The common sculpin is an inhabitant of pure fresh waters. It is found in small rivers or transparent lakes. Picks a rocky bottom. The reservoirs where an ordinary sculpin lives are not very deep.
This is a lone fish, which almost never meet even in small flocks. Their favorite habitats are under-stone spaces. Very rarely, these are holes in the sand. This behavior explains the name of the species. The features of this fish can be traced using an aquarium, where conditions are created that are identical to its environment.
Appearance
Common sculpin (cottus gobio) is distinguished by its original appearance and behavior.
Outwardly, it is a small fish that is about 10-15 cm long. Her head is quite wide, and the body is small and tapers toward the tail. This is one of the main structural features of the common sculpin (cottus gobio).
The head is wide and long, flattened from below and convex from above. At its very top are red eyes, looking in different directions.
The mouth is quite large, which allows the sculpin to catch rather large fish. The jaw has a number of small teeth.
On each side of the head, the fish has a large hook-shaped spike. In case of danger, this gives the sculpin a more formidable look.
Body structure
The ordinary sculpin is characterized by a naked body (photo is presented below). It has small warts that secrete mucus. This makes the fish slippery and makes it easier to get away from predators.
The old ordinary sculpin has a darker color, and the young one is pale. The fins are also quite original. Dorsal ridges consist of one small semicircular and a second long. The pectoral fins are small and the ventral fins are wide. The anal fin is long, similar to the dorsal crest. The tail of the common sculpin can be described as small, as if chopped off.
This fish does not have a swim bladder. It is superfluous for a species that lives in shallow water and does not surface.
Free behavior
The common sculpin (photo is presented below) in the conditions of a reservoir leads a sedentary lifestyle, hides under stones and swims very rarely.
But at the time of hunting or danger, the fish is able to develop a very decent speed due to its strong pectoral fins.
The sculpin has few enemies. More often it goes to trout prey. Inhabited in the immediate vicinity of the minnow and the white-toed minnie, the common sculpin is not too much sought after by predators.
The sculpin does not suffer from a lack of appetite. It feeds mainly on wood lice, crustaceans, and water-beetle larvae. It happens that they eat caviar of toads or fish. A large individual of this species is even able to eat young fish. Common sculpin and whitefin gudgeon often coexist. Therefore, it is the latter that often lands on the table to cottus gobio.
Aquarium conditions
In the aquarium, a common sculpin is very rare. This is due to their sensitivity to environmental conditions. Fish of this species love cold water, which should be well saturated with oxygen. This should be done with the help of the editor or change the water every day.
The depth should be small, and closer to the corner should be arranged like a mainsail. The sculpin will be able to climb close to the surface.
Color change
A healthy common sculpin, the description of which was presented earlier, has beautiful dark spots. Their accumulation is observed on the back.
If you look closely, this color consists of small black dots, which at a high concentration look like a dark spot.
While in the aquarium, the sculpin is very sensitive to all restrictions. If his color has become pale, you should change the water. Otherwise, the fish will die. As soon as it enters oxygenated water, the color will be the same very quickly.
According to Newman, who studied the behavior of sculpin under aquarium conditions, they are able to change color depending on the lighting. Such ability, he said, is also observed in fish exposed to irritants or strong muscle tension.
Aquarium Observations
Frankfurt researcher Frenkel was able to observe the behavior of such a species as an ordinary sculpin in an aquarium. He caught several representatives of this family of fish in a stream and placed them in an aquarium 120 x 50 x 40 cm. He contained 20 buckets of water.
The soil was made of sand 5 cm thick. Places at the bottom were placed in groups of smooth stones. The vegetation was represented by water moss and bushes of Vallisneria.
The researcher carried out ventilation and air enrichment artificially using an injector.
When fish were placed in this ecosystem, each large individual took its place near one of the piles of stones and began to protect its territory. They aggressively drove everyone away from her. Small fish tried to stick together.
The first two days, scullers mastered the new conditions. And starting from the third day, he was offered food in the form of earthworms and enchitrea. Fish threw themselves on food with greed, catching it on the fly and collecting it from the bottom.
Twice a week, 5 buckets of water were taken from the aquarium and a new one was added. It was noted that the common sculpin felt good under these conditions.
Reproduction in the aquarium
After a month, the abdomen markedly increased in 5 fish. Males acquired a brighter color. In females, he also became clearer, but not so clearly. The fish began to actively move around the aquarium. The males behaved aggressively with each other. The largest of them raged more than others. But he treated females differently, especially the largest. He swam over them and muzzle touched the pectoral fins.
This made the female swim away. Then this sculler followed her. They swam around the aquarium for some time.
A few days later, the female and male sank to the stone. She cleansed them with pectoral fins and muzzle. The male stood guard at that time and did not let anyone near her. Then he swam to his partner, and they quickly swirled around each other.
After that, the fish descended onto the largest peeled stone. They settled their heads in one direction. The female began to spawn eggs, and the male watered them with milk.
It lasted about an hour. Then the fish parted and lay motionless at the bottom. After a while, the male stood guard over eggs. He violently beat everyone who approached them.
After 4 weeks, fry appeared. During this time, their father ate almost nothing. In total, about 500 fry were hatched. They swam in a flock and, at the slightest sign of danger, hid under the stones.
Having plunged into the world of habitat of such an underwater predator as the common sculpin, we can understand the processes taking place in this ecosystem. This is an original fish in all respects, which is very interesting and informative to watch. Especially if you do it in an aquarium.