Seaweed Reproduction
Seaweed is grouped in two types of categories, perennial seaweed and annual seaweed. Seaweeds that are perennial may live for many years, whereas annuals live for only one year. Annual seaweeds usually begin its growth during the spring and continue throughtout the summer. They may lose stipes and blades during powerful fall and winter storms, but if the holdfast manages to survive, new blades will sprout again during spring.
Alternation of generations
In the joining of specialized male and female reproductive cells, called gametes, seaweeds can reproduce sexually. The adult seaweed plant cells are diploid, which means they contain two sets of chromosomes. Diploid plants, sporophytes, poduce and release spores. Spres are produced by a cell division process (meiosis) that halves the number of chromosomes and forms two new cells each containing only one set of chromosomes (haploid cells).
After being released from the sporophyte, the haploid spres settle and grow into gametophytes. The gametophytes then produce sperm or eggs. When the sperm and egg are fused together, a diploid zygote is formes, and as the zygotes develop into diploid sporophytes, the cycle continues.
Some seaweeds also reproduce asexually, through a process that does not involve gametes. Fragmentation or division occurs when parts of the seaweed plant breaks off and can regrow directly into new plants. All seaweed plants that result from asexual reproduction are clones. Offspring and parent seaweed plants are genetically identical.