A local grocery store was overstocked, so they had a big sale. When I arrived, the place was packed with people having sex and grabbing groceries.
People were even rolling around in shopping carts having sex and stuffing groceries in with them. Things I won’t describe were happening in the produce section. And there were so many people flopping around that I couldn’t navigate my cart through them.
The scene reminded me of the sea nettle jellyfish (Chrysaora fuscescens).
Sea nettles commonly wash up on our local beaches. Their bell, which is often more than a foot in diameter, is typically an amber color with a sort-of sunburst pattern of lighter lines radiating from the center. The edge of the bell is scalloped with notches, and 24 thin, maroon feeding tentacles hang from these notches. Additionally, sea nettles have four feeding arms that hang from the middle of the bell. The arms are bushy looking and are usually pale yellow, pink or white. However, the arms and tentacles are often eroded away in the surf.
The arms and tentacles are covered in stinging cells and can reach 15 feet long. And as their name suggests, the pain of their sting is supposedly similar to nettle stings. But unlike some other jellies, they are not considered deadly unless the victim has an allergy to the specific toxin.
Sea nettles periodically undergo huge population “blooms,” which occur when ocean conditions are favorable for food production. Populations may become so dense that commercial fishers’ gear becomes fouled and unusable. The sea nettle’s curious reproductive cycle facilitates these blooms.
In addition to heavy feeding, female sea nettles produce tens of thousands of eggs per day while males release sperm in their presence. The resulting larvae settle on any convenient surface where they turn into stalked, tentacled polyps. The polyps then duplicate themselves asexually many times until environmental conditions are favorable again.
Then the zillions of polyps lose their feeding tentacles, and their bodies divide into a tiny tower of potentially dozens of immature jellies in a process called “strobilation.” These snowflake-like discs break free and quickly become mature adult sea nettles. Then the polyps regrow their tentacles and do it again, possibly for several years.
The adults prey upon any animal their barbed stinging cells can hold on to, including eggs and juveniles of commercially important fish. Research has shown that sea nettle blooms may have adverse impacts on populations of these fish by direct predation and depletion of the fishes’ prey items. These blooms seem to be getting more frequent and may be due, in part, to increasing artificial structures that provide good attachment spots for the polyps.
Sea nettles have an odd relationship with some species of crab. The swimming larval crabs attach to the jelly without being stung. And they ride along until the jelly gets to water shallow enough for the crabs to live in. Then the crabs let go. The crabs also appear to feed on the jellies as they ride. Given the large numbers of sea nettles and the number of juvenile crabs each can carry, this relationship could be an important mechanism of crab dispersal and survival.
Anyway, when I returned to that grocery store a year later, conditions were poor with little food on the shelves. And the wheels of my shopping cart became fouled by the abundant starving babies.
The checker asked if I’d donate $10 to feed a starving baby. I said, “No. If you are going to adopt sea nettle reproductive strategies, you should delay strobilation until you have enough food for your babies.”
Biologist Mike Kelly (he/him) also writes science-based satire as M. Sid Kelly. It’s available at Eureka Books or everywhere e-books are sold.
This article appears in Step Aside Prop. 47, Proposition 36 Has Arrived.