Wednesday, Sept. 12, 2007
* Japanese name: Koi (Nishiki-goi)
* Scientific name: Cyprinus carpio
* Description: A big, colorful fish, with large scales and barbels (those are the "whiskers" growing down from the upper lips). They can grow to well over a meter in length, and live for more than 15 years. They are related to other familiar fish such as goldfish, but can be distinguished from them by the presence of those barbels.
* Where to find them: They live in fresh water, and were originally native to China, but became widely known throughout the world via Japan, where they were first bred in Niigata in the 1820s. The mountain people there kept the fish as food animals for the winter, but people also came to appreciate them for their bright colors. Carp became known as "living jewels." Now they are found all over the world, and you are likely to find them in any decent-sized pond in Japan, especially in the grounds of temples.
* Food: Basically vegetarian, carp feed on water plants. But they will certainly also take plankton, insects and shellfish, and even scavenge dead fish that might be bobbing around in the water. They feed by snuffling about in the sediment on the pond floor. For this habit, they are regarded as a pest species in the United States, because the silt they stir up is detrimental to other fish.
* Special features: Carp can be amazingly prolific breeders. Females may become sexually mature as young as 1 year old, and can spawn 100,000 to 300,000 eggs per kg of their body weight. In the breeding season, they spawn three times over a 2-week period. Not surprisingly, a gravid female (one full of eggs) is followed eagerly by a group of several males, all hoping to shed their sperm over the eggs when they are laid. The tiny yellow eggs (about 1.3 mm in diameter) are not guarded, but are simply dumped onto grass blades where they hatch after three days. This is the reason carp lay so many eggs — they make tasty snacks for a range of predators, including other fish, so the only chance of ensuring that some make it to adulthood is to lay thousands of eggs. A tasty fish, as I write this I would like to eat one cooked with miso soup, in a dish called koi-koku.