Nudibranch – Species of the Reef

The colourful nudibranch

One of the most brightly coloured species of the reef the Nudibranch, is a strange and beautiful creature.  Nudibranch literally means “naked gill”.  They have no hard bones or shells to protect their gills.  They are often refered to as sea slugs, although a lot more beautiful then the commmon garden variety.  They feed on soft corals and are immune to the toxins that some of these corals produce.  They come in a large variety of bright colours and forms. these colours help them blend in with the corals in their surronding environment.

They have the sex organs of both sexes but do not normally fertilize their own eggs.

Trigger Fish – Balistidae

The Trigger Fish

Triggerfish derive their common name from a stout first dorsal spine which can be locked into potion by a small second spine, looking like a trigger.  The trigger is used by the fish to wedge themselves into coral crevices at night.  They come in a variety of beautiful colors and patterns, making them something to behold. These fish are also characterised by a leathery skin and a small mouth with powerful, crushing jaws.  But don’t worry they do not are not looking to you for a meal. However, sometimes they guard their nest as we guard our homes.  Triggerfish feed on a wide variety of invertebrates including sponges, gorgonians, crabs, shrimps, molluscs and echinoderms.  They are often seen head down ‘blowing’ water into the sand to excavate food. They swim by undulating the second dorsal and anal fins, bringing their tail into action only when speed is needed.

Turtle Rescue Cairns – Saving the Sea Turtle

Cairns Turtle Rehabilitation Centre was established as a facility designed for treatment of ill and injured turtles in Far North Queensland and Cape York Peninsula. The centre works towards the recovery of threatened marine turtle species in conjunction with a local veterinary clinic. Since 2002, 21 turtles have been successfully rehabilitated and released in the region where they were found. Unfortunately 24 turtles have died during attempts at rehabilitation, a not unexpected result when considering the poor condition of these animals when brought into the centre. The majority of the stranded animals brought to the centre from Great Barrier Reef waters had ‘floaters disease’ with only one suffering from fibropapilloma virus. Qantas -Link Airlines has assisted in transport of turtles from the west coast of Cape York Peninsula where the Napranum Land Protection Unit rescued many stranded turtles. These have been injured due to entanglement in ‘ghost nets’. Injuries can be so severe that flippers have been lost or had to be amputated.
Donations Can be made at:
Marlin Coast Veterinary Surgery
Cnr Aropa St & Cook Hwy, Trinity Beach, QLD 4879
Phone: +61 (0)7 4057 6033

Giant Clams – Species of the Reef

One of our guests’ favourite sights on our Great Barrier Reef Tours are the Giant Clams. They come in various brilliant colours and impressive sizes, colours include bright purples, reds and blues. Divers get to experience the larger specimens up close, but if you are not a certified diver don’t worry you can probably take an introductory dive (FAQ#5).

The giant clam, Tridacna gigas, is the largest living bivalve mollusk. They can weigh more than 200 kilograms (440 pounds), measure as much as 1.2 metres (4 feet) across, and have an average lifespan in the wild of 100 years or more. By day, the clam opens its shell and extends its mantle tissue so that the algae receive the sunlight they need to photosynthesize.

History and Legend
As is often the case with uncharacteristically large species, the giant clam has been historically misunderstood. It was known in times past as the killer clam or man-eating clam, and reputable scientific and technical manuals once claimed that the great mollusk had caused deaths; versions of the U.S. Navy Diving Manual even gave detailed instructions for releasing oneself from its grasp by severing the adductor muscles used to close its shell.
Today the giant clam is considered neither aggressive nor particularly dangerous. The process of closing the shell valves is slow enough not to pose serious threat. Furthermore, many large individuals are unable to close their shells completely.

Conservation Status
The IUCN lists the giant clams as vulnerable. There is concern among conservationists for the sustainability of practices among those who use the animal as a source of livelihood. The numbers in the wild have been greatly reduced by extensive overharvesting for food and the aquarium trade. On the black market, giant clam shells are sold as decorative accoutrements, and the meat, called Himejako in Japan, is prized as an honor.

Giant clams are found in abundance on our dive sites, and make brilliant photos that you are sure to treasure for years. If you don’t have a underwater digital camera, you can hire them through us as well. Just let us know at time of booking or the day before the trip.

Scuba Diver and Giant Clam