Water Crayfish Research Articles

Reusable neuronal biosensor for the determination of 3-acetyl pyridine neurotoxin

Development of a reusable neuronal sensor selective to the neurotoxin 3-acetyl pyridine is reported. The antennular structure from fresh water crayfish ( Procamburus clarkii) was used as a sensing element to measure the frequency of action potential responses evoked by chemical stimulation of nerve cells. Reusability of the sensor was studied with emphasis on the reproducibility of action potential responses. Characterization of the novel sensor in terms of selectivity, response time and dose/response relationship is reported. Current status of lifetime extension and future directions of neuronal biosensor research are discussed.

Crayfish in British waters: D. Holdich & I. Reeve, NERC News, 17, 1991, pp 4–7

Crayfish in British waters: D. Holdich & I. Reeve, NERC News, 17, 1991, pp 4–7

Dense granule-containing cells in the wall of the branchio-cardiac veins of a fresh water crayfish (Astacus leptodactylus)

The anatomical structure of oxygen-sensitive receptors in branchio-cardiac veins of a crayfish (Astacus leptodactylus) was studied with fluorescence and electron microscopy. Fluorescent cells were observed in the wall of a restricted part of the branchio-cardiac veins which was electrophysiologically shown to be a chemoreceptor region. Electron microscopy disclosed that they were dense granule-containing cells, and form, together with supporting cells and nerve terminals, complex structures that show gross similarities with arterial chemoreceptor structures in vertebrates.

The effects of temperature and light on particles associated with crayfish visual membrane: a freeze-fracture analysis and electrophysiological study.

Depending on the pre-experimental treatment, densities as well as sizes of particles associated with the visual membranes in the eyes of Procambarus clarkii varied. The highest mean particle density (5268 +/- 969 microns -2) and the smallest mean particle diameter (5.57 +/- 1.35 nm) were found in crayfish which had been kept in the dark for 10 weeks in aerated fresh water of 10 degrees C. Crayfish kept under a 12 h dark/light regime in water of 10 degrees C or 30 degrees C for three weeks displayed particle densities of 1076 +/- 180 and 2899 +/- 249 microns -2, respectively; particle diameters were of the order of 8 nm. Temperature did not alter the shape or the slope of the V/log I curves, but ERG recordings show that maximum spectral sensitivity was shifted from lambda max = 560 nm in cold water crayfish (10 degrees C) to lambda max = 580 nm in crayfish from the 30 degrees C tank, and that the 10 degrees C curve was somewhat narrower than the 30 degrees C curve. It is suggested that the observed shift was caused by a combination of factors, of which the following may have played key roles: (1) The filter effect of screening pigment granules and other intracellular components such as vesicles, vacuoles, endoplasmic reticulum, and mitochondria, some of which were developed to a considerably greater extent in 30 degrees C material; (2) increased membrane fluidity due to higher temperature as well as the presence of photoproducts in the light, and the 'countermeasures' taken by the visual pigment molecules to stabilize the lipid bilayer, e.g. higher density, possible 12-s-cis linkages etc.; and (3) increased regeneration or synthesis of rhodopsin due to higher metabolic activity of retinula cells at higher temperatures. Temperature-induced changes of visual pigments in a variety of organisms are discussed and evidence for the rhodopsin-aggregate model of crayfish visual pigment is presented. It is concluded that the retinula cytoplasm is involved in restoring depleted stocks of photopigment, and that the biological sense of possessing an increase in red sensitivity during the warm summer months lies in the correlation of light penetration in the natural habitat of P. clarkii and optimal exploitation of the habitat.

Evaluation of the nutritive value of some lesser known protein sources in nigerian peasant diets

The nutritive values of some lesser known protein sources in Nigerian peasant diets were evaluated by in vitro enzyme digestion studies and by in vivo studies with rats. Snail (Vivapara quadrata), periwinkle (Littorina littorea), dried crayfish (Palamonetes varians) and locally smoked fresh water fish (Tilapia melanopleura) had a range of digestibility of 57–75 percent with pepsin/trypsin hydrolysis. The digestibility of smoked fresh water fish and crayfish in rats ranged between 91.2 percent and 89.5 percent while that of periwinkle and snail was 80.4 percent and 85.9 percent respectively. Crayfish gave the highest PER (1.8) while the others had values ranging from 0.7 to 1.5. These values were considerably lower than that of whole hen's egg (3.5). These protein samples had high biological values (70.8–81.6) which were, however, still lower than whole hen's egg (92.0) and fairly high NPU values (60.3–73.0). In general, these lesser known protein sources if consumed in adequate quantities would alleviate ...

Crayfish respiration as a function of water oxygenation

Crayfish, Astacus leptodactylus, for several hours breathed water equilibrated either with a hypoxic gas mixture, or air, or oxygen. The hydrostatic pressure in the right epibranchial cavity was recorded and the left epibranchial water sampled from time to time. The higher the water oxygenation, the less the duration of ventilation, the frequency of the scaphognathite beats which ensure water convection, the negativity of the water hydrostatic pressure relative to ambient water pressure, and the respired water flow. The water convection per unit quantity of oxygen consumed decreased by a factor of about 20when the animal passed from hypoxic water at P O 2 of 72 torr to hyperoxic water at P o 2 of 697 torr. Prolonged hyperoxia. up to 100 days, results in a hypercapnic acidosis of the prebranchial blood. pH decreased about 0.2 unit, P CO 2 increased from 2.5 torr to a value of 6 torr, and [HCO - 3] from 6 to a value of 9 meq. L -1. This hypercapnic acidosis remained uncompensated during several weeks exposure to hyperoxia. Observations on the fresh water crayfish, a marine crab, and several species of fish, suggest that in aquatic animals (1) the ventilatory activity depends greatly on the degree of water oxygenation: the higher the water oxygenation, the lower the ventilation; (2) the change of ventilation may be accompanied by a new equilibrium of the blood acid-base status, quite different from that observed in normoxia.

Recording bioelectric action potentials of marine decapod crustacea by remote electrodes: A bioassay procedure for monitoring hydrocarbon pollution

Bioelectric action potentials may be picked up by appropriate electrodes from aquatic animals without their being injured by the introduction of electrodes into, or the affixation of electrodes onto, their bodies for this purpose. The method has been applied successfully to record gross muscle action potentials of crayfish in freshwater and distilled water, where the obliterating effects of the water-surrounded ions of strong electrolytes, as in seawater, are not in play. However, it has been found that, provided the bioelectric generator or experimental animal is active and powerful enough, readable action potentials from such an animal can be picked up by suitable non-polarising electrodes even in seawater. Motor behaviour of mechanically unimpeded animals may be used as a quick and useful way to determine lethal concentrations of named hydrocarbons soluble in water and reciprocally to monitor water pollution by oil and other pollutants.

Partition of ruthenium-106 between the fresh water environment and crayfish.

Partition of ruthenium-106 between the fresh water environment and crayfish.

Haemolymph concentrations of two species of New Zealand freshwater crayfish in relation to the concentration of their external media

1. 1. Both species of New Zealand fresh water crayfish Paranephrops planifrons and P. zealandicus inhabit fresh waters which differ greatly in ionic concentration. 2. 2. Each species maintains an essentially constant haemolymph concentration, independent of the external concentration. 3. 3. Haemolymph concentration is unrelated to sex or body size in either species. 4. 4. The haemolymph concentrations of both species are higher than those of fresh water crayfish of the northern hemisphere. 5. 5. P. zealandicus maintains a significantly higher haemolymph concentration than P. planifrons.

Ionic composition and distribution of myogen proteins in the tail muscle of fresh water crayfish

1. 1. The ionic concentrations in the myogen of the fresh water crayfish tail muscle are, in m-moles/kg, 22 for Na, 65 for Cl, 1·1 for Ca, 9·5 for Mg, 42 for K and 41 for P; the first 3 ions are predominantly extracellular and the others intracellular. 2. 2. Several major myogen proteins have been shown; one of them binds most of the calcium present in the myogen and appears to be different from the calcium-binding proteins described so far in muscle.

Hemolymph DNA concentrations during the molting cycle of the fresh water crayfish, Procambarus clarkii

1. 1. Hemolymph DNA concentrations in the fresh water crayfish, Procambarus clarkii, were found to be 35·9 ± 15·6 μg/ml. 2. 2. Premolt concentrations were significantly higher than intermolt concentrations. 3. 3. It was postulated that the increase in hemolymph DNA concentrations in premolt was the result of cell destruction as a consequence of the molting phenomenon, synthesis of new DNA before or during mitosis, and possibly other factors.

The importance of opsonic factors in the removal of bacteria from the circulation of the crayfish (Parachaeraps bicarinatus).

SummaryData presented in this paper show that the removal of bacteria from the circulation of the fresh water crayfish (Parachaeraps bicarinatus) follows an exponential curve as in vertebrates and is dependent on the presence of opsonic factors in the haemolymph.

Induction of molting in crustacea by an insect molting hormone

Molting in a terrestrial isopod, Armadillidium vulgare, and in a fresh water crayfish, Procambarus sp. can be induced by an insect steroid hormone, ecdysterone. This is the first demonstration of induction of molting in a crustacean by a specific chemical. Arguments are presented that steroid hormones evolved in pre-Cambrian times, more than 600 million years ago.

Two New Species of Plistophora (Microsporida, Nosematidae) in Decapods, with Particular Reference to One in the Blue Crab*

SYNOPSIS. Plistophora cargoi n. sp., found in the muscles of Callinectes sapidus Rathbun, is described. Spores are ellipsoidal and about 3.3 by 5.1 μ when alive. The coiled polar filament is PAS positive. When extruded the filament appears thick throughout most of its length but has a short and fine terminal portion. The sporont gives rise to many (32 to more than 100) spores. P. sp. Sogandares‐Bernal, 1962, found in the muscles of the fresh water crayfish Cambarellus puer Hobbs, is given the name P. sogandaresi n. sp.

Storage of silver chloride electrodes

Bioelectric action potentials may be picked up by appropriate electrodes from aquatic animals without their being injured by the introduction of electrodes into, or the affixation of electrodes onto, their bodies for this purpose. The method has been applied successfully to record gross muscle action potentials of crayfish in freshwater and distilled water, where the obliterating effects of the water-surrounded ions of strong electrolytes, as in seawater, are not in play. However, it has been found that, provided the bioelectric generator or experimental animal is active and powerful enough, readable action potentials from such an animal can be picked up by suitable non-polarising electrodes even in seawater. Motor behaviour of mechanically unimpeded animals may be used as a quick and useful way to determine lethal concentrations of named hydrocarbons soluble in water and reciprocally to monitor water pollution by oil and other pollutants.

THE UPTAKE OF INORGANIC ELECTROLYTES BY THE CRAYFISH

1. Reasons are given for believing that the uptake of Na(+), Cl(-), and NaCl by the crayfish occurs through the gills. 2. A crayfish in fresh water, with a Cl concentration of about 0.2 mEq./l., can) by active Cl absorption, compensate entirely for Cl lost in the urine. 3. The carbonic anhydrase activity of the gills is markedly higher than that of other tissues of the crayfish, but the equivalent CO(2) output of the crayfish is far in excess of the equivalent Cl absorption per unit time and weight and thus fails to warrant the supposition that Cl absorption is of respiratory importance. 4. The carbonic anhydrase activity of the soft integument of the lobster, before and after molting, and of the hypodermis of the hard-cuticled animal is almost identical and of the same order as that of other tissues of the lobster. 5. The concentration of the electrolytes was about 7.5 mEq./l.; i.e., considerably lower than in the blood of the crayfish. Cl(-) can be taken up independently of the complementary cation. Na(+) can be taken up independently of the complementary anion. K(+) and SO(4) (=) are not taken up at all. In pure NaCl, the Na(+) and Cl(-) are absorbed evidently largely together. Ca(++) is absorbed only in newly molted animals and in animals preparing to molt but is not absorbed by hard-cuticled animals not preparing to molt. Ca(++) is taken up independently of Cl(-) in pure CaCl(2). 6. Newly molted animals absorb Ca(++) at a rate exceeding that of the absorption of other absorbable ions (Na(+) and Cl(-)) in the same equivalent concentration. 7. A crayfish utilizes the Ca(++) in fresh water in the calcification of its cuticle. Since the animal does not swallow water, the Ca(++) must enter through the exterior. Reasons are given for believing that, unlike Na(+) and Cl(-), Ca(++) is absorbed directly from the exterior by the integument and does not enter the body through the gills. 8. During molting, only about 4 per cent of the raw ash and 2.3 per cent of the organic material of the old cuticle is resorbed.

Cases of noma

Noma, water crayfish, was first described in 1816 (Baron). This severe suffering affects most children between the ages of 2 and 4. Cases of illness in older age are rare. The etiology of the disease is unknown. Chernyakhovsky considers it to be a maranth necrosis, and Krasin as an anemic necrosis. Oppel says that noma is a traumatic injury to the mucous membrane with the addition of infectious blood clots. Lexer argues that noma begins on the basis of inflammatory changes in the mucous membrane of the mouth. Schmidt finds no reason to isolate noma as an independent form of the disease and considers it to be a simple gangrene of the oral cavity. As the causative agents of the disease, diphtheria sticks, Vincent's sticks, streptotrix, leptotrix, cladotrix and symbiosis of spirochetes with a fusiform bacillus are called.

I. On the extraction of uric acid crystals from the green gland of Astacus fluviatilis

The so-called green glands of the fresh water crayfish lie in the cavity of the head below the front part of the cardiac division of the stomach. The openings of these organs are to be found at the base of each antenna. The organ carefully dissected out of the head of a freshly killed crayfish is seen to consist of two principal parts: an uppermost one which is a transparent and delicate sac-like body filled with a clear fluid, and an underlying portion of a green colour, glandular in appearance, containing granular cells.