Also known as FitzRoy Dolphin (Lagenorhynchus obscurus), the dusky dolphin gives splashes of magic and mischief in the calm waters of the gulf. Feel the energy of man’s best friend in the sea. It’s a marine mammal from the cetacean group, Odontoceti subgroup (such as orcas). It has a short, dark beak, and the dorsal fin is black with a grey crescent clearly visible in the back half. The tail is dark and has pointed ends, with a deep notch marked in the centre. The pectoral fins are long and pointed, with the curved edge and a darker colour than the surroundings. Both eyes are surrounded by a small dark spot.
The back is dark grey or bluish black, with a light grey stripe on the flanks that runs from the caudal peduncle to the centre of the body and opens on both ends where it ends, generally below the dorsal fin. The ventral side is white and extends up above the pectoral fins to end in a narrow strip between the beak and forehead. 
Behavior
Dolphins are very curious and easy to approach with vessels, as the animal seems to prefer swimming in the line of the bow of the boat. It is a very acrobatic dolphin. It usually jumps very high on the surface of the water and makes a series of pirouettes as single and double somersaults, both forward and backward. It also usually jumps backward into the water, falling headlong, it collapses on the surface followed by aftershocks, jumps repeatedly giving “headers” to the surface and is able to perform jumps with twists and turns.
It can be observed in pods that vary from 20 to 100 individuals, although, pods of nearly a thousand dusky dolphins have been recorded. It seems to be very sociable and associates with other species both for feeding and for coexistence. Examples are three cases found in Golfo Nuevo, Chubut coast, in which a bottlenose dolphin, two common dolphins and a possible hybrid, a cross between a dusky dolphin with southern right whale dolphin (Lissodelphis peronii), lived within a dusky dolphins herd. It is distributed exclusively in the Southern Hemisphere and can be seen in South America, New Zealand, Kerguelen Islands and South Africa.
Reproduction
Gestation lasts nine months, after which, the female gives birth to a single calf which remains in constant contact with her, swimming next to her body below the dorsal fin and only leaving that position to breastfeed. Lactation lasts a year or more. The average length for a newborn is 80cm.The maximum age recorded was 35. Females are sexually mature from six or seven years. From there it takes about a year to have her first baby in the summer.
Feeding
The Dusky Dolphin feeds mainly on fish (anchovies, hake, and small mackerel) and squids. When hunt- ing, the pod will divide into several small groups. When a group locates a school of fish, it is communicated to others, who can answer the call from 8km away. Dolphins enclose the shoal and lead it to the surface swimming around and below it. Seabirds often take advantage of this concentration of fish to feed, making it easy to detect the pres- ence of dolphins when you see a large number of seabirds in a very small area.
The Relationship with the man
Dolphin sightings in Valdes Peninsula-
Dolphin sightings or watching are a creative way to enjoy wonderful beings released. In this UNESCO Natural Reserve, enjoy contact with many marine mammals species from Puerto Pirámides o Puerto Madryn.
In Argentina, they are often caught in nets set for anchovies.In Patagonia there are between 100 and 200 deaths per year as a result of trawling for hake and shrimp. In the Rest of the World: in Peru this species was exploited commercially for their meat. Even today , several thousand animals are caught each year and generally eaten as cold cuts of meat. Chile also hunts them, although to a lesser extent, mainly to use their meat as bait in fishing traps.
Commerson’s dolphin
Length Adult: up to 2.70 m. Newborn: 80 cm.
Weight Adult: 70 Kg Newborn: 6 kg
The Commerson´s Dolphin (Cephalorhynchus Commersonii) are considered coastal dolphins, although they have been observed more than 100 miles offshore. In the Argentine coast, they are found from San Matías Gulf to the island of Tierra del Fuego. They inhabit coasts, fjords, bays, estuaries and river mouths. Watching dolphins usually takes place in Playa Union, about 6 km from Rawson, a city that is 152 km away from Puerto Piramides.
They live in pods and you can see small groups of 2 to 10 dolphins, scattered over a large area. However, sometimes the size of the pod can reach a hundred. Commerson’s dolphins are fast swimmers and active. You can easily see them on the surface and frequently jumping, often making several jumps in a row before diving for 15 or 20 seconds. They can be seen swimming upside down so you can see the genital spot and determine its sex. Sometimes they can be seen surfing waves, the wakes from stem to stern of boats, and even in the wake of a whale. The maximum recorded age, determined by the growth bands on the teeth, is 20 years. They reach sexual maturity between 7 and 8 years. At birth, the calves are between 55 and 75 cm. long and weigh 6 kg. The first calves are observed in mid- November and it is possible that the time of calving is extended throughout the summer. During this season you can see mothers with calves swimming in sync with the rest of the pack.
