Then there are the squids and cuttlefish, and the porpoises, dolphins and great whales.
For example a Banded snake eel mimicking a venomous sea snake in order to deter predators. Often a fish can be involved in two symbiotic relationships at once; suffering from parasitism on the one hand, and benefiting from mutualistic cleaning attention on the other.
Adaptations of the anglerfish will begin by looking at commensalistic relationships, as there are some very interesting examples of this form of symbiosis where we have been diving, here in Papua New Guinea.
Commensalism usually occurs between a species that is either vulnerable to predation or with an inefficient means of locomotion, and another species with a relatively effective system of defence.
In both instances the fish benefit, while their host is neither advantaged nor disadvantaged by the relationship. The Anemone crab on its host sea anemone. Crabs and Shrimps often form commensalistic symbiotic relationships with anemones in tropical waters, again for the purposes of protection from predation.
For instance the Anemone crab, Neopetrolisthes oshimai, which is a filter feeding Porcelain crab, lives and captures its food from within the tentacles of giant anemones. While diving in Papua New Guinea we have been fortunate enough to see several interesting commensalistic relationships.
Apart from the Anemone crabs, we have also filmed Imperial shrimps, Periclimenes imperator, hitching a ride on the large sea cucumbers found here, genera Stichopus. The shrimps get transported through a large area of potential food by their host with only a minimal expenditure of energy on their part.
They can be observed getting off their host cucumber to feed in productive areas, and back on for a ride to the next spot! The Imperial shrimp also rides on large nudibranchs such as genus Dendrodoris, which although slow moving, afford the shrimp with protection by virtue of their toxic chemical secretions and warning colouration.
Although this is currently classed as a commensalistic relationship, it is possible that the Emperor shrimp may assist the nudibranch by removing parasites.
Imperial shrimp hitching a ride on a Sea-cucumber One especially amazing example of commensalism that I have yet to witness occurs between the Pearlfish and a particular species of sea cucumber. In this manner it gets a safe place to live; and while not appearing to gain any benefit from the relationship, the cucumber is not harmed.
In a parasitic relationship, the host species is always exploited to some degree, although often in such a way that its health is impaired only slowly.
This allows the parasite to exploit its host over a longer period. Many parasites only spend a portion of their lives in the relationship, either to reproduce, or during an initial growth stage. Parasites can be divided into two basic categories, Ectoparasites and Endoparasites, the former referring to external parasites, and the latter internal parasites.
Although parasitism is an unpleasant concept to many people, the adaptations of parasites are quite amazing when viewed objectively.
Isopods for example have a flattened body shape for streamlining against the body of their host, complex sucker-like organs for firm attachment and a set of sharp mandibles.
An interesting adaptation of isopods is their ability to moult only half their exoskeleton at a time unlike most crustaceans, which shed their entire exoskeleton at once. Parasitic Isopod on fish Although Isopods are usually parasitic, there are some species that attach themselves to a fish without damaging tissue, and scavenge floating food particles rather than feeding on their host, ie they are in a commensalistic interrelationship.
Mutualism is one of the most interesting forms of symbiosis, as it is a benefit to both species involved. When approached by a predator it waves these around presenting the stinging tentacles so as to deter the marauder. The anemones benefit from the small particles of food dropped by the crab during feeding.
In some cases, notably with many of the Wrasses, it is just the juvenile of a fish species that is a cleaner, while the mature fish progress onto a diet of larger invertebrates.
As well as removing parasites, cleaners also remove dead skin, tissue and mucous, and in doing so, perform a valuable function in maintaining the health of marine populations.
In fact most reef fish spend a reasonably significant proportion of their day at cleaning stations. One example of a mutualistic relationship we witnessed in the waters around Milne Bay was that of Alpheid shrimps and certain gobiid species.
The shrimp digs a deep burrow, and while underground is quite safe, however it has poor vision and once above ground it is vulnerable to predators. The goby stands guard at the entrance, and signals the shrimp with a flick of its tail when it is safe to come out.
The goby benefits by getting a burrow to live in and the shrimp gets warning of predators!Object Class: Safe Special Containment Procedures: All adult SCP specimens are to be contained in a sealed 5m by 5m by 5m terrarium simulating desert conditions under electronic surveillance and implanted with tracking devices.
In event of an escape, the affected sector will be locked down until all specimens have been recaptured. Pelagic fish live in the pelagic zone of ocean or lake waters – being neither close to the bottom nor near the shore – in contrast with demersal fish, which do live on or near the bottom, and reef fish, which are associated with coral reefs..
The marine pelagic environment is the largest aquatic habitat on Earth, occupying 1, million cubic kilometres ( million cubic miles), and is.
Discover the incredible anglerfish, denizen of the ocean's deep, lightless realms. Learn how these predators attract their victims with bits of luminous flesh. The anglerfish can extend both its jaw and its stomach to an incredible size, allowing it to swallow prey twice the size of its entire body.
Since food can be scarce in the deep sea, this special adaptation allows it to stock up on food during times of plenty. The Angler fish has many adaptations, one of which involves the way it catches its prey.
It has a long stalk protruding from its head, with a lure on the end of it. Some lures simply resemble a worm, where as others glow to attract prey (this is caused by a type of bacteria within the lure).
Item #: SCP Object Class: Euclid Special Containment Procedures: SCP is kept in customized Containment Unit in Bio-Site The floor is to be rinsed daily, and drain grates are to be checked weekly for buildup.
Personnel are to wash SCP once .