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
226Ontarios Loonhaunt Lake delivers memorable fishing adventure for first-time visitorsechopress2024-08-23CA
227Underwater speed demon breaks ocean recordsessa news2024-08-09US
228Rare, giant doomsday fish washes ashore along California coastlineSoCal Bureau Chief2024-08-14US
22935 astonishing images from Ocean Photographer of the Year 2024discover wildlife2024-08-15US
230Mass fish die-off in Iraq is environmental disasterRudaw2024-08-17IQ
231Ловля карася и карпа с помощью сбирулиноohotniki2024-08-21RU
232Assams aquaculture advocatethefishsite2024-08-23IN
233Boy reels in colossal 118-pound white marlin on NantucketFox News2024-08-23US
234Biologists truck Snake River sockeye salmon to cooler Idaho watersopb2024-08-04US
235Fishing scandal costs Lake Erie Walleye Tournament cheaters $100,000 boatdispatch2024-08-04US
236Sturgeon endure in Alberta rivers, but their future is uncertaincitynews2024-08-05CA
237Robo-tuna reveals how foldable fins help the speedy fish manoeuvrenewscientist2024-08-05CN
238What is a walking catfish and why were they in St. Pete streets during Debby?wtsp2024-08-08US
239Fisherman catches his second state record, shattering previous bestkansascity2024-08-08US
240Indonesian fishermen are using a government AI tool to find their daily catchrestofworld2024-08-09ID
241Urban fishers drawn to Montreals Lachine Canal despite industrial pastglobal news2024-08-16CA
242Around $500,000 worth of baby eels seized at Toronto Pearson AirportGlobal News2024-05-18CA
243Low water levels affecting salmon migration in B.C. riversglobalnews2024-08-17CA
244Xenogens: a new frontier for aquatic conservationthefishsite2024-08-21US
245A Rarely Seen Deep Sea Fish Is Found in CaliforniaAssociated Press2024-08-15US
246Еще одно чудо на рыбалкеohotniki2024-08-16RU
247Frankenfish or frankly misunderstoodlehighvalleylive2024-08-09US
24812-year-old girl nets top Md. fishing awardwashingtonpost2024-08-05US
249We struggle a lot: Cormorants continue to wreak havoc on Lake Ontariowwnytv2024-08-08CA
250SIU researchers hoping to curb cannibalism among large-mouth basskfvs122024-08-09US

219 220 221 9 of [222 - pages.]