Ahead of Rosh Hashanah, Israeli scientists find carp relatives can resist deadly virus

For carp farmers, koi herpesvirus can wipe out entire populations within days. A new international study involving Israeli and American researchers has found that several close relatives of common carp may help stop the disease from spreading.

The findings arrive just before Rosh Hashanah, when many Jewish families serve carp as a symbol of abundance and prosperity. Fish heads also represent the wish to be “the head and not the tail” in the coming year, while the fish’s ability to reproduce in large numbers carries hopes of fruitfulness and blessing.

Common carp are highly vulnerable to CyHV-3, also known as koi herpesvirus. Outbreaks can cause major economic losses in aquaculture and inflict lasting damage on wild fish populations. The popular mirror carp, a selectively bred variety of common carp widely found in Europe and cultivated elsewhere, is also susceptible.

Researchers from the Hebrew University of Jerusalem and Michigan State University worked on the study for 15 years. Their results, published in Aquaculture under the title “Differences in CyHV-3 infection and infectivity among common carp and Asian carp species,” show that goldfish, grass carp, silver carp and black carp rarely become infected naturally. Even when scientists deliberately infected them, the fish resisted the virus and limited its spread.