|
Fossil Records
1.) The 1st. turtles appeared during the Triassic Period, 248 to 208 million years ago.
2.) The earliest known sea turtles appear in the fossil records in the Late Jurassic Period, 208 to 144 years ago. Scientists believe that modern sea turtles are derived from marsh-inhabiting ancestors that lived during the Late Triassic Period.
3.) Fossil records show that the now-extinct sea turtle, Archelon Ischyros, from the Late Cretaceous Period, 144 to 65 million years ago was one fof the largest turtles that ever lived and reached a length of 3 to 4 meters (9.8-13 ft).
Leatherback Sea Turtle (Dermochelys Coriacea)
Details
Named for smooth, rubbery shell
Endangered Species (Worldwide)
Largest sea turtle in the world
Travels the farthest
Feeds on Jellyfish
Adults: 700 to 2000 pounds/4 to 8 feet in length
Hatchlings: 2 1/2 in. long
Nest in Florida from April-July
About 50 nests a year reported in Florida/estimated 70,000-115,000 females
Agencies & Private Organizations
Centre for Marine Conservation
Greenpeace
National Audbon Society
Florida Power and Light Company
ST. Croix Environmental Association
University of Virgin Islands Extension Service
Environmental Association
VIDFW & NPS
Hawksbill Sea Turtle (Eretmochelys Imbricata)
Details
It's name derives from its hooked beak formed by its yellowish jaws
Endangered Species
Exploited for "tortoiseshell" jewelry
Only sea turtle with overlapping carapace scales
The have two pairs of prefrontal plates between the eyes
Adult's keeled shell is amber with streaks of red-brown, black-brown, or yellow. The underside is whitish-yellow, occasionally with black spots.
Adult females range from 24-38 in. (61-96cm) in length and weigh 60-190 pounds.
They are considered omnivores, mostly eating algae, sea grasses, soft corals, crustaceans, mollusks, sponges, jellyfish, and sea urchins.
Habitat: Prefer warm, coastal shoal waters less than 50 ft. deep with abundant submerged vegetation. Ideal habitats: Coral reefs, lagoons, inlets and bays.
They can be found all over the world, Atlantic, Pacific, Indian Ocean, Persian Dulf, Red and Mediterranean Sea.
There shell is used for medicinal purposes. Their body parts are used for leather, oil, perfume, and cosmetics.
Agencies & Associations
The National Marine Fisheries Service
Riverhead Foundation
Marine Research and Prevention
Loggerhead Sea Turtle (Caretta Caretta)
Details
Named for its exceptionally large head and powerful jaws.
Carapace: They have a bony heart-shaped, reddish-brown carapace with yellow-brown plastron.
Status: Federal and state threatened. Internationally endangered.
Population: Estimated 44,560 nesting females.
Life Span: Estimated 50 years or more.
Sexual Maturity: 15 to 20 years of age.
Hatchlings: Dark-brown carapace with pale brown flippers.
Size: Typically, 2.5 to 3.5 ft. (73-107cm) in carapace length.
Weight: Adult weigh upto 350lbs. (159kg).
Diet: Primarily, carnivorous and feeds mostly on shellfish that live on the bottom of the ocean as well as horseshoe crabs, clams, mussels, and other invertebrates.
Habitat: They prefer to feed in coastal bays and estuaries, as well as in the shallow water along the continental shelves of the Atlantic, Pacific, and Indian Ocean.
Nesting: Nests in intervals of 2,3, or more years. They lay 4 to 7 nests per season, approx. 12 to 14 days apart. They lay an average of between 100 to 126 eggs in each nest. Eggs incubate for about 60 days.
Range: Found in all temperate and tropical waters throughout the world.
Threats to survival: Loss of nesting due to coastal development, predation of nests, and human disturbance that causes disorientations during the emergence of hatchlings.
Protective Legislation: Federal-Endangered Species Act of 1973.
Interesting Facts: Thought to be the largest living hard-shelled turtle. It is exceeded in length and weight only by the Leatherback Sea Turtle. Its skull is broad and massive, providing an anchor for the strong jaw muscles that are needed to crush shellfish. It is the only living species in the genus Caretta.
Protective Agencies: Caribbean Conservative Corporation & Sea Turtle Survival League
Black Sea Turtle (Chelonia Agassizii)
Details
Considered to be a subspecies of the Green Sea Turtle.
Status: Endangered
Range: Tropical Eastern Pacific. Found in the Pacific Ocean along the coasts of North & South America from central Baja to Peru. They prefer bays and protected shores and is usually not found in open seas.
Diet: Algae, Sea grasses, jellies.
Size: Upto 4 ft. long (1.2cm)
Weight: 278lbs. (126 kg).
Sexual Maturity: Between 8 and 13 years old.
Relatives: Closely related to the Green Sea Turtle and in the same family as the Loggerhead Sea Turtle, Hawksbill Sea Turtle, Kemp's or Atlantic ridley, olive or Pacific ridley and Australian Flatback.
Exploitation: Overutilization as a food source, loss of nesting habitat and inadvertent drowning when they're trapped in fishing gear meant for other sea animals.
Cool Facts: Female sea turtles may travel thousands of miles to return to their nesting site to lay eggs. The sex of each hatchling is determined by the temperature at which it was incubated while in its egg. They can drink sea water due to the fact that they have glands near their eyes that remove excess salt from the water.
Protective Agencies: NGO Wildcoast & Mexican NGO Pronatura
Green Sea Turtle (Chelonia Mydas)
Details
Their shell is dark brown or olive colored.
Status: Currently designated as Endangered in the breeding colony populations in Florida and on the Pacific coast of Mexico. It is designated Threatened throughout the remainder of its range.
Size: Adults 2 to 4 ft. long.
Weight: 100 to 400lbs. (almost the weight of a human).
Life Span: 30-50 years.
Diet: Their favorite food would be sea grass and mangrove leaves with small amounts of animal foods such as sponges, crustaceans, sea urchins, and molluscs.
Habitat: They inhabit shallow waters such as shoals and lagoons. Inlets, bays, and estuaries are preferred by them.
Nesting: Occurs in all subtropical to tropical oceans of the world between 35 degrees North and South latitude, in waters that remain above 68 degrees during the coldest months. Eggs incubate in the sand for 48-70 days. Between March and October with the greatest activity being along the Gulf of Mexico beaches between June and August.
Migration: During the summer months, they come as far as from Labrador.
Threatening Survival: This species are used in turtle soup. They are also caught for their leathery skin, shells, and fat. Other threats are trawl nets, habital destruction on their beaches, egg poaching, trash pollution in the oceans, collisions with watercrafts, and artificial lightning on nesting beaches, and a disease called fibropapillomatosis .
 Ireth0283 · Wed Oct 25, 2006 @ 06:44pm · 0 Comments |
