Know your islands
Under the clear blue sea surrounding Cayman, busy communities of ocean creatures live together in brightly coloured structures called coral reefs.
The coral reef around the Cayman Islands is home to many different types of fish and creatures.
The reef system contains a delicate balance between the animals and plants. Ecology is a term meaning the relationship between the habitat, the plants, and the animals that live there. The balance of this relationship forms an interconnection of the entire system. Effecting one part of the system can change the entire system. Photographs generously provided by Nick Buckley.
A cleaning station is a location where fish, and other marine life, gather to be cleaned. The cleaning process includes the removal of parasites from the animal’s body (both externally and internally), and can be performed by various creatures (including cleaner shrimp and numerous species of fish, especially wrasse, butterflyfish and gobies). There are more than one hundred known species of shallow water fish which engage in cleaning on a full to part time basis. Hosts include reef and pelagic animals; rays, sharks, bony fishes, groupers, turtles, crustaceans, sea urchins, starfishes, even marine mammals. If the parasites are not cleaned away, they quickly multiply until the fish becomes sick.
Many hosts assume unnatural positions in front of potential cleaners to signal to the cleaner fish that they will not eat them. They strike motionless, open-finned poses, on their sides, head up, head down, even upside down to get the cleaners attention. Several hold their gill covers open, allowing the filaments to be cleaned. Color changes are common among fishes seeking to be cleaned. The cleaner fish will then eat the parasites directly from the skin of the cleaned fish. It will even swim into the mouth and gills of the fish to be cleaned. Cleaning stations are often associated with coral features, located either on top of a coral head or in a slot between two outcroppings.
A turtle cleaning station is a place where sea turtles gather in order to get their shells and skin cleaned by various algae and parasite eating fish. Turtles will assume one of several cleaning postures or lie on the reef to allow the fish to scrape away the algae or get at the parasites. Gobies are primarily fish of shallow marine habitats including tide pools, coral reefs, and seagrass meadows; they are also very numerous in mangroves and salt marshes. The gobies form the family Gobiidae, which is one of the largest families of fish, with more than 2,000 species in more than 200 genera. Most are relatively small, typically less than 10 cm (4 in) in length. Gobies include some of the smallest vertebrates in the world, like species of the genera Trimmaton and Pandaka, which are under 1 cm (3/8 in) long when fully grown. There are some large gobies, such as some species of the genera Gobioides or Periophthalmodon, that can reach over 30 cm (1 ft) in length, but that is exceptional. The most distinctive aspect of goby morphology is the fused pelvic fins that form a disc-shaped sucker. Gobies can often be seen using the sucker to adhere to rocks and corals.
Cleaning Symbiosis is a mutualistically beneficial behavior involving the removal of harmful and unwanted materials from hosts and food for cleaners. The types of behavior and kinds of organisms involved as cleaners are highly varied. This behavior may be so casual as to appear accidental, or else they may involve complex relationships, the hosts and cleaners being completely dependent on each other.
The role of cleaning symbiosis is a source of nutrition. It may be an adaptive role, only providing a food supplement or it may be what the cleaner species must do for food collecting. Some cleaning organisms are highly specialized, physically and behaviorally, but most cleaners are not so highly specialized, obtain only part of their nutrition from this behavior. Regardless, cleaners are crucial organisms in many community ecosystems, with large pelagics coming to visit, and happy underwater photographers using such stations as waiting stations for taking shots!
Protect Cayman’s Marine Wildlife! For more information, to share your knowledge or if you would like to get involved with the many activities in the National Trust’s Know Your Islands Program, please visit www.nationaltrust.org.ky or call 949-0121. The weekly column from the National Trust is submitted by Marnie Laing, Education Programs Manager at the Trust.
Last week’s answer: Complete emancipation of slavery in the Cayman Islands occurred in 1835.
Trivia question: What is Cayman’s National Flower?
Look for the answer in next week’s feature!