Paddlefish are poor subjects for home aquaria. They grow large, need lots of
food, and damage their sensitive rostra easily. Occasionally, hatchery
reared juveniles are for sale in pet shops, as appears to be the case in
Taiwan and Bangkok, but you should resist the urge to purchase these
undeniably cute fish. The best place to observe and admire paddlefish is in
public aquaria. Even here, most specimens have damaged rostra and are
conspicuously skinnier than their brethren in the wild. Although the paddle
may be useful in locating microscopic prey, it does a poor job of telling
the paddlefish when it's about to bump into the aquarium glass and various
submerged structures. Should you insist in keeping juvenile paddlefish,
elliptical tanks or round pools (e.g., kiddie wading pools) are preferred,
the larger the better.
Even though they're primarily plankton feeders in the wild, aquarium-kept
paddlefish readily adapt to commercially prepared foods. At the Tennessee
Aquarium, paddlefish are fond of pellets and will flip upside down to take
them from the surface. They're also fond of live brine shrimp, which are
dripped into the tank through an air hose leading from a bucket placed above
the water's surface. The paddlefish immediately sense when the brine shrimp
begin hitting the water and commence their open-mouthed, filter-feeding
behavior. Aquarists at the Mississippi Museum of Natural Science allow their
paddlefish to filter feed by turning off filters and dropping a "plankton
cocktail" into their tank a couple of times a day.
I checked some hatchery reports in my files, and 23'C seems to be the
thermal maxima of the species. When paddlefish are oxygen-starved, they are
often seen "billing," in which they swim with their rostra out of the water.
The function of billing appears to be the paddlefishıs effort to deflect
oxygen-rich water from the surface into its mouth. Billing paddlefish have
stopped feeding and soon die.
Chris Scharpf
Baltimore
/-----------------------------------------------------------------------------
/"Unless stated otherwise, comments made on this list do not necessarily
/ reflect the beliefs or goals of the North American Native Fishes
/ Association"
/ This is the discussion list of the North American Native Fishes Association
/ nanfa_at_aquaria.net. To subscribe, unsubscribe, or get help, send the word
/ subscribe, unsubscribe, or help in the body (not subject) of an email to
/ nanfa-request_at_aquaria.net. For a digest version, send the command to
/ nanfa-digest-request_at_aquaria.net instead.
/ For more information about NANFA, visit our web page, http://www.nanfa.org