Alabama shovel sturgeon

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Alabama shovel sturgeon
Alabama shovel sturgeon

Alabama shovel sturgeon

Systematics
Subclass : Cartilage organoids (chondrostei)
Order : Sturgeon (Acipenseriformes)
Family : Sturgeon (Acipenseridae)
Subfamily : Shovel sturgeon (Scaphirhynchinae)
Genre : Scaphirhynchus
Type : Alabama shovel sturgeon
Scientific name
Scaphirhynchus suttkusi
( JD Williams & Clemmer , 1991)
Alabama shovel sturgeon

The Alabama shovel sturgeon ( Scaphirhynchus suttkusi , English : Alabama sturgeon ) is an endangered species of fish from the family of sturgeon (Acipenseridae). It is endemic in the so-called Mobile Basin , below the waterfalls in Alabama , Tombigbee and Cahaba River , in river sections with a total of only 130 mi (210 km). The fish has a characteristic yellow-orange color and can grow up to 30 in (76 cm) long and 2-3 lb (0.9-1.4 kg) in weight. It is assumed that the animals live to be 12–20 years old. Biologists have known the fish since the 1950s / 1960s, but the species was not described until 1991.

Surname

The German and English as well as the scientific name refer to the shovel-shaped rostrum . Scaphirhynchus translated means "spade snout". The scientific nickname "suttkusi" honors the ichthyologist and fish collector Royal D. Suttkus .

features

The Alabama shovel sturgeon has big eyes. The length reaches 6.5 to 8.2 times the width of the head, usually 2.3-2.6 ft (70-80 cm). The sturgeons are characterized by rows of bone plates (scuta) along the sides and four barbels on the underside of the rostrum . The number of lateral bone plates behind the dorsal fins is 27–32, the dorsal bone plates 15–21 and the plates between the anal fin and the caudal fin attachment 7–8. The back and most of the dorsal, pectoral and caudal fins are brown-orange. The sides of the body on the abdominal row of bones turns yellowish. The abdomen, pelvic fins, and most of the anal fin are cream-colored.

distribution and habitat

The species is endemic to the Mobile Basin in Alabama. The species description was based on 32 museum specimens from the Alabama , Cahaba- , Coosa and the upper Tombigbee River . Burke and Ramsey collected five specimens in the lower Alabama River in 1985. Only three other animals have been caught in the Alabama River since 1993, all downstream of the Claiborne Lock and Dam . The type location is Smith Lake , Monroe County , Alabama.

The species prefers deep, fast-flowing waters over sandy or gravelly bottoms. Williams and Clemmer found mainly insect larvae in the stomachs of the animals. On March 21, 1969, 12 specimens, including 2 females ready to spawn, were caught at the mouth of the Cahaba River . This suggests that the species spawns in late March through early April.

Protection efforts

At the beginning of the 1990s, a protection status was considered for the first time, although the survival of the species was already uncertain at that time. Protective measures were rejected by a number of industrial companies feared economic obstacles. The opponents assumed that the species could no longer be saved or was already extinct or was not a species of its own. The US Fish and Wildlife Service then failed to put the fish on the list of threatened species. It was only when Ray Vaughan , an environmental attorney in Montgomery, Alabama , complained about the service and won the case in 2000, that the Fish and Wildlife Service was obliged to grant the fish protection status.

In 1993, state and federal biologists started a conservation breeding program with caught fish. Unfortunately, only six specimens, all of them males, have been caught since then. The last specimen in captivity died in 2002. In April 2007, another specimen was caught. Since this animal was also a male, its sperm was removed, it was equipped with a transmitter and after a complete recovery it was released again. Unfortunately, a year of follow-up has not resulted in more copies.

In May 2008 the Fish and Wildlife Service proposed the establishment of a 245 mi (394 km) section on the Alabama River and 81 mi (130 km) on the Cahaba River as a sanctuary. The rivers are dammed in various places and water management should not be changed in the foreseeable future. In August 2013 the Fish and Wildlife Service published the "Recovery Plan for the Alabama Sturgeon ( Scaphirhynchus suttkusi )". This now includes a plan for a breeding group and improvements to the habitat through structural measures at Claiborne and Miller's Ferry Lock and Dams .

Individual evidence

  1. ↑ a b Katherine Bouma: Alabama sturgeon caught in Wilcox, raises hopes for possible breeding. In: The Birmingham News 2007-04-05 Archivlink ( Memento of September 27, 2007 in the Internet Archive ).
  2. ↑ Williams and Clemmer, 1991.
  3. ↑ Burke and Ramsey, 1985, 1995.
  4. ↑ Katherine Bouma: Alabama sturgeon a male, to be freed carrying tracker. In: The Birmingham News 2007-04-06 archive link ( September 30, 2007 memento in the Internet Archive ).
  5. ↑ Katherine Bouma: Biologists hope tagged sturgeon will lead to others. In: The Birmingham News 2007-04-18 archive link ( September 30, 2007 memento in the Internet Archive ).
  6. ↑ Sean Reilly: "Critical habitat" set for sturgeon. In: Press-Register 2008-05-27. Archive link ( memento from September 27, 2012 in the Internet Archive ).
  7. ↑ WTVY.com: Alabama Sturgeon Recovery Plan Released ( February 1, 2014 memento on the Internet Archive )

Web links