Hebrew University researchers have raised Israel's first sturgeon at Kibbutz Dan in the Upper Galilee to help Israel cash in on the world's growing demand for caviar due to declining fish populations in the Caspian Sea. Prof. Berta Levavi-Sivan, of the university's faculty of Agricultural, Food and Environmental Quality Sciences, and Dr. Avshalom Hurvitz began rearing the fish in 2000, when they brought fertilized sturgeon eggs to Israel from the Caspian Sea. It takes eight to 15 years for the female sturgeon to reach puberty and start producing eggs, while male sturgeon become fertile after four or five years. Before the age of four, it's impossible to determine the gender of the fish. The sex is then determined via endoscopy and the two sexes are separated. Male sturgeon are sold for food, while the females are kept to produce caviar. The average female sturgeon can produce $3,000 worth of caviar a year. The kibbutz is now raising 40,000 sturgeon in outdoor pools. Yigal Ben-Tzvi, the managing director of Caviar Galilee on the Kibbutz, estimates that by 2010, the company's annual revenues will reach $7.3 million. Levavi-Sivan is also now working on ways to speed up the puberty process of the female sturgeon to reduce the time it takes to produce the eggs. Sturgeon - and hence caviar - is not generally considered to be kosher due to the fish's apparent lack of scales. To be considered kosher, fish must have both fins and scales. However, Levavi-Sivan, who has undertaken similar fish-rearing projects in Uganda and the Palestinian Authority, disagrees. "If you ask me, it's kosher! I can even prove it has scales," she says, insisting that the sturgeon does in fact have tiny scales that can be viewed with a stereoscope. A number of Jewish sages - including the 12th century Jewish rabbi and scholar Maimonides - approved the kashrut of a fish called the "esturgeon." However, it has yet to be determined whether this is the same fish as the sturgeon. In the past, the Caspian Sea was the world's main source of the sturgeon that produce the black fish roe delicacy. However, over-fishing and pollution have led to dwindling stocks in the region. While there is much demand for caviar among Israel's sizable Russian population, the kibbutz intends to export the fish to Europe and North America. While kosher caviar may be a long way from hitting Israel's supermarket shelves, the researchers hope that in the meantime, Israeli caviar will at least prove to be a profitable export.