In 1991 mass spawns of RR. RG, and GR were produced. For RR, 30X 106 C. rivularis eggs (from six females) were fertilized by sperm from three C.rivularis males (:RR-). For RG, 2l x 106 C. rivularis eggs (from the same six R females ) were fertilizd with sp€nn from frve C. gigas males ( : RG- ) . For GR, 17x 106C. gigas qgs (from six females) were fertilized by sperm from three C. rivularis mala (:GR-). No mass GG group was produced.