The marine megalopa of the terrestrial hermit crab Coenobita compressus wears a small gastropod shell that it carries onto land before metamorphosing into a juvenile crab. This paper gives the first detailed account of temporal shifts in shell-related behaviors that occur as the megalopa approaches metamorphosis. Megalopae placed in individual containers shortly after metamorphosing from the la...

Shell selection indices of the dominant hermit crab Clibanarius signatus Heller, 1861, in the Larak Island were studied from September 2011 to June 2012. Among 739 sampled specimens, 41 different gastropod shell types were selected as shelters based on their abundance and local availability. A significant positive correlation (P<0/01) was found between the dimensions of the hermit crab, Cli...

Biomarkers are biologically produced organic compounds that can be used to identify sources of organic matter in geologic materials (soils, sediments, rocks). This information allows scientists to track important environmental and ecological changes over time and space. Some of the most commonly used biomarkers are a class of lipids called fatty acids. These compounds resist degradation and are...

Defenses against predators and parasites offer excellent illustrations of adaptive phenotypic plasticity. Despite vast knowledge about such induced defenses, they have been studied largely in isolation, which is surprising, given that predation and parasitism are ubiquitous and act simultaneously in the wild. This raises the possibility that victims must trade-off responses to predation versus ...

Background: Chitin is an important natural resource. The annual worldwide production is estimated in approximately 10 10 -10 12 ton. It is produced by arthropods (insects and crustaceans), molluscs and fungi. Its main biological function is structural. Crustacean shells are the most important chitin source for commercial use due to its high content and ready availability. Chitin and its derivat...

Chitin the second most abundant after cellulose biopolymer found in nature after, is produced by many living organisms, and is present usually in a complex with other polysaccharides and proteins. Chitin was found as a major component in arthropods (insects, crustaceans, arachnids and myriapods), nematodes, algae and fungi. In this study Chitin was isolated from various species (crab, squilla, ...

Chitin, one of the most abundant organic substances in nature, is consumed by marine bacteria, such as Vibrio cholerae, via a multitude of tightly regulated genes (Li and Roseman 2004, Proc Natl Acad Sci USA. 101:627-631). One such gene, cod, is reported here. It encodes a chitin oligosaccharide deacetylase (COD), when cells are induced by chitobiose, (GlcNH(2))(2), or crude crab shells. COD wa...

treatment with these acids may cause disorder to the stiff fibril structure of native chitin with a slight cleavage of glycosidic linkages, and afford enzymatically digestible colloidal chitins. The enzymic digestibility varies mainly with these acids used for its preparation. Wenow wish to report an improved method for the preparation ofcolloidal chitin by treatment with aqueous methanesulfoni...

Global warming is expected to result in milder New England winters. In this study we monitored changes in hermit crab shell quality at Nahant, Massachusetts, USA, at intervals during 17 yr between 1997 and 2014 for a single species of hermit crab Pagurus longicarpus occupying the shells of the intertidal periwinkle Littorina littorea. The incidence of hermit crabs occupying damaged shells, shel...