Early onset of sexual maturity is a problem in cod aquaculture because of negative effects on growth, feed conversion and health. Farmed cod that escape can also affect the genes of wild fish.
Research fellow Adrijana Skugor of the food research institute Nofima has examined biological mechanisms that control the development of the sex organs in cod for her doctorate.
She has studied both individual genes and the whole cod genome to obtain more information about how the germ cells of the embryo develop into eggs and sperm.
Skugor has previously studied zebrafish and has made use of the knowledge she gained then. In zebrafish, the dead end gene (DnD) is necessary for sexual maturity, and Skugor has now been studying the significance of this gene in Atlantic cod.
She injected cod embryos with a molecule that blocks DnD and found that inactivation of the gene affected the development of germ cells also in cod. In addition, Skugor used micro array screening to study the effects of DnD inactivation in a wider context.
Several species dominate world aquaculture production. We read stories on salmon, trout, shrimp and tilapia on an almost daily basis. Of course the species deserve the attention they receive but once in a while it's refreshing to hear about something different.
Mark Zaslavsky has spent a decade trying to become the first US aquaculture company to sell farm-raised beluga sturgeon.
In 2003 Zaslavsky's shipped brood fish from Germany to his farm Sturgeon AquaFarms, Florida, USA.
Beluga sturgeon is the largest species of sturgeon, reaching 20 feet in length and a ton in weight in the wild. However, they are difficult to grow in the captivity as it takes 12 years for them to reach sexual maturity.
The next challenge for Zaslavsky is to get permission from the federal government to sell his decade-old fish.
Malta's National Aquaculture Centre may be moving home as government plans for a new site have been welcomed by various interested parties.
Since 1988, the centre has been housed in the historic Fort San Lucian in Marsaxlokk.
The Fondazzjoni Wirt Artna (the Maltese heritage trust) has supported the government's plans saying that relocation of Malta's aquaculture centre should be a top priority. The foundation has also suggested restoring a tower on the site and opening the fort as a tourist attraction.
The fort was originally built by the Order of St John in 1610 to ward off corsair attacks.
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| Beluga (sturgeon) (Photo credit: Wikipedia) |
