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Walter & Group...
We have some excellent answers to questions on genetically altered fish by Lewis Hinks :
QUESTIONS:
1.) What is the weight of the current IGFA World record rainbow trout (Oncorhynchus mykiss) ? 48 lbs
2.) Where was it caught ? Lake Diefenbaker, Canada
3.) Was this a "genetically engineered" fish ? Yes, a triploid
4.) What is the difference between a DIPLOID fish and a TRIPLOID one ? Diploid = 2 sets of chromosomes, Triploid = 3 sets and are sterile
[GH] According to Ted Williams (I don't know his sources) :
- These triploid trout have been stocked in streams in the UK. One reason is that they are sterile and, therefore, not able to directly mate with the indigenous wild trout.
- Ted also writes, however, that there is evidence that some of the triploid males may not be sterile. If that proves true, then the genetic pool of the wild fish may eventually be altered directly.
5.) Can you usually tell the difference by looking at them ? Not really at smaller sizes. Triploids are eating machines and size might be a clue as it gets older.
6.) Do you think that genetically engineered fish should still retain the original scientific name of their natural counterparts ? Depends on what was changed. At least have an (*) next to the name.
7.) Genetically engineered fish can grow much larger than natural fish. Do you think they should be placed in a different category for IGFA record keeping purposes ? Sounds like a good idea, but how will you tell without a genetic analysis?
[GH] True... can't just tell be appearance alone. One mucus swab or a scale could be used, however for a chromosome count.
8.) Can you think of at least one advantage to genetically altering fish species ? Disease resistance.
[GH] Yes ... if engineered to that end. However, some reports have indicated a lower resistance to disease in genetically altered species.
Of course, we can readily see an advantage to altering species in order to produce increasing quantities of food.
9.) Do you know of any other species of fish which have been genetically altered ? pacific salmon. Do you want to include sterile crosses such as a tiger trout.
[GH] Well... that is a kind of genetic alteration.
10.) What do you think the FFF policy should be with respect to genetically altered fish ? Not to support GMOs
[GH] Agree.... at least with respect to sport fish. Of course, then we'd get into consideration of what is and what isn't a "sport fish".
11.) In recent years, the atomic and molecular structures of certain metals have been altered in the laboratory. Scientists have given these new names and a different place on the periodic table of elements. Should this logic be applied to the taxonomic (species) listing of these genetically altered fish ? Yes
12.) If I were to catch a genetically altered trout using my favorite fly in a pond which weighed 20 lbs., and then on the following day caught a 2 lb. natural trout on the same fly in a clear mountain stream, which one would deserve greater "bragging rights" ? The 2lb mountain stream trout.
[GH] I'd sure look at it that way.
13.) Without resorting to laboratory gene alteration, do you think the practice of releasing hatchery fish into the wild fishery will eventually change the fish gene pool ? Yes, if the same genetic line is used.
14.) If you answered YES to 13.), tell us the likely result. Loss of fitness and reduced ability to survive and resist disease.
15.) Do you think the ongoing practice of farming Atlantic salmon will have an effect on the natural fishery gene pool ? Yes, the way it is currently practiced.
16.) Most of the laws governing the commercial take of ocean fish result in the taking of a high percentage of large breeders. The "undersize" fish are routinely protected. Do you think this will eventually result in alteration of the gene pool of the species biomass ? Yes
17.) If you answered YES to 16.), then tell us what you think the likely result will be. No large fish. Reproductive success will be based on reproducing at a younger age.
[GH] Reason: If you keep taking the large breeders and protect the small fish, the population of fish with the genetic makeup to make them large decreases while the biomass of small fish with genetic pattern which makes them small increases. Lots of "small fish genes" out there and fewer "large fish genes" remain.
18.) Can you tell us about at least one species of fish which is being farmed with no apparent impact on the natural biomass of the species ? How far do you want to extend the definition of farming? Tuna, which are angled, then brought to pens to be fed until the buyers show up, would fit that category.
[GH] I was thinking of inland fish farming as with catfish and talapia.
One interesting fish farming industry is that of raising milkfish (Chanos
chanos) in many Far East countries including the Philippines. This is a very popular food fish in those areas. I understand that this is a particularly efficient venture largely because these fish feed on the very algae which sometimes grows out of control ... so the "farmers" don't have the expenditure of $$$ to feed them.
These milkfish are found in salt water in the wild. They are excellent game fish. I have caught them on fly in Australian waters and at the Bat Islands off the Costa Rican Pacific coast. They thrive in fresh or salt waters.
19.) Most steelhead fishers consider the true wild fish to be superior to a hatchery fish. They are technically the same species .... so what is the difference ? Wild exposure. Have had to fight to live from day 1.
20.) An anadromous fish just returning from the ocean fights a lot harder when hooked than a member of the same species which does not go to sea. Why is this so ? Same as for 19, predator avoidance, long distance swimming.
Gordy
* FREAK TROUT : Conservation by Ted Williams, Summer issue 2010, Fly Rod & Reel, pp. 22-29
[GH] Lewis adds this :
Hi Gordy,
Thought I should clarify my answer on the farmed salmon, and tuna, it should read captured, not just angling.
Often, these fish are captured in traps as well, and then moved to a pen to be fed, prior to selling.
Lewis
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COMMENTS
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[GH] Interesting comparison by Bob Rumph :
Hi Gordy & group,
I can't help with fish figures, but here are some actual husbandry figures you may find interesting. You can trust my figures, for many years I had 232,000 birds in 11 housing units eating at all times.
When I started raising poultry it required 12 weeks to raise a chicken to 3.5 lbs. The feed to meat ratio, or how much feed it takes to make a pound of chicken, called feed conversion in the business vernacular, was 3.5 lb. of feed to make a pound of chicken. When I left the business many years later, it was taking 6 weeks to raise a 4.25 lb. chicken and the feed conversion was an incredible 1.75 - 1.85 lb. of feed to make a pound of chicken. This may all be accredited to genetic engineering of the birds along with computer aided, vastly improved feed formulating.
Regards,
Bob Rumpf
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[GH] Comment from Liam Duffy :
Gordy,
For the love and honour of .J.C. how far do you want to go!!!. Lets get back to nature, wild Browns, Rainbows, Cutthroats, Atlantic Salmon and Sea Trout. Just spent a week on the Moy ( river in the west of Ireland) which produced 900+ Atlantic Salmon to rod and line in a six mile stretch!! BEAT THAT! (weights up to 20lbs)
Best Regards,
Liam Duffy.
P.S. Am looking forward to that drink at the Conclave
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[GH] Liam,
I suspect that is in part due to the lack of Atlantic Salmon fish farming there (?)
Gets back to the wonders of an unaltered natural fishery.
As with sports .... if the use of anabolic steroids and other performance enhancing drugs is not curtailed, competition would boil down to the winners being the players with the best chemicals !
So with genetically altered fish grown so large as to sweep the record books.
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