Predator crustacean

Ham, L., R. Quinn, and D. Pascoe. 1995. Effects of cadmium on the predator-prey interaction between the turbellarian Dendrocoelum lacteum (Muller, 1974) and the isopod crustacean Asellus aquaticus (L.). Arch. Environ. Contam. Toxicol. 29 358-365. 

Greig, R. and D. Wenzloff. 1977. Final report on heavy metals in small pelagic finfish, euphausid crustaceans and apex predators, including sharks, as well as on heavy metals and hydrocarbons (C 15+) in sediments collected at stations in and near deepwater dumpsite 106. Vol. III. Contaminant inputs and chemical characteristics. Pages 547-564 in U.S. Dep. Com. NOAA, Rockville, MD, Baseline Report of the Environmental Conditions on Deepwater Dumpsite 106. 

Fry of the Atlantic salmon, Salmo salar, probably rely on olfactory and gustatory stimuli for their first meal. Injured prey such as small crustaceans will leak free amino acids, which can serve as a feeding signal to the fish fry. Such handicapped prey will be easier to catch for the fry. If the prey is dead, and/or its free amino acids are depleted, the fry show no interest in them. In this way, the salmon can optimize its capturing efforts as well as its prey digestion. In laboratory experiments, frozen daphnids leaked as much as 35% of its methionine upon thawing. On their first 3 days of feeding, salmon fry typically chose undepleted daphnids first and virtually all spit-out prey were depleted daphnids (Holm and Walther, 1988). Table 12.2 lists some chemical predator-prey relationships in freshwater fish. 

Reports on copepods and other crustaceans dominate available zooplankton grazing data on Phaeocystis spp. These data show a wide range of rates, even for similar predator-prey combinations. We therefore attempt to summarize available quantitative data in relation to some of the mechanisms proposed to control the feeding on Phaeocystis. The shortage of quantitative feeding studies on microzooplankton and Phaeocystis was pointed out already a decade ago (Weisse et al. 1994), and the number of such studies is still limited, especially for protozoan microzooplankton, whether using laboratory cultures (Table 3)... 

Fig. 1 First factorial plane of MCA of data on crustacean grazing experiment on Phaeocystis. (A) Projections of continuous illustrative variables in the correlation circle (radius 1) and ordination of active variables Phaeocystis species (A), growth (

Two types of evidence indicate that vanadium may function as a anti-feedant for unicates. First, there is evidence based on observation that species whose outer coverings (tunics) are rich in vanadocytes are shunned by predatory fish65,66. These tunics are often acidic, which confers further protection from predation on an individual specimen exhibiting this characteristic. Since vanadium would be expected to hydrolyze in sea water, this acidity could result from release of vanadium due to rupturing blood cells. Second, pieces of fish deliberately dosed with appreciable amounts of vanadium, and offered as food pellets to crustaceans and fish, resulted in reduced food consumption by these predators67. ... 

Of the 25 animal phyla, almost half are worms. Thus, it is not at all surprising that some worms contain toxins. The nemertines are a phylum of over 800 known species which resemble flatworms but are active predators on crustaceans and other worms. This phylum is exceptionally toxic among the various worm phyla. The Heteronemertine side possesses peptide toxins which appear to be only defensive, as these animals have no means of injecting a venom. The peptides include neurotoxins, which enhance excitability of nerve membranes, and cytolysins, which permeabilize and destroy cell membranes. Members of the Hoplonemertine class inject a venom into their prey using a mineralized stylet located in their proboscis, which is also used to immobilize the prey. Their toxins are alkaloids similar to nicotine which in minute amounts paralyze crustaceans and annelid worms and primarily activate nicotinic acetylcholine receptors. Another well-known worm toxin is nereistoxin, a disulfide-containing alkaloid which also binds to nicotinic... 

Heteroxenous (marine crustacean/fish or squid/fish-eating sea mammal or bird) Heteroxenous (predator or scavenger behavior, cannibalism)... 

Specificity of chemoreception in predators generally is very pronounced. With the actinia Boloceroi des sp., valine is a powerful activator of the feeding response, whereas leucine has no action in this sense and isoleucine inhibits this behaviour (Lindstedt, 1971). A further example of stereospecificity in detection is furnished by the crustacean Homarus gammarus, which reacts to a complex mixture of laevo-rotatory amino acids, but shows no response to the same elements in their dextro-rotatory form (Mackie, 1973). 

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