amphibian reproduction notes

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  • Amphibian ReproductionBy Mr. Where does a tadpole come from Chapman

  • ReproductionWhat is 1 difference between male frogs/toads and newts/salamanders on how they attract females?

    Male frogs/toads have vocal sacs to call and attract females and other males during mating season.

  • ReproductionFrogs males arrive first at the breeding sites and they emit a call (advertisement call) to attract other males and females. Males form a chorus (lots calling together).

    Females are attracted to their species adv. call. The biggest male attracts the most females.

  • ReproductionOnce the female finds a suitable mate, the male climbs on the back of the female and grabs the female from behind.

  • ReproductionThis formation is called Amplexus.

  • Anuran ReproductionTo help maintain their grip on the female, males develop rough skin patches, called nuptial pads, on the inside of the forearms. In some species males forearms and thumbs become swollen and muscular during mating season.


  • ReproductionWhile in the water the female releases the eggs and the male covers them with sperm to fertilize them.

    What type of fertilization is this?

    External Fertilization- fertilization is done outside of the body.

  • ReproductionThe eggs usually attach to plants, rocks, and some time float on the surface.

  • ReproductionIf you see an egg mass in a pond how do you tell if it is toad eggs or frog eggs?

    Frog eggs are in clumps and toad eggs are in strands.

  • ReproductionEggs (anurans) hatch into larvae called tadpoles.Tadpoles are tiny and easy prey.Females may lay up to 50,000 eggs.

  • ReproductionTadpoles have.......1. gills2. dorsal and ventral (anal) fin3. lateral line system4. Anurans have Jaws for scraping algae. - herbivores

  • ReproductionWhat is the difference between frog/toad tadpoles and salamander tadpoles?

    Salamander tadpoles are carnivorous and frogs/toads are herbivores.

  • Metamorphosis the change from a tadpole to a frogSteps in Growth:1. Develop rear legs2. Mouth begins to change from algae scraper to the wide mouth of a frog - cant eat.

  • Energy is stored in the fat of their tail.If there was plenty of fat, then some of the tail will remain after metamorphosis.If the tadpole didnt make enough fat, it will die during metamorphosis.

  • 3. Front limbs appear.4. Lungs begin to form.5. Gills are absorbed.... skull widens & eyes to top of the head.

  • Anuran Reproduction6. Mandible and Maxilla is completed7. Digestive system and enzymes must change from plant digestion to animal digestion.

    This process can take from 3 weeks to 3 years depending on species.

  • ReproductionMetamorphosis ends > froglet/toadlet can move to land. Adults - carnivores.

  • Salamander ReproductionSalamanders most species breed in late winter (Feb to mid March). They approach their pond, both males and females), on the first warm (55 degrees), rainy night of the late winter.

  • Sal ReproSalamanders do not make noises, but find each other by smell.

    In the water, males release pheromones (external hormones).

    Fs smell and approach the pheromones. Males fan the pheromones towards the F with their tail.

  • Sal. ReproductionM does a courtship dance.

  • Sal. Repro.F lays her chin on males pelvis

  • ReproductionM deposits a sac of sperm on the bottom of the pond.The sac of sperm that the male lays on the bottoms is called a Spermatophore.

  • F picks off the sperm packet with her cloaca- packet of sperm opens and fertilizes her eggs. Fertil. is internal.

    Next night F climbs onto a submerged twig and laysher eggs on it.

  • Salamander TadpolesLarvae hatch > external gills, 4 legs.

    Diet - zooplankton (tiny animals) carnivores as larvae.

  • Metam. > lungs develop > gills absorb and they leave the water. Adults carnivores.

  • ReproductionIn aquatic species they keep these external gills and are considered to be Neotinic (incomplete metamorphosis)

  • FeedingFeeding as Larva:Frog/Toad tadpoles are herbivores.Salamander tadpoles are carnivores.

    Feeding as Adult:Anurans are carnivoresCaudatans are carnivores

  • FeedingTadpoles in captivity can be fed rabbit pellets or fish flake food.