed to be reluctant to give nutritious foods to their infants during this study period. Infants, rather than mothers, were responsible for initiating and experiencing the diversity of adult foods in chimpanzees.Electronic Supplementary Material Supplementary material is available in the online version of this article at     

Food restriction induced thyroid changes and their reversal after refeeding in female rats and their pups

In the present study, two groups of pregnant female rats were submitted to food restriction (24 h fast versus 24 h diet intake) from the 14th day of pregnancy until either the 14th day (group B) or the 4th day after parturition (group C). All pups and their mothers were sacrificed on day 14 after delivery. The body weight of the 14-day-old pups (group B) was 46% less than the controls (group A). Free thyroxine and free triiodothyronine levels in the plasma were reduced by 44 and 16% in pups and by 20 and 36% in their mothers, respectively. These reductions were correlated with a decrease in thyroid iodine content of the pups (-50%) and their mothers (-24%). Radioiodine uptake (131I) by the thyroid gland of pups was significantly increased by 27%. Plasma TSH levels were decreased by 38% in pups and by 44% in dams. Morphological changes in thyroid glands were observed in energy restricted dams and in their pups. Some of follicles in pups were empty. Moroever in dams, we noted the presence of peripheral resorbed vacuoles, sign of thyroid hyperactivity. After a refeeding (group C) period of ten days, total recovery occurred in plasma thyroid hormone levels (FT4 and FT3) and in thyroid iodine contents of pups in spite of a partial recovery of body weights and plasma TSH levels. In dams, a partial recovery occurred in plasma thyroid hormone levels in spite of total recovery in thyroid iodine contents, while plasma TSH levels exceeded control values. A significant amelioration in thyroid histological aspects was observed in pups and their dams.     

转基因作物及其食品的安全性

对转基因食品存在的潜在危害进行了全面分析,概述了对转基因食品的安全性评价的主要方面及世界各国对转基因食品安全的态度和对转基因食品的管理模式。     

Bivalve suspension-feeding dynamics and benthic-pelagic coupling in an eutrophicated marine bay

The open exposed Laholm Bay in the Kattegat is eutrophicated through riverine input, mainly of N. The benthic macrofauna down to 10 m depth (60 km²) is dominated by the suspension-feeding bivalves Cardium edule and Mya arenaria. To estimate the seasonal and annual consumption of seston by the suspension-feeders in Laholm Bay, we carried out three sets of observations. (1) The abundance and biomass of the macrofauna in this depth interval were assessed along eight transects. (2) The secondary production of the two bivalves was estimated over a 10-month period in two sampling squares. (3) The filtration rate of C. edule was determined in natural seawater in laboratory experiments during different seasons. The bivalves can in theory filter all of the water volume down to 10 m in 3 days and, thus, make a significant impact on the phytoplankton concentration. In our study, however, they filtered only approximately half of their potential feeding capacity, perhaps because food availability was low due to low turnover close to the bottom or due to physical disturbance. The majority of the phytoplankton is exported from the bay. Bivalve abundance, biomass, production and growth rate were moderate and generally lower than in adjacent areas to the north. In autumn, the bivalves consumed >90% of the seston in comparison with net-zooplankton consumption. An energy-flow diagram for the bivalves is presented including estimates of bivalve N excretion and biodeposition.     

Experimental Assessment of the Effects of Temperature and Food Availability on Particle Mixing by the Bivalve Abra alba Using New Image Analysis Techniques

The effects of temperature and food addition on particle mixing in the deposit-feeding bivalve Abra alba were assessed using an experimental approach allowing for the tracking of individual fluorescent particle (luminophore) displacements. This allowed for the computations of vertical profiles of a set of parameters describing particle mixing. The frequency of luminophore displacements (jumps) was assessed through the measurement of both waiting times (i.e., the time lapses between two consecutive jumps of the same luminophore) and normalized numbers of jumps (i.e., the numbers of jumps detected in a given area divided by the number of luminophores in this area). Jump characteristics included the direction, duration and length of each jump. Particle tracking biodiffusion coefficients (D_b) were also computed. Data originated from 32 experiments carried out under 4 combinations of 2 temperature (Te) and 2 food addition (Fo) levels. For each of these treatments, parameters were computed for 5 experimental durations (Ed). The effects of Se, Fo and Ed were assessed using PERmutational Multivariate ANalyses Of VAriance (PERMANOVAs) carried out on vertical depth profiles of each particle mixing parameter. Inversed waiting times significantly decreased with Ed whereas the normalized number of jumps did not, thereby suggesting that it constitutes a better proxy of jump frequency when assessing particle mixing based on the measure of individual particle displacements. Particle mixing was low during autumn temperature experiments and not affected by Fo, which was attributed to the dominant effect of low temperature. Conversely, particle mixing was high during summer temperature experiments and transitory inhibited by food addition. This last result is coherent with the functional responses (both in terms of activity and particle mixing) already measured for individual of the closely related clam A. ovata originating from temperate populations. It also partly resulted from a transitory switch between deposit- and suspension-feeding caused by the high concentration of suspended particulate organic matter immediately following food addition.     

Intracellular Symbiosis and Energetic Role of Bacteria in Gill Epithelium of Freshwater Mollusks and Fishes

Penetration of bacteria by endocytosis into gill epithelial cells has been revealed in animals of different evolutionary levels (freshwater mollusks and fishes). These data confirm the leading role of endosymbiosis in the origin of eukaryotes from prokaryotes and in the evolution of animal life.     

Spatiotemporal Variation in Shallow-Water Freshwater Fish Distribution and Abundance in a Large Subtropical Coastal Lagoon

Patos Lagoon is located off the southern Brazilian coast and represents one of the largest coastal lagoons in the world. We estimated hydrological and physicochemical conditions associated with spatial variation in the abundance and diversity of freshwater fishes along the lagoon, and inter-annual variability in abundances of freshwater fishes occurring in its estuarine zone. During our study, the region experienced two periods of average rainfall and two periods with above-average rainfall. The characids Astyanax eigenmaniorum and Oligosarcus jenynsii and the siluriform Parapimelodus nigribarbis were the most abundant freshwater fishes in the estuary during wet periods when water levels were higher and salinity was lower. Increases in abundance of these species in the estuarine area, all of which members of primary-division freshwater families, apparently were associated with pulses of reproduction and passive transport from freshwater habitats located near middle and upper lagoon reaches. Abundance of species from secondary freshwater families, such as poeciliids and cichlids, were less correlated with hydrological conditions, and their patterns of occurrence in the estuary suggest active migration from nearby freshwater habitats draining into this area. Findings indicate that freshwater discharge in the basin and expansion/retraction of freshwaters in the middle-upper lagoon determined patterns of freshwater fish abundance and species richness in the estuarine zone.