Here’s a detailed comparison to help you distinguish between the eggs (spawn) and tadpoles of the Australian green tree frog (Ranoidea caerulea) and the invasive cane toad (Rhinella marina).
Eggs (Spawn)
| Feature | Green Tree Frog (Native) | Cane Toad (Invasive) |
|---|---|---|
| Appearance | Laid in foamy clumps or jelly-like masses | Laid in long, transparent jelly strings |
| Structure | Eggs often in clusters, sometimes foamy | Eggs form double rows in a gelatinous string |
| Location | Floating on surface or attached to vegetation | Strands often wrapped around plants, submerged |
| Egg Color | Varies, but not in bead-like strings | Tiny black eggs, bead-like in appearance |
| Quantity | Hundreds to a few thousand per clutch | 8,000–35,000 eggs per clutch |
| Protection | Foam or jelly helps prevent drying and predation | No individual casing, less protected |
- Key ID Tip:
Green tree frog eggs are in clumps or foamy masses; cane toad eggs are always in long, bead-like gelatinous strings.
Tadpoles
| Feature | Green Tree Frog Tadpoles | Cane Toad Tadpoles |
|---|---|---|
| Color | Brown, sometimes with visible veins in tail | Shiny jet black on top, blue-grey/black belly |
| Shape | More elongated, tail fin slightly veined, pointy tip | Oval-shaped, broad, with a pointed snout |
| Tail | Tail fin slightly marked with veins, pointy tip | Transparent fin, short tail |
| Behavior | Often solitary or loosely grouped | Swarm in large, slow-moving groups |
| Size | Generally larger than cane toad tadpoles | Small (up to 3 cm), usually smaller than frog tadpoles |
| Breathing | Come up to surface to breathe | Rarely surface to breathe |
| Toxicity | Non-toxic | Highly toxic at all life stages |
- Key ID Tip:
Cane toad tadpoles are small, black, and form dense groups; green tree frog tadpoles are brown, larger, and more solitary.
Summary Table
| Stage | Green Tree Frog (Native) | Cane Toad (Invasive) |
|---|---|---|
| Eggs | Clumps/foam/jelly masses | Long, bead-like gelatinous strings |
| Tadpoles | Brown, larger, pointy tail tip | Jet black, smaller, oval, group together |
Other Notable Differences
- Toxicity: Cane toad eggs, tadpoles, and adults are all toxic to most native predators, while green tree frogs are not.
- Ecological Impact: Cane toads breed prolifically and their young outcompete and poison native species, including green tree frogs.
In summary:
Green tree frog spawn appears as clumps or foamy masses, and their tadpoles are brown and somewhat solitary. Cane toad spawn is laid in long, bead-like strings, and their tadpoles are small, shiny black, and gather in dense groups-plus, they are highly toxic at all stages.
