Production of Triploids and their Reproductive Capacity in Rana rugosa

Kashiwagi Keiko

Scientific report of the Laboratory for Amphibian Biology

Of the 1209 eggs of Rana rugosa refrigerated after insemination with sperm of the same species, 832 (68.8%) cleaved normally, and 338 (28.0%) became normally feeding tadpoles. By counting the chromosomes of these tadpoles, it was found that 254 (82.5%) were triploids (3n=39), seven were diploids, eight were mosaics, and the remaining 39 were uncertain in ploidy. Of the triploid tadpoles, 242 became normally metamorphosed frogs and 11 of them were reared until sexual maturity. No significant differences were observed between these triploids and the control diploids in development and growth rate. All the 211 triploid frogs were males or hermaphrodites which were transforming into males. Of the 2272 eggs from four field-caught females mated with eight of the 11 triploid males, 360 (15.8%) cleaved normally and 136 (6.0%) became normally feeding tadpoles. Only one of these tadpoles completed metamorphosis, while none of the eggs of the same four females mated with the other three triploid males cleaved normally. The chromosomes were counted in 81 tadpoles produced from four diploid females mated with five triploid males. The results showed that 79 of them were aneuploids between diploid and triploid, and the remaining two were diploids.

Zoology [ 480 ]

eng

Institute for Amphibian Biology, Hiroshima University

[Created] 2006-03-21

[ISSN] 0386-3166

[NCID] AA00837669