Growth and Welfare of Juvenile Lumpfish (Cyclopterus lumpus)

Abstract

Lumpfish (Cyclopterus lumpus), is becoming more and more of a key player in the Atlantic salmon breeding business, since it has proven to be effective in cleaning sea lice off the Atlantic salmon. The Faroese aqua culturing industry has great interest in producing a Faroese product, since they currently use Icelandic lumpfish, risking both contagion and mixing of genetic material with the Faroese wild lumpfish. This experiment checked if the growth and welfare of the lumpfish can be controlled with feeding methods and environmental adjustments, thus leading to a more controlled production of lumpfish. Two hundred lumpfish were assigned to treatments in a balanced crossed design, crossing feeding method (handfeeding in meals vs. continuous automatic feeding) with shelter availability (shelter vs. no shelter), resulting in four groups of 50 fish. One group which were hand fed with access to shelter, one group which were hand fed with no access to shelter, one group which were fed by automated feeders with access to shelter, and one group which were fed by automated feeders with no access to shelter. The fish were measured in weight, length and height and were scored for bites, before and after the experiment, which lasted one month.
The results showed a significant interaction between the feeding method and shelter availability in the weight and length measurements. The lumpfish which were handfed and had access to a shelter had the largest growth results, and the lowest growth results resided with the tanks containing sheltering and which were connected to automated feeders; the difference in weight growth was 51 % between these two treatments. Differences could be due to the fish getting full meals and a resting spot, leaving them with a place and time to rest and grow between meals.
The predictability of a specific feeding spot, could have triggered some fish to turn dominant and larger than their subordinates, leaving us with a much larger variety of fish size, in the tanks connected to automated feeders. There were no significant differences in the biting scores of the fish.

Date of Award	2017
Original language	English
Supervisor	Eyðfinn Magnussen (Supervisor) & Ása Johannesen (Supervisor)