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Fraser’s Dolphin

Fraser’s Dolphin (Lagenodelphis hosei) or Sarawak Dolphin is a cetacean in the family Delphinidae found in deep waters in the Pacific Ocean and to a lesser extent in the Indian and Atlantic Oceans.

Taxonomy

The earliest known interaction between mankind and a Fraser’s Dolphin came on a beach in Sarawak, Borneo in 1895. Mr. Charles E. Hose found a skull there and donated it to the British Museum. The scientific specific name is given in his honor. The skull remained unstudied until 1956 when Francis Fraser examined the skull and concluded that it was similar to species in both the Lagenorhynchus and Delphinus genera but not the same as either. Simply merging these two names together created a new genus.

Physical description

Fraser Dolphins’ are about 1 m long and 20 kg weight at birth, growing to 2.75 m and 200 kg at adulthood. They have a stocky build, a small fin in relation to the size of the body, conspicuously small flippers. The dorsal fin and beak are also insubstantial. The upper side is a grey-blue to grey-brown. A dirty cream-colored line runs along the flanks from the beak, above the eye, to the rear. There is a dark stripe under this line. The belly and throat are usually white, sometimes tinged pink.

Fraser Dolphins swim quickly in large tightly packed groups of about 100 to 1000 in number. Often porpoising, the group chops up the water tremendously.

The species feeds on pelagic fish, squid and shrimp found some distance below the surface of the water 218 to 546 yards (200″“500 meters). Virtually no sunlight penetrates this depth, so feeding is carried out using echolocation (biological sonar ) alone.

Population and distribution

Though only accounted for relatively recently, the number of reported sightings has become substantial””indicating that the species may not be as rare as thought as recently as the 1980s. However the species is still not nearly as well understood as its more coastal cousins. No global population estimates exist.

The Dolphin is normally sighted in deep tropical waters; between 30° S and 20° N. The Eastern Pacific is the most reliable site for viewings. Groups of stranded dolphins have been found as far away as France and Uruguay. However these are regarded as anomalous and possibly due to unusual oceanographic conditions, such as El Niño.

The species is also relatively common in the Gulf of Mexico but less so in the rest of the Atlantic Ocean.

Fraser8217s Dolphin


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