Portuguese man-o-war

A Portuguese man-of-war (Physalia physalis) washed up on a beach. Photo by Dr. Alex Mustard, more can be found at www.amustard.com

Domain: Eukarya
Kingdom: Animalia
Phylum: Cnidaria
Class: Hydrozoa
Order: Siphonophorae
Family: Physaliidae
Genus: Physalia
Species: Physalia physalis

It’s summer time, the time of year I get to listen to the “jellyfish invasion.” Now, don’t get me wrong; jellies are increasing in number, and there are concerns about their large populations. However, Portuguese man-o-wars are not jellyfish—they’re siphonophores!

Siphonophores are the misunderstood cousins to jellyfish, especially Physalia physalis. Jellyfish are typically a single individual with a polyp stage. Siphonophores are a colony of individual organisms called polyps, and each group of individuals does a specific job for the colony.

Portuguese man-o-wars are made up of four separate polyps: the sails, the tentacles, the digestive organs, and reproductive system. Imagine that you and three of your clones, called zooids, live in an RV together. You are in charge of driving the RV, one clone is in charge of gathering food to feed everyone, one is the cook, and the other is responsible for replacing damaged or missing zooids. Without one of your clones, everyone in the RV would die, and RV would eventually stop moving. Same can be said about siphonophores and P. physalis.

The pneumatophore is the gas-filled bladder at the top; it’s the purple-bluish structure you can see floating on top of the water. This zooid is responsible for the colony’s movement. However, the gas-filled bladder works more like a sail; the wind and surface currents do the actual moving of the colony. This is how they got their name, because the gas-filled bladder resembled the sails of man-o-wars, a type of naval ship.

The tentacles are another organism, or zooid, of P. physalis. On average, the tentacles can extend 30 feet below water, but a single colony was recorded with tentacles as long as 165 feet! The tentacles contain venom-filled nematocysts, which they use to paralyze and capture prey. Portuguese man-o-wars feed on fish, shrimp, and other small creatures.

Gastrozooids are the polys in charge of digesting the prey and distributing the nutrients to the other polyps in the colony. Essentially, they are the digestive system of the colony. Unlike the sail and the tentacles, they have no distinctive “structure” on the colony, so they can’t be identified in a photograph.

The last type of zooid is responsible for reproduction. These polyps create other polyps for each of the groups, replacing those that have died or have been damaged. They are also responsible for exchanging genetic material with other Portuguese man-o-wars.

Portuguese man-o-wars are found in tropical and subtropical waters, and they can be found floating in large numbers—even in the thousands. I know in the US every summer, media warns the East Coast about these siphonophores washing up on public beaches.

P. phyaslis can be harmful to humans. I’d hate to be out swimming and get stung by the long tentacles! While live man-o-wars can be harmful to swimmers, dead ones are also a concern. While the venom is rarely fatal, it hurts worse than an army of wasp stings, and the nematocysts can still sting humans after death. So if you seem a dead one wash up on the beach—DON’T TOUCH IT!

If you notice Portuguese man-o-wars in the water or washed up, notify the lifeguards and everyone around you immediately. If you’ve been stung, do not use urine or vinegar on the inflamed area.

Dive manuals suggest that you carefully remove any remaining tentacles and flush the area with sea water, never fresh water. As soon as possible, immerse the affected area in hot water of at least 112°F for twenty minutes. This will denature the toxin and break up the chemicals.

I have never seen a Portuguese man-o-war in person despite living on the eastern coast of the United States and frequenting beaches in the summer. However, I don’t think I’m terribly upset with the idea, because with my luck, I’d get stung! Siphonophores are pretty interesting, though, and I can’t wait to share more with you!

Links and sources:
Reef Creature Identification Florida Caribbean Bahamas 3rd edition by Paul Humann, Ned DeLoach, and Les Wilk ⇐had the info on how to treat the sting
https://www.nationalgeographic.com/animals/invertebrates/p/portuguese-man-of-war/ ⇐in-depth look into the sections of the man-o-wars
https://oceanservice.noaa.gov/facts/portuguese-man-o-war.html ⇐simplified info
https://www.britannica.com/animal/Portuguese-man-of-war

Mushroom Coral

Domain: Eukarya
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Scleractinia
Family: Fungiidae
Genus: Fungia
Species: Fungia scruposa

Do you know what gets my attention? An old article about a species of coral that was documented eating jellyfish. But I’ll get to that later; first, I want to introduce you to Fungia scruposa, or the mushroom coral!

Found in the tropical waters of the Red Sea, Indian Ocean, and western Pacific Ocean, mushroom coral are unique for a few reasons. Unlike other hard corals, F. scruposa lives as a single individual instead of as a colony, much like the Atlantic mushroom coral of the family Mussidae. Don’t let their similar common names fool you, though. These two corals are not closely related to each other.

Juvenile mushroom coral start out as raised disks that attach to dead coral or rock. When they grow to about an inch in diameter, they detach themselves from their substrate. However, this does not mean that they’re super mobile. Instead, mushroom coral typically stay in the same area and inhabit the sediment or rubble.

But what happens if a strong wave comes through and turns them over? Fungia scruposa use their tentacles to right themselves when knocked over by waves or by another animal.

Mushroom coral get their name from their appearance. They have an irregular disk shape that is about 1 inch in diameter, sometimes a little larger. At the center of the disk is a raised mound with a deep-looking cut, which is the polyp’s mouth. The coral’s hard exoskeleton has several thin ridges that spread out from the center, making it look like the underside of some mushrooms.

Fun fact: did you know that the ridges on the undersides of mushrooms are called gills?

I’ve yet to see this coral while diving, but I absolutely cannot wait! Mushroom coral are unique for their class, because they live as solitary polyps and spend their adult lives not attached to anything. But on top of all that, they were also recorded eating whole jellyfish in the late 2000s—something that was completely unheard of!

There are some species of sea anemones—distant cousins to coral—that are known to eat jellyfish. However, these are the first hard corals that scientists have seen eating jellies. Unfortunately, the divers were only able to see the jellies disappear into the mouths of several mushroom coral, but they could never see how the mushroom coral captured the moon jellies. Still, it’s absolutely fascinating and may prove how resilient hard coral can be in a changing ocean environment.

And maybe you can be the researcher that discovers how they do it! Maybe you can discover more species of coral that will dine on jellyfish when the opportunity presents itself.

Sources and links:
Ocean The Definitive Visual Guide made by American Museum of Natural History
http://www.coralsoftheworld.org/species_factsheets/species_factsheet_summary/fungia-scruposa/
http://news.bbc.co.uk/earth/hi/earth_news/newsid_8350000/8350972.stm ⇐an article about mushroom coral eating jellies
https://link.springer.com/article/10.1007/s00338-009-0507-7 ⇐another article about them eating jellies but with more detail

Bobbit Worm

A bobbit worm (Eunice sp.) emerges from its hole in black sand at night to feed. Photo by Dr. Alex Mustard, more can be found on www.amustard.com

Domain: Eukarya
Kingdom: Animalia
Phylum: Annileda
Class: Polychaeta
Order: Einicida
Family: Einicidae
Genus: Eunice
Species: Eunice aphroditis

Annileda is the phylum of segmented worms, with over 22,000 extant species, including leeches and earthworms. Today, I’m going to share with you the shiny rainbow horror that is the bobbit worm.

Eunice aphroditis looks like a creature from a horror writer’s drug-induced fever dream.

Averaging about 3 feet long and 1 inch wide, the bobbit is also a member of the bristle worms. Along each side of its body are paired, spike-like appendages called parapodia. Each fleshy protrusion contains several bristles. The bobbit worm comes in an array of colors, from black to purple to metallic. The body appears to have this shimmery rainbow effect to it, especially in photographs.

The bobbit worm is an ambush predator. It conceals its body, all 3‒10 feet of it, beneath the sand of the seafloor, except for its antennae. When a fish or crustacean brushes up against the antennae, the bobbit worm emerges from the sand to grab its prey and pull it under.

What make this creature appear nightmarish are its powerful mandibles protruding from its mouth and the speed at which it grabs its prey. The mandibles are scissor-like appendages that extend far from the mouth, and they’re used to grab prey. On occasion, the bobbit worm has been seen cutting its prey in half with the mandibles.

The bobbit worm is found in tropical waters, mostly in the Indian and Pacific Oceans. Not much is known about its reproduction. They are considered rare, and these worms are hard to find because of how they bury themselves beneath the sand.

Eunice aphroditis supposedly gets their common name from the Bobbitt Case in the 1990s involving a married couple with the last name Bobbitt. It’s a disturbing case to read about, so learn about it at your own risk; it involved domestic abuse and violence between the couple.

Despite its nightmarish appearance, the bobbit worm was pretty interesting to look into. There’s still room for research, so if you’re looking for something to focus on, look into polychaetas and the bobbit worm! If you want an idea for a freaky yet colorful horror thriller, I think this worm might give you an idea or two.

Sources and links:
Ocean the Definitive Visual Guide made by the American Natural History Museum
http://www.marinespecies.org/aphia.php?p=taxdetails&id=130053#links
https://eol.org/pages/404312
https://www.ourbreathingplanet.com/bobbit-worm/

Hamelin Cockle

Domain: Eukarya
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Cardiida
Family: Cardiidae
Genus: Fragum
Species: Fragum erugatum

When I wrote about Shell Beach, Australia, I mentioned the Hamelin cockle, Fragum erugatum. Today, I want to expand on what I wrote.

The Hamelin cockle is a bivalve that belongs to the phylum Mollusca, along with oysters, snails, and squids, to name a few. It’s native to the shallow shores of Western Australia, though it is prevalent in Shark Bay and Shell Beach.

Shark Bay is a hypersaline marine environment. Its seagrass beds restrict tidal movement, and the rate of evaporation is higher than the rate of precipitation, which makes the water really salty. In fact, the water is plankton-deficient because the high salinity makes it hard for plankton to survive.

So what does the cockle do for food? Isn’t it a filter feeder like many of its bivalve brethren?

Hamelin cockles are not strict filter feeders. Instead, they have a partnership with our favorite oceanic BFFs, zooxanthellae. Like coral, the cockle receives leftover food from the zooxanthellae in exchange for protection in well-lit waters. Fragum erugatum will siphon plankton from the water when they can, but it’s never enough to sustain them.

The soft body of the cockle is brown, and the photosynthetic algae live in the soft tissue. The shells are white and appear translucent in the light. Fun fact, zooxanthellae also help to collect calcium carbonate that the cockle uses to make its shell. The entire organism is less than 20 millimeters, which is a little smaller than an inch.

Hamelin cockles are hermaphrodites, meaning they have both male and female sex organs; however, they still need other individuals to reproduce. Between winter and spring, F. erugatum will release their gametes, or eggs, into the water to be fertilized by other Hamelin cockles. The fertilized eggs develop into zooplankton that float around in the water before they settle to the ground and further develop into cockles.

I find these bivalves to be every interesting. They entered Shark Bay over 4000 years ago and really put forth the effort to make the bay and Shell Beach their home. Most living things do not prosper in extreme conditions, especially in areas of high salinity. However, the Hamelin cockle not only adapted to the hypersaline water, but they prospered so beautifully that they left a noticeable mark in the local geology.

Four thousand years’ worth of cockle shells replaced the sandy beach of Shell Beach. Building material was made from the dense accumulation of these shells that, over time, became cemented together. It just blows my mind to think how successful these tiny little organisms are, and that makes them special!

Sources and links:
Ocean the Definitive Visual Guide made by the American Museum of Natural History
https://www.sharkbay.org/publications/fact-sheets-guides/hamelin-cockle/

Anemones

A close up of jewel anemones (Corynactis viridis). Photo by Dr. Alex Mustard, more can be found at www.amustard.com

Domain: Eukarya
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Actiniaria

I have often heard people refer to sea anemones as flowers or sea flowers, and I always wondered why. Apparently, these organisms gained their common name because their bright colors reminded people of the terrestrial anemone flower.

It makes sense why people would consider sea anemones as flowers. Sea anemones don’t appear to move, they’re brightly colored, and their tentacles can resemble petals. However, like their coral and jellyfish cousins, sea anemones are animals.

A sea anemone is a single large polyp that lacks any skeletal structure and contains stinging cells called nematocysts. They have cylindrical bodies that are attached to hard substrates by their adhesive pedal disk, or foot. Its mouth, or oral disk, rests near the top of the body and is surrounded by tentacles, which they can retract into their body when feeling threatened.

Sea anemones come in all shapes, sizes, and colors. There are over 1000 species that range from half an inch wide to over 6 feet wide. They appear in various shades of blue, green, yellow, and red. Many species are more than one color or shade; often, the tentacles can be a different color than the body. Species in warm tropical waters are often larger and more colorful than sea anemones found in deeper, colder water.

Sea anemones are found in every ocean. They can be found at various depths, from shallow water to over 3000 meters deep in the ocean. They inhabit various crevices of coral reefs, rocky substrates, and sea walls. Some have been recorded on the backs of sea turtles.

Sea anemones are carnivores. They feed on planktonic organisms, crustaceans, small fish, and occasionally mollusks and sea urchins. The tentacles of sea anemones are used in defense and for capturing food. These stinging tentacles are touch sensitive. When potential prey brush up against the tentacles, harpoon-like filaments, called nematocysts, are launched at the prey. The nematocyst hooks into the prey and releases a neurotoxin that paralyzes the creature, then the tentacles pull the prey to the oral disk to be consumed.

Some organisms are immune to the stinging tentacles and coexist with various species of sea anemones.

Many people are aware of clownfish and their mutualistic relationship with sea anemones. Clownfish have a unique adaptation that allow them to live within the tentacles of the anemone. The sea anemone provides protection for the clownfish, and the clownfish will keep the anemone clean and lure potential prey to the anemone.

Other symbiotic relationships with sea anemones include various small crustaceans and zooxanthellae.

The stinging tentacles of the sea anemone don’t protect it from every organism. Various species of starfish, sea slugs, eels, and some species of fish prey upon anemones. Occasionally, sea turtles have been recorded munching on sea anemones when given the chance.

I don’t believe there is a Cnidarian that I don’t find fascinating. At the aquarium where I volunteer, there’s an exhibit that shows how some sea anemones rely on wave action to supply them with food. It’s one of my favorite exhibits because it’s so bright and colorful, and I find it relaxing to watch. Every few minutes, the exhibit simulates incoming waves, and you can watch the water whooshing down toward the sea anemones.

Sources and links:
Reef Creature Identification Florida Caribbean Bahamas 3rd edition by Paul Humann, Ned DeLoach and Les Wilk
Ocean: A Visual Encyclopedia (Smithsonian) by John Woodward
https://www.nationalgeographic.com/animals/invertebrates/group/sea-anemones/
https://www.britannica.com/animal/sea-anemone
https://aqua.org/Experience/Animal-Index/anemones
https://animals.net/sea-anemone/

Blue Glaucus

Domain: Eukarya
Kingdom: Animalia
Phylum: Mullusca
Class: Gastropoda
Order: Nudibranchia
Family: Glaucidae
Genus: Glaucus
Species: Glaucus atlanticus

The other day, I got a strange text from my dad talking about an article that he found on the Internet describing a blue dragon that had washed up in Texas. He seemed really excited to show me the article because he thought I could blog about it. Well, “blue dragon” didn’t ring any bells, and I thought that it might have been an oarfish, which is dragon-esque. Instead, what I found is a nudibranch, most commonly known as a sea slug.

Glaucus atlanticus goes by many common names: blue glaucus, blue dragon, sea swallow, and blue sea slug, to name a few. No, it does not look like any slug you might have seen or land.

The creature has what looks like a head and a tail. Along its body are three pairs of fan-like appendages that look like wings. The blue sea slug can grow up to 1.2 inches (3cm) in length, which would make it the smallest dragon in the Guinness World Record book. However, it is not the smallest sea slug!

Most sea slugs live on the seafloor. They can live on coral, or the sandy substrate, or even rocky surfaces. Glaucus atlanticus isn’t like its cousins, though. Instead, they are a pelagic sea slug, meaning they live in the open water column. They have been sighted more often up towards the ocean’s surface.

The blue sea slug floats in the water column by storing an air bubble in its body, acting like an air bladder in fish. If it hangs out near the surface, how does it hide from sea birds?

Glaucus atlanticus has a special coloration that allows it to blend into its surroundings called countershading. The blue sea slug floats on its backside, showing the bright blue underbelly toward the sky. The blue helps it blend into the waves and makes it hard for sea birds to see the creature. On the other side, it is a grayish color that blends in with the surface water from below, making it nearly invisible to its underwater predators.

Countershading isn’t the only defense it has against predators. In fact, like most sea slugs, this is a creature you don’t want to touch—no matter how pretty it looks!

One of the things blue dragons consume is the Portuguese man o’ war, a type of hydrozoan known to give nasty stings to beach-goers. The Portuguese man o’ war has long tentacles, almost 30 feet long, which are full of stinging cells.

When the blue dragon consumes the Portuguese man o’ war it stores the hydrozoan’s stinging cells in those fan-like appendages. When a diver or predator gets too close, the blue dragon will brush up against the perceived threat and sting them with the stinging cells. It’s been reported that a sting from a Glaucus atlanticus hurts more than a sting from a Portuguese man o’ war—so watch out for these critters when swimming! They’re found in the warm waters of the Pacific, Indian, and Atlantic Oceans.

If anyone has any suggestions or requests, like this one, let me know! I want to write about what interests you.

Sources and links:
Reef Creature Identification: Florida, Caibbean, Bahamas 3rd edition by Paul Humann, Ned Deloach, and Les Wilk
https://oceana.org/marine-life/corals-and-other-invertebrates/blue-glaucus
https://scubadiverlife.com/marine-species-glaucus-atlanticus/ ⇐has dive-related news articles as well

Sea Whip

Domain: Eukarya
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Gorgonacae
Family: Gorgoniidae
Genus: Leptogorgia
Species: Leptogorgia virgulata

I’ve realized that so far the only corals I have mentioned have been hard corals—reef builders. I will admit, that I like more hard corals than soft, but that doesn’t mean soft corals aren’t worth talking about. Continuing with my Chesapeake Bay theme, I’m going to talk about a native soft coral, the Sea Whip.

Cue the 80s music: “Crack that whip!” “Just whip it!”

The major difference between hard and soft corals is the composition of their bodies. Hard corals have permanent, rigid exoskeletons that house the coral polyps. These structures require large amounts of energy to build, which is why it can take a year for hard corals to grow just an inch, at best. Soft corals, however, lack that rigid calcium carbonate skeleton. Instead, soft corals are mostly made of living tissue that allows the soft corals to assume more creative shapes.

Sea whips, Leptogorgia virgulata, have long, thin branches that can grow up to a meter long. Their coloring can vary from red, to tan or orange, to purple. The polyps are always white, so sea whips look like they’re covered in white fuzz. Most soft corals are more colorful than their harder cousins.

Sea whips are found in reef environments and can tolerate low levels of salinity, so they are most common in nearshore areas that are more influenced by the tide. They range from New York to the Chesapeake Bay and from Florida to Brazil. In the Chesapeake Bay they thrive in the salty waters of the lower section of the bay.

L. virgulata are suspension feeders, so the polyps use their long tentacles to snag plankton and other tiny particles that are suspended in the water. When sea whips are born, the tiny polyps are carried by waves and currents. When they reach adulthood, so to speak, they become sessile meaning they cannot move from the hard substrate they land on. So they rely heavily on water circulation to stir up the water and bring in more plankton and nutrients for them to feed on.

I have yet to see a sea whip while diving, which is something I wish to change. But I wanted to share this soft coral to show that not all corals are found in tropical places, and that corals can be a lot more diverse than we think. And I’m happy to report that as of this writing, the populations of sea whips in the Chesapeake Bay and other monitored areas are considered stable!

Sources and more info:
https://www.chesapeakebay.net/discover/field-guide/entry/whip_coral
http://www.dnr.sc.gov/marine/sertc/octocoral%20guide/Leptogorgia_virgulata.htm
https://naturalhistory2.si.edu/smsfp/IRLSpec/Leptog_virgul.htm

Zebra Mussels

Domain: Eukarya

A colony of zebra mussels (Dreissena polymorpha), living in freshwater. Photo by Dr. Alex Mustard, find more at www.amustard.com

Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Myida
Family: Dreissenidea
Genus: Dreissena
Species: D. polymorpha

Today, we’re going to talk about zebra mussels. We’re not going to talk about zebra muscles like I had originally written down on my blog schedule. Honestly, why would I talk about the muscles of a zebra? They’re not even aquatic!

I know that was a lame introduction. It just doesn’t have enough strength to land a clever opening—maybe it needs more mussels…

Okay, I’ll stop!

Zebra mussels, D. polymorha, are freshwater bivalves native to Eurasia. Bivalves are shelled creatures; specifically mollusks with two shells that close together, like clams and oysters. Zebra mussels are about an inch long and are shaped liked a stretched out “D”. They are named from the black, zigzag patterning on their shells.

Humans can be so creative with their naming schemes.

Zebra mussels have a relatively short life span, between 2‒5 years, reaching reproductive maturity at 2 years of age. Each female can produce up to a million eggs per year, spewing them into the surrounding water and using the currents to transport the eggs.

The reason I’m bring up D. polymorpha is because it is an invasive species in the United States and Canada. The mussels were first discovered in the early 1980s near the Great Lakes and are believed to have been transported by accident in the ballast water of a ship. Since then they have been found in the Great Lakes, the Mississippi and St. Croix rivers, and the Chesapeake Bay.

Why are the zebra mussels bad for these environments? Don’t they help filter the water in their surroundings, and isn’t that a good thing?

In their natural habitat their job as filter feeders is absolutely amazing; in other habitats, it can have devastating effects. In fact, zebra mussels are so efficient as filter feeders that they can clean a body of water of particulates in record time, faster than the native filter feeders. But this is not a good thing.

The environments that the mussels invade have a special balance that is maintained by the native populations of animals. If you change one aspect of that balance, then it creates a domino effect.

Let’s say that we have an imaginary river, the River Sága, which is home to large, healthy beds of freshwater bivalves called blue purses (not a real bivalve). In this river there are also a few species of fish that go there to spawn and where the juvenile fish live until they’re big enough to move on. One day, an old fisherman dumps water into the River Sága from his boat and unknowingly releases several thousand eggs of the zebra mussel. A couple of years later, the river is no longer the same. The once-healthy beds of blue purses are now completely covered in smaller bivalves, smothering the native species. The water of the river is the clearest it’s ever been, but downstream there are enormous patches of algae, and there are no fish to be seen. What was once a nice fishing spot for man and animal alike is now barren, save for the zebra mussels and the algae.

Zebra mussels, like any invasive species, are horrible for the environments that they infiltrate because they have no natural predators, and they often outcompete the native species. Because zebra mussels are so good at filtering the water, it makes it easier for predators to find their prey in the water, whether it’s a larger fish or a bird hunting the juveniles that have spawned there. And because zebra mussels reproduce so much, they can easily smother their competitors, becoming the dominate species of the environment and changing it for the worse.

Zebra mussels also have an impact on human property. They have been known to block the drainage pipes of factories. They can incapacitate boats by clogging pipes and engines, or even by covering the sides of the boat and making it too heavy to float properly. It can take an absurd amount of money to remove them, and we have to do it often because they regularly come back and are so hard to eliminate.

I wanted to talk about zebra mussels because they have been noticed in the Chesapeake Bay, which is an important part of my life, and because it helps introduce the topic of invasive species. From what I understand, there is not much you can do once the zebra mussels appear, only that we must strive to prevent their spread elsewhere. But this also means that there is a potential opportunity for you, because maybe you can find a way to remove them from their nonnative habitats.

More information can be found:
https://www.chesapeakebay.net/discover/field-guide/entry/zebra_mussel
https://www.tn.gov/twra/fishing/twra-fish-species/zebra-mussel.html
https://www.invasivespeciesinfo.gov/profile/zebra-mussel
https://www.usgs.gov/faqs/what-are-zebra-mussels-and-why-should-we-care-about-them?qt-news_science_products=0#qt-news_science_products
https://www.nps.gov/articles/zebra-mussels.htm

Atlantic Mushroom Coral

Domain: Eukarya
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Scleractinia
Family: Mussidae
Genus: Scolymia
Species: Scolymia lacera

Not all hard coral grow to be great big structures. And while most coral are considered to be a colony of polyps—i.e., individuals living together—there are some that are quite solitary. Some of them, like the cup corals, live a bit differently than their cousins and distant relatives.

Atlantic Mushroom coral, or Scolymia lacera, is one of a few cup corals found in the Western Atlantic Ocean. In fact, they occasionally can be found in deep-reef environments and on reef walls in the waters around Florida, the Bahamas, and the Caribbean. They prefer well-lit areas on rocky surfaces and outcroppings, somewhere nice and stable with enough light to help out their zooxanthellae friends.

S. lacera varies in color from shades of light gray to green, blue-green, and brown. The few that I have seen while diving were a mix of blues and greens, almost like an alternating stripped pattern—though this isn’t the same of all individuals.

Unlike other coral, the whole structure that is S. lacera is made up of a single polyp. That’s right; this species of coral is not a colony like its other hard coral cousins. Instead, it is a single large, fleshy, roundish polyp that looks a bit rough around the edges—texture-wise, that is. The whole structure that you see is the corallite, or the skeletal cup in which an individual polyp sits in and can retract into. For S. lacera, the center of the corallite can be either flat or curved inward; rarely is it seen with a raised center.

The Atlantic Mushroom coral can grow to between 2.5 and 6 inches and is the only type of cup coral that you can identify in person if it’s larger than 4 inches in diameter. Any specimen smaller than 4 inches has to have its corallite structure examined for identification.

During the night and in turbid, cloudy conditions, the polys will extend their tentacles in the hopes of grabbing food.

I think these guys are really cool because they break the mold, so to speak, when it comes to most hard corals. Instead of being a colony of individuals, each structure is a single large individual. They’re also pretty neat to spot on the reefs because they can be these bright colorful spots amongst drab shades. When I first saw them I didn’t think they were coral. It wasn’t until I started taking classes and we discussed them that I learned what they were.

Sources:
Reef Coral Identification: Florida, Caribbean, Bahamas 3rd edition Paul Humann and Ned DeLoach

https://coralpedia.bio.warwick.ac.uk/en/corals/scolymia_lacera <–At the time of posting this article, I hadn’t gotten the rights to share any photos of the coral, but you can see pictures of this species at the link–please take a look!

Cannonball Jellyfish

Pictured here is a cannonball jellyfish. Notice the brown coloring around the bottom of its bell.

Domain: Eukarya
Kingdom: Animalia
Phylum: Cnidaria
Class: Scyphozoa
Order: Rhizostomeae
Family: Stomolophidae
Genus: Stomolophus
Species: Stomolophus meleargis

For today’s species we’re going to head back to the phylum Cnidaria! Honestly, it’s one of my favorite phyla because it has coral, jellyfish, and siphonophores which are all really cool creatures to check out. So let’s go ahead and cannonball into today’s topic…

I’m trying too hard again, aren’t I?

Stomolophus meleagris, also known as the Cannonball Jellyfish, is aptly named because it is about the size and shape of a cannonball used to load cannons in the days of massive sea voyages, pirates, and colonization.

Though, compared to cannonballs, S. meleagris can be a lot prettier to look at. They range in color from white to brown and will have very neat looking markings of various colors around the bases of their dome heads. Unlike other jellyfish, cannonball jellies don’t have tentacles. Instead, they have short, forked oral arms that extend out and away from the dome a little.

Cannonball jellyfish are native in both the Atlantic and the Pacific oceans, found right off the coast and in estuaries. They’re most abundant in the waters off the southeastern United States and the Gulf of Mexico. S. meleagris populations span from New England to Brazil in the Atlantic Ocean, and from the Sea of Japan to the South China Sea in the Pacific.

In fact, they are considered a common menu item in Asian markets and are dried and processed right after capture. Humans aren’t the only species that eats these guys; the most important is the endangered leatherback turtle, which only eats S. meleagris.

The jellies themselves eat macrocrustaceans, certain fish larvae, and zooplankton; and they eat by sucking water in where several tiny “mouths” are located. Fun fact: their scientific name roughly translates to “many mouthed hunter”.

Like other cnidarians, these guys do have stinging cells, however they don’t pose much of a threat to people. The pain of their stings isn’t too great, and it will cause mild irritation though, if you get stung in the eye that is a whole other can of worms—so make sure you always wear protective eyewear when in the ocean!

I first saw these jellies in aquariums growing up, and I always thought they looked a little goofy. I love watching them move about their tanks, and I can watch them for hours—just ask my husband!

I’ve never seen these guys while diving or snorkeling, which is a little disappointing, but there’s always next time. I’ve also not come across them while playing in the ocean on beach days, though I have seen plenty of them wash up on the sand. In fact, during one of my internships, I watched a few of them get pulled into estuaries during high tide, and it looked like they were just rolling with the current like a runaway cannonball!

Sources and cool links:
https://animaldiversity.org/accounts/Stomolophus_meleagris/ (totally check this out, it has a lot of good information!)
https://sites.google.com/site/barrierislandecology2013/aquatic-fauna/cannonball-jellyfish (this one also has more links and things to check out at the end.)
https://animalsake.com/facts-about-cannonball-jellyfish