Orange Roughy - Life History

Life History

Orange roughy are generally sluggish and demersal; they form aggregations with a natural population density of up to 2.5 fish per square meter, now reduced to about 1 per square meter. These aggregations form in and around geologic structures, such as undersea canyons and seamounts, where water movement and mixing is high—ensuring dense prey concentrations. The aggregations are not necessarily for spawning or feeding; it is thought that the fish cycle through metabolic phases (active or feeding and inactive or resting) and seek areas with ideal hydrologic conditions to congregate during each phase. They lose almost all pigmentation while inactive, during which time they are very approachable. Predators include large deep-roving sharks, cutthroat eels, merluccid hakes, and snake mackerels.

When active, they feed primarily on zooplankton such as mysid shrimp, euphausiids, mesopelagic and benthopelagic fish, amphipods, and other crustaceans; adults also take smaller fish and squid. The orange roughy's metabolic phases are thought to be related to seasonal variations in prey concentrations. The inactive phase conserves energy during lean periods. Orange roughy can live up to 149 years.

Read more about this topic:  Orange Roughy

Famous quotes containing the words life and/or history:

    Die two months ago, and not forgotten yet? Then there’s hope
    a great man’s memory may outlive his life half a year.
    William Shakespeare (1564–1616)

    Whenever we read the obscene stories, the voluptuous debaucheries, the cruel and torturous executions, the unrelenting vindictiveness, with which more than half the Bible is filled, it would be more consistent that we called it the word of a demon than the Word of God. It is a history of wickedness that has served to corrupt and brutalize mankind.
    Thomas Paine (1737–1809)