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
1251Salmon are vanishing from the Yukon River — and so is a way of lifegrist2023-11-09CA
1252Sixth grader hooks mammoth koi fish from a Houston-area pondchron2023-11-09US
1253Key Indonesian fish populations depleted & new assessments neededmongabay2023-10-31ID
1254Why don’t fish have tonsils? They have a good alternative, study suggestsscience2023-11-01US
1255Why volunteers rescue 1,000s of stranded fish every fall from this irrigation canalcalgaryjournal2023-11-01CA
1256Japanese consumers are eating more local fish in spite of Chinas ban due to Fukushima wastewaterabcnews2023-11-02JP
1257Fish travel in style on train as man keeps tanks air filter goingFox News2023-11-03US
1258Abundance of Fraser River pink salmon run exceeds forecastCTV News2023-08-23CA
1259Newfoundland fishermen get 'best news' on northern cod stocks in a generationCTV News2023-11-03CA
1260Fishing Equipment Market to Reach $23 Billion, Globally, by 2032 at 4.8% CAGRwfmz2023-11-16US
1261N.W.T. fishing camp creating community for active and veteran military membersCBC News2023-11-17CA
1262Frisch: Season Highlightsechopress2023-11-17US
1263Generation of B.C. salmon wiped out by central coast landslidethestar2020-12-15CA
1264Massive landslide on B.C. coast imperils dwindling salmon stocksCBC News2020-12-15CA
1265Study of 17,000 years of fish fossils reveals rapid evolutionscience2023-10-04US
1266America’s eel RAS superstarthefishsite2023-11-15US
1267Таежный крокодилohotniki2023-11-09RU
1268Fishing school takes students out of the classroom and out on the waterCBC News2023-10-29CA
1269Sea-lice outbreak on Icelandic salmon farm a ‘welfare disaster’, footage showstheguardian2023-11-03UK
1270CBS News Sacramento Nimbus Fish Hatchery's salmon ladder opens after low oxygen levels in waterCBS Sacramento2023-11-03US
1271Row over plans to build new type of fish farm in Scottish lochthenational2023-11-01UK
1272Killing salmon to lose money: A costly, questionable plan on the WillametteOregon Public Broadcasting2023-11-01US
1273Maryland Fishing Reporteinnews2023-11-15US
1274Fishing guide wants new gate at Grand Lake park unlocked to extend seasonCBC News2023-11-15CA
1275Scottish salmon sales leap 7 percentthefishsite2023-11-10US

219 220 221 50 of [222 - pages.]