I recently saw Dr. Peter Buston from Boston University speak
about his research on the clownfish Amphiprion
percula. The talk reminded me of some fun clownfish facts.
Clownfish live in anemones that keep them protected from
predators with their stinging cells. The fish are immune to those stings and
predation is pretty much a non-issue because of this relationship. Maybe that
is how they live so long!
When eggs hatch the larvae are dispersed into the water and
rarely settle on their family anemones (this makes sense when you think about
genetic diversity). Makes you wonder how Nemo ended up in the same anemone as
Marlin in “Finding Nemo.”
Each anemone can have a group of clownfish living in it – a
breeding pair and possibly some others. The group dynamic is based on a size
hierarchy – the largest and most powerful fish is the breeding female. In these pictures from Horn Point Lab you can see that the size difference in breeding pairs.
If the female dies, the next largest male then rises to the
occasion – literally. The male will turn into a female and the most dominant
fish in the group! That gives a whole new twist to “Finding Nemo” – Marlin
would have become Mandy after Coral got eaten by the barracuda at the beginning
of the movie.
When I worked at Horn Point during college (the same place I
learned more about Blue Crabs) we had a few projects going on with clownfish.
The lab was doing feeding studies to learn what food would make the clownfish
grow the fastest and have the best coloration. The idea was to figure out how
to breed the best-colored clownfish fast for the aquarium trade. Using
aquaculture to breed clownfish is a better option for aquarist because the fish
aren’t taken from reefs in the wild – sometimes by environmentally damaging
methods like cyanide fishing.
The clownfish were by far the favorite animal of the school
kids who came through to visit over the summer. One thing I remember about the
clownfish is that they were quite territorial. We would put terracotta tiles in
the tanks for the females to lay their eggs on – mimicking the hard surface
that an anemone would attach to in the wild. Then the female would lay her eggs
and after several days we had to take the tiles out of the tank, transfer them
to another tank, and count all the eggs.
It was the lab joke to have the newest person reach in to take out the tiles – without telling them that the fish would fight for it! I remember them drawing blood a few times. In high salinity water, that wasn’t a good time but watching the babies hatch out and grow was totally worth it.
It was the lab joke to have the newest person reach in to take out the tiles – without telling them that the fish would fight for it! I remember them drawing blood a few times. In high salinity water, that wasn’t a good time but watching the babies hatch out and grow was totally worth it.
Visit Dr. Buston’s website to learn more about his research.
Photos by Sara K. MacSorley
