playful disposition?

I’m sure all my readers will recall how while getting my head turned completely around exploring the Axial Twist Hypothesis I kind of glossed over that part of the literature which referenced zebrafish because glossing over is how I manage to cover such a broad diversity of topics ranging from the Axial Twist Hypothesis to Very Large Pencils. Turns out zebrafish are good for aquariums due to their “playful disposition, rapid breeding, aesthetics, cheap price, and broad availability.” Plus I’ve learned that zebrafish can regenerate their damaged spinal cords which is why the market for zebrafish wheelchairs remains vanishingly small.