| 1. | After two months, the embryo measures long and has well-developed external gills.
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| 2. | They go through paedomorphosis and retain their external gills, thus resembling axolotls.
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| 3. | They are viviparous animals, giving birth to young that possess external gills.
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| 4. | The salamander has blood-red external gills for absorbing oxygen from the water.
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| 5. | Most other species have external gills, often associated with the parapodia.
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| 6. | The balancers eventually fall off and their external gills grow larger.
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| 7. | Four gill slits lined with gill rakers are hidden underneath the external gills.
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| 8. | When the embryo is long, the external gills are resorbed and pigmentation develops.
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| 9. | The larvae have external gills, and live in seepage areas until they metamorphose.
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| 10. | Small external gills adapted for small stream living can be found on their larvae.
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