Decapod crustaceans exhibit considerable variation in fertilisation strategies, ranging from pervasive single paternity to the near-ubiquitous presence of multiple paternity, and such knowledge of mating systems and behaviour are required for the informed management of commercially-exploited marine fisheries. We used genetic markers to assess the paternity of individual broods in the European l...

We investigated the prevalence, transmission mode and fitness effects of infections by obligatory intracellular, microsporidian parasites in the freshwater amphipod Gammarus roeseli. We found three different microsporidia species in this host, all using transovarial (vertical) transmission. All three coexist at different prevalences in two host populations, but bi-infected individuals were rare...

The amphipod Gammarus duebeni harbours several species of vertically transmitted microsporidian parasites. G. Duebeni were collected from 3 localities in the UK. Animals from Budle Bay, Northumberland, were infected with Octosporea effeminans, and those from Millport, Isle of Cumbrae and Fenham Flats, Northumberland were infected with microsporidia of the genus Nosema. We derived expected distr...

Methods were developed to assess uptake and elimination kinetics in Gammarus pulex of nine pharmaceuticals (sulfamethazine, carbamazepine, diazepam, temazepam, trimethoprim, warfarin, metoprolol, nifedipine and propranolol) using targeted LC-MS/MS to determine bioconcentration factors (BCFs) using a 96 h toxicokinetic exposure and depuration period. The derived BCFs for these pharmaceuticals di...

Tandem mass spectrometry (MS) was used to detect herbicide residues in wild populations of amphipods collected from microcosms spiked with a single pulse of either Avadext-BW (triallate) or HoeGrasst (diclofop-methyl) at three different concentrations (1.0, 10.0, and 100.0 mg·L21). Independent confirmations of both herbicides were obtained by spiking amphipod tissues with 50 pg of authentic sta...

We report the effects of n-alkanols (n-butanol to n-octanol), methyl carboxylic esters (methyl propionate to methyl octanoate) and n-alkyl ketones (2-pentanone to 2-nonanone) on a fast reflex escape response to a mechanical stimulus in Gammarus. ED50 concentrations and the relationships between In ED50 and chain length are given for each compound and series. For the n-alkanols, this relationshi...

Two field experiments were carried out to investigate the effects of mussels (Mytilus edulis) on fauna and on sediment characteristics. In the first experiment mussels were removed from within an established mussel bed to create bare patches and in the second experiment mussels were transplanted to an adjacent bare sandflat. In the mussel removal experiment, mobile epibenthic crustaceans (predo...

The adult lobster Homarus gammarus is a weak hyper-regulator at low salinity. The objective of this study was to locate the ion-transporting tissues in the branchial chamber of this species, using electron microscopy and confocal laser scanning microscopy with a fluorescent vital stain for mitochondria, DASPMI, which is widely used to locate mitochondria-rich cells in ion-transporting epithelia...

As the tempo of biological invasions increases, explanations and predictions of their impacts become more crucial. Particularly with regard to biodiversity, we require elucidation of interspecific behavioural interactions among invaders and natives. In freshwaters in The Netherlands, we show that the invasive Ponto-Caspian crustacean amphipod Dikerogammarus villosus is rapidly eliminating Gamma...

Decapod crustaceans synthesize highly active proteolytic enzymes in the midgut gland and release at least a part of them into the stomach where they facilitate the first step in peptide hydrolysis. The most common proteinases in the gastric fluid characterized so far are serine proteinases, that is, trypsin and chymotrypsin. These enzymes show highest activities at neutral or slightly alkaline ...