Good Afternoon Everyone!
For our tide pool ecosystem, I have selected the octopus as my main research organism. Octopuses belong to the Cephalopoda class under the Coleoidea clasde and are among the smartest of molluscs. They mainly credited for their agility, ability to camouflage, and having complex learning behavior. Currently there are 800 identified living species of cephalopods. All cephalophods have arms, but not necessarily tentacles. The combined strength of their arms and the suckers underneath them allows octopuses their flexibility and speed. Their ability to rapidly change color is affected by the presence of chromatophores that can extend and contract to reveal or hide spots on their skin. Their intelligence is largely due to their centralized brain and they are the largest of all invertebrates.
Reference for This Entry
Octopus Rubescens
After a brief hiatus from our last post, we figured it's time to move back into our Tide Pool project. We may have been gone for several weeks, we were still fast at work in our research. Today I would like to announce the species I will be conducting my research primarily on: Octopus Rubescens (also known as the red octopus).
Image from: Octopus Rubescens Berry, 1953. Dave Cowles. May 1997. Walla Walla University. May 03, 2011 <http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Mollusca/Cephalopoda/Octopus_rubescens.html>
They are relatively small in size with their body ranging from 15-20 cm in diameter. Being an invertebrate, they lack a skeletal structure. Their body is consist of muscular tissues with a reddish and bumpy outside appearance. Much of their diets consists of mollusks, crabs, and various small preys. Some of their defense mechanism includes a venomous internal beak and melanin ink sprays. While mostly found along the shallow western coastline of North America, they are heavily dependent on tidal levels in terms of food supplies and providing for their offspring. In a research study conducted by the National Marine Fisheries Service, the octopus rubescens have three different types of capture methods when hunting. One of them is the pouncing method where they abruptly attack their prey from below. The second form requires them to use their legs to form a net near the sea floor to capture unwary preys. The third form is the "side arm attack" where in a stationary position, the octopus would attempt to sweep their prey with one arm.
Reference for This Entry
(National Oceanic and Atmospheric Administration. Baxter, Charles and John Butler. 1995. "Feeding on Euphausiids by Octopus Rubescens." May 03, 2011. <http://swfsc.noaa.gov/publications/FED/00169.pdf>)
(Marine Life 1011. Evergreen State College. February 29, 2011. "Octopus Rubescens." May 03, 2011. <http://wikis.evergreen.edu/marinelife1011/index.php/Octopus_rubescens#Biology>)
Geological Interaction
Its relation with the geological aspects of the ocean is that it’s a bottom dweller. Their habitat is consisted of kelp beds, rocky areas, and sandy mud bottoms. Their source of food, mostly small crabs, hermit crabs, and krill, are found on the sediments. Based on an observation by the National Marine Fisheries Service, one of the octopus’ hunting method, the pounce attack, involves the octopus from rising from the seafloor to attack unsuspected prey from underneath. They also considered the seafloor as more comfortable grounds as they would return to the bottom to consume their prey. Both adults and larvae use the sediments as a hiding ground from predators. Adults would bury themselves under the sand for extended periods of time to avoid predators while larvae settle in sediments until they’re mature.
Image From: Photos of the Week #17. Dave Beadle. August 10, 2005. Divebums. May 06, 2011. http://www.divebums.com/week/Aug15-2005/index.html
Reference for This Entry
(Marine Life 1011. Evergreen State College. February 29, 2011. "Octopus Rubescens." May 03, 2011. <http://wikis.evergreen.edu/marinelife1011/index.php/Octopus_rubescens#Biology>)
Octopus Rubescens Berry, 1953. Dave Cowles. May 1997. Walla Walla University. May 03, 2011 <http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Mollusca/Cephalopoda/Octopus_rubescens.html>
Chemical Interaction
The Red Octopus is a highly sensitive animal. There are thousands of chemical receptors throughout its body. Although rarely happened, the red octopus can deliver a venomous bite if provoked. As part of their defense mechanism, they release ink to help cover their movements. As a result, they’re partly responsible for the low level of melanin to concentrate in oceans. The Red Octopus is also sensitive to densities of water as one of their methods of attack, according to the National Marine Fisheries Service, involves them in being suspended in waters more than 1m from the seafloor. As a result, densities of water affect the hunting behavior of the red octopus.
Image From: Octopus Fishing - Fripp Island, South Carolina. Barry Gooch. 2011. Cooperative Research Program of South Carolina Department of Natural Resources. May 06, 2011. http://www.sciway.net/sc-photos/beaufort-county/octopus-fishing.html
Reference for This Entry
(Marine Life 1011. Evergreen State College. February 29, 2011. "Octopus Rubescens." May 03, 2011. <http://wikis.evergreen.edu/marinelife1011/index.php/Octopus_rubescens#Biology>)
Physical Interaction
Waves and currents do not affect the red octopus as much as tides since their primarily mode of travel, according to Evergreen State College, is through jet propulsion of water. Because their primary habitat is in the tide pool, they’re affected by tidal levels. In times of low tides, they would be forced to crawl to areas of water. Female red Octopi also have constantly tended to their eggs since the movements of tides would dry their eggs. Female octopi often crawl to moist areas to gather water to bring back with them to spray their eggs with.
Reference for this Entry
(Marine Life 1011. Evergreen State College. February 29, 2011. "Octopus Rubescens." May 03, 2011. <http://wikis.evergreen.edu/marinelife1011/index.php/Octopus_rubescens#Biology>)
