Quote:
Originally Posted by dos ballenas
Are you kidding Jim? .... age and growth rates of mako sharks are yet to be validated..... For example it is unknown if mako sharks create one, two, or three growth rings per year. This fact alone is why the jury is still out on aging sharks.
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Hell I'm no expert just opinionated
Actually your preaching to the choir..... No doubt the jury is still out, and nothing is definitive.
Like Kieth I've been interested in these sharks for decades, read a lot about them, and put a lot of time in on the water, but I've not heard anything all that concrete. I think the first estimates were based on two rings a year, then they went to one. Used to be people were estimating something like twenty years, then last I heard they kicked it up to thirty, but I'm not a biologist just someone who's interested in fish, and I'm just throwing out my opinion based on what I've read in the past.
If I had to personally guess I'd go with 30 to 40 years but the highest estimates I've read were only thirty.
Reproduction wise. I used to think they pupped every year, then some studies on Whites showed that they probably carried their young longer and took time off between pregnancies. That was a while back and they based it on migration patterns and sat tags. I.E. the Great White females varied their migrations in cycles and went to specific areas when carrying pups and after they dropped them. Since they changed their migration pattern the next year, the theory was that they skipped years in their reproductive cycles. Later I read somewhere that Makos might have a similar cycle even though their migrations are not the same. Makos and Salmon sharks are biologically closer to whites then most sharks so it kinda makes sense. I'm not sure where I read it, but it stuck with me since it challenged my preconceptions.
Speaking of preconceptions where do you think they pup? I've heard they probably have a reduced feeding response around the time they give birth to keep them from eating their young. Since Big females can be caught local, I always thought they probably pupped elsewhere in Mexican waters then swam up here afterwards.
Then I caught this.
That's a 22 inch female mako that I caught trolling off the West end of Catalina. It probably only weighed three pounds max and still had part of it's umbilical attached from it's egg sac. That shark attacked a skirted Bonita trolled on the downrigger. The bait was as big as it was but it still manged to rip off it's back end and put a 9/0 hook right through it's gills.
The guy I was fishing with and I have a running joke about that shark. We may of not caught biggest local Mako but we probably got the smallest, at least for one that hit a bait and was outside it's mother. I figure it had to be fresh pupped so the question in my mind is if the females loose their desire to feed when they are in they are in there pupping grounds, then why do we still catch full sized adults here like the 1300 pound fish that I started the thread with.
I'd say a on again off again breeding cycle like the whites have might explain that, but of course that's just a guess, and can't back it up with hard data.
Fortunately I'm just an amateur so I don't have to
You know how it is, fishing always involves a lot of guess work especially for us non-scientists.
Good to hear Matt got you some of the spinal cartilage, I was hoping you guys got it. I'd be really interested to know how many rings they find. It's my understanding is they do not stop growing as they age, so no matter how old that shark is in years just it's size suggests it's one of the oldest makos ever caught, and likely maxed out in life expectancy.
Jim