Crab spiders

Crab spiders below center) have as many distinctly different colors as birds. Females are often paler, but both sexes can change color to blend in with the background. 

During a field study of the attraction of scavenging flies to the defensive compounds of true bugs, Aldrich and Barros (1995) found considerable numbers of crab spiders (Thomisidae) in their traps. More detailed study showed that both (E)-2-octenal (12) and (E)-2-decenal (13) were attractive to four American crab spider species ... 

Males of a European species, Xysticus kochii, also were attracted to 12 and 13 (S. Toft and S. Schulz, unpublished data). The aldehydes 12 and 13 were not found in odors collected from females, although the saturated analogs octanal and decanal were present. However, neither they nor any of the other identified compounds attracted males (S. Schulz and S. Toft, unpublished data), and the reason for the attraction of male crab spiders to aldehydes 12 and 13 remains unknown. 

Aldrich, J. R. and Barros, T.M. (1995). Chemical attraction of male crab spiders (Araneae, Thomisidae) and kleptoparasitic flies (Diptera, Milichiidae and Chloropidae). Journal of Arachnology 23 212-214. 

Anderson, J. T. and Morse, D. H. (2001). Pick-up lines cues used by male crab spiders to And reproductive females. Behavioral Ecology 12 360-366. 

Evans, T. A. and Main, B. Y. (1993). Attraction between social crab spiders silk pheromones in Diaea socialis. Behavioral Ecology 4 99-105. 

There are about 30,000 species of spiders, virtually all of which produce venom. Fortunately, most lack dangerous quantities of venom or the means to deliver it. Nevertheless, about 200 species of spiders are significantly poisonous to humans. Many of these have colorful common names, such as tarantula, trap-door spider, black widow, giant crab spider, poison lady, and deadly spider. Space permits only a brief discussion of spider venoms here. 

Ommin has been found in all investigated orders of the Insecta and Crustaceae. It is an especially common eye pigment in crabs, spiders, insects and cephalopoda, and it is also present in the epidermis of Cragnon, Limulus and Gryllus, but not Carcinus and Portunus. Ommin is present in the eyes and skin, but not in the ink, of Sepia ofpcianalis (Cephalopoda). About 75% of the pigment known as om-... 

Phylum Arthropoda Scorpions, spiders, crabs, insects, millipedes, centipedes... 

Tissue accumulation of exogenously added tritiated PGs was shown for the spider crab Libinia emarginata [107]. The earliest report of possible oxylipin production in marine arthropods was from gill and stomach tissues of the lobster Homarus sp. [15]. These were tested for their ability to produce prostaglandins in incubations with all-cis-[8,9,ll,12,14,15-3H6]eicosatrienoic acid. Carrier PGEj was added and the PGErtype compounds from the extract were purified by TLC. Quantitation was done by UV absorption at 278 nm after... 

A limited amount of information is available on the formation of metabolites of aromatic hydrocarbons in aquatic invertebrates however, some studies have elucidated the structures of conjugated and non-conjugated derivatives produced in these organisms. The bioconversion of naphthalene by the spider crab (Maia squinado) has been studied by Corner et al. (45). These workers identified... 

Tropomyosin is a protein found in vertebrates and invertebrates, but only the protein from invertebrates has allergic properties. It is frequently found in sea foods, such as shrimps, crabs, American lobsters. Pacific flying squids, and also in some species of cockroaches (Blattela germanica, Periplaneta americand), moths, spiders, and house dust mites (Dermatophagoides pteronyssinus, Dermatophagoides farinae) (Witteman et ah, 1994). 

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. 

Stensvag, K., Haug, T., Sperstad, S. V., Rekdal, O., Indrevoll, B., and Styrvold, . B. (2008). Arasin 1, a proline-arginine-rich antimicrobial peptide isolated from the spider crab, Hyasaraneus. Dev. Comp. Immunol. 32, 275-285. 

Specific chemical substances associated with flight responses have rarely been isolated, but this has apparently not been necessary for the adaptation of this phenomenon to applied problems. As one example, spider crabs in the genus Libinia are a nuisance for lobster fishermen in the northeastern United States because they have little market value, consume bait, and increase the number... 

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