zondag 9 juni 2013

Strombus Gigas, Part Two

Alle benamingen van deze beeldschone schelp op een rij:
Queen Conch
Grote Kroonslak
Roze Vleugelhoorn
Strombus Gigas, synoniem Tricomis Gigas

Conch Shell Magic (Music)
Conch Shell Sacred (You Tube Link)

The Queen Conch
Bron: Nature Foundation St. Maarten

The Queen Conch has a large, spiral shell often lined in pink. The conch's mantle, a thin layer of tissue located between the body and the shell, creates the shell. The conch builds the hard shell from calcium carbonate that it extracts from the seas. The shell is up to 1 foot (30 cm) long. The lip of the shell is flared and there are spines to deter its many predators.

Queen Conch is one of the largest snails and protected by a very hard shell. The body is divided into the head, the visceral mass, and the foot (which is small). The small operculum (which is like a trap door) is located on the foot and looks a bit like (and works like) a claw. Young conchs can bury themselves in the sand when they are in danger. Conchs have a characteristic leaping motion, using their pointed, sickle-shaped, horny operculum to propel themselves forward.

How does a Queen Conch grow?
The Queen Conch starts building its shell as soon as it hatches from the egg and even before. At hatching, the shell is transparent; it has only one and a half whorl. At metamorphosis, it has already four whorls and it is no more transparent. It is large enough so that the small conch can shelter inside. Its shell grows as its body grows bigger. Then it becomes hard and thick.

When the small conch is 2 or 3 months old, its shell is white; when it is 5 or 6 month old, it starts to show brown stripes. On its foot, a horny claw called operculum enables it to leap, so it can escape or fight against predators and lock itself up within its shell.
When you encounter small queen conchs that are about 10 centimetres long, they are about one year old. Their shell forms pointed spines, a true fortress! When the Queen Conch grows, its shell lengthens and continues to grow in a spiral.
When it is about 3 years old, its shell stops growing and starts to form a broad flared lip. This shell lip shows that the Queen Conch has reached its full growth and that it will come to maturity, which means that it will be able to reproduce. The Queen Conch is now like a teenager; its shell lip is still fine and fragile. It thickens and reaches its adult size and thickness (about 5 mm) when it is about three and a half to four years old.

When the Queen Conch is growing older, its shell becomes much thicker and heavier. The spines which were long and pointed become blunted and worn. The old conch shells are often covered with algae, and even small animals settle on them as if they were rocks. The thick shell of old conchs is often smaller than that of the young adult because the edge is worn.
The conch has two pairs of tentacles on the head; it has a light-sensitive eyespot located on each of the larger tentacles. True conchs have long eye stalks with colorful ring-marked eyes. The smaller pair of tentacles is used for the sense of smell and the sense of touch.
Diet Conches eat grasses, algae, and floating organic debris. They eat using a radula, a rough tongue-like organ that has thousands of tiny denticles (tooth-like protrusions).
Mating and Baby Conch
Queen Conchs have separate sexes and reproduce through internal fertilization. After mating, females lay eggs in long, gelatinous strands. These long egg masses contain hundreds of thousands of eggs, which hatch after about 5 days. Larvae then spend about 18-40 days floating and feeding in the "plankton" before settling to the bottom and changing into the adult form. Once they change into adult form, they feed on algae and detritus (broken down bits of organic matter).
How long can the Queen Conch live?
The Queen Conch is a relatively slow-growing animal. Queen conchs achieve full size at about 3-5 years of age, growing to a maximum of about 12 inches (30.4 cm) long and weighing about 5 pounds (2.3 kg). The queen conch is a long-lived species, generally reaching 20-30 years old; however, the lifespan has been estimated as up to as long 40 years.
People and conch
Conchs are eaten by many animals, including rays, loggerhead sea turtles and people. The beautiful shell is also collected by people; the shell is also used for jewelry and for conch trumpets.
Because people enjoy conch meat, fishermen are taking too many from the ocean. The meat is also used as fishing bait. This is making the conch population get smaller. We used to have a large conch population but because of over-fishing we hardly have any conch left. Over-fishing of conch is also a problem because of the demand for conch shells, which are used for jewellery.
Conch Conservation
Queen Conch is protected under the international treaties Convention on International Trade in Endangered Species of flora and fauna (CITES) and Specially Protected Areas and Wildlife (SPAW). CITES controls how many conch meat, conch shells and conch shell products may leave or enter a country. For instance, if you would like to take a conch shell with you for a friend in another country, you would need to get a CITES permit. The conch permit gives you permission to come into a country and not have the customs officer take away the shell. These international laws help to keep conch populations at the highest possible levels. SPAW also helps protects it affords to special areas in the marine environment.
Some counties have regulations that say how big a conch must be and how much it must weigh before you can take it and also how many people may take each year depending on the size of the conch population.

Did you know?
Some Queen Conch produce a pink pearl. The pink or conch pearl is produced by the Queen Conch. Conch pearls are porcelain-like, have a silky glimmer and in most cases a wavy pattern. If the bright points are looked at through a magnifying glass, you will see closed structures which resemble little flames. The colours range from a whitish yellow to a pale or bright pink. Conch pearls are extremely rare.

Native people dating A.D. 1000 – 1700 made tools from conch shells.Today people still use conch shells to make music.
When you listen through a conch shell it’s not the sound of the ocean you hear but the sound of blood rushing through the veins in your head.

2 opmerkingen:

  1. Die parels, wat mooi. Dit heb ik nooit geweten....

  2. he, wat jammer nu. Het is niet de zee die ik hoor..... Wat een prozaïsche uitleg :-). het is vast waar, maar.....

    Ik geloof mijn opa liever, die mij vertelde dat ik de zee hoorde, in de schelpen die hij meebracht van zijn grote reizen.