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.

length among the latter was, however, much greater. This difference was evén more marked when the two sets of tadpoles developed in the same aquarium (crosses 5, 6). In tadpoles that developed in separate 300 liter basins, in contrast, among the 95 tadpoles of each kind caught on day 48, the tadpoles derived from R. lessona

e eggs were slightly smaller (25-53 mm, mean 48.7) than those derived from R. ridibund

a eggs (39-57 mm, mean 49.7). The 95 tadpoles derived from R. lessona

e eggs were, however, slightly heavier (mean weight 1.69 g compared to 1.54 g) than the 95 derived from R. ridibund

a eggs. The tadpoles fathered by an Italian non-hybrid (Table 3, crosses 7, 8) presented a marked contrrst to those fathered by the Italian hybrid. Those derived from R. lessona

e eggs are shorter than those derived from R

. ridibund

a eggs

. When the two sets of tadpoles developed in separate 300 liter basins, the difference was even more marked. On day 42, we caught in one basin 49 individuals (14 froglets, 35 tadpoles) of 50 larvae derived from R. ridibund

a eggs, while in another we caught 65 individuals (18 froglets, 47 tadpoles) of 70 larvae derived from R. lessonae eggs. The tadpoles derived from R

. ridibund

a eggs were much longer(55-72 mm, mean 64.5) than those derived from R. lessona

e eggs (33-55 mm, mean 49.8). The difference is primarily in tail length relative to trunk length (Plate II: A-B). Tail length was 1.79 times body length in the R

. ridibund

a - derived tadpoles, 1.48 in those derived from R. lessona

e eggs. Body lengths of froglets were rather similar (cf. crosses 7, 8). Table 4. Morphology of froglets from crosses of the following water frog forms Parents Frogs Indices N/y 9 (f N Mean body length (mm) DP/CI T/CI L/T N/y 9 (f N Mean body length (mm) Range Mean +SD Mean +SD Mean +SD 1. 8/79 N32 N 8 23.8 2.46-3. 09 2.82 .17 9. 22 .52 2. 08 .08 2. 14/81 N N 7 22.6 2.67-2. 92 2.79 .10 8. 82 .24 2. 08 .05 3. 13/79 N H 10 18.2 2.50-3 33 2.87 .22 9 40 .62 2 08 .06 4. 14/79 «S3 H21 20 19.6 2.40-3 45 2.84 .15 9 50 .76 2 10 .06 5. 23/81 N Pf 8 18.6 2.80-3 11 3.00 .11 9 47 .39 2 15 .07 6. - 7/81 H Pf 8 18.3 2.78-3 57 3.20 .29 10 48 1.07 2 14 .08 7. 2/80 L N38 18 21.9 1.73-2 25 2.07 .13 7 60 .36 2 30 .07 8. 6/80 L N38 20 22.0 1.42-2 35 1.96 .23 7 31 .61 2 46 .28 9. 7/80 L n38 19 22.3 1.78-2 30 2.12 .15 7 80 .38 2 32 .13 10. 10/80a L N

38 9 23.2 2.15-2 42 2.28 .09 8 19 .27 2 32 .05 11. 10/80b L N 10 23.8 2.33-2 52 2.41 .06 8 62 .33 2 39 .18 12. 13/80 L N 20 18.5 1.64-1 91 1.79 .07 6 86 .30 2 46 .09 13. 12/81 N L 10 21.0 2.08-2 54 2.32 .15 8 02 .35 2 31 .08 14. 5/80 R N38 18 23.4 1.37-2 95 2.62 .35 9 12 .46 2 13 .13 15. 7/79a E N37 8 23.9 2.91-3 37 3.19 .14 10 29 .44 1 96 .04 16. 9/79 L H

2I 16 21.3 2.18-2 73 2.49 .13 8 55 .27 2 36 .06 17. 7/79b E H

2

2 6 21.8 3.20-4 00 3.49 .25 11 24 .54 2 02 .10 18. 10/79 Rt H

2I 16 21.9 3.10-3 55 3.31 .12 10 84 .77 2 09 .08 19. 1/80 L Pl2 15 20.4 1.91-2 45 2.15 .15 7 95 .33 2 25 .09 20. 9/81 L Pf 8 20.3 2.27-2 80 2.60 .17 8 85 .32 2 24 .09 21. 15/81 L Pf 8 20.4 2.33-2 70 2.50 .14 8 56 .33 2 22 .06 Italian non-hybrid - N, Italian hybrid - H, R. perez

l from France - Pf and Portugal - Pj2, R. lessona

e - L, R. ridibund

a - R, R. rldlbund

a from Turkey - Rt, R. esculent

a - E, DP - length of digitus primus, CI - length of callus Internus, T - libia length, L - body length, N/y - successive number of female (N) and year (y) of laying the eggs, N - number of Individuals, SD - standard deviation