subject: Yellow Bellies of Costa Rica [print this page] The first time I encountered one I was jigging in a sea of coffee with cream colored water at the mouth of the Rio Colorado. Suddenly a strike nearly ripped the rod from my hand and a golden colored blur went flying behind the boat as my jig flew back at me like it was launched from a sling shot.
"What the hell was that!," I asked my guide, Captain Eddie Brown. He laughed and answered, "Yellow Belly."
In the culture I grew up in a "Yellow Belly" was not a good thing. It usually meant you were afraid to do or try something and almost always had a dare attached to it. As a kid I once had a stingray spine imbedded between my thumb and fore finger because I would be a yellow belly if I didn't capture it in a mud flat pot hole at low tide by pinching its eyes and picking it up. Of course I'll never forget the black eye I received for snapping Carol Diffenbacher's bra strap in seventh grade on another yellow belly dare. The last thing anyone in my crowd of friends wanted to be was a "Yellow Belly."
In Costa Rica a "Yellow Belly" is a fish, a tarpon in fact and some believe it is a sub-species of the Megalops atlanticus. It is also the baddest of the bunch. They seem to be shorter and squattier than a normal tarpon, but weigh more. They are yellow to almost gold fish in color and judging by the way they fight, should be tested for steroid abuse. The best way to describe a hooked yellow belly would be a pinball bouncing off the bumpers. It moves so fast that most anglers only see a blur when it takes to the air.
Eddie Brown grew up in the jungle on the Caribbean side of Costa Rica. No one knows the waters better than him. In his half century of fishing Costa Rica and Nicaragua, he has seen it all. When he was 18, he caught a 56lb snook, not knowing anything about the IGFA. Later he held the 16lb test record for cubera snapper at 68lbs. His best day tarpon fishing, his boat jumped 126 tarpon landing 25. Now in his mid 50's he still has the fever like a young boy for fishing. Usually, the person that wins the annual tarpon fishing tournament in Barra del Colorado is fishing on Eddie's boat.
According to Eddie, yellow bellies start to appear in September and can be caught into November when the rains start to fall on the coast. They appear when the dirty flood waters come rushing from the mountains down the Rio San Juan and Rio Colorado. The fish are only hooked at the mouth of the river. These months the weather on the Caribbean is bright and sunny, while the mountainous regions are in a deluge. The ocean is also flat as a pancake.
Fishing at the river mouth can seem like a futile activity as dirty as the water is. One wonders how a fish could see a lure in this nasty water. The rushing fresh water floats on top of the salty Caribbean and below the water is fairly clear. It is common to hook several yellow bellies in a days fishing.
Didiher Chacon is a biologist who heads up the Latin America division of WIDECAST, a sea turtle conservation effort. Years ago he worked on tarpon projects here with Dr. Roy Crabtree and I helped collect samples for their studies.
Chacon explained the it is in fact the same fish and not a sub-species. Many think it is a different fish but it's diet gives it its color. These fish are trapped, sometimes for years, in backwater lagoons and Lake Nicaragua where they feed mainly on crustaceans. This diet is loaded with axtasantina, a form of beta-carotene which changes the color of the fish. This is the same reason that flamingos are the color they are. Change their diet and they loose their color. In zoos, flamingos are given beta-carotene in supplement form.
You really are what you eat.
The yellow bellies find their way down to the river mouth with the flood waters that set them free. They hang at the river mouth for a couple of reasons. There is plenty of freshwater which they have become accustomed to and there is a constant supply of what they are used to eating coming down the river.
The fish will either work there way back up the river or if they choose, stay in this new environment. If they do their diet will change as the water level returns to normal and the silver color will return to their bodies.
As far as their bull headed attitude, no one really knows, maybe they are just celebrating their newfound freedom
