Label: Christmas crab rearing
Ding-dong ~ ding-dong ~ how loud the ringtone is!
The beautiful melody of the music is still in the ears, accompanying us through the annual Christmas festival, Santa Claus dressed in red, giving gifts to all children from house to house, spreading joy and spreading love. But toiling, he seems to have forgotten to take away some cute little guy: Christmas crabs!
Looking at how joyful the name is, intuition makes people feel a joyful and colorful atmosphere, so why is he called Christmas Crab? Maybe it's all red as Christmas red! In short, it is a crustacean that is quite common in aquariums, and it is cheap and popular. Now let's meditate on this beautiful little one!
Small profile | Christmas crab Latin scientific name: Sesarmops intermedium De Han, 1885 Chinese scientific name: medium-sized imitation hand crab Class: Malacostraca Order: Decapoda Family: Sesarmidae Genus: Sesarmops Range: South Korea, Japan, Taiwan, Hong Kong, Myanmar Mergui Islands Indonesia Surabaja Islands Maximum carapace length: about 3.5 cm
What is a land crab
As the name suggests, land crabs refer to crabs that live on land. In a broad definition, all crabs that can maintain a certain vitality on land are collectively referred to as land crabs, so according to this definition, there are many species, and almost all crabs that inhabit intertidal zones, streams and land can be included. Although the proportion of land crabs in the total number of all crabs is not high, it is the best model for studying the evolution of organisms from aquatic environments to terrestrial environments. Crabs change from aquatic to terrestrial, in addition to changing the way of breathing, they must also cooperate with a variety of physiological and behavioral changes to adapt to the terrestrial environment. For example, some land crabs will store water in the body before molting, and then recover the old shell calcium in a variety of ways to store in the body, including the formation of gastrolars, stored in the middle intestine glands, or stored in the blood with small particles of calcium carbonate, and many land crabs will directly eat the old shell to do the most thorough recycling of calcium carbonate and organic matter. This is different from the fact that marine and freshwater aquatic crabs do not specifically recover calcium ions and do not feed on old shells before they molt.
Creating a water environment and a terrestrial environment is the only way to raise Christmas crabs
Medium-sized imitation hand crab
"Christmas Crab", whether in name or appearance, at first glance (at first glance) resembles the "Christmas Island Red Crab" in Australia, but in fact the two are different crabs. The Christmas crab, commonly known as the Christmas crab in the anecdotal aquarium Chinese, is known as the medium-sized imitation hand crab (Sesarmops intermedium) in the scientific name of the restaurant, which is one of the common land crab species in the wild in Taiwan.
The Christmas crab originally belonged to the genus Sesarmops of the family Grapsidae, which was reclassified into the family Sesarmidae and Sesarmops after the family Sesarmidae became independent of the family Crab. Due to the red color of Christmas crabs (don't think they are cooked), they are very pleasing, and the easy management is not complicated, so in recent years it has been collected by merchants from the wild to become a popular pet in the aquarium.
Christmas crabs sometimes rest in the water
Shape and appearance
The Breastplate of the Christmas Crab is square, concave in the middle of the forehead, and the sides of the nail are obliquely raised. The frontal margin is divided into two large lobes, and the crab eyes are gray and black at the tip. The anterior lateral edge has two teeth, and the second tooth is small. No buccal area fluff. It has a pair of evenly sized crab jaws (the male crab is larger than the female stinger), with a smooth and hairless surface and a white tip. Most sexually mature individuals are dark red or light red, the male individual color is particularly bright, and the juvenile individual color is mostly black and gray-brown. In terms of body size, the cephalothorax can reach a maximum width of 4 cm, but it is generally about 3 cm. 4 pairs of left and right 1 foot, red with sharp knuckles, bristles.
Range distribution
The species has a wide range of distributions, including Korea, Japan, Taiwan, Hong Kong, the Mergui Islands of Myanmar and the Surabaja Islands of Indonesia. As far as Taiwan is concerned, Christmas crabs are mainly distributed in the area from eastern Taiwan to the Hengchun Peninsula, with the largest population at the mouth of the Harbor Creek.
According to the survey, the average number of animals in July, August and September can reach more than 1,000, which is the largest ethnic group in the world's existing relevant literature. Its wild habitat is dominated by grassland, coastal shrubland or coastal forest under the banks of the lower reaches of the offshore river, and it lives in cave dwelling. Nocturnal they usually appear en masse after rain or after a high tide.
reproduction
The egg-holding season of Christmas crabs is mostly concentrated in spring and summer, which are May, June, July, August and September, and the peak breeding period is mainly concentrated in July and August. According to Zhang Huiqing's 2011 breeding study on the medium-sized imitation hand crab in the Ganggangxi Estuary of the Hengchun Peninsula, the male crab has no special courtship behavior and the courtship time is very short, the female crab is in a hard shell state when mating; at the same time, the study also pointed out that the average egg holding time of female crabs in the laboratory environment is 17.2 ± 0.5 days (n =18), about the average interval of 12± 1.4 days (n =7) can hold eggs again, and the eggs can be repeated multiple times in a breeding season; and the yield is also positively correlated with the female crab body size. The number of larvae released in a single egg holding ranges from about 6600 to 56800.
When the rainy season comes, the Christmas crabs begin to release their baby, peaking in July to August. The study observed that the female crabs with eggs had the phenomenon of synchronous release of juveniles from the sea, and the timing point was related to the day and night cycle and the half-month cycle, mostly concentrated before and after the new moon and the full moon, and within the 0.5--2.5 hours period after sunset every day, the correlation between the study and the full tide time was low. At the time of release, the egg-holding female crab will move at the mouth of the river and the water's edge to release the larvae in a rapidly inciting manner. The first stage flea larvae of medium-sized imitation hand crabs have high osmotic pressure regulation ability in low osmotic pressure environments, and can survive for more than 3 days in freshwater environments, and the best survival rate is in salinity environments of 15 ‰ (Zhang Huiqing, 2011).
However, although the reproductive ecology of Christmas crabs has been generally understood by scholars, the key to its release from the sea and the reproduction of basic food is still a major challenge for artificial breeding and mass production! Therefore, they are treated as pets, even if the female crab holds the egg, it cannot reproduce smoothly. And when the eggs mature and fall from the belly of the mother crab, they often either die of decay or become food.
Female crab
Male crabs
Feeding management
Set up a cylinder
Basically, Christmas crabs are not complicated to raise, and they can be easily raised as long as they are cared for on weekdays. First of all, the size of the feeding container is more than 1 foot, the height of the tank should not be too low, and the smooth wall of the tank can prevent escape. In terms of setting up the cylinder, it is necessary to consider its native half-water and half-land habitat environment, so it is necessary to arrange a living environment in which the water field and the land field coexist in the tank, and the water level is best to be half the height of its body; because it likes to excavate, the bottom sand placed at the bottom of the cylinder can make it more secure, of course, some people think that the bare cylinder is better managed; and then place a few stones, imitating its native environment, it is best to create a hole, which is in line with its cave life, but it must be noted that the stone block is too close to the cylinder wall (the top of the cylinder has a cover, there is no need to worry about this point), Otherwise, the jar is too low to give the Christmas crab a chance to wander out, and finally it can be combined with some planting (moss) to create an imagination of wild habitat.
Naked tanks are a very common way of feeding, and the vision is more monotonous
Christmas crabs are very good at climbing, and it is best to raise the tank high enough and the walls of the tank to be smooth
Christmas crabs usually find a place to hide when they are in danger, and they can drill holes worthy of the name
water quality
Christmas crab is not strict about the water temperature, compared with the water temperature of the general feeding fish (24 to 30 ° C). In addition, Christmas crabs have a wide tolerance range for pH, whether fresh or semi-brackish water can be adapted, even if tap water is used, as long as it is aerated, it can be safely raised. The timing of water change depends on the number of feeding and the degree of feeding, generally 3 to 7 days more than 3 to 7 days for the water change cycle.
fodder
Christmas crab feeding is omnivorous and scavengeral, whether it is vegetables, fruits, dead fish, live fish and artificial sedimentary feed can be fed, basically can be said that people do not want to eat can be thrown in. No matter what kind of food is fed, it is best to get used to regular and quantitative feeding for Christmas crabs, because food corruption will lead to water corruption, and finally affect the health of Christmas crabs.
DATA | Fish tank parameters Fish tank size: 1 foot tank Landscaping materials: fine sand, stone, water basin, triangle moss, white grass, Assisting in landscaping: The New Wave
writing. Photography / Ray Ni
Editing organize / ifish_ megabyte
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