They reduce their tissue density through high fat content, reduction of skeletal weight — accomplished through reductions of size, thickness and mineral content — and water accumulation makes them slower and less agile than surface fish.
Mereka mengurangi kepadatan jaringan melalui kandungan lemak tinggi, pengurangan berat rangka - dicapai dengan pengurangan ukuran, ketebalan dan kandungan mineral — dan akumulasi air membuat mereka lebih lambat dan kurang gesit daripada ikan permukaan.