when do brine shrimp produce eggs versus live birth
Brine shrimp Males differ from females by having the second antennae markedly enlarged, and modified into clasping organs used in mating.[12] Adult female brine shrimp ovulate approximately every 140 hours. In favourable conditions, the female brine shrimp can produce eggs that almost immediately hatch. While in extreme conditions, such as low oxygen level or salinity above 150‰, female brine shrimp produce eggs with a chorion coating which has a brown colour. These eggs, also known as cysts, are metabolically inactive and can remain in total stasis for two years while in dry oxygen-free conditions, even at temperatures below freezing. This characteristic is called cryptobiosis, meaning "hidden life". While in cryptobiosis, brine shrimp eggs can survive temperatures of liquid air (−190 °C or −310 °F) and a small percentage can survive above boiling temperature (105 °C or 221 °F) for up to two hours.[11] Once placed in briny (salt) water, the eggs hatch within a few hours. The nauplius larvae are less than 0.4 mm in length when they first hatch. Brine shrimp have a biological life cycle of one year.
Fetal pig The prenatal development of the fetus includes all the tissue and organ development. Within hours of mating, the sperm and egg undergo fertilization in the oviduct and three days later the egg moves into the uterus. The cells begin to specialize by day six, and attach themselves to the uterus lining by day eleven. From fertilization to day 18, the endoderm, ectoderm and mesoderm have been forming inside the embryo, and are completely formed by day 18, the same day the placenta forms. The endoderm transforms into the lungs, trachea, thyroid gland, and digestive tract of the fetus. The ectoderm has a greater role in the development of the fetus. It forms into the skin, nervous system, enamel of the teeth, lining of the intestine, mammary and sweat glands, hoofs, and hair. The mesoderm forms the major organ components that help keep the fetus alive. It forms the muscles and connective tissues of the body, blood vessels and cells, the skeleton, kidneys, adrenal glands, heart, and the reproductive organs. By day 20, most of the major organs are visible, and the last half of gestation focuses greatly on increasing the size of the fetuses.[13]