284 EIGHTH PACIFIC SCIENCE CONGRESS 



AMPHINEURA 



Chiton and Tonicia (Chitons) are genera of Polyplacophora with 

 some species found in the market. In a number of Chilean ports they 

 are sold under the name of COGOTES, but they find little acceptance. 



PELECYPODA 



From the industrial point of view, the following families are of 

 importance, (by order of value): Mytilidae, Ostreidae, Mesodesmatidae , 

 Veneridae and Pectenidae. 



Among the Mytilidae the total volume of production in 1945 was 

 9,950 tons and 12,289 in 1951, the highest production being in 1946 

 with 15,082 tons. The catch of the most valuable species has diminished 

 a great deal due to uncontrolled and extensive exploitation, leading to 

 the extraction of very young specimens, to the evident danger of the 

 conservation of the species. The fishing methods, which literally collect 

 every specimen from the beds, have had a depleting effect shown in the 

 disappearance of the beds nearest to the factories; therefore it has been 

 necessary to search for them in more distant places. 



To the new genus Choromytilus (Soot-Ryen, 1952) belongs C. 

 chorus (Molina, 1782) CHORO (Giant mussel) with area of distribu- 

 tion from Pascamayo (Peru) to Orange Bay (Chile). Its uncontrolled 

 exploitation continued for decades has caused depletion and there is 

 urgent need of protecting the species. It is the biggest of the marine 

 choros and is greatly esteemed from the nutritive point of view. It 

 adheres to its supports through a strong byssus and has a big oval ob- 

 long shell, bluish in colour, covered by a blackish periostracum. 



Mytilus ater Molina, 1782, Aulacomya magellanica Chemnitz, 1819 

 (Carcelles, 1942), and M. chilensis Hupe, 1854, are commonly called 

 CHOLGAS (Mussels). 1 he first has a smooth surface and is found from 

 Manta (Ecuador) to Talcahuano; the second abundant in Magallanes 

 but is found north up to Valparaiso, and the last along an extended 

 area from Callao (Peru) to Tierra del Fuego, Falkland Is., and the 

 coast off Buenos Aires. The total production of CHOLGAS is around 

 4,000 to 7,000 tons. They are usually consumed fresh or smoked. In 

 1951 canned production amounted to 2,900 tons, "au naturel," special 

 brand, and in oil. The Puerto Montt zone (Calbuco, Puerto Aguirre, 

 Quellon, Aulen, San Rafael) industrializes the greatest quota of cholgas. 

 M. chilensis, called CHILEAN or SOUTHERN MEJILLON, is caught in 

 Tierra del Fuego, Patagonia and Strait of Magellan. Aulacomya ma- 

 gellanica Chemnitz, is the GRAN MEJILLON OF MAGALLANES (Ma- 

 gellanic large mussel) or CHORO or MEJILLON RAYADO. 



