Saw many of these blue things on the beach. I believe they are some kind of jellyfish.
They are fairly large, about the size of a cantaloupe.
Does anyone know what they are and why so many were washed ashore?
With my foot for scale...
You can see 4 here in this shot...
David K - 1-19-2019 at 10:27 AM
What beach?tobias - 1-19-2019 at 10:27 AM
Where is that?
In 2015, 20 miles south of San Felipe...
David K - 1-19-2019 at 10:29 AM
About the size of a 10 peso coin... near shore at high tide.
I had never seen any jellyfish on Shell Island in nearly 40 years of camping there. As I would find out (this morning), these were not true jellyfish
but floating marine organisms... Here is the answer from Dr. Hans Bertsch (author of Sea of Cortez Marine Invertebrates and a new book mentioned in
his reply):
Dear David,
Thanks for the photos of Porpita porpita (Linnaeus, 1758); Phylum Cnidaria, Class Hydrozoa, Family Porpitidae. Although it is in the same family
as the infamous man-of-war Physalia, it is not really dangerous to humans. Both are pelagic, frequently washing ashore when the winds are right. It
is obviously in my new, in galleys, book, Invertebrados Marinos del Noroeste de M�xico.... Porpita is called "Blue Button," or "Bot�n Azul." The
shrimpers probably had nothing to do with the beaching of Porpita; winds. You just have to be at the right place at the right time.
From Wiki:
Porpita porpita From Wikipedia, the free encyclopedia Porpita porpita Porpita porpita.jpg
Blue Button Scientific classification Kingdom: Animalia Subkingdom: Eumetazoa Phylum: Cnidaria Class: Hydrozoa Order: Anthomedusae Suborder: Capitata
Family: Porpitidae Genus: Porpita Species: P. porpita
Binomial name Porpita porpita (Linnaeus, 1758)
Although it is superficially similar to a jellyfish, each apparent individual is actually a colony of hydrozoan polyps. The blue button is a
Chondrophore, which is a group of cnidarians that also includes Velella and Porpema. The chondrophores are similar to the better-known siphonophores,
which includes the Portuguese Man o' War. Characteristics[edit]
The blue button lives on the surface of the sea and consists of two main parts: the float and the hydroid colony. The hard golden-brown float is
round, almost flat, and about one inch wide. The hydroid colony, which can range from bright blue turquoise to yellow, resembles tentacles like those
of the jellyfish.[5] Each strand has numerous branchlets, each of which ends in knobs of stinging cells called nematocysts.
The blue button sting is not powerful but may cause irritation to human skin.[2] The blue button itself is a passive drifter, and is part of the
neustonic food web. It is preyed on by the sea slug Glaucus atlanticus (sea swallow or blue glaucus) and violet sea-snails of the genus Janthina.[6]
It competes with other drifters for food and mainly feeds on copepods and crustacean larvae.[7]
The blue button has a single mouth located beneath the float, which is used for both the intake of prey and the expulsion of wastes.John Harper - 1-19-2019 at 10:33 AM
Wow, what a beautiful little jelly.
JohnFatboy - 1-19-2019 at 10:35 AM
These were on several beaches on the pacific side near seven sisters...
Probably saw close to 50 of them on 6 to 8 different beaches last year.David K - 1-19-2019 at 10:42 AM
What are these?Skipjack Joe - 1-19-2019 at 07:38 PM
It’s hard to comprehend how an organism with a single mouth can be a colony. BajaBlanca - 1-20-2019 at 03:28 AM
Seems like we need a marine biologist ... or one of us should buy Dr. Hans' book!
What a gorgeous color blue that jellyfish is.wilderone - 1-20-2019 at 08:50 AM
I think it's a Cannonball Jellyfish (Stomolophus meleagris). There are different colors of them. Maybe - quick Google search OCEANUS - 1-20-2019 at 12:35 PM
David K, your pictures are of a jelly called a porpita.
Fatboy, I do not recognize/have a name for the jelly in your pictures.David K - 1-21-2019 at 02:49 PM
I think it's a Cannonball Jellyfish (Stomolophus meleagris). There are different colors of them. Maybe - quick Google search
WINNER!
I wrote to Dr. Bertsch and included Fatboy's photo...
"Dave,
Most probably it is Stomolophus meleagris, but the contracted out-of-water shape makes it a bit harder to identify. It's in my book!" Pfish - 1-22-2019 at 11:16 AM
I have always called these "Agua Males." I was spearfishing off of punta perico when I got stung by one on the ascent. Hurt like hell, but I was in
saltwater, so I kept diving. 5 minutes later I came right up into one and got the crap stung out of me. I started to feel naseous and sick and
disoriented. Had to swing 3oo yards to my boat in current. When I finally got there, I had a red rash all over me. I should have started drinking
beer and peeing all over myself . Ahhh, the lessons you learn when young and in Baja. imlost - 1-22-2019 at 03:36 PM
I think the "Agua Mala" and "Portuguese Man-'o-war" are the same thing.
I ran in to one while snorkeling near La Paz when I was in my 20's. The tentacles wrapped around my torso and arms. I spent the day in the hospital.
It was the worst pain I've had in my life. Never saw it in the water. DanO - 1-22-2019 at 04:42 PM
I should have started drinking beer and peeing all over myself.
You mean you did the opposite?
Thanks, I needed a good laugh. On a related note, I got stung on the foot once by some sort of jelly in the surf at La Fonda, BCN, and my sister's
boyfriend offered to pee on me. I told him I could handle it by myself.
vandy - 1-23-2019 at 02:31 PM
Yup. The big firm jellyfish in the first pics are blue cannonball jellyfish.
Google comes right up with a pic of one from the Sea Cortez
