Harlequin Shrimps are a very flamboyant looking and a delight to see. There are two species of harlequin shrimps, namely the Hymenocera Picta found in Hawaii and Hymenocera Elegans found in Andaman Sea. They are commonly known as clown shrimp, painted shrimp and dancing shrimps.

The Harlequin shrimp is unlike other species in that it is a slow mover and not very agile. The beautiful bodies have stunning coloration with the body being a pinkish white or white with large purple edged pink spots. There may also be red and orange tones depending on the local environment.  The shrimps vary in size averaging between 2cm-4cm. The females are larger than the males and can be identified by the coloured abdominal plates. The male’s abdominal plates are white. It is believed that the vivid appearance of the shrimp is enough to deter predators. It also indicates that it may be toxic to eat as brightly coloured creatures often are. This is not the case with the shrimp. The two large flat pincers constantly move even when the shrimp is stationery, hence the common name “dancing harlequin shrimps”. The eyes are positioned on the end of stalks and the antennae are flattened, looking very leaf like.

Harlequin Shrimps are very shy and are found in mating pairs. They are monogamous and are very territorial usually covering an area of up to 10m square.  They are predominately nocturnal and will feed during twilight or under the cloak of darkness. During the day they are found in hiding places on a rocky or coral substrate.  This species of shrimp are rare and do suffer as a result of coral damage. The Indo-Pacific species is more common that the Hawaiian species, because over the years the latter has been actively collected for the aquarium trade.

Moulting occurs once a month. During this process the shrimp will hide until the new shell hardens. It is usual for simultaneous molting to occur. The molting also gives the opportunity for the shrimp to replace missing limbs, this may take more than one regeneration.  The mating couple will reproduce after the female as completed her molting process. She will lay between 100 and 5000 eggs per season and tends to them until they are hatched.

The Harlequin Shrimps are predatory carnivores. They are ruthless and extremely strong. The shrimps work as a team and detect their prey by scent. They live on a diet of starfish. Once the starfish has been located the pair will prize the arms from the rock and overturn it, thus rendering the starfish helpless.  The starfish may be 10 to 20 times larger than the shrimps. It has been known for the shrimps to drag the starfish to the lair where it acts as a living larder. It is kept alive by the shrimps feeding it.  The shrimps dine on the tube feet starting at the tips and working inwards to the centre plate, thus keeping their food source alive for as long as possible. Occasionally, a starfish may detach an arm or two to make an escape!!!! It is fortunate that starfish have the capability to rejuvenate their limbs…..

If you would like to know more about the identification of species why not sign up for on a  Underwater Naturalist Specialty Course, which will enhance your knowledge and highlight the key things to look for or a cruise on board MV Scuba Adventure or MV Scuba Fun for a chance to see these for yourself.

Initially when people start diving on reefs they are appreciative of the beauty of the corals and marine life that inhabit the area. However, once you become familiar with the reef the finer details of the eco-system and relationships of the organisms become more apparent.

"The reef"

There are many different types of relationships that we see on every dive probably without even realizing it. One of the most famous relationships is the symbiotic one between Clownfish and the Anemone. The clownfish has a protective mucus on the body, which enables it to shelter in the tentacles of the anemone without being stung. The presence of the clownfish helps to defend the anemone, particularly from polyp eating fish. The Clownfish, also known as Anemone fish, of which there are varies species, keep the anemone clean by eating morsels that are left over from fish as well as eating parasitic critters and algae, for example, copepods, isopods and zooplankton. They also aid water circulation within the anemone as it swims amongst the tentacles. The fecal matter from the Clownfish acts as nutrients for the host anemone.

"Anemone"

The Anemone fish is an all year breeder. The nest for the eggs is found very close to the host anemone on the reef in nooks and crannies, so the eggs are protected from predators. At any one time there are between 100 and 1000 eggs laid and external fertilization takes place. Spawning normally occurs on a full moon. It is the role of the male to protect the eggs, which hatch within 4 to 5 days often 2 hours after dusk.

"Nemo"

The anemone can host many fish. If multiple fish are present then there is a distinct hierarchy with the dominant fish being the largest and most aggressive female. Should there be a reason this fish leaves the anemone, for example, death, then the largest male will turn into a female. Clownfish are hermaphrodites and are born male. Within a multiple colony there is only one breeding pair.

"Hello"

The main predator of the clownfish unfortunately is man. They are harvested for the aquarium trade.  A clownfish in the wild can live between 6 and 10 years, but this is reduced once the fish is placed in captivity. One of the most common mistakes is placing the fish in the wrong anemone. They are only ten anemones that can accommodate the fish. So, it really beneficial for the fish to stay in the natural environment.

"Look at me!"

Anemone fish can be found in the warmer waters of the following regions NW Australia, SE Asia, Japan, Pacific, and Indo Malaysia region. Surprisingly, they are not found in the Caribbean.  There are varies species of clownfish include Clarkson, Skunk, Tomato, Saddle, Yellow and False to name a few.

"Skunk Anemone Fish"

If you would like to expand your knowledge of marine relationships then why not take the Underwater Naturalist Specialty course.