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.
House finch The female lays clutches of eggs from February through August, two or more broods per year with 2 to 6 eggs per brood, most commonly 4 or 5. The egg laying usually takes place in the morning, at the rate of one egg per day.[14] The eggs are a pale bluish green with few black spots and a smooth, somewhat glossy surface. In response to mite infestation, which has a more deleterious effect on male chicks than on females, the mother finch may lay eggs containing females first, in order to reduce the length of time male chicks are exposed to mites. This strategy increases the liklihood that representative numbers of both sexes will survive.[15] The female incubates the eggs for 12 to 14 days. Shortly after hatching, she removes the empty eggshells from the nest.[16][17] The hatchlings are pink with closed eyes and tufts of fluffy down.[18] The female always feeds the young, and the male usually joins in.[14] The young are silent for the first seven or eight days, and subsequently start peeping during feedings.[13] Initially, the mother carries fecal sacs out of the nest, but when the young become older, she no longer carries them all away, allowing droppings to accumulate around the edge of the nest.[13] Before flying, the young often climb into adjacent plants, and usually fledge at about 11 to 19 days after hatching.[13] Dandelion seeds are among the preferred seeds fed to the young.[16] Most birds, even ones with herbivorous leanings as adults, tend to feed their nestlings animal matter in order to give them the protein necessary to grow. House finches are one of the few birds who feed their young only plant matter.[6]