Showing posts with label Fish. Show all posts
Showing posts with label Fish. Show all posts

Monday, November 16, 2009

The Armored Catfish of Wekiwa Springs



I was at a professional development class in Florida last week, and as I usually like to do, I ran off into the nearest woods as soon as the class was over. This time it was to Wekiwa Springs State Park, which is a beautiful little park about an hour north of Orlando. I saw some pretty cool things there, including an armadillo, which we don't get in Jersey (sorry, I only got a blurry photo of his butt as he was running away).

The photo above is of the river filling with armored catfish (aka Orinoko sailfin catfish, plecostomus, pleco). These are an invasive species that has been spreading throughout Florida since about 1971. It is believed that they escaped and/or were released from aquariums and aquarium fish farms. They are originally from the Orinoco River basin in Venezuela and Colombia.

Here is a closeup from the Army Corp of Engineers, who is interested in these invasives because they like to destroy what the Corp has built.



During the day these catfish burrow into the river banks, causing erosion. At night they come out by the thousands to feed. All of the fish in the top photo are facing to the left, so the water flowing from the spring washes algae and small critters right into their mouths. Every once in a while, they come to the surface and take a gulp of air. All of this gulping sounded like someone was dropping stones into the water. These fish were very close to the spring, which apparently has low oxygen content as it comes out of the ground. Armored catfish can breath air fairly well, and can survive out of the water up to 30 hours!

Three types of heron - a green, a little blue and a great blue (named Henry according to the ranger) - stood to the side, patiently trying to find something to eat besides an armored catfish. Because of their tough, armored skin and sharp spines, these have been known to choke birds who tried to eat them. But the bears love them. The ranger told me that last year a group of volunteers "gigged" (speared) 5000 of them and left them out in the woods for the bears.

Here is some more info about these invasives and the damage they can cause.