Table 3

Crossing experiments

Cross

Cross type

Female

Species/hybrid

Male

Species/hybrid

N of available tadpoles (at day 7 after spawning)

Ca.%

Estimated hatching success

N of tadpoles (2 months after spawning)

% Survival (2 months after spawning)

Remarks

Survival at day 40 after metamorphosis

1

F₁

Si41

balearicus

Si11

siculus

200

> 80

158

79

malformations, some dwarfed or leucistic larvae

150

2

F₁

Si337

balearicus

Si334

siculus

100

> 80

98

98

died through technical accident

N.A.

3

F₁

Si335

siculus

Si336

balearicus

100

> 80

93

93

-

4

4

Backcross (F₁ × parental species)

Si337

balearicus

F₁ Cross 13

F₁ (bal. × sic.)

100

> 80

84

84

67 (big), 17 (small)

2

5

Backcross (F₁ × parental species)

Si335

siculus

F₁ Cross 13

F₁ (bal. × sic.)

100

> 80

91

91

-

0

6

Backcross (F₁ × parental species)

F₁ Cross 11

F₁ (bal. × sic.)

Si334

siculus

100

ca. 50

1

1

-

0

7

Backcross (F₁ × parental species)

F₁ Cross 11

F₁ (bal. × sic.)

Si336

balearicus

28

ca. 30

24

85.7

1 color mutant, all dead (at day 116 after spawning)

0

8

F₂ (F₁ × F₁)

F₁ Cross 11

F₁ (bal. × sic.)

F₁ Cross 13

F₁ (bal. × sic.)

100

ca. 20

0

0

all dead (at day 17 after spawning)

0

Control1

Intra-specific mating

Ky109

turanensis

Ky103

turanensis

50*

> 80

48

94

-

47

Control2

Intra-specific mating

Ky100

pewzowi

Ky87

pewzowi

50*

> 80

47

90

-

45

Cross number, cross type, sexes, species, estimated hatching success, numbers of tadpoles at 7 day and two months after spawning, percentage of survival two months after spawning, remarks and survival at day 40 after metamorphosis for each cross. *Note, in controls from two related green toad species, only 50 tadpoles were further raised.

Colliard et al. BMC Evolutionary Biology 2010 10:232   doi:10.1186/1471-2148-10-232