Aquatic organisms often detect predators via water-borne chemical cues, and respond by showing reduced activity. Prey responses may be correlated with the concentration of predation cues, which would result in graded antipredator behavioral responses that adjust potentially costly behavioral changes to levels that are commensurate with the risk of predation. Larvae of the predatory mosquito Tox...

During the present investigation, 23 species of fish in Lithuanian inner waters were examined for helminth parasites. Of these, 63 taxa helminths – 56 Plathyhelminthes, five Nematoda, and two Acanthocephales found. Monogenea Gyrodactylus truttae was registered Lithuania first time. Metacercariae flukes Diplostomum sp., Posthodiplostomum cuticula, Tylodelphys clavata found highest number host sp...

According to sperm competition models, a male spawning in a disfavoured role should have spermatozoa with higher velocity but shorter longevity compared with a male spawning in a favoured role. Moreover, immunosuppressive androgens are needed to produce both secondary sexual characters and sperm cells. The ‘sperm protection’ hypothesis suggests that the immunosuppressive action of androgens has...

A model that assesses risks posed by feminization to wild populations of roach was developed. A population life table matrix model that considered both sexes and a newly developed fertility kinetic function was applied to calculate the intrinsic population growth rate (lambda) of roach populations where males had been feminized. The maximum sustainable yield (MSY) was used to quantify the effec...

Diplostomum is a taxonomically problematic genus of trematodes, with many members harmful at the metacercarial stage to fish in aquaculture. We found metacercariae eye vitreous humor rudd, Scardinius erythrophthalmus; bleak, Alburnus alburnus; and roach, Rutilus rutilus, Karelia (Russia) identified them as numericum based on combination morphological ecological data. Previously, D. was thought ...