Salamander Essay, Research Paper
The salamander is a curious creature. Among the kingdom Animalia, they fall in the Phylum Chordate and in the Sub-Phylum vertebrata. Their Class is Amphibia, and their order is urodela. They are amphibians, which comes from Greek words meaning both life. This truly describes the life and life cycle of the salamander.
The salamander, along with the newt, frog, and toad belong in the order Amphiba and all are ancestors to the first aquatic vertebrates to begin to colonize on land. Salamanders are found in the Americas and in the temperate zones of North Africa, Asia, and Europe. Often mistaken for lizards, salamanders have soft moist skin covering their long bodies and even longer tails. No scales are found on their body, and they have no claws or external ear openings.
There are basically three types of salamanders. The first is the aquatic, the second is the semi-aquatic, and the third is the completely terrestrial. The aquatic live out their full life cycles in water, while the semi aquatic live primarily on land, and hibernate as well as bread in the water. The Terrestrial salamander spends its entire lifetime on land, though they are never found far from water.
The larva of a Salamander is often confused with tadpoles, the offspring of frogs. The only optical difference is the size of the tadpoles head is larger then the larva of a salamander. The reproductive systems of salamanders have numerous steps. First, the Courtship?s take place. The courtships are often elaborate, and filed with specific positions and movements. Next, the male secretes a spermatophore, or sperm packet, and the female picks it up with the lips of the external opening. This opening leads to the cloaca, where the oviducts, intestine, and urinary ducts empty. Her eggs are then fertilized by the sperm packet, and may be laid right away, or retained. If the fertilized eggs are retained, several layers are secreted around the eggs, including the ?jelly? like substance that swells with water and moisture to protect the eggs as well as hold them together. The young are then retained throughout their development and then are born.
Most salamanders grow to be around ten centimeters. The largest salamander, the Andrias Japonicus, found in Japan, can grow up to seventy inches. The majority of all salamanders and their larva are carnivores. They eat anything from insects, small invertebrates, fish, frogs, and other salamanders. The salamander is voiceless and chiefly a nocturnal animal.
Salamanders from cooler climates bury themselves in soil or the mud at the bottom of ponds or lakes. They do this when they hibernate to avoid frost and to maintain an even temperature.