Ocean
Watch
Monday, July 3, 2000
This season,
beware catfish
scratch fever
Catfish made the news last week when their fishing
season opened at Nuuanu Reservoir. These odd-looking fish aren't native to
Hawaii; the state imported them from the mainland in the late '60s.
But are catfish native there? I wondered.
They are. And they're native to just about everywhere
else in the world, too. Over 2,000 species of catfish inhabit the fresh
and salt waters of Central and South America, Africa, Europe, Asia and
Australia.
Catfish get their name from their whiskers, which are
actually taste organs called barbels. Our familiar goatfish also have
these whiskery barbels, and both kinds of fish use them in the same way:
They poke and probe the ocean or pond floor to find food. In the case of
catfish, this is just about anything that falls to the bottom.
I once thought that catfish whiskers could sting you,
but they can't. It's the spines on the back (dorsal) fin and the two front
side (pectoral) fins that bear stingers.
Catfish use their venomous spines for defense only.
When a catfish gets agitated, it extends its spines, locks them in place
and waits. A frightened catfish strikes when a predator, including a human
hand, comes within range.
Glands lining catfishes' sharp spines store venom. When
the spine penetrates flesh, the glands rupture and venom trickles into the
wound. No one knows the exact nature of catfish venom, but catfish
handlers do know that it hurts like crazy.
The treatment for the pain of catfish stings is to
immerse the hand or foot in hot water, then wash the wound and wait. The
pain and swelling usually goes away on its own in a couple of hours to a
couple of days. Catfish envenomations can sometimes cause later
infections. If you get stung and have persistent symptoms, see a doctor.
We have two kinds of catfish in Hawaii: the American
channel catfish, imported by the state in 1969 as a food fish, and the
Chinese catfish, arriving with Chinese immigrants around the turn of the
20th century.
Channel catfish are the ones that people fish for in
the Nuuanu Reservoir. Dennis Shinno, a state fish biologist, told me that
these fish pack the biggest punch when they're small because the fin
spines are still sharp and can easily penetrate human hands. When the fish
get older, their spines get rounded off from rooting around the lake
bottom and therefore don't pierce skin easily. Chinese catfish, grown in
Hawaii aquaculture farms today, also inflict aching stings.
Shinno knows about catfish stings firsthand. Each year,
he scuba-dives in Nuuanu Reservoir to collect fertile catfish eggs from
nests the fish dig on the bottom. Because male catfish guard their nests,
the biologists must divert the fishes' attention with a stick, then take
the eggs quickly. These adult fish have dull spines so don't usually sting
the workers, but they can and do bite.
In about 10 days, the eggs hatch into fry. Biologists
feed and care for these young fish for six months to a year. If left in
the lake, most baby catfish would be eaten by tilapia and other cichlids
or starve to death. When the captive catfish are the proper size, they are
released into the reservoir for anglers to catch.
Some people claim these nearly boneless fish taste
better than salmon and trout. Judge for yourself. Look for catfish in the
fish markets of Chinatown, or try catching your own. To get a catfish
license, call the Department of Land and Natural Resources, Fishing
Licenses and Permits, at 587-0109.
Or hang around Nuuanu Reservoir for the next few weeks.
Maybe a lucky angler there will share.
