Fertilization

External

Most frogs and some salamanders (cryptobranchidae, sirenidae)

Amplexus

• Axillary = back pack

• Cephalic = behind, grabs head

• Inguinal = behind, grabs waist

• Straddle = on head

• Glued = attached to behind

Salamanders — polyspermy

• many sperm but only one fertilizes egg

Internal

most salamanders, a few frogs, caecilians, all reptiles (shelled eggs)

• Frogs Cloacal apposition = butt to butt

  • Male tailed frog — extra cloacal part gets everted to hold on

• Intromittent organ — penis

  • crocs and turtles = spongy tissues

  • squamates = hemipenes, uterine horns = directionality

• Caecilians — eversible cloaca = phallodeum

• Salamanders — spermatophores taken in by female

sperm storing

Alternate Methods

Hybridogenesis, Gynogenesis, Kleptogenesis, Partjenogenesis

Hybridogenesis

passes only female genome

female hybrid can mate with closely related male species but will only reproduce females with her genome

Gynogenesis

sperm may stimulate egg development but is not used genetically

clones of female

mole salamanders

Kleptogenesis

gynogenesis but steals genes from male genome to shuffle into offspring

Parthenogenesis

reproduction without sperm

female clones

female -female mating may stimulate ovulation