SYNOPSIS. The crustacean mandibular organ (MO) produces methyl farnesoate (MF), a juvenile hormone-related compound thought to have roles in crustacean reproduction and development. Therefore, the control of MF production by the MO has been of considerable interest. Current evidence indicates that the MO is negatively regulated by peptides present in the eyestalk (MO inhibiting factor, MOIH). S...

During the spring clear-water phase of 1993, an enclosure experiment was performed in the mesotrophic Schohsee (Plon, FRG) in order to assess the impact of crustacean zooplankton on the rotifer and phytoplankton community. Among the crustacean plankton, calanoid and cyclopoid copepods were abundant, but Daphnia 'longispina' reached the highest densities in this experiment. The colonial rotifer ...

1. Insect toxin, mammal toxins I and II and crustacean toxin were obtained from the venom of the scorpion Androctonus australis. Their effects on the isolated giant axon of the cockroach Periplaneta americana were investigated by current-clamp and voltage-clamp techniques. 2. In current-clamp conditions, mammal toxins and crustacean toxin (1*3—13 /IM) induced a large prolongation of the falling...

Despite major progress in our understanding of animal signaling systems, the identification of chemical signals in aquatic organisms is still in its infancy. Exemplary for this is the lack of structural knowledge of crustacean sex pheromones despite their initial description in crabs almost 40 yr ago. We hypothesized that species in which the reproductive event is linked to a short window of ma...

High-throughput RNA sequencing (RNA-seq) technology has become an important tool for studying physiological responses of organisms to changes in their environment. De novo assembly of RNA-seq data has allowed researchers to create a comprehensive catalog of genes expressed in a tissue and to quantify their expression without a complete genome sequence. The contributions from the "Tapping the Po...

Vitellogenin (VTG) has been widely used as a biomarker of estrogenic exposure in fish, leading to the development of standardized assays for VTG quantification. However, standardized quantitative assays for invertebrate, particularly crustacean, lipovitellin (also known as vitellin [VTN]) are lacking. In this study, a fluorescence-based VTN enzyme-linked immunosorbent assay (ELISA) was develope...

Results 2999 children were seen during this period with a range of allergic problems, including food allergy. 167 (5.6%) had experienced a definite clinical reaction to seafood (103 male, 62%); 94% had evidence of co-existent atopic disease. The most common seafood implicated were: Prawn (26%), Unspecified white fish (10%), Tuna (8%), Salmon (8%). In 14%, the exact type of fish could not be rec...

A novel disease of crayfish Procambarus clarkii appeared in the summer of 2004 in freshwater aquaculture in Jiangsu province of China. Light and transmission electron microscopy (TEM), molecular biological methods and in vitro culture were used to identify the pathogen. The agent was unique in having a helical morphology and rotary motility as observed by phase-contrast light microscopy and was...

Cholinesterase (ChE) activity is present in crustacean muscle extracts. However, since acetylcholine (ACh) is not a neuromuscular transmitter in these animals, the role and exact localization of ChE was unknown. The histochemical localization of the enzyme was studied in whole muscle and in the sarcoplasmic reticulum fraction of the extract, 50-microm frozen sections of glutaraldehyde-fixed cra...

In the course of evolution, crustaceans adapted to a large variety of habitats. Probably the most extreme habitat shift was the transition from water to land, which occurred independently in at least five crustacean lineages. This substantial change in life style required adaptations in sensory organs, as the medium conveying stimuli changed in both chemical and physical properties. One importa...