Over the recent years, growing number of studies suggests that intensive size-selective fishing can cause evolutionary changes in life-history traits in the harvested population, which can have drastic negative effects on populations, ecosystems and fisheries. However, most studies to date have overlooked the potential role of immigration of fish with different phenotypes as an alternative plau...

Using the widespread Eurasian perch Perca fluviatilis as a model organism, feeding ranges were investigated using stable-isotope ratios (δ15 N and δ13 C) and body condition. Differences were found between closely located sampling sites in a littoral area without obvious migration barriers, indicating that individual fish had small feeding ranges. Body condition differences between sampled stati...

Tissue samples from 1,117 fish of 25 species were collected from 1991 through 1996 at 13 locations along the River Elbe. The principal indicator species were perch (Perca fluviatilis) (n=118), chub (Leuciscus cephalus L.) (n=113) and roach (Rutilus rutilus) (n=138). Mercury (Hg) concentrations in muscle and liver were determined by atomic absorption spectrometry. The liver/muscle index in three...

Background & Aims of the Study: The aim of this study was to determine the ecology of malaria vectors in order to select the vector control masseur in the future. This study was carried out on trend of malaria cases and malaria vectors in Saravan county, Sistan & Baluchestan Province, Iran. Materials & Methods: The adult mosquitoes were collected by standard Pyrethrum space spray colle...

Theodoxus fluviatilis (Linnaeus, 1758) (Gastropoda: Neritidae) is an oligohaline aquatic gastropod that inhabits most of Europe and adjacent areas Asia. Two different ecotypes can be distinguished: One in freshwater (FW) another along the Baltic Sea coast brackish water habitats (BW). Individuals either ecotype use free amino acids urea as organic osmolytes to adjust body fluid osmolality exter...

The object of this short paper is to call attention to two facts?firstly, the finding of sporozoits in a variety of anopheles fuliginosus in the natural state; and, secondly, the variations to which a species is liable. Regarding the first point, recent study has shown that while many, if not all, anopheles may experimentally carry malarial infection, practically only two Indian species are kno...

In the light of the hydrodynamic characteristics of the river Cilloruelo (province of Salamanca, Spain) and the results on the shedding of lophocercariae of a Sanguinicola sp. by naturally infected Ancylus fluviatilis, a discussion is made of the influence of different temperatures on shedding and survival of the cercariae. Comments are also made concerning the most likely periods and zones of ...

The patterns of the anterior lateral-line afferents of Lampetra fluviatilis as revealed by transganglionic transport of horseradish peroxidase are described. The afferents form two roots in entering the rhombencephalon. Fibers of the dorsalmost root can be traced to a short dorsal fascicle which runs along the dorsal nucleus. The ventral roots form two fascicles adjacent to the nucleus intermed...

The host feeding specificity of Anopheles fluviatilis sibling species S, T, and U was determined by analyzing blood meal source using countercurrent immunoelectrophoresis. A distinct difference in the feeding patterns was observed among these species. Species S was found to be predominantly anthropophagic with 91% of the population having fed on human blood. In contrast, species T and U were ei...