Land hermit crabs, scientifically known as Coenobita clypeatus, are crustaceans found in the wild in the Western Atlantic. These crabs have three parts: a head, a body called cephalothorax, and an abdomen that they protect with their shells. To preserve moisture, hermit crabs have gills on their large claw which need to stay wet for optimal health. Despite their seemingly harmless appearance, hermit crabs have strong claws that can draw blood when frightened. In their natural habitat, hermit crabs typically travel in groups of around 25 individuals.
When it comes to reproduction, hermit crabs do not breed in captivity but instead mate on land near the ocean. The female carries the eggs on her abdomen and deposits them on wet sand or rocks for the tides to carry out to sea. Each time, there can be anywhere from 1,000 to 50,000 eggs. These eggs hatch into small larvae in the ocean where they molt multiple times until they develop into typical adult hermit crabs. After reaching this stage, they search for a suitable shell and spend the rest of their lives on land.
The growth process for land-dwelling hermit crabs involves shedding their exoskeletons. It takes approximately ten days for their skin to harden after molting. Shedding is crucial for their survival as it allows them to regenerate lost legs.These crabs have a lifespan of 25-30 years in the wild, but when kept in captivity, their life expectancy decreases to approximately 1 year.
Hermit crabs have a wide-ranging diet and will eat almost anything in their natural environment. They especially enjoy fruits like apples, coconut, and grapes. It’s also crucial for them to consume salty foods. Access to fresh drinking water is important for meeting their nutritional needs. When hermit crabs drink from a shell, they obtain the necessary calcium for their daily diet. These creatures thrive in temperatures ranging from 70 to 85 degrees Fahrenheit. If the air becomes too cold or dry, they become inactive. Hermit crabs prefer living in dry aquariums with adequate moisture rather than wet and messy cages.
During my visit to the zoo, I noticed that hermit crabs seemed inactive. However, I later discovered that this was because they are primarily active at night. It is crucial for hermit crabs’ well-being to exercise outside their enclosures as it promotes longevity in these creatures. They are attracted to dark areas likely due to their nocturnal nature but also tend to return to familiar spots despite enjoying exploring new surroundings. On average, hermit crabs live for 1-4 years. Furthermore, larger hermit crabs do not show aggression towards smaller ones; aggression usually happens between individuals of similar sizes. Being a former owner of several hermit crabs, I became interested in conducting research on them.
I selected the kangaroo as my chosen vertebrate animal because of its impressive intelligence and ability to jump long distances. When I visited the kangaroo site, I observed that they were more active than hermit crabs. Many kangaroos were lively and engaged in various activities like playing with toys, rolling in the grass, and sunbathing. However, some kangaroos were less active.
Kangaroos are marsupial mammals from the Macropodidae family and can be found in Australia, Tasmania, and New Guinea. They are herbivorous animals that graze on vegetation. Unfortunately, humans pose a threat to kangaroos as they are hunted for meat and their hides are used for shoes. Additionally, competition for food with livestock has contributed to a decline in the kangaroo population. To manage their increasing numbers, kangaroos have been systematically reduced through hunting since natural predators like the thylacine have been eliminated by Australian farmers.
Kangaroos have powerful hind legs and feet for hopping and leaping, which are their primary forms of movement. Their tails are thickened at the base and used for balance. While foraging, kangaroos often go on all fours. Each narrow hind foot has four toes. The short forelimbs perform a similar function to human arms, but the thumb is not opposable. Kangaroos possess soft, wooly fur, with some exhibiting stripes on their head, back, or upper limbs. They all possess a chambered stomach like ruminants such as cattle and sheep. These animals regurgitate the vegetation they consume, chew it as cud, and then swallow it again for final digestion.
Although kangaroos require minimal water, they can survive without drinking for months. However, when necessary, they dig wells known as kangaroo pits that can reach depths of three or four feet. These wells often serve as a water source for other animals in the kangaroo’s habitat.
Kangaroos generally have one joey per year. The joey is born alive but is very small and undeveloped, measuring about 2 cm in length and weighing less than a gram. Immediately after birth, it climbs up the mother’s body and enters the pouch. The joey attaches to one of the four teats in the pouch, which enlarge to keep the young kangaroo secure. Over time, the joey becomes more active and gradually spends more time outside the pouch. Eventually, at around 7 to 10 months old, the joey fully leaves the pouch. Female kangaroos go into estrus a few days after giving birth. They mate and conceive, but shortly after only a week of development, the microscopic embryo goes into a dormant state. This dormancy continues until the previous joey departs from the pouch. Then, development of the second embryo resumes and approximately 30 days later, the kangaroo gives birth once again.
The Macropus genus includes several species of kangaroos. These include the gray kangaroo (also known as Macropus canguru, M. giganteus or M. major), the wallaroo (M. robustus), and the red kangaroo (M. rufus). The gray kangaroo is found in open forests in eastern and southwestern Australia, as well as Tasmania. It has long silvery gray hair along the coast and a shorter dark gray coat inland.
The red kangaroo is the largest and strongest species found throughout Australia’s grasslands. Male red kangaroos can reach impressive measurements of 1.5 m head-body length, possess a 1 m long tail, stand at a height of 2 m, and weigh up to 90 kg.
Gray kangaroos are known for their incredible jumping abilities, able to leap over 9 m (30 feet) in one bound and reach speeds of up to 48 kilometers per hour.
Compared to other Macropus species, the wallaroo is smaller and stockier. It can range in color from dark gray to pinkish brown and can be found in rocky areas across Australia except Victoria.
All these large kangaroos move around in groups called mobs led by a dominant male referred to as the “old man” or “boomer.” The dominant male establishes authority over younger rivals through biting, kicking, and boxing.
