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
926Is forward-facing sonar too much fishing technology?echopress2024-02-16US
927Man comes across dried up and stiff zombie fishnewsner2024-01-26ZA
928Nuneaton man among 13 anglers named and shamed for fishing illegallycoventrytelegraph2024-01-26CA
929New study shows how industrial development decimated fish populations near Vancouvervancouversun2024-01-26CA
930Far North fishing competition goes ahead despite protests1news2024-01-27NZ
931Wind farm plan in Hokkaido called threat to endangered fishasahi2024-01-24JP
932Its a slimy, prehistoric parasite with the mouth of an aliendiscoverwildlife2024-01-25EU
933Пассивная и активная ловля налима на Кольскомohotniki2024-02-04RU
934High hopes for Kazakhstan’s high altitude fish farmsthefishsite2024-02-14KZ
935This Chinook Salmon Caught In Argentina Is One Of The Biggest Weve Ever Seenbrobible2024-01-25AR
936B.C. trawlers dump thousands of salmon, depleting orcas food sourcevancouversun2024-01-19CA
937Kayak angler lands record crappie while bass fishingyahoo2024-01-20US
938В ИСТРЕ ОТКРЫЛИ НОВЫЙ РЫБОПЕРЕРАБАТЫВАЮЩИЙ ЦЕХ ПОЛНОГО ЦИКЛАmosregtoday2024-02-09RU
939Oceana Canada Urges Caution on DFOs Phased Approach to Re-opening Redfish FisheryOceana Canada2024-02-02CA
940Baby sockeye salmon are growing faster due to climate changenationalobserver2024-01-15CA
941Kmart called out for cruel fish tank: Animals are not toysyahoo2024-01-15US
942Be a better anglerechopress2024-02-09US
943Fog and fishing flurries highlight day enjoying Lake Winnipegs winter walleye paradiseechopress2024-02-10CA
944Angler feels thump — then reels in fish hes never seen beforeMiami Herald2024-01-16US
945Tokyo couple arrested over unpermitted cultivation of glowing fishKYODO NEWS2024-01-17JP
946Fire-eyed river creature — with odd way of protecting its eggs — is a new speciesmiamiherald2024-01-17BU
947Was the Massachusetts record for largest fish caught broken in 2023?wwlp2024-01-18US
948Mysterious bass sound in South Tampa resurfacesfox13news2024-01-17US
949Indigenous effort in Bangladesh helps reverse endangered fishs slide to extinctionmongabay2024-01-19BD
950Безмотылки открывают сезонohotniki2024-02-02RU

219 220 221 37 of [222 - pages.]