Land based farming: What works for pikeperch?

The experiment was conducted in the large scale-experimental RAS and IPRS at the Laboratory of Intensive Aquaculture, Faculty of Fisheries and Protection of Waters, University of South Bohemia in České Budějovice, Czechia, and in three experimental ponds belonging to the Experimental Fish Culture Facility of the same faculty, at Vodnany.

Pikeperch (Sander lucioperca), also known as zander, is a popular fish in central Europe. Traditionally raised in pond aquaculture, increasingly pikeperch farming takes place in RAS facilities – but as the study’s authors note, increasing energy costs in Europe have hit the economics of farming in these systems, which tend to be energy-hungry.

The study compared pikeperch production in three systems: a recirculating aquaculture system (RAS), an in-pond raceway system (IPRS), and a traditional pond polyculture. Each system was stocked with 1,500 juveniles and cultured for 24 weeks.

The RAS fish demonstrated the most significant growth metrics, achieving the highest final total length, final body weight, condition factor, and specific growth rate, in addition to recording the lowest food conversion ratio (FCR). However, elevated hepatosomatic index (a measurement that expresses the liver’s weight as a percentage of the total body weight), intraperitoneal fat (fat located within the abdominal cavity, a measure usually linked with obesity) and ammonia levels all indicated an increased metabolic rate.

Notably, the researchers say, the RAS fish exhibited the highest incidence of fin erosion, which can be associated with higher population density and aggressive competition for food.

In contrast, the IPRS group showed slower growth, higher FCR, and elevated plasma glucose levels compared to other groups. IPRS fish also experienced fin erosion. Both RAS and IPRS fish recorded similar survival rates.

Conversely, the pond group had significantly lower survival rates, likely due to issues related to adaptability and water quality. Blood plasma analysis of pond fish indicated starvation, as evidenced by elevated alanine aminotransferase (an enzyme mainly found in the liver) and lipase (a digestive enzyme) levels and a lack of fat reserves.