Introduction to Reproduction
Reproduction is the act performed by all organisms in order to make offspring. The reproductive success of a species, which is a group of the same organism that can reproduce fertile offspring with each other, determines its survival.
There are two types of reproduction: sexual and asexual. Sexual reproduction, which is performed by the majority of organisms, is done by two different parents. It involves meiosis, uses half of the chromosomes from each "parent" to create an offspring, and results in genetically variable offspring. Asexual reproduction on the other hand, which, for example, is done by bacteria, includes only one organism, is mitosis, uses the same chromosomes to create an offspring, and results in genetically identical offspring. Asexual reproduction includes binary fission, which is the division of cells in prokaryotes, budding, which is when offspring branch and grow from the parent, fragmentation, when the piece of an organism forms a new organism, and vegetative propagation, when plants grow without the production of seeds or spores.
There are two types of reproduction: sexual and asexual. Sexual reproduction, which is performed by the majority of organisms, is done by two different parents. It involves meiosis, uses half of the chromosomes from each "parent" to create an offspring, and results in genetically variable offspring. Asexual reproduction on the other hand, which, for example, is done by bacteria, includes only one organism, is mitosis, uses the same chromosomes to create an offspring, and results in genetically identical offspring. Asexual reproduction includes binary fission, which is the division of cells in prokaryotes, budding, which is when offspring branch and grow from the parent, fragmentation, when the piece of an organism forms a new organism, and vegetative propagation, when plants grow without the production of seeds or spores.
Mitosis vs. Meiosis
Mitosis, which is used in sexual reproduction, is the division of one diploid cell into two diploid cells. For ninety percent of the time, a cell goes through interphase, its non-dividing phase. But, for the other ten percent of the time, it goes through first prophase, when chromosomes appear and the nucleus disappears, and spindle fibers form, then metaphase, when chromosomes line up at the center of the cell, then anaphase, when sister chromosomes divide, and lastly telophase, when two cells form using cytokinesis to divide the cytoplasm and move the cells apart.
Meiosis, which is asexual reproduction, is the division of one cell that results in four haploid cells, which means they have half the amount of chromosomes (meaning twenty-six in humans) and are gametes, or sex cells (sperm in males and egg in females), that will eventually be able to turn into an offspring. In meiosis, the cell also goes through interphase, prophase, metaphase, and telophase, but two times each (except for interphase).
Reproduction in Mantis Shrimp
Mantis shrimp usually mate with multiple partners, although there are cases in which they mate with one partner for life. In the process of sexual reproduction, the male mantis shrimp first "exhibits a unique courtship signaling his intentions"[1]. This happens when the male visits the female at her burrow to convince her to mate. However, the female will most likely have to be assured that the male will not try to steal the female's burrow. Because of this, male mantis shrimp that are smaller than the female sometimes are preferred when mating because they are less threatening to the female. Females will visually examine males before reproduction and observe any threatening behavior. Then, the male will insert his sperm into the female using a tube that reaches out of the body, where the sperm will meet with the female's egg and be fertilized. From there, are laid inside a furrow, or are kept on the female's front limbs. The eggs are held together by an adhesive substance made by the female. When females lay their eggs, it happens at night. During this period, the female will constantly turn and clean the eggs and will refrain herself from eating anything until the eggs have hatched. They will hatch into larvae, and finally develop into the adult stage. Mantis shrimp usually live from four to six years.
Mantis shrimp are reproductively mature at around 35 to 70 days for both males and females. Mantis shrimp reproduce year round, with gestation periods lasting from 9 to 60 days. However, mantis shrimp have "reproductive peaks during warmer months" [2}.
Mantis shrimp are reproductively mature at around 35 to 70 days for both males and females. Mantis shrimp reproduce year round, with gestation periods lasting from 9 to 60 days. However, mantis shrimp have "reproductive peaks during warmer months" [2}.