Distribution of the green abalone, (MacGinitie and MacGinitie, 1949), in the Pacific Ocean ranges from Point Conception in Santa Barbara, California to the mid-coast of Baja California, Mexico.
The green abalone resides in shallow water, in depths from nine meters to eighteen meters. The abalone is found in rock crevices, and other protected cavities in the inter-tidal zones. (Buchsbaum and Milne, 1960)
The green abalone has a flattened univalve shell scored with wavy lines; five to seven raised holes lie along the shell margin. These holes are used for excurrent water flow in the process of respiration. Its shell length approaches 13 cm, and ranges in color from dark shades of maroon to brown. The inside of the shell is coated with nacre of a lustrous blue-green color. A ruffle of tissue (called the epipodium) lines the edge of the wide, muscular foot which the animal uses to crawl over hard substrata. The foot is cream and brown in color, with tubercles along the edges. (Handorf, 2000; Neuman, 2009)
The green abalone reproduces by broadcast spawning, when both sexes release their gametes into the water. ("Abalone: Reproduction and Growth", 2003)
The sex of the abalone can be determined by gonad color. The gonads are creamy white in males, and green in females. During broadcast spawning, abalones release thousands of sperm and eggs into the water column; thus, fertilization is external. There is no seasonal reproductive cycle, however. Abalone release sperm or egg into the water when they sense chemicals released during spawning by conspecifics. Spawning all at once increases the odds of fertilization. Green abalone reach sexual maturity in 2 to 4 years. ("Abalone: Reproduction and Growth", 2003)
There is no parental investment, as this species is a broadcast spawner. Halitosis fulgens releases its gametes, and the offspring are independent right from fertilization on. ("Abalone: Reproduction and Growth", 2003)
Lifespan in the wild is estimated at 30 or more years. Mortality rate of young abalone is high because of predation. Lifespan is also limited by the amount of available food. Since the abalone’s diet mainly consists of drifting algae, its lifespan is directly related to the persistence of kelp forests. Due to destruction of the kelp beds via human activities and natural events, lifespan of ("Abalone Growth and Development", 1996; Neuman, 2009; Sheets, 1974)can be affected greatly.
Depending on food availability, abalone may stay in the same general area for months. Abalone are known to compete with sea urchins for crevices in rocky substrates, but they do not formally defend a territory. ("Abalone Growth and Development", 1996; Neuman, 2009)
The diet of the green abalone mainly consists of drift and attached seaweed. Species composition of the diet is directly related to the species abundance of algae in the environment. The green abalone prefers fleshy red algae, and when food is scarce, it is forced to forage. Like all gastropods, abalone use their toothed radula to scrape and ingest their food. (Anderson, 2003; Perez-Estrada, et al., 2011)
The abalone is prey to any creature that can dislodge it from its rock. Predators include seals (Phoca vitulina), sea lions (Zalophus californiaus), sea otters (Enhydra lutris), fish, octopus (Octopus bimaculoides), and sea stars (Asteroidea). Humans are another threat to abalone as well.
The abalone's greatest natural predator is the sunflower star (Pycnopodia helianthoides). The sunflower star has no problem with the shell as it simply engulfs the entire abalone and digests it. The only anti-predator defense that has is by clamping down onto its rock or by crawling away from its predator. ("Predators & Defenses", 2007)
Strongylocentrotus franciscanus. The sea urchins protect the abalone from predators in a commensal relationship. In many cases, areas with low counts of sea urchins also show low counts of abalone. However, as the abalone grow and reach adult size, they no longer need protection from sea urchins, and competition for space begins, as both creatures prefer to inhabit the same microhabitat of rock crevices. ("Predators & Defenses", 2007)has a large role in the coastal ecosystem; as a herbivorous grazer it affects algal recruitment onto bare surfaces via its radular scraping while feeding. As a juvenile, the green abalone is easy prey for secondary consumers. The young seek refuge among rocks and under the spine canopy of the red sea urchin
The abalone's shell provides a hard substrate for epifaunal organisms to colonize, including various benthic invertebrates such as worm snails, sponges, date mussels, and bryozoans. ("Abalone: Reproduction and Growth", 2003)
There are no known adverse effects ofon humans.
Joshua Williams (author), San Diego Mesa College, Sarah Yesil (author), San Diego Mesa College, Paul Detwiler (editor), San Diego Mesa College, Angela Miner (editor), Animal Diversity Web Staff.
body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.
Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
the nearshore aquatic habitats near a coast, or shoreline.
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
fertilization takes place outside the female's body
union of egg and spermatozoan
A substance that provides both nutrients and energy to a living thing.
An animal that eats mainly plants or parts of plants.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
the area of shoreline influenced mainly by the tides, between the highest and lowest reaches of the tide. An aquatic habitat.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
seaweed. Algae that are large and photosynthetic.
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
mainly lives in oceans, seas, or other bodies of salt water.
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
movements of a hard surface that are produced by animals as signals to others
uses sight to communicate
breeding takes place throughout the year
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