Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Crustacea”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed1986

Effects of long-term exposure to pentachlorophenol on the free amino acid pool and energy reserves of the freshwater amphipod Gammarus pseudolimnaeus Bousfield (Crustacea, Amphipoda).

The freshwater amphipod Gammarus pseudolimnaeus was exposed for 45 days to pentachlorophenol (PCP). The total concentration of free amino acids (FAA) decreased significantly after 5 days exposure to 0.77 or 1.25 mg PCP/liter. Exposure to PCP had no effect on the relative concentrations of individual amino acids exposed to 0.77, 1.06, or 1.25 mg PCP/liter. Whole body concentrations of glycogen, protein, and caloric content were significantly decreased after 15 days and lipid content after 30 days exposure to 0.77 mg PCP/liter. Since energy reserves and caloric content were not measured on the 5th day of PCP exposure, the relative sensitivity of FAA as a biochemical indicator of toxicant-induced stress cannot be compared directly. However, since reductions in growth and/or energy reserves can significantly influence the fecundity of amphipods, alterations in the FAA pool are indicative of future adverse effects on the organism. The use of alterations in the concentration of FAA is discussed with respect to its application as a biochemical indicator of toxicant exposure in freshwater invertebrates.

Amino Acids↗
PubMed1992

Effect of ambient oxygen concentration upon the acute toxicity of chlorophenols and heavy metals to the groundwater copepod Parastenocaris germanica (Crustacea).

Acute static toxicity experiments have been performed under normoxic and hypoxic conditions. The test animals used were adults of the groundwater-adapted copepod Parastenocaris germanica. The animals originated from a sandy, gravelly phreatic aquifer of the Meuse valley in The Netherlands. Toxicants applied were pentachlorophenol, 3,4-dichlorophenol, zinc, and cadmium. The results were statistically evaluated by a log-logistic model. LC50 and LC5 values with 95% confidence limits were calculated. Response models of application under both oxygen conditions were compared. The influence of ambient oxygen concentration on sensitivity appeared to be very small; only in the case of pentachlorophenol were hypoxic and normoxic models slightly but significantly different. Comparisons with the sensitivity of other organisms are made and the results are discussed against the specific physiological adaptations of the organisms to groundwater conditions.

Animals↗
PubMed1981

Modulatory effects of a single neurons on the activity of the pyloric pattern generator in Crustacea.

The firing of a single neuron (named anterior pyloric modulator: APM) of the esophageal ganglion considerably modifies the pyloric rhythm of the rock lobster. These modifications, characterized by a long delay to onset and a long duration, include increased frequency and amplitude of oscillations of the motor neurons, changes in the efficacy of certain synapses within the network, and voltage-dependent modifications of membrane properties of some motor neurons. APM thus seems to be a true modulatory neuron. The APM-provoked changes resemble changes seen in the whole animal, making this a suitable system for an analysis of modulation on several levels.

Animals↗
PubMed1981

Control of rhythmic behaviour by a hierarchy of linked oscillators in crustacea.

In Homarus, the central pattern generators for the rhythmic motor activities of the gastric teeth and the pyloric chamber are located in the stomatogastric ganglion. It is shown that independent gastric and pyloric oscillators are also contained in higher nervous centres (the commissural ganglia) and provide a phasic rhythmic input to the stomatogastric pattern generators. This demonstrates that rhythmic behaviour can be organized by a hierarchy of linked oscillators each capable of producing the rhythm.

Animals↗
PubMed1992

Purification, biochemical characterization and N-terminal sequence of a serine-protease with chymotrypsic and collagenolytic activities in a tropical shrimp, Penaeus vannamei (Crustacea, Decapoda).

1. Two chymotrypsin variants, with collagenolytic activities, were purified from the hepatopancreas of Penaeus vannamei using radioactive protein as the substrate. 2. These proteases are very close as far as amino acid composition, molecular weight, inhibitors studies and specificity against small synthetic substrates are concerned. 3. N-terminal amino acid sequences of both variants are identical and are very close to other known crustacean serine proteases.

Amino Acid Sequence↗
PubMed1986

A preliminary study of Cu-, Cd- and Zn-binding components in the hepatopancreas of Palaemon elegans (Crustacea: Decapoda).

Three low molecular weight, metal-binding components have been isolated from the hepatopancreas of the shrimp Palaemon elegans. The two larger components P-I (11-15,000) and P-II (4-6000) were associated with large amounts of copper in field-collected and copper-exposed shrimps and with cadmium in shrimps exposed to elevated Cd concentrations. A smaller component, P-III was associated with zinc. The recovery of these components was dependent upon the use of a protease inhibitor and the reducing agent mercaptoethanol (2-M) during the separation procedure. Copper, zinc and cadmium are not evenly distributed between individual tissues of P. elegans, the highest concentrations occurring in the hepatopancreas, gills and eyes.

Animals↗
PubMed2005

Development of a quantitative enzyme-linked immunosorbent assay for vitellin in the mysid Neomysis integer (Crustacea: Mysidacea).

Mysid crustaceans have been put forward by several regulatory bodies as suitable test organisms to screen and test the potential effects of environmental endocrine disruptors. Despite the well-established use of mysid reproductive endpoints such as fecundity, egg development time, and time to first brood release in standard toxicity testing, little information exists on the hormonal regulation of these processes. Control of vitellogenesis is being studied intensively because yolk is an excellent model for studying mechanisms of hormonal control, and vitellogenesis can be chemically disrupted. Yolk protein or vitellin is a major source of nourishment during embryonic development of ovigorous egg-laying invertebrates. The accumulation of vitellin during oocyte development is vital for the production of viable offspring. In this context, we developed a competitive enzyme-linked immunosorbent assay (ELISA) for vitellin of the estuarine mysid Neomysis integer. Mysid vitellin was isolated using gel filtration, and the purified vitellin was used to raise polyclonal antibodies. The ELISA was sensitive within a working range of 4 to 500 ng vitellin/mL. Serial dilutions of whole body homogenates from female N. integer and the vitellin standard showed parallel binding curves, validating the specificity of the ELISA. The intra- and interassay coefficients of variation were 8.2% and 13.8%, respectively. Mysid vitellin concentrations were determined from ovigorous females and eggs at different developmental stages. The availability of a quantitative mysid vitellin ELISA should stimulate further studies on the basic biology of this process in mysids. Furthermore, it could provide a means to better understand and predict chemically induced reproductive effects in mysids.

Animals↗
PubMed2005

Mesopodopsis slabberi (Crustacea: Mysidacea): can it be used in toxicity tests?

Mesopodopsis slabberi is a euryhaline and suprabenthic mysid with a wide geographic distribution and one of the most important mysid species in coastal shallow waters. Nevertheless, no references were found to its uses in ecotoxicological experiments (TOXNET, AQUIRE, ISI Web of Knowledge). This work is part of an ecotoxicological study, representing the first step in establishing a description of this species' tolerance to chemical pollutants typical of estuarine environments. It is possible to assert that acclimation was achieved, for it occurred during a period of time, with a low mortality. Due to the short life cycle of M. slabberi it is strongly believed that 12 days of acclimation is a far too long time, when experiments are to be made after this period. This species is suitable for acclimation in the laboratory, tolerant, and easy of handling. Logistics and materials used to maintain the acclimation system as described are simple and not costly and could easily be used in other laboratories.

Adaptation, Physiological↗