Ontogenetic Change in Behavioral Responses to Structural Enrichment From Fry to Parr in Juvenile Atlantic Salmon ( L.).

Enrichment is widely used as a tool for studying how changes in environment affect animal behavior. Here, we report an experimental study investigating if behaviors shaped by stimuli from environmental enrichment depending on the stage animals are exposed to enrichment. We used juvenile Atlantic salmon () in their first autumn.

Life history shifts in an exploited African fish following invasion by a castrating parasite.

Evolutionary theory predicts that infection by a parasite that reduces future host survival or fecundity should select for increased investment in current reproduction. In this study, we use the cestode and its intermediate fish host in Wissman Bay, Lake Nyasa (Tanzania), as a model system. Using data about infection of fish hosts by collected for a period of 10 years, we explored whether parasite infection affects the fecundity of the fish host , and whether host reproductive investment has increased at the expense of somatic growth.

The tapeworm Ligula intestinalis alters the behavior of the fish intermediate host Engraulicypris sardella, but only after it has become infective to the final host.

Ligula intestinalis is a tapeworm using copepods and cyprinid fish as intermediate hosts and fish-eating birds as final hosts. Since some parasites can increase their own fitness by manipulating the behavior of the intermediate host, we explored if this parasite affected predator avoidance, swimming activity and depth preference of the fish intermediate host, Engraulicypris sardella. We found that when L.

Invest more and die faster: The life history of a parasite on intensive farms.

Organisms are expected to respond to alterations in their survival by evolutionary changes in their life history traits. As agriculture and aquaculture have become increasingly intensive in the past decades, there has been growing interest in their evolutionary effects on the life histories of agri- and aquacultural pests, parasites, and pathogens. In this study, we used salmon lice () to explore how modern farming might have affected life history evolution in parasites.

Spatial and temporal distribution of Ligula intestinalis (Cestoda: Diphyllobothriidea) in usipa (Engraulicypris sardella) (Pisces: Cyprinidae) in Lake Nyasa.

Engraulicypris sardella is an endemic and economically important cyprinid species in Lake Nyasa/Malawi which has recently been infected by the tapeworm Ligula intestinalis. This parasite is known to induce severe pathological and behavioural effects on other cyprinids, including castration, followed by a collapse of infected populations. As a first step to understanding the dynamics between this parasite and E.