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.
External fertilization External fertilization is a male organism’s sperm fertilizing a female organism’s egg outside of the female’s body.[1] Internal fertilization, on the other hand, is the occurrence of internal insemination as the mode of combining sperm and egg.[2] External fertilization occurs in water or a moist area because it gives the sperm external mobility to get to the egg.[3] While in the water, the sperm and ova can shed simultaneously to fertilize the egg.[3] The release of eggs and sperm into the water is known as spawning.[4] When females spawn, they release a batch of eggs into a spot of their choice or just into the water, as in bottom dwelling or sessile species and all of the males start to release sperm that are in close proximity.[4] Within vertebrates, it is the amphibians and fish that use external fertilization.[5] When it comes to invertebrates, most are benthic, sessile, or benthic sessile combined animals such as coral, sea anemones, and tube dwelling polychaetes.[3] The benthic zone is the lowest level of the ocean where organisms called benthos reside.[6] An organism that is sessile does not have the ability to move or be mobile.[7] Benthic marine plants such as algae also go through external fertilization to reproduce.[3] Overall, environmental factors and the timing have a heavy influence over the success of external fertilization.In external fertilization some of the eggs laid by the animals gets wasted due to huge rainfall, floods etc.