68
A. R. MAIN
within the egg membrane without water being present. When the
burrow is flooded by winter rains the larvae hatch immediately.
Where Reveral species occur sympatrically, e.g. Beechina 30 milea
east of Perth, breeding of albqunctatw, eyrei, pearn~nuphihs and inornatua oocurs at the same site and burrows of the species occur within
feet of each other. Lee (1967), in a study extending over several years,
found only three males with intergrading calls which he regarded aa
hybrids from the crom H. eyrei x H . pamm.uphiZus. These findings
indicate that hybridization between the siblings H. eyrei and H . psammuphilw is rare and suggest that introgression between the species does
not occur. Such a conclusion suggests that gravid females actually identify the call of con-specific males and go to a burrow when one is calling.
A pictorial representation and tabulation of the physical characteristics of the distinctive calls is shown in Littlejohn and Lee (1955), Littlejohn (1967), Littlejohn and Main (1969), and Littlejohn (1965).
Because of the peculiar method of egglaying and embryonic development it has been found extremely difficult to apply the technique of
in Vitro crosses to confirm species status. Lee (1967) attempted 116
in Vitro crosses but in only 30 were the controls sufficiently successful
to test hybrid inviability. The results obtained show that when either
barycragw or inmnatus are crossed to the other species, few embryos
develop 8s far as gastrulae and none hatch as normal larvae. Crosses
between eyrei, p8ammophih.a and albopunctatua usually produce gastrulae and frequently produce a few larvae (Lee, 1965, 1967) but
abnormalities are common.
On the basis of theae crosses alone, one could only say that barycragwr
and inornatw were distinct from the other three species of the genus.
However, the sympatric occurrences of the distinctive call types without the production of intergrading male calls are taken aa conclusive
evidence that each distinct call type is characteristic of a population
which is reproductively isolated from the other different call types.
B. Neobatrachus
The genus Neobalrachua is composed of moderate-sized burrowing
frogs. Small heavily pigmented eggs are laid in water. The genus waa
formerly synonymised with Hekioporus by Boulenger (1882). However, Main (1966a) has shown that the two are morphologically and
biologically very distinct and that their similarities in appearance are
superficial and related to their similar burrowing habits.
The breeding biology of the genus is typical. Eggs are laid in long
strings in ponds recently formed by rain showers. Neobatrachus pelobatoides lays eggs following winter rains, while the other three western
species lay eggs following warmer (usually summer) rains.
A. R. MAIN
within the egg membrane without water being present. When the
burrow is flooded by winter rains the larvae hatch immediately.
Where Reveral species occur sympatrically, e.g. Beechina 30 milea
east of Perth, breeding of albqunctatw, eyrei, pearn~nuphihs and inornatua oocurs at the same site and burrows of the species occur within
feet of each other. Lee (1967), in a study extending over several years,
found only three males with intergrading calls which he regarded aa
hybrids from the crom H. eyrei x H . pamm.uphiZus. These findings
indicate that hybridization between the siblings H. eyrei and H . psammuphilw is rare and suggest that introgression between the species does
not occur. Such a conclusion suggests that gravid females actually identify the call of con-specific males and go to a burrow when one is calling.
A pictorial representation and tabulation of the physical characteristics of the distinctive calls is shown in Littlejohn and Lee (1955), Littlejohn (1967), Littlejohn and Main (1969), and Littlejohn (1965).
Because of the peculiar method of egglaying and embryonic development it has been found extremely difficult to apply the technique of
in Vitro crosses to confirm species status. Lee (1967) attempted 116
in Vitro crosses but in only 30 were the controls sufficiently successful
to test hybrid inviability. The results obtained show that when either
barycragw or inmnatus are crossed to the other species, few embryos
develop 8s far as gastrulae and none hatch as normal larvae. Crosses
between eyrei, p8ammophih.a and albopunctatua usually produce gastrulae and frequently produce a few larvae (Lee, 1965, 1967) but
abnormalities are common.
On the basis of theae crosses alone, one could only say that barycragwr
and inornatw were distinct from the other three species of the genus.
However, the sympatric occurrences of the distinctive call types without the production of intergrading male calls are taken aa conclusive
evidence that each distinct call type is characteristic of a population
which is reproductively isolated from the other different call types.
B. Neobatrachus
The genus Neobalrachua is composed of moderate-sized burrowing
frogs. Small heavily pigmented eggs are laid in water. The genus waa
formerly synonymised with Hekioporus by Boulenger (1882). However, Main (1966a) has shown that the two are morphologically and
biologically very distinct and that their similarities in appearance are
superficial and related to their similar burrowing habits.
The breeding biology of the genus is typical. Eggs are laid in long
strings in ponds recently formed by rain showers. Neobatrachus pelobatoides lays eggs following winter rains, while the other three western
species lay eggs following warmer (usually summer) rains.