This compact body shape plus a thick layer of blubber retains heat in the icy Arctic waters in which they live.
(This compact body shape plus a thick layer of blubber; retains; heat; L:in the icy Arctic waters) (they; live; L:the icy Arctic waters)
This compact body shape plus a thick layer of blubber they
retains live
heat L:in the icy Arctic waters
L:the icy Arctic waters