Senin, 09 Januari 2023

Century-old fish found off Alaska

An ear bone containing growth rings helped determine age

A commercial fishing boat has caught what may have been one of the oldest creatures in Alaska - a giant rock-fish thought to be about 100 years old.The 44in (1.1m), 60lb (27kg) female shortraker rock-fish was hauled in by a Seattle-based vessel, trawling for pollack in the Bering Sea last month.Scientists estimate the fish was between 90 and 115 years old.The fish was brought up from a depth of 2,100ft (640m), south of the Pribilof Islands, AP news agency reported.Reproductive potentialThe discovery was made by the crew of the Kodiak Enterprise, owned by Trident Seafoods, when they pulled up an estimated 75 tons of pollack and 10 rock-fish in March.

The huge specimen was handed over to scientists at the Alaska Fisheries Science Center in Seattle where it was measured, photographed and documented.The age of the fish was determined by removing an ear bone, known as the otolith, which contains growth rings similar to those in tree trunks. The estimated age was between 90 and 115 years old - which is towards the upper end of the known age limit for the species, said scientist Paul Spencer.The contents of the rock-fish's stomach were also examined and tissue samples were taken to measure its reproductive potential. "The belly was large. The ovaries were full of developing embryos," Mr Spencer said.However, scientists said the specimen was not the biggest - a 47in (1.19m) shortraker rock-fish has been recorded.(af/angler)

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