Housing & Husbandry
The Zebrafish involved in the experience were of AB strained originally supplied by a donating laboratory and housed in Aquaneering 2.8 and 6 liters tanks in reverse osmosis water supplied with balanced salt and bicarbonate solutions, heated at 27o Celcius with light:dark cycle 10:14 exposure 10Am to 12AM. Water pH, temperature, and conductivity is monitored daily, while nitrate, nitrites, hardness and alkalinity is monitored weekly, to ensure acceptable water quality. Fish are fed twice daily with Gemma Micro 300 (Skretting, USA). Fish were housed in groups of 3 fish or more. All experiments were performed under Institutional Animal Care and Use Committee-approved protocols at the Research Institute of McGill University Health Centre.
2 x Vertical Large Panels (A) (Figure 1)
2 x Vertical Small Panels (B) (Figure 1)
2 x Horizontal Small Panels (C) (Figure 1)
2 x Red Igloos (Figure 2)
5 x 2.8 liters Aquaneering Inc. Laboratory Fish Tanks
1 x 6 liters Aquaneering Inc. Laboratory Fish Tank
1 x Metal Tally Counter
(1) Vertical Large + Vertical Small Panels in a 2.8 liters tank
(2) Vertical Large + Horizontal Panels in a 2.8 liters
(3) Vertical Large + Horizontal Panels in a 6 liters tanks
(4) Horizontal Panel in a 2.8 liters tank
(5) Igloo in a 2.8 liters tank
Testing Aquariums & Recording
The components of the Aqualabyrinth were produced by the Janet Wood Innovation Award (JAWI) group as a prototype. The different panels consisted of a small vertical panel, a large vertical panel, and a small horizontal panel (Figure 1). As a comparison, we used mouse Igloos (Bioserv, NJ, USA). In each 2.8L tank except for Testing Tank (4), 3 adult fish were housed together (males and females mixed together). For Testing Tanks (3) and (4), 17 adult fish were together. For Testing Tanks (3) and (4), data were adapted such that we can compare with the other tanks. Namely, the approximate number of interactions from 17 to 3 fish was done by divinding the total number of interactions in 30 seconds by the number of fish (17 fish) and tehn multiplying this value by 3 fish.
The tanks were placed such that they all had neighbour tanks on the right and left side to rule out side preference during the experiment. The fish were provided 1 type of enrichment and were acclimated to it 5 days or more before the recording of the data.
To record and compare the different enrichment interactions, videos of 2.5 minutes were taken during a non feeding time of the day (1 hour after the first feeding of the day was performed) and the camera was set to record without human presence to avoid distracting the fish.
A 30 seconds time frame was taken at 60 seconds and at 90 seconds and the average was calculated to analyse the behavior. For the igloo, the number of times a fish passed at a minimum distance of 1 cm of the enrichment and above or below was counted as an interaction and for the Aqualabyrinth configurations, the number of times a fish passed through an opening was counted as an interaction. Two tanks with enrichment (5) were used to collect data. For all the other enrichments (1)(2)(3)(4), 1 tank for each was set up to gather data.