Animal PregnancyAnimal Biology

by: Miko Atkins, Staci Davis, and Ofelia Patrick

Topics of Discussion● Pregnancy in Deuterostomes● Pregnancy in Protostomes● Gestation Periods

Deuterostomes● Morphologically complex● Share similar development● Variable morphology & behavior● Develop anus first, as opposed to protostomes

4 Phyla of Deuterostomes:- Echinodermata: sea stars & sea urchins- Hemichordata: acorn worms- Chordata: vertebrates- Xenoturbellida: worm-like organisms *more recently discovered

Deuterostome Gestation Period

Sea Horse 14 days - 4 weeks

Starfish No gestation period, but the time it takes for a fertilized starfish egg to develop into a baby starfish is around 2 months depending on the species

Human 36-40 weeks

Chimpanze 32-33 weeks

Humpback Whales 12-15 months

Elephants 20-21 months

Deuterostome Gestation

The Seahorse

https://www.youtube.com/watch?v=GMzMuLmjMW4

Male Pregnancy… Yes, Males

Ummm i’m sure there must be some type of mistake...

We’re not related riiight???

Protostome Reunion

● Protostomes have true tissues, they are bilaterally symmetric, and the mouth develops first during embryonic development

● Protostomes also have an anterior brain, central nervous system, and a coelum.

Protostomes

Development of C. elegans ● There are precisely 959 cells

during development● Development of C. elegans

from larvae to adulthood takes 2.5 days at 25 degrees celsius.

● During periods of starvation C. elegans develops into Dauer larvae, once food is available the dauer larvae reaches the L4 stage and the life cycle takes about 3 days.

C. elegens

C. elegans Embryonic Development

Snail Embryonic Development

HCG Placenta produces Stop ovaries from maturing egg ea month during pregnancy High level= increase nausea and vomiting

Hormones in pregnancy

Progesterone corpus luteum produces until 10 weeks then placenta takes over production relaxes uterus muscle, help keep immune system healthy relaxes smooth muscle and blood pressure increase hair growth

Estrogen develop fetus organ and other bodily systems enhances uterus response to oxytocin responsible for skin changes

Oxytocin stretches cervix for labor stimulates milk production Prolactin prepare breast tissue for lactation and milk release