Anemones

Description

Sea Anemones are found in both deep oceans and shallow coastal waters worldwide. The greatest diversity is in the tropics, although there are many species adapted to relatively cold waters.

Like jellyfish and Corals, Anemones belong to the group Cnidarians.

The name Cnidaria comes from the Latin Cnidae which means ‘nettle’.

Coloration can vary from red, pink and purple to yellow, blue and orange. 

Sea Anemones are simple animals, often attached to hard surfaces such as rocks and boulders.

However there are also burrowing Anemones that bury themselves in sand, mud or gravel on the Sea Floor.

A typical Sea Anemone is a sessile Polyp attached at the base to the surface beneath it by an adhesive foot, called a basal or pedal disc , with a column-shaped body topped by an oral disc.

Most are from 1 to 5 cm (0.4 to 2.0 in) in diameter and 1.5 to 10 cm (0.6 to 3.9 in) in length, but they are inflatable and vary greatly in dimensions.

Some species burrow in soft sediment and lack a basal disc, having instead a bulbous lower end, the physa, which anchors them in place.

All of the animals within this group have stinging cells which they use for the capture of prey and to protect themselves against predators.

An Anemone’s stinging cells, called nematocysts, are found throughout the body but are primarily used in their tentacles as a hunting tool and defence mechanism.

Each tentacle is equipped with thousands of nematocysts that contain a tiny, coiled, harpoon-like structure which is ejected upon contact with prey, piercing their skin and pulling them into their mouth.

Luckily, most Anemones don’t have large enough stinging cells to affect humans, but there are some to be wary of. If you have ever touched a small Anemone, the sticky feeling you may have felt is caused by those tiny harpoons as the Anemone tries to eat your finger.

Some species known for their Symbiotic relationship with Clownfish.

The Fish’s thick coating of mucus protects it from the potentially deadly sting of the Anemone.

The Anemone provides the Clownfish with protection from predators and scraps from leftover meals.

The Fish removes parasites and dead skin from its host, provides protection from some predators and, by swimming, ventilates the Anemone.

Water Parameters

It is necessary to ensure that the water indicators are normal 

• Calcium: 400 - 450 ppm
• Nitrates : 2 and 20 ppm
• Phosphates: 0,05-0,3
• Magnesium: 1200 - 1350
• Strontium: 8 - 10
• Temperature: 72°-78° F (22°-26°C)
• Salinity / Specific Gravity: 1.023 - 1.025
• pH: 8.1 - 8.4

Diet / Nutrition

Anemones are carnivorous, feeding on tiny Plankton or Fish.

Their stinging tentacles are triggered by the slightest touch, firing a harpoon-like filament called a nematocyst into their prey.

Once injected with the paralyzing neurotoxin, the prey is guided into the mouth by the tentacles.

An Anemone has a single opening in the center of an oral disc, by which it consumes food and excretes waste. At the Aquarium, they are fed pieces of Shrimp, Fish and Krill.

Fragging / Propagating

Sea Anemones have many fascinating methods of reproduction with some species using a combination of techniques.

Some, including beadlet and daisy Anemones are vivaporous (so are humans!) and reproduce through internal fertilisation, releasing fully formed young Anemones from their mouths. 

Most Anemones can reproduce asexually through budding, where fragments break off and develop into new individuals.

Some stretch themselves along their base and split Across the middle resulting in two new Anemones of equal size.

This method is called longitudinal fission. In others, small pieces of tissue break from the base forming tiny Anemones. This method is called basal laceration.

Sea Anemones can move slowly by gliding on their base.

Many are also capable of moving rapidly to avoid predation or competition by detaching, catching a current and re-attaching elsewhere.

In some species, when individual Anemones move too close to each other, someone usually gets upset.

This can spark battles as the Anemones unleash secondary defence tentacles and engage in some seriously slow and seriously intense fighting.

Their thicker, club-like secondary tentacles will emerge from beneath their main tentacles and begin slowly attacking their rival Anemone.

The flight can be long as they compete for a good spot on the seafloor, and unfortunately, sometimes both Anemones lose if they sustain too much damage.