Biblical Zoogeography: Fishes of Jordan River and Sea of Galilee

Authors: Robert Behnke

Year: 2009 (xli)

Abstract

My understanding of the fishes of the Jordan River basin is peripheral and indirect. Thirty five years ago I was advisor for a graduate thesis on the freshwater fishes of Iran and subsequently, as advisor for thesis on the fishes of Saudi Arabia. The fishes of the Jordan basin were considered as potentially zoogeographically informative in regards to ancestors and routes of invasion. The Jordan River flows mainly below sea level. Although highly fluctuating in elevation through time, the ‘standard’ surface elevation of the Sea of Galilee (old testament name is Lake Kinneret, also Lake Tiberias) is given as 686 ft. below sea level and the terminus of the Jordan River at the Dead Sea is given as 1296 ft. below sea level. The Jordan valley is the remnant of a great rift that extended through the present Red Sea and into eastern Africa. During the Pliocene, when the southern end of the Red Sea was closed to the Indian Ocean, the Red Sea was a freshwater lake providing a route for African fishes to invade the Jordan River. Groups of Jordan basin endemic Barbus and cichlids are of African origin. The Sea of Galilee, historically, has been a highly productive fishery, significant in the early history of Jews and Christians. The most abundant species, commonly known as ‘sardine’ , is a planktivore cyprinid. It was named as a monotypic genus, Mirogrex (miracle fish), of uncertain origin and ancestry. Many years ago, Brian Coad visited and examined collections of Arabian fishes then at Colorado State University. He found a peculiar specimen collected from a permanent water area in the wadi Hadiyah, a large drainage on the NW coast of Saudi Arabia. Its diagnostic traits are intermediate between Acanthobrama and Mirogrex. In 1983, Coad, Behnke, and Al Kahem published a description of Acanthobrama hadiyahensis. The ‘sardine’ of the Sea of Galilee is highly specialized to fill a pelagic niche and is derived from Acanthobrama via an ancient connection with the Euphrates basin. I believe A. hadiyahensis is the only known example of a southward movement of fish from the Jordan basin into the present Red Sea.