My source for this observation is taken from The Oregon Fish Commission Research Briefs Number One Volume One dated April 1948.
( I quote)
“Albacore Have Higher Temperature than Surrounding Water
While accompany the crew of the tuna boat “Western Sun” on a fishing cruise in August 1947, George Harry, biologist stationed at Astoria, found that the body temperature of albacore off the Oregon Coast was about 20 degrees higher than that of the surrounding water. Although fish are generally regarded as cold blooded animals, it has long been known that some species on being warm blooded.
“Mr Harry checked nine fish by simply inserting a pocket thermometer through an incision and into the viscera immediately atrer the fish were landed. The albacore temperatures ranged from 80 to 86 degrees whereas the water remained at 63 degrees (F). the albacore were found to be feeding largely on anchovies. ”
More recent observations reported by Oregon Sea Grant in 2009 indicate that the temperature differential is more on the order of fifteen degrees, but the elevated temperatures were each observed in tuna after being landed, and no mention was made regarding whether the battle prior to landing could have elevated the temperature.
These observations of elevated body temperature are consistent with the traditional practice of immediately chilling and bleeding albacore in order to achieve the highest possible quality and taste in the flesh.
Ideally, each albacore will be pithed, the gills cut, and the fish immersed in chilled saltwater which allows the fish to be chilled rapidly as it is bled.
Here are some age vs. average weight figures I gleaned from the Internet.
One year old: 8 Lbs.
Two years old: 18 Lbs.
Three – Four years old ( and older): twenty five pounds and up
Note please, my dear friends caught several albies last week while I was recuperating from hernia surgery, fish that pressed the scales to twenty five pounds.
Oh my goodness, how large might these tuna be a month from now?
I hope to find out shortly.
Best wishes to all
Jay Nicholas (July 16 2015)