Cannibalism Of The Young Allows Individual Fish To Specialize 
SW Source: Underwatertimes 5/23/2007

If you go fishing for Arctic char you may end up catching distinctly different-looking individuals although they were all caught in the same lake. Similarly, whitefish, threespine stickleback, and some sunfishes also display quite discrete groups living in the same lakes but utilizing different food resources in order to survive. The phenomenon is called resource polymorphism and has been observed and documented as early as in the 18th century, but has continued to receive a lot of scientific interest since it gives us a chance to study ongoing evolution. However, not all species display resource polymorphism, and naturally, in order to gain deeper understanding of evolutionary facilitators, the question arises: Why do some species display resource polymorphism, whereas other don't?
 

In this study, a team of European researchers combines literature data and advanced ecological theory in order to look for species-specific life history patterns explaining the presence/absence of resource polymorphism in fish. Interestingly and not at all obvious, the study suggests that early cannibalism, which is found in all species displaying resource polymorphism, is a promoting factor. However, incorporating recently explored and presented population dynamic theory, based upon the population's size distribution and the effect of the individual's size on its relative competitiveness, a logic explanation is given. The effect of early cannibalism is twofold. First, it stabilizes the variation in the number of individuals over time, which in turn increases the benefit of specializing on any resource since the risk of being dependent on a vanishing resource decreases. Second, an early disappearance of small newborn individuals increases the abundance of their prey due to decreased consumption from the small ones, hence increasing the benefit for larger individuals to specialize on this specific prey (typically zooplankton). The team now plans to do new modeling exercises and practical experiments in order to further explore the suggested hypothesis.

 
Char, Arctic Continue...

News Id SourceStampcountry
701World Record catfish caught by Italian angleryahoo2023-06-07IT
702Whatevers making sawfish spin and die in Florida watersCBC News2024-04-01US
703Aquatic predator — with bad reputation — discovered in Boliviamyrtlebeachonline2024-04-02BO
704Dozens of fish killed at aquatics centre after being deliberately poisoned with bleachdailymail2024-03-26UK
705Lebanese youths take up rods and reels to learn sustainable fishingmongabay2024-03-27LB
706Man cited for allegedly illegally spearfishing in Waikikispectrumlocalnews2024-03-27US
70792-pound fish that somehow made it into a Louisiana lakenola2024-03-28US
708Montgomery County fertilizer spill kills nearly 750,000 fishkcrg2024-03-28US
709Experts sound alarm over major threat to one-fifth of major rivers fishthecooldown2024-03-30CN
710Cambodian aquaculture centre supporting farmers with thousands of fishthestar2024-03-30MY
711Sticking up for fish against humanitys cruel double standardswaikatotimes2024-03-31NZ
712Maine fishermen caught more fishAssociated Press2024-03-25US
713Tennessee wildlife officials will pay you $100 to catch these invasive carpstennessean2024-03-25US
714UKs largest fish pass completed to help salmonnottinghampost2024-03-26UK
715Metal detected by X-ray of record fish caught in Kansasmainstreetmediatn2024-03-29US
716Julia Roberts brother Eric Roberts believes he can speak to fishiosconews2024-03-29US
717Georgia lawmakers strip public trust language from law affirming right to fishajc2024-03-29US
718Sawfish Rescued in Florida as Biologists Try to DetermineAssociated Press2024-04-12US
719Aquatech collaboration aims for salmon farming circular economythefishsite2024-04-17UK
720How Uttar Pradesh is expanding its aquaculture sectorthefishsite2024-04-12IN
721Florida girl, 12, hooks multiple fishing recordsFox News2024-04-13US
722No signs of herring stocks rebounding 2 years into moratoriumCBC News2024-03-30CA
723over hundreds of fish spinning and whirling dead onto South Florida shoresABC News2024-03-29US
724Liquid nitrogen mishap kills 750,000 fish in rivers in Iowa and Missouriyahoo2024-03-29US
725Pet warning after toxic pufferfish washout hits Fish Hoek and Glencairn beachesiol2024-03-18ZA

219 220 221 28 of [222 - pages.]