Crayfish

Erebs, m. cancer crayfish grain, hard particle (in clay, etc.) knot (in ore, etc.) wart canker crab crustacean. 

Losses of crustaceans, crayfish, mayflies, and some algal and zooplankton species occur as the pH approaches 6, but most fish are largely unaffected. In the range from pH 6 to 5, major population losses are experienced. Major changes of plankton species happen while progressive loss of fish species is hkely. Fish decline is often reflected in a failure of the species to reproduce... 

Figure 4. Effects of dihydro-brevetoxin B (H2BVTX-B) on Na currents in crayfish axon under voltage-clamp. (A) A family of Na currents in control solution each trace shows the current kinetics responding to a step depolarization (ranging from -90 to -I-100 mV in 10 mV increments). Incomplete inactivation at large depolarizations is normal in this preparation. (B) Na currents after internal perfusion with H2BVTX-B (1.2 a M). inactivation is slower and less complete than in the control, and the current amplitudes are reduced. (C) A plot of current amplitudes at their peak value (Ip o, o) and at steady-state (I A, A for long depolarizations) shows that toxin-mOdified channels (filled symbols) activate at more negative membrane potentials and correspond to a reduced peak Na conductance of the axon (Reproduced with permission from Ref. 31. Copyright 1984 American Society for Pharmacology and Experimental Therapeutics).

Electrophysiological protocols utilizing crayfish and squid giant axons revealed that external application of brevetoxin caused a concentration-dependent... 

In squid giant axons, PbTx causes a depolarization of the plasma membrane, repetitive discharges followed by depression of action potentials, and a complete blockade of excitability. This action is antagonized by TTX (83,84). PbTx depolarizes nerve terminals and induces neurotransmitter release (85,86) it depolarizes skeletal muscle cells (87) and increases the frequency of action potentials in crayfish nerve cord (88). PbTx also produces a contraction of the guinea pig ileum (89). All these effects are prevented by TTX. 

Suberitine, a small protein from the sponge Suberites domcuncula, has a variety of actions. It is not very toxic but causes hemolysis in human erythrocytes, flaccid paralysis in crabs and depolarization of squid axon and abdominal nerve of crayfish. A variety of extracts from Porifera have been shown to be toxic to fish and generally have cytotoxic and hemolytic actions (62,63). As discussed previously, a variety of sponges exude substances that are toxic to fish. 

The dietary importance of benthic invertebrates to many species of fish, birds, and mammals (Vander Zanden and Vadeboncoenr 2002) signifies their importance in the trophic transfer of MeHg and their potential relevance as biological indicators. Some benthic invertebrates (e g., oysters, clams, shrimp, crabs, and crayfish) are consumed by humans, providing a direct pathway for exposure to MeHg. In the United States, shellfish rank below fish as a source of dietary MeHg in the human population (NRC 2000 Schober et al. 2003). 

Peimuto CM, Lane OP, Evers DC, Taylor RJ, Loukmas J. 2005. Mercury in the northern crayfish Orconectes virilis (Hagen), in New England, USA. Ecotoxicology 14 149-162. 

Bierkens J, Vangenechten JHD, Van Puymbroeck S, et al. 1986. Effect of Al and humic acids on the 241Am adsorption on the exoskeleton of the crayfish Astacus leptodactylus eschscholtz. Health Phys 50(2) 277-280. 

Sugawara, A., Nishimura, T., Yamamoto, Y., Inoue, H., Nagasawa, H. and Kato, T. (2006) Self-organization of oriented calcium carbonate/polymer composites effects of a matrix peptide isolated from the exoskeleton of a crayfish. Angewandte Chemie International Edition, 45, 2876-2879. 

Faria M, Huertas D, SotoDX, Grimalt JO, Catalan J, Riva MC, Barata C (2010) Contaminant accumulation and multi-biomarker responses in field collected zebra mussels (Dreissena polymorpha) and crayfish (Procambarus clarkii), to evaluate toxicological effects of industrial hazardous dumps in the Ebro river (NE Spain). Chemosphere 78(3) 232-240... 

First, a brief explanation of the current knowledge regarding the sources and cycling of Hg and its transformation into MeHg is presented. Later, in this chapter, THg and limited data on organomercury levels in aquatic organisms of the Ebro River basin are detailed. The aquatic organisms most commonly studied in the Ebro River basin are zebra mussel, red swamp crayfish, and different fish species, namely European catfish, northern pike, common carp, rudd, roach, barbell, and bleak. 

Keywords Aquatic organisms, Chlor-alkali plants, Crayfish, Fish, Mercury, Methylmercury, Zebra mussel... 

Fig. 2 Location of the lower Ebro River catchment, zebra mussel, crayfish, and fish species sampling sites in the Flix dam area. Samples were taken at several stations in the four areas (RF = control site upstream WR = wildlife reserve HS = hot spot or chlor-alkali plant, and MD = meander). Positions of dams (black bars) and overflow dams (grey bars) are indicated to illustrate the mutual isolation of aquatic organisms sampled...

Red swamp crayfish (Procambarus clarkii) is a crustacean native to the South-central United States and Northern Mexico. It has been introduced in all continents except Australia and Antarctica, thus becoming the most widely distributed crayfish all over the world [52]. Procambarus clarkii is an omnivorous species, feeding mainly on... 

Table 2 Comparison of mean concentrations of THg (pg/gdw) in zebra mussels and crayfish from...

The species dig holes at the bottom and slopes of lakes and canals, causing severe impacts on invaded ecosystems. In the Ebro River, the crayfish is considered responsible for the disappearance of native fauna such as newts, frogs, and the autochthonous crayfish. Furthermore, it affects economically the rice crops in the Delta [53]. 

As zebra mussel, red swamp crayfish can be used to monitor the aquatic environment for Hg pollution owing to its capacity to accumulate metals in its tissues [54]. Other features, namely abundant populations, long life cycle, widespread distribution, and relatively sedentary lifestyle, also contribute to use this crayfish as bio-indicator of monitoring environmental quality [55]. 

In the Flix area, the determination of THg levels in muscle of red swamp crayfish individuals sampled has been reported [48]. Several specimens were collected in the same stations as zebra mussels. 

Finerty MW, Madden JD, Feagley SE, Grodner RM (1990) Effect of environs and seasonality on metal residues in tissues of wild and pond-raised crayfish in southern Louisiana. Arch Environ Contam Toxicol 19 94—100... 

Hothem RL, Bergen DR, Bauer ML, Crayon JJ, Meckstroth AM (2007) Mercury and trace elements in crayfish from northern California. Bull Environ Contam Toxicol 79 628-632... 

Huner JV (2002) Procambarus. In Holdich DM (ed) Biology of freshwater crayfish. Iowa State University Press - A Blackwell Science Company, Ames (IA), pp 541-584... 

Alikhan MA, Bagatto G, Zia S (1990) The crayfish as a biological indicator of aquatic contamination by heavy-metals. Water Res 24 1069-1076... 

Sanchez Lopez FJ, Garcia MDG, Martinez Vidal JL, Aguilera PA, Frenich AG (2004) Assessment of metal contamination in Donana National Park (Spain) using crayfish (Procam-burus [Procambarus] clarkii). Environ Monit Assess 93 17-29... 

Elvira B, Nicola GG, Almodovar A (1996) Pike and red swamp crayfish a new case on predator-prey relationship between aliens in central Spain. J Fish Biol 48 437 146... 

The effects of Flix sediment pollution on invertebrates were examined at two levels. Local populations of zebra mussels and crayfish (P. clarkii) were sampled right over the Flix residue sediment, across the reservoir, in a meander immediately downstream the dam and in Asco, in addition to the Riba-roja reference site (Fig. 5a, b). Results from a battery of biochemical biomarkers (Fig. 5c) were similar... 

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