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Posts: 1275
Location: Hayward, Wisconsin | From the Fishing Wire:
BOFFFF's (Big, Old, Fat, Fertile, Female Fish) Sustain Fisheries, Scientists Say
| October 24, 2014
Recreational fishermen prize large trophy fish. Commercial fishing gear targets big fish. After all, larger fish feed the egos of humans as well as their bellies.
A new compilation of research from around the world now shows that big, old, fat, fertile, female fish - known as BOFFFFs to scientists - are essential for ensuring that fishery stocks remain sustainable.
"Information on many different kinds of freshwater and marine fish tell the same story," says lead author Dr. Mark Hixon of the University of Hawaii. |
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Location: Green Bay, WI | Interesting. Here are a couple sources for that:
http://manoa.hawaii.edu/biology/news/2014/10/17/dr-mark-hixon-savin...
http://www.natureworldnews.com/articles/9781/20141022/old-fat-ferti...
The one thing that immediately comes to mind after reading that article is that although a larger female might indeed carry many times more eggs than a smaller female, this might not affect the total number of eggs deposited in the system. I think it would also be determined by the relative number of those smaller fish in comparison to the number of the larger ones. For instance in their article the quote was that a large bluefish trevally produces 84 times more eggs than a smaller fish. However (for example) if there are 100 times more of the small fish than of the larger fish, the magnitude of the overall spawning contribution made by the smaller fish would then be higher than that made by the larger fish. So we'd really need to see the relative numbers of small vs large fish spawning to know for sure just how valuable these bigger fish are, in terms of overall contribution to the spawn. I'd like to see that data.
The other thing worth pointing out here though is that even though the sheer number of eggs deposited might indeed be greater, it doesn't necessarily mean that the fish hatched from those eggs will grow as large as possible. I think there probably is something to the whole idea that parents can have big offspring. So in that sense, the larger spawning fish may indeed be bringing something to the fishery that smaller fish cannot.
TB |
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Posts: 1275
Location: Hayward, Wisconsin | Here is some food for thought: While working with Dr. Bernard Lebeau at Eagle Lake in 1986, we received the eggs from an Eagle Lake 55 pounder that had been caught the previous year. These eggs were at least 3 or 4 times LARGER than any other muskie eggs I have seen anywhere!
Do the big girls pass on these "get big" genes via egg size? Wisconsin DNR Research Biologist Leon Johnson noted in some of his work that there were different size eggs in the WI system and it had a definite impact on the "number of eggs" per quart...the method used in those days to calculate numbers. A lot we still don't know... |
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Location: Green Bay, WI | Genetic material is genetic material, would be my guess. That being said though, one could hypothesize that if the egg is larger because of a greater yolk volume, then it might increase the likelihood that the larvae will make it to the fry stage of life. I've never done any research on that, however it does seem to make sense when you think about it.
EDIT: Just re-read my post and wanted to clarify. I do in fact think that (for whatever reason) having BIG fish spawn in a system is very good for the system. What I meant above is that I think the size difference he observed in the eggs is not likely due to there being more genetic material. Chromosomes are chromosomes, and they should all be about the same size. So the genotype of large vs small muskies should be pretty similar as I understand it, but maybe there are differences in the phenotype of the fish (how those genes are expressed) that result in the size differences across the population.
Have you ever read anything that shows why the eggs are larger? Is there in fact more yolk, for instance? That would be my first impression, but it may not be correct...
TB
Edited by tcbetka 10/24/2014 12:27 PM
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Posts: 1275
Location: Hayward, Wisconsin | Tom:
No, only thing I have ever found about egg size was what Leon Johnson noted in his research papers, but he didn't, as far as I know, pursue it any further. |
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Location: Green Bay, WI | Bummer. It would have been nice to know why the eggs were larger.
TB
Edited by tcbetka 10/26/2014 9:28 AM
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