Question: Is there a symbiotic relationship between whales and
barnacles?
Reply:
Dear Ann,
There does not seem to be a symbiotic relationship between whales and
barnacles unless you consider humpback whales using their barnacles as
weapons for fighting during times of competition symbiotic. A response
by Dr. Phil Clapham explains the relationship:
There is no symbiosis between whales and barnacles as far as we can
tell. Barnacles use the whale as a substrate, essentially hitching a
free ride and filter-feeding off the water around the whale. If
anything, they are a disadvantage for the whale since they create some
drag in the water.
There is a rather better case for symbiosis - albeit speculative - in
right whales. Right whales (genus Eubalaena - now recognized by many of
us as three species: E. glacialis in the North Atlantic, E. japonica in
the North Pacific, and E. australis in the southern hemisphere) have
odd-looking bumps on their heads called callosities. These are patches
of roughened skin ("cornified epithelium") which are natural and part of
the whale. However, the callosities (and some other places on the
body)are covered with hundreds of thousands of parasites called cyamids
("whale lice" is the common term). We know these are parasitic because
their guts have been found to contain whale skin. However, the
suggestion has been made that they may serve a cleaning function
(getting rid of dead skin). A more bizarre idea is that the cyamids may
somehow cue the whale in to densities of its prey (zooplankton, mostly
copepods) around it by somehow changing their behavior. The idea is
that, by sensing the activity of the copepods, the right whale may be
able to judge the density of prey right in front of it (since right
whales need high-density patches of copepods). There is no real direct
evidence for this idea, but it's an interesting hypothesis!
http://whale.wheelock.edu/archives/ask00/0316.html.
Good luck on your project!
Kim Marshall
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