Asellus aquaticus removal of unfertilized fish eggs and possible use in aquaculture as a biological control organism

Abstract

The aim of the present experimental study was to better understand the foraging behavior of Asellus aquaticus. Different numbers of A. aquaticus were introduced into different experimental setups of unfertilised eggs, viable eggs, hatched larvae of Danio rerio. The number and time of A. aquaticus significantly affected the ratio of consumed non-fertilised eggs in each experimental cycle (MANOVA, p<0.05). A. aquaticus belongs to the aquatic saprophytes and no predatory behavior was observed during the experiments. They were able to distinguish between the dead eggs and those containing living embryos. Additionally, zebrafish larvae were not harmed by the A. aquaticus, even when there was not an alternative food source. The results help to understand the potential sanitary role of these crustaceans in natural waters and provide new insight into their possible application as a biological control organism in aquaculture hatcheries. Finally, our results indicate that there is a potential for A. aquaticus application against pathogens by reducing bacterial and fungal growth substrates.

A practical guide for the husbandry of cave and surface invertebrates as the first step in establishing new model organisms

“…Studies of Asellus cave populations yielded several important insights into its evolution, behavior, as well as the molecular basis for some of its phenotypes [60,61]. Also, its surface morphotype is bred for laboratory experiments, such as ecotoxicology [62], for biological control in aquaculture [63], but also as aquarium pets, or food for aquarium fish. Subterranean crustaceans from several groups, mostly copepods, amphipods and isopods, have been used for ecotoxicity studies (for review see 54), but the tests were conducted on field-collected animals and only within a few days of collection, so no culturing was necessary.…”