The effect of alkylphenols on lobster shell hardening
Bobbitt, James M.
MetadataShow full item record
KeywordAmerican lobster; Homarus americanus; Alkylphenols; Bisphenol A; Shell hardening; Sclerotization; Tyrosine; Molting; Lobster; Cuticle
Alkylphenols, anthropogenic estrogenic endocrine disruptors in vertebrates, have been found in lobsters (Homarus americanus) in New England sites. We hypothesize that alkylphenols interfere in the shell hardening during molting. We used an in vitro cuticle bioassay to investigate the effects of 2 alkylphenolic compounds—2,4-bis-(dimethylbenzyl) phenol (compound 3) and bisphenol A (BPA; 4,4′-dihydroxy-2,2-diphenylpropane (also referred to as 4,4′-(propan-2-ylidene) diphenol)) on tyrosine incorporation during the hardening of new cuticle following lobster molting. During sclerotization, both alkylphenols and cold tyrosine competed with C14-tyrosine incorporation in a concentration-dependent manner. This process was also phenoloxidase dependent, as treatment with phenylthiourea (PTU; a phenoloxidase inhibitor) significantly decreased C14-tyrosine incorporation. We also found that incorporation of C14-2,4-bis-(dimethylbenzyl) phenol during the shell hardening process was inhibited by cold alkylphenol, cold tyrosine, or PTU, and competition was concentration dependent. Furthermore, incorporation of tyrosine and derivatives into new cuticle decreased with time after molting from 27% incorporation 1 day after a molt to 6% by 4 days after a molt. In nonmolting cuticles, there was no incorporation of alkylphenol or tyrosine derivatives. When lobsters were injected with 2,4-bis-(dimethylbenzyl) phenol during the premolt stage, it took the shells 12 ± 1 days to harden sufficiently to resist deflection by 5 lb pressure exerted by a pressure gauge, compared with 7 ± 1 days for control shells. Thus, shell hardening is delayed significantly by the presence of 2,4-bis-(dimethylbenzyl) phenol. The effects of this compound on shell hardening may result in lobsters' susceptibility to microbial invasion and, therefore, may contribute to the onset of shell disease.
Author Posting. © National Shellfisheries Association, 2012. This article is posted here by permission of National Shellfisheries Association for personal use, not for redistribution. The definitive version was published in Journal of Shellfish Research 31 (2012): 555-562, doi:10.2983/035.031.0215.
Showing items related by title, author, creator and subject.
Altered gene expression associated with epizootic shell disease in the American lobster, Homarus americanus Tarrant, Ann M.; Stegeman, John J.; Verslycke, Tim A. (2010-07-21)Epizootic shell disease is a poorly understood condition that has significantly affected the American lobster fishery in New England (northeastern US) since the 1990s. Here we present the results of a study to identify ...
Tarrant, Ann M.; Franks, Diana G.; Verslycke, Tim A. (National Shellfisheries Association, 2012-06)Epizootic shell disease (ESD) has been reported widely in American lobster (Homarus americanus, Milne Edwards) in southern New England. The appearance of irregular, deep lesions—characteristic of ESD—has been associated ...
Laufer, Hans; Demir, Neslihan; Biggers, William J. (National Shellfisheries Association, 2005-10)Shell disease is a problem affecting lobsters in eastern Long Island Sound causing disfiguration of the shell, decreasing the lobsters' value, and whereas mild and medium levels of the disease are not lethal, ultimately, ...