California two-spot octopus
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|California two-spot octopus|
|Immature Octopus bimaculoides|
|Octopus bimaculoides at the Santa Monica Pier Aquarium|
Pickford & McConnaughey, 1949
The California two-spot octopus (Octopus bimaculoides), also known as the "bimac" octopus, is an octopus species found off the coast of California. One can identify the species by the circular blue eyespots on each side of its head. Due to their friendly temperament and relative hardiness, they are considered by most experts to make the best pet octopus. Bimacs usually live to be about two years old. They are closely related to Verrill's two-spot octopus (Octopus bimaculatus).
This species of octopus is found in the intertidal and benthic zones, from the low tide to subtidal depths of about 20 m (65 ft). It prefers sandy substrate and caves of rock or debris for hiding. It tolerates a wide temperature range (at least 60-80°F), though it prefers 65-72°F.
O. bimaculoides reaches a mantle size of 7 inches (17.5 cm) and arms to 23 inches (58 cm). Not usually heavily textured, it has several common colors, such as grey with yellow splotches, and uses highly developed crypsis (camouflage or color changing to match their environment). Octopuses achieve color change in part by chromatophores, iridophores, and leucophores; all are structures of the skin in increasing depth. Chromatophores are generally known as elastic pigment sacs with muscle fibers attached to let them expand and contract. The leucophores are important because they allow for the reflection of white light and consequently allow the skin to reflect wavelengths of light which are prevalent in their habitat and produce disruptive patterns. The other aspect to cephalopod camouflage is the brain, which contains nerves coated in chromatophore fibers, controlling coloration patterning.
It gets its name from the false eye spot under each real eye known as the ocellus. In O.bimaculoides, the ocellus is an iridescent blue, chain-link circle set in a circle of black.
These octopuses live one to two years. The end is signaled by egg-laying in the female or senility in the male.
- tonmo cephcare BimacCareSheet.php
- "CephBase: California two-spot octopus". Archived from the original on 2005.
- TONMO.com: Bimac Care Sheet — Octopus bimaculoides
- eol.org: Octopus bimaculoides — Pickford and McConnaughey, 1949.