The Israeli Journal of Aquaculture - Bamidgeh 54(2), 2002
The Annual Dan Popper Symposium


DIFFERENCES IN RESISTANCE TO KOI HERPES VIRUS
AND GROWTH RATE BETWEEN STRAINS OF CARP (CYPRINUS CARPIO)
AND THEIR HYBRIDS


Yechiam Shapira¹, Ayana Benet-Perlberg², Tanya Zak², Gideon Hulata³, Berta Levavi-Sivan¹*

1 Department of Animal Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University, Rehovot 76100, Israel
2 Aquaculture Research Station Dor, M.P. Hof Hacarmel 30820, Israel
3 Department of Aquaculture, Institute of Animal Science, Agricultural Research Organization, Volcani Center, P.O.Box 6, Beit Dagan 50250, Israel


Abstract

Following the temperature change in the beginning of spring 1998, an outbreak of unknown etiology caused mass mortality in koi and carp (Cyprinus carpio) on the northwestern coast of Israel. The disease resulted in 40-90% mortality of fingerlings and mature fish within three weeks. Preliminary bacteriological and virological studies revealed virus-like particles in the nuclei and cytoplasm of respiratory epithelial cells of the gills, identified as Koi Herpes Virus (KHV). To improve the genetic resistance of local carp strains, frozen sperm of a wild carp was brought from Czechoslovakia (Cyprinus carpio haematopterus; Sassan; S) to increase heterosis by producing hybrids.

We compared crosses and hybrids of three strains of local and wild carp (WxW, UxU, WxU, WxS, SxU) by challenging them with the virus using cohabitation. The hybrid WxS was the most.resistant (60% survival), while UxU was the most sensitive (8% survival). Differences in survival between the hybrids can be used to estimate the genetic mechanism of the resistance trait.

Other commercial performance factors (growth rate, feed consumption, survival) were tested in outdoor ponds to evaluate economic value. The WxS hybrid, due to its low fertility rate, had a small advantage in all the above parameters. No significant differences between the other hybrids were recorded.

*Corresponding author. E-mail: sivan@agri.huji.ac.il

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