aquaculture

The Center for Tropical and Subtropical Aquaculture (CTSA) is one of five regional aquaculture centers in the United States established by the U.S. Department of Agriculture. The regional aquaculture centers integrate individual and institutional expertise and resources in support of commercial aquaculture development.

The Center produces a number of publications, including this ‘Manual for Commerical Production of the Gourami, Trichogaster trichopterus, a Temporary Paired Tank Spawner‘.

Gouramis are commonly known as labyrinth fishes. These fish are characterized primarily by an accessory breathing organ called the labyrinth organ. The labyrinth organ is located next to the gill cavities and is made up of folded membranes mounted on a bony frame. The delicate tissue has a high concentration of blood vessels and functions much like a terrestrial lung. If a labyrinth fish is denied access to the air it will drown because the gills alone will not provide sufficient oxygen to the fish.

This ‘lung’ adaptation is essential in the oxygen depleted waters that are home to gouramis. The image below shows typical Trichogaster habitat.

Interest in eel farming in New Zealand began in the late 1960s, and in the early 1970s there were five trial eel farms, ranging from a traditional Japanese outdoor pond farm to an indoor intensive heated water system. By late 1975 only one farm remained. The reasons for farm closures were combinations of high overheads, slow growth, persistent disease problems and associated mortality, and uncertain supplies of glass eels. Today there is an upsurge of interest in eel farming to supply markets in Southeast Asia and Europe which have been affected, at least in part, by reduced supplies of glass eels of Northern Hemisphere species.

NIWA’s Christchurch laboratory has carried out trials on the early culture of glass eels of both the common New Zealand species, the shortfinned eel (Anguilla australis) and the longfinned eel (Anguilla dieffenbachii). The relatively modest aims of the first year’s programme were to develop suitable culture techniques, to develop experience in the husbandry of juvenile eels, and induce them to feed.

World First in Shortfinned Eel Production – July 2005
A New Zealand research team has scored a world first by not only being the first to successfully breed the shortfinned eel in captivity, but also in hatching commercial quantities of any eel species.

Scientists at the Warkworth-based Mahurangi Technical Institute (MTI) have, in the last few weeks, achieved spectacular results in their eel breeding project, a breakthrough which has the potential to end severe shortages constraining the international eel farming industry.

“This is one of only a handful of occasions that eels of any species have ever been produced in captivity in the world and, we believe, the only time they have been hatched in commercial quantities,” says MTI Director, Paul Decker. “When literally thousands of hatchlings began emerging in the middle of the night, at 3am, the whole team was so excited we felt like parents again.”

The project team at MTI has been working on breeding New Zealand’s shortfinned eel, Anguilla australis, for the past five years.

It’s hard to imagine anyone would try to establish an aquaculture facility specialising in raising Mbuna – the african Rift Lake cichlids – outdoors – in Southern Oregon’s harsh temperatures. But, if there’s enough water, at the right temperatures, anything is possible.

This report outlines how Ron Barnes tapped an abundant local supply of geothermally heated water and is commercially breeding thousands of african cichlids for the specialty tropical fish market on the U.S. West Coast and beyond.

A seasoned fisheries expert, Barnes earned a bachelor of science degree in marine biology from the University of California, Santa Barbara, and a masters in aquaculture from University of California Davis. He started out wholesaling tropical fish in Santa Cruz, CA, in 1988, before buying a small and remote (located near Merrill in the Lower Klamath Valley – about 10 miles south of Klamath Falls), tropical fish hatchery in 1990.

Barnes raises more than 100 different varieties of fish, including cichlids from Central America that also thrive in his alkaline geothermal water. He stocks no more than three species per pond to prevent interbreeding. Minnow traps are used to catch the bulk of the two-inch fish he sells, while a seine is used to catch larger fish and brood stock. Barnes and assistant Pete Booth perform all necessary chores at the year-round breeding and growing facilities.

Sturgeon AquaFarm is a Florida USA based aquaculture operation is dedicated to restoring the world’s resources of sturgeon. The company was established in order farm various sturgeon species for commercial production of sturgeon meat and caviar – beluga, osetra, sevruga.

Sturgeon are prehistoric fish that can live up to 100 years and grow to be 2800 lb. Further images of these huge freshwater fish can be found at anglingbc.com’s sturgeon fishing gallery. Some of the sturgeon photographed there are over 2 metres (7 ft) long. Sturgeon are fine sporting fishing.

Species of sturgeon are also natives of Canada – SaskPower is a proud partner in a number of initiatives to protect Saskatchewan’s ecosystem and species at risk, including the lake sturgeon.

The lake sturgeon is the largest freshwater fish in Canada – it can grow to more than two metres in length and weigh more than 140 kilograms. These slow-maturing fish have been known to live more than 150 years. With an outer armour of bony plates, bones made of cartilage and a shark-like tail, sturgeon resemble fossils from the Upper Cretaceous period, more than 100 million years ago.

Species of sturgeon are also found in the Caspian Sea. Iran has participated in efforts to build sustainable fishing industry. This has included the release of more than 123 million juvenile sturgeon and bony fishes into the Caspian Sea in Guilan Province.

The Growth Performance and Food Conversion Ratio of Siberian Sturgeon (Acipenser baeri Brandt) at Different Daily Feeding Rates has been documented in Turkey.

The Cui-ui lakesucker, Chasmistes cujus, is listed as an endangered species, and Pyramid Lake, in Nevada, USA, is the only place in the world where it is found. The Pyramid Lake Paiute Tribe built a hatchery based in Sutcliffe in 1973 – it is now operated and maintained by the Pyramid Lake Fisheries.

The US Fish and Wildlife Service and the Tribe are conducting ongoing recovery efforts, focusing on the lower Truckee River. The hatchery is a precautionary measure against the extinction of the Cui-ui. In drought years, when there is not enough flow in the Truckee River to support ‘natural’ spawning, the hatchery is able to produce a viable year-class, which is vital to a healthy population structure.
Cui-ui once flourished in Pyramid Lake but the population began to decline after the construction of Derby Dam and the establishment of the Newlands Reclamation Project in 1905. Subsequent agricultural diversions further reduced the amount of water entering Pyramid Lake. As the Lake’s surface elevation receded, downcutting along the river resulted in the formation of a sand-bar delta at the mouth of the river which blocked access to the Cui-ui spawning grounds. Cui-ui are fresh-water spawners, and their eggs cannot survive in Pyramid Lake water.