Horseshoe Crab --- Arthropods

Limulus polyphemus

Million of year ago, the oceans were filled with many different types of horseshoe crabs. Today there are only 5 species left. Limulus polyphemus live at the edge of the ocean, along the Atlantic coast from Canada to the Gulf of Mexico. It is the only horseshoe crab in the Atlantic Ocean. The others live off the coast of Asia.

The horseshoe crab has a thick body shell shaped like a horseshoe like a horseshoe. It also has a long tail that trails behind it. From below you can see 5 pair of legs ending in little claws. It is called the horseshoe crab because it has a general body shape similar to the crab. But it isn’t crab at all! In fact, it’s more closely related to scorpions and spiders.

The animal usually stays in the sand on beaches. There, it uses its legs to bury itself. It finds its food--- molluscs and worms--- in the sand. When it has to move, its long tail works like a lever to help push it out of the sand. The tail also helps it put itself back on its legs when it has been turned over by a large wave. In the water, the horseshoe crab swims easily on its back.

When it’s time to lay their eggs, males and females cross the sand to get to the highest part of the beach. The female digs a hole and lays up to 10,000 eggs. The eggs hatch in about 2 weeks and young horseshoe crabs reach the sea with the help of the rising tide.

PHYLUM: Joint-legged animals

ORDER: Horseshoe crabs

FAMILY: Living horseshoe crabs

LENGTH: up to 24 inches

DIET: molluscs, worms, and algae

NUMBER OF EGGS: up to 10,000

HOME: Atlantic Ocean off east coast of North America.

 

Western Diamond-Back Rattlesnake --- Reptiles

Crotalus atrox

Western diamond back rattlesnake lives in the United States from Missouri to California, and in northern Mexico. They live in all environments: deserts, prairies, brush, woods, or river valleys. They are among the largest and most dangerous of the rattlers and are responsible for several deaths each year.

The famous “rattle”- is found at the end of the tail. It is made up of scales shaped like rings that are fitted one inside the other to form a loose chain. When the snake feels threatened, it lifts its tail up and shakes the rattle hard. The rings vibrate and make a noise that can be heard from more than 100 feet away. The more the snake feels threatened, the more it shakes its rattle.

Rattlesnakes are pit vipers, a group of poisonous snake found in many parts of the world. They have a small dimple, or pits, between their eyes and nostrils that can feel the smallest change in temperature. This “sixth sense” is very useful to the rattlesnake. It helps the snake spot its prey even in the dark. Once it has found its victim, the rattlesnake kills it by striking it with its 2 long poison fangs. Approximately 20 people die in the United states each year from rattlesnake bites.

The western diamond back rattlesnake gives birth to live young. Its eggs develop in the female’s body, and the young hatch inside just before they are born in summer. There are usually 10 to 20 offspring.

CLASS: Reptiles

ORDER: Lizards and snakes

FAMILY: Pit vipers

LENGTH: 3 to 7 feet

WEIGHT: 13 pounds

DIET: carnivorous

NUMBER OF YOUNG: 10 to 20

HOME: United States and Mexico

 

Red Piranha --- Fish

Serrasalmus nattereri

Piranhas lives in the waters of the Amazon region in schools that are made up of several hundred fish. Most piranhas are about a foot long, but in eastern Brazil 1 type of piranhas may reach 2 feet in length. Piranhas are famous because they eat flesh, but of about 20 kinds, only 4 types, including the red piranha, are aggressive and dangerous.

The lower jaw of the red piranha has very strong muscles and large, pointed teeth, as sharp as razor blades. The smallest teeth of the upper jaw are also very sharp. The piranha usually feeds on smaller fish. But sometimes schools may attack large mammals. They eat them completely to the bones in just a few minutes. The attack is so fast and awful that the river seems to boil with blood. The male is especially aggressive when watching over the eggs placed in water plants by the female. When the piranha is starving because it lives in a part of the river that is cut off from the main river during a dry period, for example, it is really dangerous to mammals. A hungry piranha will attack and eat almost anything. Otherwise, it sticks mostly to eating fish. Oddly enough, in South America, people often swim in rivers that are full of piranhas. These people are usually unharmed. Red piranhas are often kept in aquariums as pets. The aquarium has to be large and must have lots of plants. Several piranhas can live together, but it is not a good idea to put other kinds of fish in an aquarium with piranhas.

CLASS: Bony fishes

ORRDER: Carps, minnows and characins

FAMILY: Characins

LENGTH: 12 inches

DIET: fish and invertebrates

NUMBER OF EGGS: 5000

HOME: river system of the Amazon, Orinoco, and Parana

 

Gorilla --- Mammals

Gorilla gorilla

Few other animals have been the subject of as many legends as the gorilla. However, it isn’t the man-eating monster that many people imagine. In fact, it eats nothing but leaves, fruit, and plant shoots.

Gorillas live in groups of 2 to 30. Each group occupies a territory that can cover as much as 12 square miles. Their highly structured families include a dominant male, usually the largest and the strongest; 2 to 3 smaller males; several females; and young gorillas of all ages. Gorillas travels slowly through the forest at the rate of no more than half a miles a day. They leave behind them a powerful scent that can be detected from 150 feet. Gorillas spend nearly 15 hours a day sleeping. Each night they build their nest out of branches. Gorillas are shy animals and only charge when they are taken by surprise. Even then, they charge more to hide their fear than to attack others.

There are two subspecies of gorillas. The lowland gorillas are found in the forests of Cameroon, Gabon, the Central African Republic, Congo, and Zaire. The mountain gorillas live in the mountains that separate east from central Africa. The number of gorillas is decreasing. There are now only several thousand left, but although they are legally protected, illegal hunting and loss of natural habitat continue to destroy them.

CLASS: Mammals

ORDER: Primates

SUBORDER: Anthropoids

FAMILY: Apes

HEIGHT: up to 6 feet

WEIGHT: 175 to 200 pounds (Female)          

                  300 to 400 pounds (Male)

DIET: mostly leaves and shoots

NUMBER OF YOUNG: 1

HOME: West and central Africa

Common Goldcrest --- Birds

Regulus regulus

A fine, high- pitched call that sounds like “see see see” signals the presence of a goldcrest. The goldcrest is easier to hear than to see. Although the male has a red- orange crown on its head and the female, a yellow one, its overall olive-green colour blends well with the spruces in which it lives. It eats aphids or other insects living in the trees. Its also eats moth and butterfly eggs as well their cocoons. But the goldcrest lives in the spruce forest for another reason. In the winter, the trees ‘leaves provide shelter against rain or snow.

During the mating season, the female builds, her nest, with help from the male. The nest is a deep bowl made of moss and lichen which the female attaches to a tree branch with a silk from spiderwebs. Inside, it is lined with down feathers and moss. In April the female lays 6 to 10 tiny eggs. They weigh less than a tenth of an ounce each. The young hatch blind and open their eyes a week later. During the 15 to 17 days they stay in the nest, they are well cared for by their parents. A second group of chicks arrives in July.

The goldcrest and its cousin, the firecrest, are the smallest European birds. When you are lucky enough to see these 2 small birds, you can tell them apart because the firecrest has a black mask across its eyes and its white brows. Otherwise these birds are very much alike.

CLASS: Birds

ORDER: Perching birds

FAMILY: Old world warblers

LENGTH: 3 to 4 inches

DIET: insect

NUMBER OF EGGS: 6 to 10

HOME: Eurrasia

 

Migration of Birds

Birds migrate the farthest of any creature in the animal world. The ruby-throated hummingbird, which weighs only 1/10 of an ounce, briskly travels 500 miles across the Gulf of Mexico. The record belongs to the Arctic tern, which travels 11,000 miles each way. Not all birds migrate, however; the crow stays in the same place all year round.

Migration is usually tied to the change of seasons. Birds often leaves as winter comes, when food becomes scarce. They go to warmer places to spend the winter. In the spring they come back to mate. But the link between climate changes and migration is not always clear. For example, around the equator, where there are no seasons, many birds still migrate. In this case, it is possible that migrations are tied to periods of rain and drought.

To track down the places where birds go when they migrate, scientists put lightweight rings around their legs. They then catch the birds all over the world and can draw migration maps. Very light radio transmitters are also used to pick up the birds movements. The results of these studies show that migration tend to go from north to south and south to north.

Species that breed in the north tend to migrate to the south and the other way around. For a given group of birds, the distance flown and the points of departure and arrival are always the same. For instance, the Kirtland’s warbler always nests in the pine woods of north central Michigan. Near the end of the summer it heads southeast toward the Bahamas, where it arrives in mid- September. In April, it flies over Florida, Georgia, and South Carolina on its way back to Michigan. It arrives in May.

Some birds fly at night and use the starts to guide them. Mallards in lllinois head in the correct direction on clear nights, but become confused when the stars are hidden by clouds. Other birds, such as starlings, use the sun to stay on the right course.

Red Sea Star --- other Invertebrates

Asterias rubens and Asterias forbesi

Sea star are commonly called “ starfish” but biologist call them “sea stars” because these strange animals are not at all like fish. Their relatives are sea lilies, sand dollars, sea urchins, and sea cucumbers.

The red sea star, pictured on this card, is the common sea star of Europe. A very similar one, Asterias forbesi, is found along the Atlantic coast of the United States. Like most sea stars, Asterias lives in tidal zones. It stays on rocks, in the sand, or in tidal pools at low tide. It can even stay out of water for a rather long period of time. The sea star’s body has a rugged look, and its back is dotted with short spines. In a groove on the bottom of each of its 5 arms are dozens of “tube feet” which have suckers on the ends.

These suckers help it move and cling to its surroundings. Asterias have 5 thick arms. The arms often break off at the base if a predator grabs one. The lost arm grows again little by little, so sea stars are often found with 1 arm shorter than the others.

Sea stars digest mussels and oysters in a strange way. They wrap mussels or oyster shell in their arms and then pull open the 2 parts of the shell using their tube feet. They squeeze very tightly until the muscle of the shellfish tires out. The sea star then turns its stomach inside out and puts it into the open shell. The sea star eats its prey while the shellfish is still in the shell.

PHYLUM: Echinoderms

CLASS: Sea Stars

ORDER: Forcipulatids

FAMILY: Asterids

WIDTH: Generally 4 to 6 inches --- often as much as 20 inches

DIET: Mollusks, Such as calms and oysters

METHOD OF REPRODUCTION: Egg Layer

HOME: north Atlantic coast and Mediterranean Sea