Elemental composition (C,N,H) in larval and crab-1 stages of Pagurus bernhardus (Decapoda, Paguridae) and Carcinus maenas (Decapoda, Portunidae)

1980 ◽  
Vol 57 (1) ◽  
pp. 17-23 ◽  
Author(s):  
R. R. Dawirs
2009 ◽  
Vol 66 (9) ◽  
pp. 1837-1845 ◽  
Author(s):  
K. M. Hamilton ◽  
P. W. Shaw ◽  
D. Morritt

Abstract Hamilton, K. M., Shaw, P. W., and Morritt, D. 2009. Prevalence and seasonality of Hematodinium (Alveolata: Syndinea) in a Scottish crustacean community. – ICES Journal of Marine Science, 66: 1837–1845. Protist parasites of the genus Hematodinium were detected in seven crustacean species (Cancer pagurus, Carcinus maenas, Liocarcinus depurator, Munida rugosa, Necora puber, Pagurus bernhardus, and Pagurus prideaux) from the Clyde Sea in Scotland. Seasonal screening of different tissues with sensitive molecular probes showed average infection of 3–23%, with prevalence reaching almost 60% in hermit crabs (P. bernhardus) and brachyuran hosts in spring and >30% in C. pagurus and N. puber in autumn. During summer, Hematodinium infections were rare. Hematodinium seemed to be present in all host sizes sampled. The infection was equally distributed between males and females in most host species, except C. maenas, where males seemed to be more susceptible to infection. PCR amplification of the Hematodinium ribosomal RNA gene in crustacean tissue detected the parasite most frequently in muscle, gills, and heart throughout the 2-year sampling period.


Author(s):  
Jean-Marc Guarini ◽  
Jennifer Coston-Guarini ◽  
Tim Deprez ◽  
Laurent Chauvaud

The technical difficulties of performing underwater observation mean that marine ecologists have long relied on behavioural experiments to study reactions of marine organisms. In this article, we examine the underlying complexity of assumptions made in raceway experiments and we propose a statistical inference procedure tailored to this type of experimental protocol. As an example, experiments were performed to test if light of two different intensities affects the proximal behaviour (i.e. direct, local and immediate) of two species of crustaceans, the hermit crab (Pagurus bernhardus), and the green crab (Carcinus maenas). Individuals were collected in the vicinity of the Sven Loven Marine Center in Tjarnö (Sweden). Their movements in raceways were recorded and the statistical distance between the resulting experimental distribution and a simulated null distribution was used to compare their behaviour in two situations: dim (when they were expected to feed) and bright light (when they were expected to shelter). Initial tests indicated no differences of behaviour between dim and bright light for the two species. However, when compared with the reference state (here, a null distribution) the behaviour in dim light deviates significantly from the null distribution suggesting non-random behaviour. Our results suggest that efforts should be made to understand the behaviours of the individuals of these two species to establish a comprehensive reference state as a basis for comparison. This fundamental information should be a prerequisite before implementing experiments testing how potential disturbances affect individual organisms in behavioural ecology.


Author(s):  
A. R. Crooker ◽  
M. C. Myers ◽  
T. L. Beard ◽  
E. S. Graham

Cell culture systems have become increasingly popular as a means of screening toxic agents and studying toxic mechanisms of drugs and other chemicals at the cellular and subcellular levels. These in vitro tests can be conducted rapidly in a broad range of relevant mammalian culture systems; a variety of biological and biochemical cytotoxicity endpoints can be examined. The following study utilized human keratinocytes to evaluate the relative cytotoxicities of nitrofurazone (NF) and silver sulfadiazine (SS), the active ingredients of FURACIN(R) Topical Cream and SILVADENE(R) Cream, respectively. These compounds are anti-infectives used in the treatment of burn patients. Cell ultrastructure and elemental composition were utilized as cytotoxicity endpoints.Normal Human Epidermal Keratinocytes (HK) were prepared from the EpiPackTM culture system (Clonetics Corporation, Boulder, CO). For scanning electron microscopy (SEM) and transmission electron microscopy (TEM), cells were seeded on sterile 35 mm Falcon plastic dishes; for elemental microanalysis, cells were plated on polished pyrolytic carbon discs (E. Fullam, Latham, NY) placed in the culture dishes.


Author(s):  
G.M. Vernon ◽  
A. Surace ◽  
R. Witkus

The hepatopancreas consists of a pair of bilobed tubules comprised of two epithelial cell types. S cells are absorptive and accumulate metals such as copper and zinc. Ca++ concentrations vary between the S and B cells and during the molt cycle. Roer and Dillaman implicated Ca++-ATPase in calcium transport during molting in Carcinus maenas. This study was undertaken to compare the localization of Ca++-ATPase activity in the S and B cells during intermolt.


Author(s):  
A. J. Tousimis

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.


Sign in / Sign up

Export Citation Format

Share Document