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Order: Laminariales (Kelps)
Copyright © 2006
Mary Jo Adams
Of the hundreds of species of green, red, and brown seaweeds covering the Pacific Northwest intertidal areas, the brown kelps are the jaw dropping giants which, at first sight, amaze us by both their size and their morphological varieties. They form the protective “tree top” layer for the all of the underlying seaweeds, fish, and invertebrates inhabiting kelp beds.
Kelps are attached to a hard substrate by a holdfast either disk shaped or composed of numerous finger-like projections called haptera. From the holdfast, a stem-like stipe leads to the vegetative photosynthesizing blade. New growth takes place at the junction of the stipe and the blade – an area called the meristem. The kelps we see at the beach are sporophytes, one of two alternating growth phases. At maturity special blades or patches separate from the sporophyte phase and release spores into the water. The spores will give rise to microscopic male sperm producing and female egg producing gametophytes. These remain on bottom of the seafloor - at least one kelp species gametophytes is known to have a symbiotic relationship with red seaweed. When conditions are right, the gametophytes release eggs and which unite to produce another macroscopic kelp sporophyte.
This
page was created by Jan Holmes and Mary Jo Adams on 1/6/07.
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