Land hermit crabs are crustaceans known as Coenobita clypeatus. They live in the wild in the western Atlantic. Hermit crabs have three sections: a head, a body (cephalothorax), and an abdomen, which they protect with their shells. Hermit crabs have gills on their big claw in order to conserve moisture. Hermit crabs sometimes go for long periods of time without food or water. However, hermit crabs need to keep their gills wet to maintain good health. Although hermit crabs might look harmless, they can use their claws to grip things tightly. Even the very smallest hermit crabs can draw blood if it becomes frightened.
Hermit crabs usually travel in groups of 25 (approximately) in the wild. Hermit crabs do not reproduce in captivity. Instead, they mate on land near the sea. After the eggs develop, the female carries the eggs on her abdomen to the sea where she leaves them on wet sand or a wet rock for the tide to carry them out to sea. There are usually 1,000 to 50,000 eggs at a time. They are small larvae at sea where they molt several times in order to grow to reach the characteristics of a typical adult hermit crab. After reaching the adult larvae stage, the hermit crabs begin looking for a shell to live in.
Once they mature and find a suitable shell, they come to live on land for the rest of their lives. Hermit crabs grow on land by shedding their exoskeleton. It takes about ten days for a hermit crab’s skin to harden after molting. Shedding is a necessary part of their livelihood since they will grow back missing legs during this time. In the wild, hermit crabs can live up to 25-30 years. But normally in captivity they live around 1 year.
Hermit crabs can eat a variety of foods. In the wild they are scavengers and will eat about anything. Hermit crabs like a variety of fruits (apples, coconut, and grapes). Also, hermit crabs need salty foods in their diet. Another important part of a hermit crab’s diet is fresh drinking water. When crabs drink out of a shell, they receive calcium from the shell that they need in their daily diet.
Hermit crab lives in temperatures between 70-85 degrees. If the air is too cold or dry, the crabs will become inactive. Hermit crabs do not like to walk around a wet sloppy cage, but prefer to be in a dry aquarium with lots of moisture in the air.
When I was at the zoo the hermit crabs that I saw where not showing much movement. As I read I found out that the reason the hermit crabs where not moving much was because most hermit crabs are nocturnal, so they may seem inactive during the day, but active during the night. It is important for a hermit crab’s well being that they get exercise outside the cage.
Hermit crabs tend to live longer on the whole when they get more exercise. I also noticed that the hermit crabs will go towards dark areas, such as dark shady areas, since they are nocturnal. Hermit crabs seem to like having the freedom to move, but they always return to the same location eventually. Hermit crabs live between 1-4 years on the average. I also noticed that large hermit crabs are not aggressive towards smaller hermit crabs. Usually, hermit crabs are only aggressive to hermit crabs of similar sizes.
The hermit crabs caught my attention because I used to have a bunch of them a couple years ago, and thought it would be interesting to do research on hermit crabs.
The animal I chose for my vertebrate selection was the kangaroo. What I observed at the kangaroo site was a very active behavior contrary to the hermit crabs. The kangaroos were all very lively except for a few. One or two were playing with their toys, another rolling in the grass, and the others catching some rays. I chose the kangaroo for my vertebrate selection because they were very lively, and I have always been interested in kangaroos, because of their incredible intelligence, and their speed and ability to jump such great distances.
Kangaroos are marsupial mammals and comprise 47 species within the family Macropodidae. Kangaroos are found in Australia, Tasmania, and New Guinea. Most are terrestrial and all are herbivorous, grazing and browsing for their food. Their principal enemies are humans, who kill kangaroos for meat and for their hides (used in shoes), and because kangaroos compete with livestock for food. By the late 20th century, the number of kangaroos in Australia had increased to the point that the animals had to be systematically reduced by hunting because its natural predators (such as the thylacine) had been virtually eliminated by Australian farmers.
Kangaroos possess long, powerful hind legs and feet for hopping and leaping, their predominant forms of locomotion. Their long tails, thickened at the base, are used for balancing: kangaroos frequently “go on all fives” when foraging. Each long, narrow hind foot has four toes. The short forelimbs are used almost like human arms, but the thumb is not opposable. Kangaroos possess soft, wooly fur, and some have stripes on the head, back, or upper limbs. All kangaroos have a chambered stomach that is functionally similar to those of such ruminants as cattle and sheep. They regurgitate the vegetation they have eaten, chew it as cud, and then swallow it again for final digestion.
Kangaroos need very little water to survive and are capable of going for months without drinking at all. When they do need water, they dig “wells” for themselves, frequently going as deep as three or four feet. These “kangaroo pits” are a common source of water for other animals living in the kangaroo’s environment.
Kangaroos usually have one young annually. The young kangaroo, or joey, is born alive at a very immature stage, when it is only about 2 cm long and weighs less than a gram. Immediately after birth it crawls up the mother’s body and enters the pouch. The baby attaches its mouth to one of four teats, which then enlarges to hold the young animal in place. After several weeks, the joey becomes more active and gradually spends more and more time outside the pouch, which it leaves completely between 7 and 10 months of age.
Female kangaroos enter into heat within a few days after giving birth; they mate and conceive, but after only one week’s development the microscopic embryo enters a dormant state that lasts until the previous young leaves the pouch. The development of the second embryo then resumes and proceeds to birth after a gestation period of about 30 days.
The three largest species of kangaroos belong to the genus Macropus; they are the gray kangaroo, or forester, Macropus canguru (sometimes called M. giganteus or M. major); the wallaroo, M. robustus; and the red kangaroo, or red flyer, M. rufus. The best-known species, the gray kangaroo, is found mostly in open forests of eastern and southwestern Australia and Tasmania. It is long-haired and silvery gray in eastern coastal regions but short-haired and dark gray inland. The red kangaroo, which is found throughout Australia’s interior grasslands, is the largest and most powerful species.
A male may attain a head-body length of 1.5 m; have a tail 1 m long; stand 2 m tall; and weigh 90 kg. A gray kangaroo can clear more than 9 m (30 feet) at a bound and attain a speed of 48 kilometers per hour. The wallaroo, a smaller and stockier animal, may be dark gray to pinkish brown; it lives in rocky country throughout Australia except Victoria. These large kangaroos travel in groups (mobs) under the leadership of the largest male (“old man,” or “boomer”), which dominates younger rivals by biting, kicking, and boxing.