Chlorophyta

Caulerpa sertularioides

This species, Caulerpa sertularioides, is commonly known as green feather algae. It is found all over the world, including places like the Great Barrier Reef and the Philippines. Also, it is appearing in large numbers, and spreading, throughout the coral reefs on the Northern Pacific coast of Costa Rica. There, it is considered to be an invasive species.

This type of green feather algae prefers shallower, warmer waters, usually along coastlines. Depths of ten meters is most common for this species, though there have been a very small number found in water 110 meters deep.

Caulerpa sertularioides is important to the ecosystem because it provides a habitat for a number of marine species. This includes small fish and invertebrates that may also use the algae for protection for other organisms that may be seeking them as prey. Not only is it a habitat, but also a food source for smaller fish and shrimp.

Caulerpa sertularioides can reproduce both asexually and sexually. The way it reproduces asexually is through fragmentation. When fragmentation occurs, a piece of the original algae breaks off and then develops into a new individual. The new individual is genetically identical to the one it broke off of. Sexual reproduction of this begins with sporophytes. Sporophytes release spores that grow and develop into male and female gametophytes, which produce gametes. When the sperm and egg are released from the gametophyte and they enter into the surrounding water, the egg becomes fertilized when the two gametes fuse together. After the fusion the two cells form a zygote and then the zygote grows and develops into the mature algae.

This species and other species of macroalgae are able to adapt to the environment by varying their pigments. Varying pigments would allow them to grow in areas receiving different amounts of sunlight.

Ulva australis

Ulva australis is a species of the genus Ulva that is commonly known as sea lettuce. It is often found on rocks and in the sand and grows in shallow depths of up to seven meters. It also grows most abundantly in water that is 16-23°C (60-73°F).

This species is photosynthetic so one of its roles in the ecosystem is to produce oxygen. It is also an important food source for a variety of organisms such as snails, sea urchins, and crustaceans.

Sea lettuce is considered to be a bioindicator. This means that its presence can be an indicator of the health of the ecosystem. High amounts of this species indicates high nutrient concentrations, particularly nitrogen and phosphorus.

Ulva australis uses the same sexual reproduction method as the previous species.

Sea lettuce has adapted to increase their surface area and minimize their volume. They are long and wide, but are only a few cell layers thick, reducing volume significantly.

"Marine Algae." Marine Algae. Accessed January 05, 2017. http://mesa.edu.au/marine_algae/default.asp.

"Sea Lettuce." Sea Lettuce | CRD. November 14, 2013. Accessed January 05, 2017. https://www.crd.bc.ca/education/our-environment/wildlife-plants/marine-species/sea-lettuce.

"Smithsonian Marine Station at Fort Pierce." Caulerpa sertularioides. Accessed January 05, 2017. http://www.sms.si.edu/irlspec/Cauler_sertul.htm.

Report abuse