BIOL 1902 Lecture Notes - Embryonic Diapause, Altricial, Skink
20 Jul 2012
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Walking stick eggs end up underground too: eggs guarded by ants. Northern water and garter snakes internally hold eggs until they hatch: ovoviviparity, do not guard their young. Female wolf spiders carry eggs in an egg sac held by the spinnerettes. Female nursery web spiders carry the egg sac in their chelicerae (jaws: before hatch, they build a nursery web and guard the sac. Giant water bugs offer male-only parental care. All of these animals provide very little parental investment internally. 95% of mammals, females provide all of the parental care. Moose have 8-month gestation with a placental connection. Wolves, coyotes and red foxes exhibit biparental care. Black bear cubs are born highly altricial. Opossum more altricial: born after 12-day gestation. Bears mate in june and give birth january: gestation is 2 months. Delayed implantation allows bears to mate and to give birth when the time is right!
