Re: NANFA-- Collecting on the St. John's River Plain

Doug Dame (dameda_at_shands.ufl.edu)
Tue, 10 Sep 2002 16:50:52 -0400

Das Boat wrote (highly snipped):

>> I caught a very, very small catfish (about 3/4 of an
>> inch long and about 1/8 of an inch tall.) It had 5 visible
>> bands on its body starting from behind the head and
>> finishing at the caudal peduncle. Almost like a bumble
>> bee goby. It had a green bar on its gill plate, and an
>> iridescent green J shaped marking running from its
>> barbels, under its eye and ending just behind its eye.
>> It was incredibly small. I would say it is probably a fry
>> of the Armored catfish but I only say that because they
>> are found sympatrically in the Saint Johns River.
>> ..... and caught a small armored catfish, (Hoplosternum
>> littorale?) that was about 3 inches, which I released.

The tiny guy was probably a Hoplosternum littorale too. I caught some small
ones recently over near Sarasota, filed a web report on them and ended up
taking them over to the USGS Non-Indigenous Species research center. According
to the expert there, the very small ones have markings that disappear
reasonably quickly. My guys were also small, one perhaps only =", but
apparently already past that blotched/banded color stage and were the normal
semi-iridescent grey/green/purple that seems to be the standard issue for
these guys when fresh-caught. Here's something else I didn't know ... they're
bubble-nest builders !!! Also they're air-breathers (and thus able to survive
in low D.O. conditions) and reportedly also have land-mobility capabilities.

Not your everyday catfish, and apparently spreading fast throughout the state
since first reported in 1995. Environmental impact: unknown, research on that
is just beginning. But they're eating and flourishing, so clearly they must be
impacting/displacing something somewhere in the food chain.

Realistically, they're pretty well established and we probably can't do much
about it ... but seeing as how they are a non-indigenous invasive fish, I've
vowed that any I don't want to keep will NOT be returned alive to the water.
(Actually, they're a decent aquarium fish, although mine have tended to die
abruptly for unknown reasons. I've seen them at the LFS for $10 apiece.)

* * * * *

Re "keeping them alive" ... I try to:
- take several 48-qt igloo coolers with me to keep the fish in
- use only "good water" from the collection site/s. (i.e., I don't bring any
from home.)
- empty the "collecting bucket" into the coolers every 15 or 20 minutes
before it gets too crowded or warm
- use killie-mops or other artificial items to provide hiding places to
reduce stress
- keep the coolers in the shade and be alert to how warm they're getting
- keep any plants I've collected in separate containers (plants in coolers
with the tops closed are going to be net consumers of oxygen, in competition
with the fish)
- try to have the coolers = full for the trip home.

With the favorable surface area and total water volume (thermal buffering, so
to speak) of regular coolers, I typically do not use either chemical or
aeration for day-trips, even here in Florida in the summer time, and on most
trips generally have minimal losses. Upon arrival home, the coolers go into
the "fish room", sit overnight with tops open to equalize temperature with the
house, and the next day I start gradually diluting the water in the coolers
with home water. Depending on how busy I am, it will be 2 to 7 days before the
fish actually migrate from the coolers to tanks.

The only other essential technique I have invented is to use a use a
single-bed size water-bed liner to keep sloshing water and other incidental
spills from soaking into the carpet of my wife's new mini-van. While
we-NANFites enjoy a certain eau de bayou when driving around doing the daily
chores (to remind us of the NANFA bumper-sticker, "I'd rather be neck-deep in
the muck"), it's a sad but true fact that many of our spouses feel otherwise.
+/- $18 at W*store, an excellent investment in domestic tranquility.

Igloo has recently come out with some new highly-insulated "5-day coolers" ...
I'm very keen to upgrade to those.

HTH

doug dame
interlachen fla
-------------------------------
"The coolers are all broken, we'll have to get some new ones."
"That's odd ... what happened to them?"
"Sledge hammer."
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