The relationship between ontogenetic changes and both feeding and habitat preferences was studied in a stream catfish population of Argentine Patagonia. Fish capture, as well as habitat data recording, was performed during a 1-year long period. Larvae–juvenile transition was determined between 22.4 and 29.4 mm standard length (SL), on the basis of the relative growth changes and morphogenesis, ...

SUMMARY 1. Large scale classifications such as nutrient ecoregions have been established in the United States to help regulate surface water resources. These classifications and their constituent classes are hypotheses which may be tested by establishing the strength of the classes to differentiate within class and between class variation. The purpose of our study was to test the strength of th...

Anhydrobiosis is an extremely dehydrated state in which organisms show no detectable metabolism but retain the ability to revive after rehydration. Thus far, two hypotheses have been proposed to explain how cells are protected during dehydration: (i) water replacement by compatible solutes and (ii) vitrification. The present study provides direct physiological and physicochemical evidence for t...

The Chironomidae family is one of the main groups of aquatic insects present in streams. This work aimed to investigate the influences of anthropogenic pressures and substrate types on chironomid community composition and structure. Chironomid larvae were collected during the summer of 2007 at four sites along the Vacacaí-Mirim River microbasin, chosen based on the different available benthic s...

This study investigates a phytophylous community of Chironomidae larvae on the submerged plant species Myriophyllum spicatum L. in a eutrophic lake (Lake Sakadaš, Danube floodplain area in Croatia) during summer 2004. This macrophyte species appeared for the first time in the lake in 2004, lasted approximately three months and was considered as a temporary habitat. The chironomid community was ...

Mercury (Hg) trophic transfer and bioaccumulation in fish from a mine-impacted, eutrophic lake were examined in relation to foraging habitat, trophic position, and size. Diet analysis indicated that there were clear ontogenetic shifts in foraging habitats and trophic position. Pelagic diet decreased and benthic diet increased with increasing fish length in bluegill, black crappie, inland silver...

The paper provides information on the biological parameters and feeding of rainbow trout Oncorhynchus mykiss (Walbaum, 1792) that has entered Krasnoyarsk Reservoir by escaping from fish farm cages. In diet studied individuals, eleven groups food components are found; imagoes terrestrial insects chironomid larvae dominate in ration. At same time, individuals characterized slow linear weight grow...

Among insects, haemoglobin is known to occur only in certain chironomid larvae, in Gastrophilus larvae, and in the water bugs Macrocorixa geoffroyi and those belonging to the subfamily Anisopinae. Only in the chironomid (Walshe, 1950) and Gastrophilus larvae (Keilin & Wang, 1946) is much known of its function and properties. A useful summary of the characteristics of haemoglobin in these insect...