I recently had one of those “major milestone” birthdays — one of the ones with a zero on the end of the number. I’d rather not say which one, but if you flip it upside down, I’d be only nine years old. I don’t think of myself as “old” just yet, but there are plenty of signs that I’m headed down that path.
I’ve been getting AARP solicitations for at least a decade. My hairline, waistline, hearing and vision are all changing. Aches and pains are accruing. Each morning begins with attacking a pile of pills. And all of my favorite songs are “oldies.”
As I ponder mortality, I’ve been thinking age-related thoughts lately. Old means different things to different people, and it means different things to different creatures. Some short-lived insects have lifespans that can be measured in days. Those pesky lovebugs which tormented us a couple months ago live as flying adults for less than a week, though their underground larvae can survive for a year.
On the other end of the insect lifespan spectrum are termites. The queens of some termite species can live up to 60 years.
Different species of birds have widely differing lifespans too. Most mourning doves don’t live long enough to celebrate their second birthday, but some species of parrots can live to be more than 100 years old. Bald eagles live to an average of about 20 years in the wild, but ospreys are doing well to make half that age.
Fish have growth rates and lifespans that vary wildly. As you might guess, some of the baitfish have short lifespans. Sardines and bay anchovies (glass minnows) mostly don’t make it a year, though they can live up to two or three.
Tarpon are often described as “overgrown sardines” but they live a lot longer than sardines. Tarpon don’t reach maturity until about age 7 and are thought to have an average lifespan of 30 to 50 years in the wild. One tarpon lived to the well-documented age of 63 in captivity.
Many fish species follow the examples of sardines and tarpon — smaller baitfish with shorter lifespans and larger predators with longer lifespans — but not all. Mahi are a great example of a rapidly growing and short-lived predator fish. The maximum lifespan of mahi is thought to be only 4 years. That’s right: A huge trophy 50-pound bull dolphin is most likely just a couple years old. One mahi was reportedly placed in an aquarium at just over a pound in weight and fed heavily until it died 18 months later at a weight of 68 pounds. That’s packing on a lot of pounds in a short time.
Cobia are another fast-growing fish that doesn’t live very long. The oldest cobia documented in the Gulf was reported to be 13 years old, but these fish can reach weights of more than 100 pounds in less than 10 years of life.
The maximum lifespan of snook is thought to be 12 to 15 years. For redfish, it’s more like 40 years. Sea trout may last 8 or 10 years. But there are creatures in the ocean that live far longer than any fish.
Have you ever eaten a clam? If so, you might well have dined on something far older than yourself. It has been documented that some quahog clams can live to be hundreds of years old. An ocean quahog collected off the coast of Iceland a few years back was found to be 507 years old.
But it gets better. There is a species of jellyfish that might actually be immortal. No, not a vampire jellyfish. They are called — get ready for this — immortal jellyfish. They have the ability to revert from adult to larval stages, kind of like a butterfly if it had the ability to turn back into a caterpillar.
Immortal jellyfish can die if they are eaten or damaged. But if they are not killed, then in theory they could go back and forth between adult and juvenile stages indefinitely — so they might be able to live forever. Where do I sign up for that program?
Capt. Ralph Allen runs the King Fisher Fleet of sightseeing and fishing charter boats located at Fishermen’s Village in Punta Gorda. He is an award-winning outdoor writer and photographer, and is a past president of the Florida Outdoor Writers Association. Contact him at 941-639-2628 or Captain@KingFisherFleet.com.