Lagenorhynchus+Obscurus

Genus: Lagenorhychus Species: Obscurus Class: Mammalia Order: Cetartiodactyla Family: Delphindia
 * Dusky Dolphin**

The dusky dolphin was assessed in 2008 because it has been caught directly and by accident. Now the global population is unknown because there is insignificant data on the amount of decline.
 * Endangered Species Act**

//Ecosystem// The lagenorhychus obscurus is a coastal species that is ususally found over continental slopes and shelves.
 * Habitat**

Dusky dolphins are very spreadout throughout the southern hemisphere. They are known to live in the waters off of Tasmania, southern Australia, New Zealand, both central and southern South America, southwestern Africa, and around the coasts of many different oceanic islands. Research has shown that dusky dolphins cannot swim deeper than 200 meters. Also, they have been spotted swimming out as far as 200 miles from the shore but, current information states that they normally do not stray to far from the coasts.

//Physical Features// In the Pacific Ocean where the dolphin lives from the surface to 200 meters down, the average temperature is around 57° F. The salinity of these areas of the Pacific are about 35 PPS.

//Geologic Processes// There are earthquakes in the Pacific Ocean quite frequently and they are very spread out but few exactly where the dolphins live. New Zealand has had a decent amount of earthquakes in recent history some nearly reaching a magnitude of 7 on the rickter scale. There are a number of volcanoes where the dolphins live on the coasts of New Zealand and Australia.

//Currents// The ocean currents that affect the dusky dolphins are the Peru current, the Brazil current, the South Atlantic current, the Benguela current, the South Indian current, and the East and West Australia currents. These are both warm and cold currents.

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 * Physical Discription**
 * medium sized dolphin reaching up to 2 meters long
 * bluish-black tail and back, underside is white, tips of the snout and lower jaw are dark, grey from the eye to the flipper
 * 24-36 pairs of small, pointed teeth in each jaw with the upper jaw usually having 2 less teeth then the lower
 * Reproduction**
 * mating pattern similar to that of humans
 * males compete for females
 * usually takes place during spring
 * gestation last 11 months
 * one young per birth
 * mother's milk is produced for 18 months
 * Anatomy**
 * streamlined body for fast swimming
 * tail is used for propulsion, pectoral fins/tail are used for directional control, dorsal fin provides stability
 * unlike most mammals, dolphins do not have hair
 * breath through the blowhole on top of their heads
 * unlike most dolphins, dusky dolphins virtually has no beak because the head slopes down from the blowhole to the snout
 * have a large and complex brain
 * sensitive skin that contains an elaborate system of nerve endings
 * teeth aren't used for chewing but to grab prey because dolphins shallow thier food whole
 * Food Habits**
 * main food sources are fish (anchovy), squid, aquatic crustaceans, and mollusks
 * usually hunt cooperatively around large school of fish with up to 300 dolphins
 * main predators are killer whales
 * Economic Importance**
 * their meat is sold in markets with nearly 10,000 killed each year
 * attracts the tourist population to go dolphin-watching or swimming with them
 * Threats and Reasons for Endangerment**
 * being caught is the main reason for the decline in dusky dolphins
 * pollution such as garbage and oil spill still are not helping the species
 * their low reproductive rate (one offspring every 2-3 years) does not help
 * they are protected by the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act), which is an Australian doctrine that protects the Australian environment and wildlife species
 * My Solutions**
 * have Peru and Chile (the main fishers of the dusky dolphin) put out documents similar to that of the EPBC Act that will protect the dolphins and other wildlife
 * hold conferences and assemblies to urge to the people of the world that if we don't stop these people from overfishing that not just the dolphins but other oceanic species will also be destroyed
 * reproduce the species in a remote and safe area where they can get repopulated
 * __Questions to Answer__**
 * 1) What is the average temperature where the dusky dolphin lives?
 * 2) How long is the offspring inside the mother?
 * 3) Why were the dusky dolphins put onto the endangered list?

"IUCN Red List (version 2009.1) - Lagenorhynchus obscurus (Dusky Dolphin)." __IUCN Red List - Home Page__. 11 June 2009 [].
 * Works Cited**

"Dusky Dolphin, Lagenorhynchus obscurus at MarineBio.org." __MarineBio.org - Marine Biology, Ocean Life Conservation, Sea creatures, Biodiversity, Oceans research...__ 11 June 2009 [].

"ADW: Lagenorhynchus obscurus: Information." __Animal Diversity Web__. 11 June 2009 [].

"Lagenorhynchus obscurus — Dusky Dolphin." __Environment, Water and Heritage (Department of the Environment, Water, Heritage and the Arts - DEWHA) - Home Page__. 16 June 2009 .

//Webpage was designed and produced by Steven Pateman//