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Page 1 of 12 Octopus. The octopus (pronounced /ˈɒktɵpʊs/, from Greek ὀκτάπους (oktapous), "eight-footed", with plural forms: octopuses /ˈɒktəpʊsɪz/, octopi /ˈɒktəpaɪ/, or octopodes /ɒkˈtɒpədiːz/, see below) is a cephalopod of the order Octopoda that inhabits many diverse regions of the ocean, especially coral reefs. The term may also refer to only those creatures in the genus Octopus. In the larger sense, there are around 300 recognized octopus species, which is over one-third of the total number of known cephalopod species.
An octopus has eight arms, which trail behind it as it swims. Most octopuses have no internal or external skeleton, allowing them to squeeze through tight places. An octopus has a hard beak, with its mouth at the center point of the arms. Octopuses are highly intelligent, probably the most intelligent invertebrates. For defense against predators, they hide, flee quickly, expel ink, or use color-changing camouflage. Octopuses are bilaterally symmetrical, like other cephalopods, with two eyes and four pairs of arms. All octopuses are venomous, but only the small blue-ringed octopuses are deadly to humans.
Biology Octopuses are characterized by their eight arms, usually bearing suction cups. These arms are a type of muscular hydrostat. Unlike most other cephalopods, the majority of octopuses – those in the suborder most commonly known, Incirrina – have almost entirely soft bodies with no internal skeleton. They have neither a protective outer shell like the nautilus, nor any vestige of an internal shell or bones, like cuttlefish or squid. A beak, similar in shape to a parrot's beak, is the only hard part of their body. This enables them to squeeze through very narrow slits between underwater rocks, which is very helpful when they are fleeing from morays or other predatory fish. The octopuses in the less familiar Cirrina suborder have two fins and an internal shell, generally reducing their ability to squeeze into small spaces.
Octopuses have a relatively short life expectancy, and some species live for as little as six months. Larger species, such as the North Pacific Giant Octopus, may live for up to five years under suitable circumstances. However, reproduction is a cause of death: males can only live for a few months after mating, and females die shortly after their eggs hatch. They neglect to eat during the (roughly) one month period spent taking care of their unhatched eggs, but they don't die of starvation. Endocrine secretions from the two optic glands are the cause of genetically-programmed death (and if these glands are surgically removed, the octopus may live many months beyond reproduction, until she finally starves).
Octopuses have three hearts. Two pump blood through each of the two gills, while the third pumps blood through the body. Octopus blood contains the copper-rich protein hemocyanin for transporting oxygen.
Although less efficient under normal conditions than the iron-rich hemoglobin of vertebrates, in cold conditions with low oxygen pressure, hemocyanin oxygen transportation is more efficient than hemoglobin oxygen transportation.
The hemocyanin is dissolved in the plasma instead of being carried within red blood cells and gives the blood a blue color. Octopuses draw water into their mantle cavity where it passes through its gills. As mollusks, octopuses have gills that are finely divided and vascularized outgrowths of either the outer or the inner body surface.
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Koh Racha Yai:
Dive sites at Koh Racha Yai:
Bungalow Bay, Home Run, Lucy's reef, Eastern coast, Siam Bay etc.
Bungalow Bay:
Bungalow bay is situated on the west coast of Koh Racha Yai. Average depth is around 17 meters / maximum depth 30 meters. This site can be split; you can opt to follow either of the bay's shorelines.
The rocky formations visible above the surface continue underwater, with a good presence of reef fish. Around the rocks swim surgeonfish and fusiliers, while below you can see inquisitive paired goatfish, nudibranchs, urchins and plenty of blue spotted ribbontail rays.
Eastern Coast:
The first site begins at the northeast tip of Koh Racha Yai and heads south, the second follows the southeastern apex. Average depth is around 12 meters / maximum depth 22 meters. This is a very popular diving destination and is suitable for all levels of diver. There's also enjoyable snorkeling around the rocks in the shallow waters off the islands coastline.
The shallower sections of the reef feature table corals and smaller examples of leaf corals; the deeper waters have similar species, but larger. There are many featherstars, lionfish, puffers and a few parrotfish and wrasse.
The site's southern end has the bonus of encountering mating cuttlefish along with a greater display of reef creatures, including good sized titan triggerfish, moray eels and octopus; plus on a smaller scale, a better selection of colorful fish and invertebrates. Leopard sharks and hawksbill turtles are occasionally seen around the coastline.
Koh Racha Noi:
Dive sites at Koh Racha Noi:
The rock, North Pinnacle, Kanpela point. The beach, South pinnacle.
Northern Tip:
Average diving depth is around 17 meters / maximum diving depth 30 meters at Koh Racha Noi. A very reasonable multilevel dive site, which takes divers around pinnacles and large rocks. There is a fair display of hard corals and soft corals, and the usual reef fish are present in reasonable quantities.
If you are lucky you should be able to sight small reef sharks, but the main attraction is probably the presence of large bullet-head parrotfish, and the magical manta rays. However, diving here can be demanding because of the currents.
Southern Tip:
Average diving depth around 23 meters / maximum diving depth 40 meters +. This is a really great dive for the experienced diver. The underwater terrain is similar to that around the island's northern tip, but much deeper, the shallowest part of any consequence is at 18 meters.
Fine soft corals highlight the smooth sided boulders. Crinoids and featherstars are well represented. There are fairly plentiful, reasonably sized fish, including lionfish, parrotfish, wrasse and triggerfish, as well as large visiting pelagic's such as barracuda, rainbow runners and trevally.
Manta rays and marbled rays frequently seen here as are whale sharks, although with slightly less regularity. All in all, this site can be compared with some sites found around Ko Similan Marine National Park, Thailand.
Phi Phi Islands:
Dive sites at phi Phi Islands:
Koh Bida Nok, Koh Bida Nai, Maya Bay.
The spectacular Phi Phi islands lie in the mouth of the Phang Nga Bay and form the Haad Nopparattara Mo Koh Phi Phi National Park. White limestone crags splashed with greenery jut vertically up wards out of the clear turquoise waters to tower over magnificent sandy beaches.
You will see an amazing variety of fish life, beautiful soft corals, staghorn coral gardens and huge sea fans. On the sandy bottom, leopard sharks can be found resting. Diving in the Phi Phi islands is an experience not to be missed. From shallow sheltered bays to wall and drift dives, there's something for every level of diver.
Visibility ranges on average from 10-25 meters with weak to moderate currents. Water temperature remains a fairly constant 27 - 30C throughout the year, depths from 10 - 30 meters, and, there's plenty of marine life! For non divers the Phi Phi area offers superb snorkeling, with the opportunity to see not only beautiful coral gardens but also some of the larger fish at shallow depths.
Koh Doc Mai:
Koh Doc Mai is a small island off Phuket, In Thai language Doc Mai means "Tiny Flower".
When you scuba dive here you will see why this island has this name. Koh Doc Mai's underwater area is famous for its hard and soft corals covering the vertical outcrop. Also famous for its circumnavigational wall dropping down to 30 meters.
Koh Doc Mai also has a few caves were you will find some weird and wonderful reef species. Perfect for macro photographers who want to spot that little yellow seahorse. Lots of soft and hard corals, white eyed moray eels, schools of trevally, trigger fish and lots lots more.
For more detailed dive site information: Koh Doc Mai, Kata Beach, King Cruiser, Koh Poo, Koh Racha Yai, Koh Racha Yai Bays, Koh Racha Noi, Anemone Reef, Similan Islands,Anita's Reef, Beacon Reef, Boonsung Wreck, Boulder City, Breakfast Bend, Christmas Point, Deep Six, Donald Duck Bay, East Of Eden, Elephant Head Rock, Honeymoon Bay, Koh Bon, Richelieu Rock, Rocky Point, Shark Fin Reef, Tachai Pinnacle, Tachai Reef, Turtle Rock, Waterfall Bay, West Of Eden.
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Day Trip Diving