dangerous animals
Africa's most feared snake the Black Mamba is the largest venomous snake in Africa, and is considered to be one of the world's fastest. Mambas have been described as aggressive, although there is little hard evidence of this. Most mambas if approached, move away or freeze, hoping to remain unseen. However, it will bite if threatened.
The Nile Crocodile (Crocodylus niloticus) is one of the 4 species of crocodiles found in Africa, and the second largest species of crocodile. Nile crocodiles can be found throughout most of Africa south of the Sahara, and on the island of Madagascar. The Nile crocodile can, and sometimes will, easily snatch and devour a human. While it is no longer threatened with extinction as a species, the population in many countries is in danger of vanishing.
Billy, the Pygmy Hippo, or William Johnson Hippopotamus (1920 � October 11, 1955) was one of the most unusual pets ever kept by a President of the United States. In addition to his fame as an exotic presidential pet, Billy is also notable as the common ancestor to most pygmy hippos in American zoos. However, the hippo you see in this photo is not a pygmy hippo, it's just a baby hippo with baby fat, but I'm sure his name was Billy, or at least that's what he told me.
The hippopotamus is semi-aquatic, inhabiting rivers and lakes in sub-Saharan Africa in large groups of up to 40 hippos. During the day they remain cool by staying in the water or mud; reproduction and childbirth both occur in water, where territorial bulls preside over a stretch of river. They emerge at dusk to graze on grass. While hippos rest near each other in territories in the water, grazing is a solitary activity and hippos are not territorial on land.
He was rejected by his herd and had to gain weight to fight back into group. He was very aggressive.
The Cape Buffalo is a very powerful creature, demanding respect from even a pride of lions when paths cross. Other than humans, they have few natural predators and are capable of defending themselves against (and sometimes killing) lions. Lions do kill and eat buffalo regularly, but it typically takes multiple lions to bring down a single adult buffalo; only large male lions have been known to take down adult buffalo on their own. The leopard and spotted hyena are a threat only to newborn calves. The African Buffalo has never been domesticated.
Sea spiders have long legs in contrast to a small body size. The number of walking legs is usually eight (four pairs), but species with five and six pairs exist. Because of their small size and slender body and legs, no respiratory system is necessary, with gases moving by diffusion. A proboscis allows them to suck nutrients from soft-bodied invertebrates, and their digestive tract has diverticula extending into the legs.
Pycnogonids are so small that each of their tiny muscles consists of only one single cell, surrounded by connective tissue. The anterior region consists of the proboscis, which has fairly limited dorsoventral and lateral movement, and three to four appendages including the ovigers, which are used in caring for young and cleaning as well as courtship. In some species, the chelifores, palps and ovigers can be reduced or missing in adults. In those species that lacks chelifores and palps, the proboscis is well developed and more mobile and flexible, often equipped with numerous sensory bristles and strong rasping ridges around the mouth. The last segment includes the anus and tubercle, which projects dorsally.
In total, Pycnogonids have four to six pairs of legs for walking as well as other appendages which often resemble legs. A cephalothorax and much smaller abdomen make up the extremely reduced body of the Pycnogonid, which has up to two pairs of dorsally located simple eyes on its non-calcareous exoskeleton, though sometimes the eyes can be missing, especially among species living in the deep oceans. The abdomen does not have any appendages, and in most species it is reduced and almost vestigial. The organs of this fascinating chelicerate extend throughout many appendages because its body is too small to accommodate all of them alone.
The morphology of the sea spider creates a perfect surface-area to volume ratio for any respiration to occur through direct diffusion. The most recent research seems to indicate that waste leaves the body through the digestive tract or is lost during a moult. The small, long, thin pycnogonid heart beats vigorously at 90 to 180 beats per minute, creating substantial blood pressure. These creatures possess an open circulatory system as well as a nervous system consisting of a brain which is connected to two ventral nerve cords, which in turn connect to specific nerves.