Reproduction of external fertilizing vertebrates is typically constrained to either fresh or salt water, not both. For all studied amphibians and fishes, this constraint includes immotile sperm that are activated after ejaculation only by the specific chemistry of the fertilizing medium in which the species evolved (fresh, brackish, or salt water). No amphibians can reproduce in the sea. Althou...

Alternative migratory pathways in the life histories of fishes can be difficult to assess but may have great importance to the dynamics of spatially structured populations. We used Sr/Ca in otoliths as a tracer of time spent in freshwater and brackish habitats to study the ontogenetic movments of white perch Morone americana in the Patuxent River estuary. We observed that, soon after the larvae...

An attempt has been made to estimate methane fluxes from a tropical coastal wetland the Vembanad Lake, a lagoon along the West Coast of India. It has been found that Vembanad Lake contributes significant amount of methane to the atmosphere. Average emissions varied spatially within the lake. Methane emissions were 193.2 +/- 24.5 mg m(-2) h(-1) at Kumaragam (fresh water) as compared to 9.3 +/- 9...

The evaluation of a simple and rapid tristimulus colorimetric method for the determination of arsenic in brackish waters and its application to brackish water samples taken from brackish Lake Nakaumi are described. The determinations of arsenic in brackish water samples were made satisfactorily independent of sample salinity. By applying this method to lake water samples, the distributions and ...

beluga sturgeon ( huso huso linnaeus, 1758) fingerlings are released into the caspian sea for recruiting and enhancing commercial and recreational fishing purposes. these fingerlings are reared in fresh water, but released to the estuaries that may be caused mortalities due to acute osmotic stress. in this study, the fingerlings in whole ( in vivo ) or their gill tissue ( in vitro ) were expose...

Global climate change can potentially increase the transmission of mosquito vector-borne diseases such as malaria, lymphatic filariasis, and dengue in many parts of the world. These predictions are based on the effects of changing temperature, rainfall, and humidity on mosquito breeding and survival, the more rapid development of ingested pathogens in mosquitoes and the more frequent blood feed...

this paper presents a total of 11 known crustacean parasite species from 51 host species belonging to 7 families, with 17 genera reported from cultured and wild fishes in three faunal regions of iran. among them, one belonging to branchiura order, namely argulus foliaceus, was found on capoeta capoeta in makoo reservoir as well as on cyprinus carpio, chalcalburnus sp., hypophthalmichthys molitr...