Amazing Facts About Oysters
Amazing Facts About Oysters
Scottish oysters – full of nutritional value.
- Oysters have a three chambered heart, colourless blood and a pair of kidneys.
- The Ostrea genus (of which our native oyster is a member) is bisexual. These are “protandrous alternating hermaphrodites”, which means that they start off as males producing sperm then switch to egg producing females and can then switch back to being males again. Eggs produced during the female stage are held in the gills and mantle cavity and are then fertilized by sperm drawn in from the surrounding waters (larviparous). The fertilized eggs are then incubated within the oyster for 7-10 days before being expelled to begin their veliger stage in the open sea.
- The Crassostrea genus (of which the Pacific Oyster is a member) is intersexual. These oysters begin life as males and change to females the next season. They tend subsequently to remain as females but can revert to males if they so choose. In reproduction both eggs and sperm are released directly into the open sea where cross-fertilization takes place (oviparous).
- The female oyster can release well in excess of 1 million eggs over the spawning season.
- Although all oysters can secrete pearls, the pearl oyster family (Pteriidae) comes from a different family to the edible oyster. An oyster produces a pearl when a grain of sand or some other irritant becomes trapped inside. The oyster then coats it repeatedly with nacre, a combination of calcium and protein, otherwise known as Mother of Pearl, to reduce the irritation.
- Most people think that pearls are round and white; however natural pearls can be coloured yellow, rose or even black. Cultured pearls take 3-6 years to reach a commercial size and are produced by placing a polished piece of mussel shell inside the oyster.
- Among other families there is the tree oysters family (Isognomonidae) and the thorny oyster family (Spondylidae).
- Oysters are a source of vitamins A, B1 (thiamine), B2 (riboflavin), B3 (niacin), C (ascorbic acid) and D (calciferol). 6 oysters would also more than meet the daily recommended intake of iron, copper, iodine, magnesium, calcium, zinc, manganese and phosphorous.
- Oysters have been around for 180 million years and Neolithic man consumed vast quantities some five thousand years ago.
- The Chinese were probably the first to raise oysters artificially in ponds and to use their crushed shells in medicines.
- In 320BC, Aristotle pondered their regenerative process in his “Historia Animalium”. The Greeks served them in wine and used empty oyster shells as ballot papers. The word “ostracise” is derived from the Greek astrakeon (oyster shell) because the Athenians used to vote with oyster shells to banish unpopular citizens.
- The Romans imported oysters by boat direct from England to Italy and Roman Emperors paid for them by their weight in gold.
- It is said that Henry IV liked to toss back 300 as an appetizer and that Casanova reportedly consumed 50-60 oysters a day with his evening punch.
- The Guinness World Record for the most oysters eaten in 3 minutes is 187 set by Norwegian Rune Naeri in 2003. Any challengers?