C+commersonii

 Questions at bottom...


 * Genus ** : // Cephalorhynchus //**Species **: // C. commersonii //
 * Class **// : Mammalia //** Order **// : Cetacea  //** Family ** //: Delphinidae//


 * Endangered species Act ** : Assessed 2008. Information about the species has increased since last reading in 1996, but still too little data known about population size, trends, and threats to assess whether the species is continuing in a decline.

As far west as (53°33’S, 79°25’W), as far south as (61°50'S), As far east as ( 51°10'S, 59°00'W) ** Salinity – Temp – Pressure – Other ** **Temp**
 * Description of Habitat ** – Commerson’s Dolphin are found in cold waters closer to shore; such as along coasts, bays, harbors, and river mouths, and sometimes rivers are included. Their offshore exploration is unknown but few have been sighted 100 nautical miles or 115 miles offshore in water as deep as or deeper then 1000 m. They are Epipelagic, and dwell mostly towards the surface.
 * Latitude and Longitude ** –
 * Salinity**
 * //  33 to 37 parts per thousand (3.3 - 3.7%) by mass and varies with latitude and season.   //
 * //32 Degrees Fahrenheit to 62 Degrees Fahrenheit//

  South Atlantic high pressure area is centred around 30° S. This anticyclone (circulation of winds around a central region of high atmospheric pressure) leads to southeast trade winds on its north side.
 * Pressure **

There is no real data that Commerson's Dolphin migrates. Although fishermen off the coast of South America believe that there is an absence in late Autumn. This may be on account that the Dolphins might follow fish (Robalo and Merluza). **Population Estimates** Commerson's dolphin seems to be the most abundant species of the genus //Cephalorhynchus.// Estimated in the mid-2000s was estimated at about **40,000**, with at least half of that number in Tierra del Fuego and southern Patagonia.
 * Migration Patterns**

//Unknown(unknown as to whether increasing or decreasing)// They are not endangered but are protected...
 * Population Trend**

Size:** 47 to 67 in. (120-170 cm)
 * Physical features


 * Weight:** 77 to 132 lbs. (35-60 kg)


 * Color:** Mainly white with black spots around head, fins, tail, and underbelly.

Females reach breeding maturity at ages 6-9 and males about the same age as well. Gestation period will last 11 months and give live birth. Parents will typically care for young and stay in groups, usually up to 3 dolphins are in one group.
 * Reproduction**:

Small, blunt-headed dolphins without a beak. Also has rounded fins paddle-shaped fins and a large rounded dorsal fin. Although mistaken for porpoises, their behavior is unmistakabley dolphin. They are a light grey while young and still maintain the dark spots. As they age the grey fades into white until they are a pure white with black spots. The spots are along the head and there is a large spot that starts just before the dorsal fin and covers all the way to the tail. The fins are also black and are connected underneath by a single black marking. And there is also a black marking over the genital area.
 * Physical description**

Feed on a mix of coastal and pelagic fish and squid with the those pertaining to South America feeding on Crustaceans. Shrimp and squid are also very common. Like to feed near fishing boats which accounts for the accidental catchings. Is mainly uneaten thanks to cold waters, sharks and other top predators cannot reach its location.
 * Food Behaviors**

Commerson Dolphin is not an important piece to our way of life. But they do play a role in our entertainment industry. About two dozen Commerson's Dolphins are captive in aquariums in the world, including SeaWorld San Diego, Aquatica in Florida, Zoo Duisburg in Germany (till 2004), and several aquariums in Japan.
 * Importance**

//Direct Catch// - In recent years, the harpooning of Commerson's Dolphin was used as bait in the southern king crab ("centolla") fishery in both Argentina and Chile. And were used elsewhere as a variety of bait.
 * Threats**

//Indirect Catch// - Commerson Dolphins were most often taken in fishing nets, due to its coastal habits and narrow-band sounds where fishing took place. Although the exact size of the by-catch is unknown, at least 5 - 30 Commerson's dolphins die each year in the nets.

//Pollution// - Chemicals such as chlorinated hydrocarbons were found in the blubber of Dolphins off the coast of the Indian Ocean. Though these levels were not as sever as dolphins in the North Atlantic

The harpooning of the dolphins is now illegal since the 1980's, acccidental deaths still occur in the gillnets and other fishing gear continues and represents an ongoing threat as by-catch. The laws and restricitions on where to fish are now more strict then ever.
 * Conservation**

1) Find better bait to fish for Chilean Crab. Other marine organisms that are not in danger would make for better bait then Dolphin. The Fishermen in South America must be put under laws for the amount of bait they can have. 2) Restrict the times when fishermen can fish for crab. The abscense of Commerson's Dolphin in the winter leaves a perfect opportunity for crab fishermen. 3) Study more about Commerson's Dolphin before we can predict their population trends.
 * Solutions**

1) Commerson's Dolphin are found mostly in what ocean? 2) Commerson's Dolphin are often mistaken for? 3) Commerson's Dolphin eat mostly?
 * Questions

Citation** [|**http://www.cms.int/reports/small_cetaceans/data/c_commersonii/c_commersonii.htm**] (both picture and information) [] [] picture and information)