Redescriptions of Aphanurus stossichii (Monticelli, 1891) and A. virgula Looss, 1907 (Digenea: Hemiuridae)

Aphanurus stossichii (Monticelli, 1891) is redescribed from Boops boops (L.) from various localities in the NE Atlantic region (off Spain), the Mediterranean (off Spain and Turkey) and the Black Sea (off Bulgaria). The material from the Atlantic coast of Spain showed differences in egg-size and shape and a characteristic ornamentation of the anterior third of the hermaphroditic duct. A comparison with samples from B. boops collected off Antalya (Turkey) and off the Bulgarian Black Sea coast revealed a considerable size variation and confirmed the presence of tubercles in the terminal part of the hermaphroditic duct. A. virgula Looss, 1907, previously considered a synonym of A. stossichii, is redescribed on the basis of voucher material from Engraulis encrasicolus ponticus Alexandrov collected off the Bulgarian Black Sea coast and previously identified as A. stossichii. A. virgula can be distinguished from A. stossichii by its smaller size and substantially lower range limits for all metrical features, the more posterior position of the base of sinus-sac, and the eggs being less numerous and larger in relation to the size of the body and gonads.