The transition from aquatic to aerial respiration is associated with dramatic physiological changes in relation to gas exchange, ion regulation, acid-base balance and nitrogenous waste excretion. Arapaima gigas is one of the most obligate extant air-breathing fishes, representing a remarkable model system to investigate (1) how the transition from aquatic to aerial respiration affects gill desi...

The main objective of the study was to use a species comparison approach in order to understand sensitivity and tolerance differences to copper. We hypothesized that species differences in toxicity would be reflected by differences in copper binding to high-affinity sites on the gill. Specifically, the strength of copper binding (affinity, logK) and maximum number of binding sites (saturation, ...

Epitheliocystis, a disease characterised by cytoplasmic bacterial inclusions (cysts) in the gill and less commonly skin epithelial cells, has been reported in many marine and freshwater fish species and may be associated with mortality. Previously, molecular and ultrastructural analyses have exclusively associated members of the Chlamydiae with such inclusions. Here we investigated a population...

Direct mass spectrometric analysis of animal tissues is an emerging field enabled by recent developments in ambient ion sources. Label-free in situ analysis of metabolites, lipids, and peptides/proteins from intact tissues in whole fish specimens of different gender and age were performed by laser ablation electrospray ionization (LAESI) mass spectrometry (MS). Hypertrophied glandular tissue (g...

An articulated endoskeleton that is calcified is a unifying innovation of the vertebrates, however the molecular basis of the structural divergence between terrestrial and aquatic vertebrates, such as teleost fish, has not been determined. In the present study long-read next generation sequencing (NGS, Roche 454 platform) was used to characterize acellular perichondral bone (vertebrae) and chon...

A basic question in neuroscience is how different forms of learning are related. To further address that question, we examined whether gill withdrawal in Aplysia, which has already been studied extensively for neuronal mechanisms contributing to habituation, sensitization, and classical conditioning, also undergoes operant conditioning. Animals were run in pairs. During the initial training per...

This study addressed the hypothesis that the secretion of catecholamines from trout (Oncorhynchus mykiss) chromaffin cells, during hypoxia, is triggered by stimulation of O(2) chemoreceptors located within the gills. Sodium cyanide was administered into the inspired water (external cyanide) or injected into the gill circulation (internal cyanide) to pharmacologically stimulate external (water s...

Ossifications associated with the gill filaments of members of the Balitoridae and Cobitidae are described for the first time. Although gill-filament ossifications are common in teleosts, similar ossifications were not observed in other members of the order Cypriniformes. Their presence is interpreted as a shared and derived character uniting the families Balitoridae and Cobitidae as a monophyl...

Experiments were performed to test the hypothesis that the marked ventilatory and cardiovascular responses to hypercarbia in rainbow trout Oncorhynchus mykiss arise from specific stimulation of chemoreceptors localised to the first gill arch. This was accomplished by measuring cardiorespiratory variables during acute hypercarbia (20 min at P(CO(2))=8 mmHg; 1 mmHg=0.133 kPa) in fish subjected to...

pattern of feeding and reproduction of amblypharyngodon mola (hamilton, 1822) was studied in two floodplain lakes of north 24 parganas districts of west bengal in india during 2011.  results indicated that the fish exhibited a predominantly herbivorous diet with algae as the main content of gut. a long, thin walled, coiled gut and closely packed filamentous gill racker suited this feeding habit...