O. G. Dely szerk.: Vertebrata Hungarica 21. (Budapest, 1982)
Berger, L., Uzell, Th. ; Hotz, H.: Crossing experiments between some Western Palearctic species of water frogs (Salientia: Ranidae) 33-46. o.
In the series in which all tadpoles metamorphosed, the time between appearance of forelimbs on the first and last Individuals was usually 3 to 12 days. Two crosses between Italian non-hybrids and hybrids (crosses 9, 10) had a wider range of dates for onset of metamorphosis. The females laid eggs 30 and 31 July. Initially, the tadpoles developed outdoors, but after 11 September, they were placed in an incubator at 28°C. The last tadpole metamorphosed 5 November. Nine tadpoles of cross 9 began to transform within 13 days (days 74 to 86), but the 10th, which was scoliotic, transformed on day 98. In cross 10, 18 tadpoles began to transform somewhat sooner, within 9 days (days 70 to 78), but two were abnormal. One, which was scoliotic, transformed on day 91, the other, which was completely black, transformed on day 93. The vitality of the progeny and the time required for development depended on the parental combination and on the progeny phenotype, as can be seen from comparisons between half slbs that shared one parent (Table 2). Italian hybrid male H 2i was crossed with three females (Table 2, crosses 5-7). All tadpoles derived from R. lessona e eggs completed metamorphosis earlier than the others. Two tadpoles derived from R . rldlbund a eggs had not metamorphosed by day 47 and were preserved; the others metamorphosed on average in 42 days. Tadpoles derived from eggs of an Italian nonhybrid metamorphosed on average in 75 days, but these results are not comparable, since development took place outdoors. The eggs of R. lessona e female 9/79 varied in size. Only one of the three triplold tadpoles derived from the three large eggs was normal; It metamorphosed on day 37; diploid tadpoles derived from medium-sized eggs metamorphosed later, between days 38 and 46 (mean 39.8; Table 2, cross 5). Tadpole size. Table 3 gives the body lengths of selected series of tadpoles to point up certain regularities. In general, tadpole length depended on the parents. Tadpoles derived from eggs of and R. esculent a female were much larger when the father was not a hybrid than when It was (cross 1, 2). This same pattern can be seen In crosses 9 and 10, but in this case the hybrids and non-hybrids are the females. Among the tadpoles fathered by Italian hybrid H21, those derived from R. lessona e eggs were longer than those derived from R. rtdibund a eggs (crosses 3,4). The variation in body Table 3. Comparison of body lengths of some series of progeny from crosses of water frog forms Parents Body length of tadpoles (mm) at day 34 of development Body length of froglets (mm) after metamorphosis N/y 9 TF N Range Mean N Range Mean 1. 2. 7/79a E N 37 7/79b E H22 8 65-70 68.4 7 46-62 56.7 8 22.8-25.0 23.9 6 21.0-23.0 21.8 3. 4. 9/79 L H 2I 10/79 Rt H 2I 16 60-70 66.0 16 50-72 61.7 16 19.8-23.0 21.3 14 19.5-23.0 21.7 5. 6. 9/79 L H 2I 10/79 Rt H 2I Common aquarium 8 63-69 65.9 8 46-65 55.7 8\ 19.4-23.0 21.6 7 \ 20.2-22.4 21.1 \ 7. 8. 10/80a L N38 5/80 R N38 9 62-71 67.0 20 65-77 70.1 9 22.0-24.3 23.2 18 20.8-25.5 23.4 9. 10. 7/81 H Pf 9/80 L P12 8 21-25 22.4 15 56-67 62.0 8 17.2-19.0 18.0 15 19.2-21.6 20.4 Explanations in Table 1.
