Sunday, August 21, 2016
A Quick Guide To Some Of The Fish You Will See Diving In Phuket Thailand and The Similan Islands IX
Here in Phuket Thailand and many parts of the tropics the Parrot fish is seen just about everywhere. They are sometimes alone or in large groups. They come in so many different colors just as the flying parrot does. They also have a strange swimming style which uses the fins just behind the gills to swim with just as birds have their wings. These can be seen just about anywhere but in the marine national parks like the Similans then they can be found in large schools (or flocks) as they can resemble flocks of birds. The Similan island national park is only open for 6 months of the year and is patrolled all year to keep out all fishing boats and any boat thats there out of season. This keeps the Similan islands as some of the best scuba diving Thailand has to offer.
Parrot fish are named for their dentition; their numerous teeth are arranged in a tightly packed mosaic on the external surface of the jaw bones, forming a parrot-like beak which is used to rasp algae from coral and other rocky substrates (a process called bioerosion). Many species are also brightly coloured in shades of blue, green, red and yellow, but are not especially popular as pets. Although they are considered to be herbivores, parrot fish eat a wide variety of organisms, that live on coral reefs. Some species, for example Bolbometopon muricatum may include corals (polyps) in their diet. Their feeding activity is important for the production and distribution of coral sands in the reef biome and can prevent algae from choking coral. The teeth grow continuously, making it hard to curb overgrowth in the aquarium. Ingested during feeding, coral rock is ground up by the pharyngeal teeth. After they digest this it is excreted as sand thus at times creating small islands and the idyllic sandy beaches of the Bahamas and Caribbean. This is quite clear in the tropics too which is what makes a Similan liveaboard so appealing. One parrot fish can chew coral into 90 kg of sand each year. Maximum sizes do not vary widely within the family, with the majority of species reaching 30 centimeters to 40 centimetres (16 in) in length. However, a very few species, such as the humphead parrot fish , are much larger, up to 100 centimeters. Their bodies are deep, with large, thick cycloid scales, large pectoral fins and homocercal tail fins. The pectorals are the parrot fish's primary means of locomotion, the tail only used when speed is required. Some parrotfish females can turn into male parrot fish.
The development of parrot fish is complex and accompanied by a series of changes in color termed polychromatism. For most species, adult males and females have different color, the females usually displaying drab tones of green, brown or gray, and the males a vivid, neon color. In the Mediterranean parrotfish (Sparisoma cretense), it is the females that have neon color with the males being a drab gray. ParrotfishIn most species, the juveniles have a different color pattern than the adults and some tropical species this juvenile coloration can be altered temporarily to mimic the appearance of other species. As the juveniles mature they enter what is termed the initial phase coloration during which they may change color and gender. For most species, initial phase fish are usually males that have the beginnings of the adult male coloration. However, initial phase fishes may include generally mature females. The many varieties of color the parrot fish has presented to us are all part of the many phases the parrot fish goes through. Feeding parrot fish of most tropical species form large schools grouped by size. Fights of several females presided over by a single male are the normal in most species, the males vigorously defending their position at any challenge. If the dominant male of a school is removed, one of the females will change gender and adopt the dominant male role. Parrot fish are pelagic spawners; that is, they release many tiny buoyant eggs into the water which become part of the plankton. The eggs float freely, settling into the coral until hatching.
A commercial fishery exists for some of the larger tropical species. Their meat is rarely consumed in the US; however, it is considered a delicacy in many other parts of the world. Protecting parrot fish is proposed as a way of saving Caribbean coral reefs from being overgrown with seaweed. Although any good Phuket dive shop is strongly against fishing on these reefs they are around in huge numbers and they are a great quality meat. But again they do keep the reefs clear of weed and stop the reefs from choking. large numbers can also chew through vast areas or coral in a very short time if the delicate balance is disrupted too much.
A number of parrotfish species, including the Queen parrotfish (Scarus vetuala) excrete two different mucus types during day and night. Prior to going to sleep each night, the parrotfish extrudes mucus from its mouth, forming a protective cocoon that envelopes and secures the fish at a particular location and hides its scent from any predators. It also acts as an early warning detection system, allowing the parrotfish to flee, when it detects its protective membrane is disturbed by predators, such as a moray eel. The mucus also has antioxidant properties to repair any bodily damage and to repel any parasites, which when produced during the day, provides added protection for the parrotfish from UV light.
As said for many other types of fish. Here in Phuket scuba diving we are blessed with great day trip sights just off the coast. You dont need to go on a Similan liveaboard to get great diving and see all these amazing creatures. But as anyone who has been will tell you that the Similan diving is as good as people say and if you can make the time to join one of the Similan islands liveaboards then you really should and you may just see the giant Humphead Parrot fish.