Carnivorous Algae!?

Mon, 28 Feb 1994 13:31:44 -0500 (EST)

Hi Folks,

Just an interesting addition to the fringe elements of CP. North
Carolina estuaries have been plagued in recent years by numerous unexplained
fish kills. Although apparently related to declining water quality, the exact
causes (fertilizer runoff, sewage sludge release, etc.) where always unclear.
Apparently a newly described form of dinoflagetate algae, similar to the kind
responsible for red tides may be responsible. Normally this critter lays
encysted and dormant in estuarine mud. When a fish swims by they dump the cyst
swim up as release toxins capable of killing the fish (elapse time about 30
seconds). They feed on the dead fish, then head back to the mud and reenter
the cystic phase (total time around 30 min.). When the NC Fish and Wildlife
folks arrive 1-2 days later to investigate the fish kill they find nothing.
Even if the fish leave the area they are so weakened other opportunistic
infections finish them off. This has been duplicated in aquaria too. No
Jan, this one doesn't belong on your list :-), but it does belong out there
with nematode eating fungi. Take care!

Jeff in NC
(fighting off the killer algae)