The Homozygosity of Clones of the Self-Fertilizing Hermaphroditic Fish Rivulus marmoratus Poey (Cyprinodontidae, Atheriniformes)

Two clones of the hermaphroditic fish Rivulus marmoratus Poey, identified by their intraclonal histocompatibilities and interclonal histoincompatibility, were kept through successive uniparental generations, each fish in isolation. These hermaphrodites emit internally self-fertilized eggs incubated up to 2 1/2 days intraparentally and thereafter extraparentally. By extraparental incubation at low temperature, primary males can be produced at will from eggs otherwise yielding hermaphrodites. Secondary males originate from hermaphrodites, usually late in life, if the ovarian component of the ovotestis involutes. There are no females. Eggs from an aberrant hermaphrodite chronically emitting un-self-fertilized eggs were cross-fertilized artificially and also naturally by sperm from a primary male. A fin graft from the clone of the male parent was accepted (autograft reaction) by the interclonal hybrid, showing that amphimixis had occurred and that the clone of the graft donor is homozygous for the histocompat...