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- Paddlefish in the pond :

Paddlefish (Polyodon spathula)

courtesy to : www.sturgeon-web.co.uk/paddlefish-polyodon-spathula

If you ever see paddlefish for sale DO NOT buy one unless you are absolutely certain that you can provide for it's very specialized needs.

The Paddle Fish (Polyodon spathula) has been seen for sale but is very rare and extremely difficult to keep. It is a filter feeder and almost impossible to keep alive in clear water.

It needs very specialised conditions and this is beyond most fish keepers.

I have been tempted to buy these fish but the extreme condtions required caused common sense to kick in! Now farmed in many countries to produce caviar it grows very quickly and it is farmed in ponds with heavy zooplankton often with carp or catfish (polyculture; growing two species in a single pond but both used different parts of the water column).

The paddle fish swim all the time and carp/cat fish live on the bottom.

Description :

The Paddlefish (Polyodon spathula) has a very distinctive appearance. It's easy to see where the common name comes from, about 30% of the overall length of the fish is the extended paddle-shaped snout (rostrum).

The genus name, Polydon spathula, comes from the Greek (poly meaning 'many/much', odous meaning 'tooth' and spathula meaning 'blade or paddle'), 'many tooth' refers to the hundreds of gill rakers, which are specialized for filter feeding, and 'blade or paddle' refers to the shape of the rostrum.

Polyodon spathula can grow to 2.3m and 80kg with an average lifespan of 20-30 years. The body is and scaleless

and grey in colour. The tail is heterocercal. The skeleton is cartilaginous. Males are generally larger than females.

Wild distrubution :

The Paddlefish (Polyodon spathula) is a potamodromous (freshwater only) North American species found in the zooplankton rich, slow-flowing deep water of large rivers in the Mississippi River basin, including the Missouri River into Montana, the Ohio River, and their major tributaries.

The Paddlefish is listed as 'Vulnerable' on the IUCN Red List of Threatened Species.

Common names : Duckbill Cat, Mississippi Paddlefish, Paddlefish, Spadefish, Spoonbill Catfish

Taxonomy :

Kingdom: Animalia

Phylum: Chordata

Subphylum: Vertebrata

Superclass: Osteichthyes

Class: Actinopterygii

Subclass: Chondrostei

Order: Acipenseriformes

Suborder: Acipenseroidei

Family: Polyodontidae

Genus: Polyodon

Species: Polyodon spathula Walbaum, 1792

Paddlefish (Polyodon spathula)

courtesy : www.pond-life.me.uk/sturgeon/polyodonspathula

by Karen Paul

Description :

The Paddlefish (Polyodon spathula) has a long spoon-shaped snout (rostrum) which is about 30% of the overall length of the fish. The large mouth has huge gill rakers which are specialized for filter feeding. The shark-like body is grey with a deeply forked tail. The Paddlefish can reach 2.2 meters in length and a weight of 90kg.

Wild Distribution :

North America; slow-flowing water of large rivers, usually in water deeper than 1.3 m and with abundant zooplankton. Mississippi River system, including the Missouri River into Montana, the Ohio River, and their major tributaries. The Paddlefish is a potamodromous (freshwater only) species.

Vulnerability :

The Paddlefish is listed as 'Vulnerable' on the IUCN Red List of Threatened Species. Dams, habitat, and water quality are cause for concern in several locations but the majority of formerly occupied

habitats remain available to the Paddlefish. Ongoing improvements to Pallid Sturgeon breeding and nursery habitats should also benefit the Paddlefish.

Biology :

The Paddlefish is a filter feeding species.

Females reach sexual maturity at 10-12 years of age, carry 15,000 to 20,000 eggs per kg of body weight and spawn every 2-4 years.

Males mature at 7-9 years of age with spawning intervals of 1-2 years.

Paddlefish (Polyodon spathula) photo © Mikaproductions

Paddlefish (Polyodon spathula) photo © Carter Warden

Spawning occurs March-June at water temperatures of 12-18 C over a rocky substrate with a water velocity of over 1m/sec.

The larvae hatch after 8-12 days and are about 8-10mm in length. Exogenous feeding begins after 7-14 days.

The maximum reported age for the Paddlefish is 55 years. Natural feeding The Paddlefish's natural diet is plankton including copepods, small crustaceans, larval insects and algae.

Paddlefish (Polyodon spathula) photo © Mikaproductions

Paddlefish (Polyodon spathula) photo by Pssymon