Leuciscus spurius, a lost mystery fish?

Leuciscus spurius was first described by Heckel in 1843 from the Qweiq in Aleppo, a region where the fish fauna was largely unknown to scientists at the time. It was frequently listed as occurring in the area by authors who copied information from Heckel’s description. After 145 years of its description, L. spurius was recorded from coastal streams in Syria, but later these fish were described as Alburnus qalilus . The generic position of L. spurius was discussed on a few occasions, partly based on the sole individual from Heckel’s collection and the accompanying illustration in the original description. Indeed, this species was never found again. A thorough examination of the type specimen in the fish collection of the Natural History Museum in Vienna revealed that the type of L. spurius is indistinguishable from the hybrids between Squalius berak and Alburnus sellal, which are often found in the Euphrates. Both parental species also occur in the Qweiq, so they are expected to hybridise there. Such hybrids exhibit a distinct phenotype that differs from their parental species. Consequently, Heckel described this individual as a different species.

Further reading. Heckel 1843 (description); Krupp 1985d (records from Syria); Bogutskaya 1994; 1997b (discussion); Turan et al. 2009a (placement in Squalius).