This article presents population and biology facts related to
gulf sturgeon, Acipenser oxyrinchus desotoi.
The gulf sturgeon is a subspecies of the Atlantic sturgeon and
was first described and recognized as a subspecies in 1955. Besides
genetic differences, gulf sturgeon differ from the Atlantic
sturgeon in relative head length and pectoral fin length, shape of
dorsal scutes (bony plates), and length and position of the spleen.
It is very difficult to visually differentiate gulf from Atlantic
sturgeon. Gulf sturgeon are native to the Gulf of Mexico, from
Florida to Louisiana.
Gulf sturgeon were listed as a threatened species on October 30,
1991, pursuant to the Endangered Species Act of 1973. Gulf sturgeon
have been covered under Appendix II of the Convention on
International Trade in Endangered Species of Wild Fauna and Flora
(CITES) since April 1, 1998. Appendix II includes species that may
become threatened with extinction if their trade is not regulated
The gulf sturgeon is an ancient fish first appearing in the
fossil record 225 million years ago and evolving to its current
form around the same time as sharks. They have a cartilaginous
backbone and external scutes, which cover their head and the top
part of their body. In addition, they have an asymmetrical caudal
(tail) fin with the top half being larger than the bottom half. The
head of the gulf sturgeon consists of a long snout preceded by four
sensitive tactile barbels (fleshy protuberances similar in function
to cat's whiskers) which sense prey.
The gulf sturgeon is anadromous and spends the major part of the
year in freshwater, migrating to saltwater in the fall. Gulf
sturgeon return to their natal stream to spawn. The best river
habitat for gulf sturgeon are long, spring-fed free-flowing rivers.
Steep banks and a hard bottom with an average water temperature of
60 to 72 degrees Farenheit are also characteristic of rivers where
sturgeon inhabit. Sturgeon occupy the river bottom downstream of
springs where they seek thermal refuge during hot summer days.
Movement from the gulf and up-river movement generally occurs
between February and April, while down-river movement occurs
between September and November.
Sturgeon can live to be over 40 years old. Some sturgeon species
can reach 10 to 12 feet in length and weigh over 1,200 pounds;
however, the gulf sturgeon averages five to six feet in length.
Sexual maturity of the female gulf sturgeon range from eight to
seventeen years; whereas, male gulf sturgeon mature between seven
and twelve years of age.
Adult sturgeon primarily feed during the winter months in marine
or brackish water; however, adult sturgeon eat very little during
their time in freshwater rivers. The gulf sturgeon diet consists of
benthic-dwelling organisms such as isopods, amphipods, mollusks,
crabs, grass shrimp, marine worms, and insect larvae. The gulf
sturgeon's mouth is tubelike and toothless. It operates like a
vacuum and can suck shrimp and polychaete worms from their