Wednesday, August 15, 2012

Marine Life in Norway - 2005

On September 30, 2005,  Norway Post  have continued to issue the marine life stamp series in two single stamps. The species of marine life that featured on stamps are Orcinus Ocra (Killer whale) and Urticina eques  (Sea anemone).
Orcinus Ocra
The killer whale (Orcinus orca) distinctively bears a black back, white chest and sides, and a white patch above and behind the eye. Calves are born with a yellowish or orange tint, which fades to white.

Males and females also have different patterns of back and white skin in their genital areas.Sexual dimorphism is also apparent in the skull; adult males have longer lower jaws than females, and have larger occipital crests.

The lifespans of wild females average 50 years, with a maximum of 80–90 years. Wild males live around 29 years on average, with a maximum of 50–60 years

The killer whale (Orcinus orca), is a toothed whale belonging to the oceanic dolphin family. Killer whales are found in all oceans, from the frigid Arctic and Antarctic regions to tropical seas. Killer whales as a species have a diverse diet, although individual populations often specialize in particular types of prey

Sea Anemone (Urticina eques)

A sea anemone is a polyp attached at the bottom to the surface beneath it by an adhesive foot, called a basal disc, with a column shaped body ending in an oral disc. 

Anemones tend to stay in the same spot until conditions become unsuitable or a predator attacks them. In that case anemones can release themselves from the substrate and use flexing motions to swim to a new location.

Similar to the more common Dahlia anemone, but it grows bigger, the base diameter may reach 20 cm. Furthermore, it lacks the warts on the cylinder wall. The up to 200 stout tentacles are longer and often arranged in multiples of ten. The color variations are pretty much the same, but the Urticina eques is often paler.

Both sexual and asexual reproduction can occur. In sexual reproduction males release sperm to stimulate females to release eggs, and fertilization occurs. Sea Anemones eject eggs and sperm through the mouth. The fertilized egg develops into a planula, which settles and grows into a single polyp.

Sea Anemones can also reproduce asexually, by budding, binary fission (the polyp separates into two halves), and pedal laceration, in which small pieces of the pedal disc break off and regenerate into small anemones.

It can be found from below the intertidal zone and down to 400 metres. It seems to prefer hard, often rocky, substrate.This species is common in northern Europe and entire coast of Norway.

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