A tactile stimulus to the siphon of Aplysia produces a defensive withdrawal reflex consisting of contraction of the siphon, the gill, and the mantle shelf. We studied long-term habituation of this reflex using two types of preparations, one focusing on the siphon component and the other on the gill component of the reflex. Siphon withdrawal, studied in unrestrained animals, showed marked habitu...

BUR[;(;RE"I, W. W., B. R. McMAHON, and J. W. COSTEIl.TON. 1974. Branchial waterand blood­ flow patterns and the structure of the gill of the crayfish Procambarus clarkii. Can. J. Zool, 52: 15111518. Water flow within the branchial chamber, blood flow within the gill filaments, and the line str.ucture of t~~ gill epithelium have been determined In the crayfish Procambarus clarkii. The epithelium...

Cage-cultured sutchi catfish Pangasius hypophthalmus (Sauvage, 1878), a favourite food fish in Southeast Asia, proved to be infected by 6 myxozoan species. Three species belonged to the genus Hennegoides (H. berlandi, H. malayensis, and H. pangasii), 1 to Henneguya (H. shariffi) and 2 to Myxobolus (M. baskai, and M. pangasii). Five myxozoans infected the gills and 1 was found on the spleen. Myx...

1. Defensive inking behavior and gill withdrawal in ApIysia offer simple test systems in which the cellular and biophysial determinants of elementary behavioral acts can be examined. Since a good deal is known regarding both the behaviors and their underlying neural circuits, it is possible to compare directly these two defensive reflexes at the cellular level. 2. Both the ink and gill motor ne...

The pattern of gill silver accumulation in rainbow trout during waterborne silver exposure has been reported to be unusual, reaching a peak in the first few hours of silver exposure followed by a marked decline with continued exposure. The potential causes of the pattern were investigated. Rainbow trout (1-5g) were exposed in a static system to 110mAg labeled AgNO(3) at a total concentration of...

An investigation on the effect of the heavy metal, cadmium sulphate (CdSo4) on the gill, liver and kidney of the Tilapia mossambica was carried out in the laboratory. Sixty fishes were exposed to continuous exposure to sub-lethal concentrations (0.084mg/l) of cadmium sulphate for a period of 20 days. The gill, liver and kidney of fish were removed for histological examination. The results showe...

The structure and stability of parasite communities have been mainly explained by high diversity and strong interactions among parasite species. During 16 months, 558 Barbus martorelli gill infracommunities were studied in a tropical zone to determine whether parasite infrapopulations interact. Three levels were retained: the infracommunity level, the gill filament level, and the filament fract...

Urea excretion by the gulf toadfish (Opsanus beta) has been shown in previous studies to be a highly pulsatile facilitated transport, with excretion probably occurring at the gill. The present study reports the isolation of an 1800 base pair (kb) cDNA from toadfish gill with one open reading frame putatively encoding a 475-residue protein, the toadfish urea transporter (tUT). tUT, the first tel...

Acidification is acknowledged as the cause for extinction or catch reductions in numerous Atlantic salmon (Salmo salar L.) populations in Norway. In freshwater, labile (cationic/inorganic) forms of Al (LAl) accumulate in fish gills, where high concentrations result in mortality due to respiratory and ionoregulatory dysfunction. At lower concentrations, Al may still have population effects by in...

diazinon is a moderately persistent organ phosphorus pesticide largely used in agriculture. thepurpose of this study was to evaluate the histopathological damages induced by diazinon in gills, kidney,spleen, and intestine tissues of rainbow trout, oncorhynchus mykiss. the fishes were exposed to sub-lethalconcentrations of diazinon (0.1 and 0.2 mg/l) for a period of 28 days. tissues analyzed by ...