The effect of environmental factors on the nesting and courtship behaviour ofTilapia zillii in Lake Kinneret (Israel)

Tilapia zillii is a polyphilic, guarding nest spawner which is widespread in west and north Africa and in the Middle East. A study of the nesting and courtship behaviour of this species in Lake Kinneret (Sea of Galilee), revealed that nesting and brood care differ according to the exposure of the nesting site to wave action and the nature of the substrate. The nests are simple and parental care is abbreviated in exposed, sandy sites whereas elaborate nests with brood chambers are excavated in sheltered areas with clayey substrates, and parental care is extensive. The implications of these findings to studies on cichlid breeding and the conservation ofT. zillii in Lake Kinneret are discussed.