New data on the morphological differences of anchovy eggs ( Engraulis encrasicolus L) in the Black Sea

Abstract

A survey was carried out on anchovy eggs in the Black Sea, within the framework of the international Coms Black programme, during the main spawning period in July 1992. Length measurements of anchovy eggs displayed regional differences, as did egg shape. The mean size of eggs found in the northern area was: longitudinal diameter, 1.18 mm (range 1.00–1.37 mm); transverse diameter, 0.74 mm (range 0.62–0.87 mm). The mean size of eggs found in the southern area was: longitudinal diameter, 1.11 mm (range 0.95–1.25 mm); transverse diameter, 0.66 mm (range 0.50–0.80 mm). Eggs in the northern Black Sea were bigger and oval in shape, while both oval and elongated eggs occurred in the southern Black Sea, and of these the elongated eggs were mainly found in coastal regions. The size and shape of the anchovy eggs could not be correlated with salinity and temperature. The occurrence of smaller, elongated eggs in the southern Black Sea, which are characteristic of the Marmara anchovy, might indicate migration of the Marmara anchovy into the Black Sea, which has not previously been recorded.