CONICET | Buscador de Institutos y Recursos Humanos

Chinooksalmon (Oncorhynchus tshawytscha) was recorded in two extensive areasduring a survey conducted between February 2012 and June 2013 to obtaininformation regarding the seasonal distribution and population structure of wildsalmonid species inhabiting the Palena River. A total of 83 Chinook salmon werecaptured, which corresponded to 13.1% of the total salmonids collected in bothareas. Juvenile of less than 15 cm were recorded in the upstream section of theriver, where fry ranged less than 5 cm and pre-smolt ranged between 5 and 10 cmaged 0+. Smolts displaying the characteristic silver colouration with absenceof parr-marks, ranged between 10 to 15 cm and aged 1+. The diet of the juvenilesalmon was composed mainly by aquatic insects. Mature salmon returning from the marine environment were collected inthe middle section of the river, size ranged between 4.6 and 28 kg and ageranged from 4+ to 6+ years in seawater, plus 1+ year in freshwater (stream typeecotype), all them were devoid of food. Immature adults, which were presumed tobe landlocked, with ages between 3+ and 4+ were collected from a small lake (ClaroSolar) and displayed a piscivorous diet, mainly based on native Galaxidspecies. Adult salmon returning from the ocean, were infested with the cestode Hepatoxylon trichuris, attached to thepyloric caeca.

enviar mensaje