Crabs, toxicity

Figure 2. Relative toxicity (LD50 and LD qq) estimates for actiniid sea anemone toxins upon crabs (Carcimis maenas) and mice. Values for Anemonia sulcata (As) and Anthopleura xanthogrammica (Ax) toxins are from ref. 24 data for Condylactis gigantea and Phyl-lactis flosculifera toxins are unpublished (Kem). The arrows indicate that the real mouse LD q values for Cg II and Pf II must exceed the values indicated in the Ogure. Although insufficient data are presently available to quantitatively define a relationship between mammalian and crustacean toxicity, it seems that there is usually an inverse relationship, which may be approximately defined by the stipple zone.

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. 

Venom from the globiferous pedicellariae of sea urchins is lethal to mice, rabbits, crabs, lobsters, and worms 70). Seasonal changes in toxicity of such toxins 71) have been observed. The LD q estimate (mice) for toxic fractions from the urchin Tripneustes gratilla ranged from 0.05-0.5 mg/kg 70). 

Toxicity of selected diorganotin and triorganotin compounds to zoeae of the marine mud crab (Rithropanopeus harrisii) exposed from hatching to age 14 days... 

Ahsanullah, M. and G.H. Amott. 1978. Acute toxicity of copper, cadmium, and zinc to larvae of the crab Paragrapsus quadridentatus (H. Milne Edwards), and implications for water quality criteria. Aust. Jour. Mar. Freshwat. Res. 29 1-8. 

Hansen, J.I., T. Mustafa, and M. Depledge. 1992a. Mechanisms of copper toxicity in the shore crab, Carcinus maenas. I. Effects on Na, K-ATPase activity, haemolymph electrolyte concentrations and tissue water contents. Mar. Biol. 114 253-257. 

Table 8.9 Toxicity of Selected Diorganotin and Triorganotin Compounds to Zoeae of the Marine Mud Crab (Rithropanopeus harrisii) Exposed from Hatching to Age 14 Days...

Lead-zinc mixtures were more-than-additive in toxicity to marine copepods (Verriopoulos and Dimas 1988) and significantly delayed development of mud crab (Rithropanopeus harrissii) larvae (USEPA 1987). Lead is accumulated up to 10 times more rapidly by marine fishes at elevated zinc concentrations in seawater (Eisler 1981). 

Devi, V.U. 1987. Heavy metal toxicity to fiddler crabs, Uca annulipes LatreiUe and Uca triangularis (Milne Edwards) tolerance to copper, mercury, cadmium, and zinc. Bull. Environ. Contam. Toxicol. 39 1020-1027. Devi, V.U. and Y.R Rao. 1989. Heavy metal toxicity to fiddler crabs, Uca annulipes Latreille and Uca triangularis (Milne Edwards) respiration on exposure to copper, mercury, cadmium, and zinc. Bull. 

In acute toxicity tests with aquatic organisms, LC50 (96 h) values — with only one exception — exceeded 130 pg/L. The exception was the larva of a marine crab with an LC50 (96 h) value of... 

Tsai, Y., Jeng, S. and Hwang, D., Seasonal and regional variations of toxicity in the Xanthid crab, Zosimus aeneus, in Taiwan, Fisheries Sci., 63, 2, 313, 1997. 

Burton, D.T. and Margrey, S.L. An evaluation of acute bromine chloride toxicity to grass shrimp (Palaemonetes spp.) and juvenile blue crabs (Calllnectes sapldusf, Bull. Environ. Contam. Toxicol, 19(2) 131-138, 1978. 

In tropical to subtropical waters, there live toxic crabs. They contain paralytic shellfish poisons in most cases. One of those toxic crabs, Atergatis lor id us, inhabits also along the Pacific Coast of the Japan Proper. Very recently, it was excavated that the crabs collected from Miura Peninsula near Tokyo possess TTX as the major toxin, along with some paralytic shellfish poisons as the minor (15). The distribution of TTX may be expanded further in the future. 

Insects, spiders, scorpions, crabs, centipedes, millipedes, and even some plankton are arthropods, the largest and most diverse animal phylum. Some are capable of producing very powerful toxins as an aid in the quest for food. Humans come in contact with these toxins, usually by accident or as a result of the animal defending itself. Some insects, mosquitoes and ticks for example, are capable of transmitting other organisms to humans that cause disease. While these organisms may be toxic to humans, they are not toxins and will not be discussed in this chapter. 

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