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ACTIVE (SHARK) ECTOTHERMS



Andrew Howey says:

> I know that under normal circumstances, sharks MUST keep moving or drown.  

Sorry, this is too much of a generalisation for me to let it go. Many
benthic sharks, including wobbegongs (orectolobids) and nurse sharks
(ginglystomatids), spend most of their time lying on the bottom. Many
neritic coastal forms, including lemon sharks (_Negaprion_) and reef
sharks (_Carcharinus_) will also do so regularly, and lemon sharks
have to do so for long periods of time when they are giving birth
(they are ovoviviparous).

Though I haven't done my homework here, I believe that the benthic
types _can_ pump water over their gills. Those that can't, but are
still able to sit on the bottom, may utilise bottom currents. It's a
well-disproved myth that sharks must 'keep moving or drown'.

"I thought that hairy beast would be the end of me"

DARREN NAISH