Goldfish, its habitats, characteristics, fishing methods and techniques.
Selective breeding over centuries has produced many different color variations, some of them far removed from the 'golden' color of the original goldfish. There are also different body shapes, fin and eye configurations. Some extreme versions of the goldfish need to be kept in indoor aquariums as they are much less hardy than varieties closer to the "natural" original. Goldfish are among the most popular aquarium fish, and as such, extremely valuable commercially. In addition, they are commonly used as bait fish, as live feed in fish production facilities, and for algal and plant control of small ponds.
A combination of understanding the fish and the techniques used to catch them will help you to hook more fish to the end of your line. Better knowing and understanding of the fish that you are trying to catch will make you a more successful angler, whether you are fishing for trout on a river or surfing on the beach or trolling on the open water.
Goldfish - Carassius auratus, are a relatively small member of the Cyprinidae or carp family. Goldfish are native to the People's Republic of China, Taiwan, southern Manchuria, Korea, Japan, Hainan, and the Lena River of eastern Europe to the Amur Basin and the Tim and Poronai rivers of Sakhalin. Although goldfishes originated in China, they have now spread worldwide in aquariums, ornamental pools, and into the wild.
As there are over a hundred varieties of goldfish, coloration and physical characteristics vary greatly. The common goldfish has two sets of paired fins - the pectoral fins and pelvic fins, and three single fins- the dorsal, caudal, and anal fin. They lack barbels on the upper jaw, and lack scales on the head. Goldfish have exceptionally large eyes and acute senses of smell and hearing. Goldfish have pharyngeal teeth (not true teeth) in their throats that counts are: 0,4-4,0, which they use to crush food.
They have stout, thick-set body, caudal peduncle thick and short. They have head without scales, broadly triangular, interorbital space broad, snout longer than eye diameter, maxillary reaching posterior nostril or not quite to eye, barbels lacking on upper jaw. Their Lateral line is complete, with 25-31 scales along their lateral lines. They have 3-4 dorsal spines; possess a long dorsal fin with 14 - 21 dorsal soft rays, 2-3 anal spines with 4-7 anal soft rays. They have dorsal and anal fins with serrate bony spines, pelvic fins short, broad and thoracic. Caudal fin with 17-19 rays. Wild-caught specimens could be olive brown, slate olive, olive green, with a bronze sheen, silvery, grayish yellowish, gray-silver, through gold (often with black blotches) to creamy white; yellowish white or white below. Cultured forms vary through scarlet, red-pink, silver, brown, white, black and combinations of these colors.
Goldfish may also change their color by varying the spectrum of light under which they are kept. Goldfish produce pigment in response to light. Cells called chromatophores produce pigments that reflect light, and give coloration. The color of a goldfish is determined by which pigments are in the cells, how many pigments molecules there are, and whether the pigment is grouped inside the cell or is spaced throughout the cytoplasm. If a goldfish is kept in the dark it will appear lighter in the morning, and over a long period of time will lose its color.
Goldfish can grow to a length of about 16 - 20 cm (6.3 - 7.87 in). However, this is rare, and few goldfish reach this size. In optimal conditions, goldfish may live more than 20 years, but most household goldfish generally live less than six to eight years, due to sub-optimal living conditions (such as being kept in bowls). The oldest recorded goldfish lived to 49 years.
The wild form of the goldfish is the Prussian carp (Carassius gibelio). Some sources claim the Crucian carp (Carassius carassius) as the wild version of the goldfish. While they are closely related, they can be differentiated by the following characteristics:
• Goldfish have a more pointed snout while the snout of a Crucian carp is well rounded.
• The wild form of the Goldfish Prussian carp often has a grey/greenish color, while Crucian carps are always golden bronze.
• Juvenile Crucian carp have a black spot on the base of the tail which disappears with age. In Goldfish this tail spot is never present.
• Goldfish have fewer than 31 scales along the lateral line while Crucian carp have 33 scales or more.
• Common carp have 32 to 38 scales along a lateral series as opposed to 25-31 of goldfish.
• Goldfish can be distinguished from other native and exotic cyprinids by the presence of the stiff, serrate spine at the origin of the dorsal and anal. Non-native Asian cyprinids have a stiff, non-serrate spine at this position.
Habitat and Habits
Goldfish are usually found in still, shallow, oxygen deficient, warm waters, with thick vegetation and muddy bottoms.
In the wild, goldfish can be found in slow-moving, freshwater bodies of water. As with their close relative the carp, they thrive in slightly sludgy water. They thrive in a pond environment thus the addition of real plants is optimal if the owner is prepared to replace them fairly regularly; goldfish enjoy eating live plants. An aquarium with a dirt bottom is ideal but difficult to maintain. Small pebbles are a suitable substitute for the pond-like bottom. Typically, goldfish will survive in water temperatures ranging from freezing to 30 °C. In the wild goldfish will school to a certain extent. Goldfish are not particularly aggressive, thus combining sizes is not often a problem.
Goldfish’s wild ancestors, Prussian carp live natively in ponds, and other still or slow moving bodies of water in depths up to 20 m (65 ft). Their native climate is subtropical to tropical and they live in freshwater with a temperature range of 40 to 90 °F (4 to 32 °C) although they will not survive long at the higher temperatures. They are considered ill-suited even to live in a heated tropical fish tank, as they are used to the greater amount of oxygen in unheated tanks. However, for centuries goldfish have been observed living in outdoor ponds in which the temperature often spikes above 86 °F (30 °C). Fancy goldfish are unlikely to survive for long in the wild as they are handicapped by their bright fin colors; however it is not beyond the bounds of possibility that such a fish, could survive long enough to breed with its wild cousins. Common and comet goldfish can survive, and even thrive, in any climate in which a pond for them can be created.
This species is omnivorous demonstrating some preference for phytoplankton and macrophytes. Young feed mostly on zooplankton and insect larvae, plants, detritus and chironomids. Adults eat plants, insects such as mosquito larvae, small crustaceans, zooplankton, plants, and detritus.
Goldfish usually mature in their second year but this varies with diet, water temperature, and other environmental influences, it could be between the ages of 1 and 3. In the wild, breeding occurs during the summer. Mature female goldfish will become rounder during breeding; males develop tubercles (small bumps) on their heads, operculi, and pectoral fins. Males chase the females for several days before spawning occurs. They can spawn at water temperatures as low as 12-13 °C. Females can produce several thousand eggs per spawning period every 8 to 10 days. Absolute fecundity varies between 191,000 and 403,000 eggs per female, with a mean of 268,000 eggs. Egg diameter is approximately 1 mm. Goldfish produce adhesive eggs that attach to aquatic vegetation, roots, or other fixed objects. Eggs are not guarded. Goldfish eggs hatch in about 4-6 days at 18-20 °C (64-68 °F.), releasing large fry look like an eyelash with two eyeballs. Within a week, the fry begin to look more like a goldfish in shape, although it can take as much as a year before they develop a mature goldfish color; until then they are a metallic brown like their wild ancestors. In their first weeks of existence, the fry grow remarkably fast - an adaptation born of the high risk of getting devoured by the adult goldfish (or other fish and insects) in their environment. Within three breeding generations, the vast majority of the goldfish spawn will have reverted to their natural olive color. Since they are carp, goldfish are also capable of breeding with certain other species of carp and creating hybrid species.