Steno+Dolphin



SIZE: A small, grayish-black dolphin with the forehead rising gradually from the beak; 20-27 fairly large teeth in each tooth row, the crowns of which have many fine, vertical wrinkles (from which feature the name rough-toothed dolphin is derived); length of rostrum of skull about three times its width. Total length, 2-2.5 m; weight, 100-135 kg. http://ojosverdes24.tripod.com/new_page_7.htm

DIET: Very limited data. Pelagic octopus, squid and reef fish. Larger fish may be taken in deep water.http://www.environment.gov.au/coasts/publications/cetaceans-action-plan/whaleap5b.html

POPULATION: No population estimates known. Believed to be uncommon throughout its range but difficulties in identification could mean abundance is underestimated. http://www.environment.gov.au/coasts/publications/cetaceans-action-plan/whaleap5b.html

LIFESPAN: Human beings, either directly or indirectly, seriously affect mortality rates for dolphins and other cetaceans. Stranded whales have been found with plastic bags (possibly having mistaken them for jellyfish) and other debris in their stomachs, which can cause internal injury or starvation. Chemical pollution in their waters may contaminate their food supply and has been linked to immune system suppression (making them more susceptible to disease), reproductive failure, and other damage. Certain fishing methods cause dolphin deaths incidentally, and in some areas of the world, dolphins and whales are still hunted. Natural death, however, usually results from one of three main causes: predators, parasites, or disease. Aside from man, Orcas and sharks comprise the largest threats as predators to bottlenose dolphins in their natural environment. Nematodes, tapeworms, and parasitic flukes have been found to infest their internal organs. Bacterial and viral infections are not uncommon, and studies have shown that they may account for over one-fourth of marine mammals found stranded or dead. Life in the ocean is not an idyllic paradise; many marine mammals killed in fisheries or in strandings are found to have ulcers believed to be stress-related. Like all animals in the wild, dolphins are most susceptible to adverse conditions, disease, and predators during the first two years of their lives. A study of beached dolphins in Florida indicated that 38% died before the age of two, and 64% of the dolphins studied died within their first ten years. It is possible for bottlenose dolphins to live into their 50's, much the same as humans may live into their 90's. Scientists have found that dolphins living in human care have approximately the same longevity as those in the wild, possibly even better because of improved nutrition, a reliable food source, and the optimum husbandry and medical care made possible by our growing knowledge. http://www.dolphins.org/Learn/lmm-nhst.htm#Life%20Span

HABITAT: Rough-toothed dolphins prefer deeper areas of tropical and warmer temperate waters where their prey are concentrated. http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/roughtootheddolphin.htm

RANGE: The Rough-toothed dolphin, //Steno bredanensis//, is most commonly found in tropical and subtropical deep water from the western Pacific to the Mediterranean. They are rarely seen ranging north of 40° latitude or south of 35° latitude. They have also been seen along the Atlantic coast of the United States, in the Caribbean, Gulf of Mexico, Mediterranean sea, eastern tropical Pacific, and Indian Ocean. Geographic distribution of this species in not well known. http://marinebio.org/species.asp?id=358

OFFSPRING: Little is known about the reproductive habits of this species. A **Rough-toothed dolphin** was bred with a [|Bottlenose] in captivity producing a hybrid offspring. What is known is that female **Rough-toothed dolphins** reach sexual maturity at about 10 years, males at 14 years. http://www.animalcorner.co.uk/marine/dolphins/dolphins_roughtooth.html

INTERESTING FACTS: The flippers and the flukes of this species are unusally large for its body size with the flippers reaching up to one-seventh and the width of the flukes reaching one-fourth of the animal's total body length. Little is known about rough-toothed dolphins, but they are notable for their "surfing" behavior during which they swim at a high rate of speed their and chins above the water as they skim across the surface. http://csiwhalesalive.org/csirough-toothed.html

THIS IS THE END OF MY REPORT.