ATTACK OF THE KILLER SPONGE

It's been a while since I've introduced a crazy-sea-creature...OK, it's been a while since I posted at all, but lets get back to our watery-roots. Today, I'd like to take you down the eddy to a seafloor nightmare: Sponge Bob's evil twin (dun, dun, dun!)



Sponge Bob's Evil Twin?

 ...the Harp Sponge.

The harp sponge (Chondrocladia lyra) is a species of carnivorous deep-sea sponge. Yes, you read that right. Carniverous. Predators.

They don't eat in the typical way of sponges that sweep water into their pores and filter out microscopic bacteria and bits of organic matter for dinner. This sponge is a hunter: it traps larger marine life like copepods and other crustaceans with Velcro-like hooks.

The harp sponge was discovered by Monterey BayAquarium Research Institute off the coast of California. As you can see in this picture, it gets its name (both common, Harp Sponge, and Latin species name, lyra from it's branching arms, or vanes, with vertical limbs that look like the strings of a harp or lyre.

A deep sea Harp Sponge. Photo from MBARI

Don't let the delicate beauty of this bad-boy-Sponge-Bob fool you. Those branching limbs are covered with barbed hooks that trap their prey. Then, the sponge encapsulates them in a digestive membrane, dissolving them into a fish-smoothie that it can absorb through its pores. Yummmm.

Here's another look.

 Just when you thought it was safe to go back in the ocean...


 

Oh, Christmas Tree Worm, Oh, Christmas Tree Worm...

In honor of the season, today I present you with the beautiful, captivating Christmas Tree worm, Spirobranchus giganteus.

The colorful set of trees in this picture actually belong to a single, lowly worm. Yes, believe it: It's a worm. This diminutive annelid (same phylum as earthworms) is a marine organisms and those swirling "branches" or radioles are the paired tentacles it uses for capturing food from the water. The spiral "trees" also helps with gas exchange.

As divers and snorkerlers will tell you, when disturbed, these whorls instantly retract and the worm pulls its door-like operculum closed behind it. Here's a Youtube video of some Christmas tree worms retracting.

Christmas tree worms take their common name from their appearance, of course. Their scientific classification tells us lots more about these animals. As annelids, they have segmented bodies. Segmentation was an important evolutionary step that allowed greater diversity in organisms' body plans. Digestive tracts could differentiate into separate parts, each with its own role: mouth and esophagus to bring food in and move it through the passage, crops, gizzards, and stomachs to store, grind and process food, intestines to absorb nutrients and water. Segmentation also lets organisms develop differentiated limbs. We see segmentation in humans through our vertebrae. Turns out, all organisms that exhibit segmentation share a similar gene, the Homeobox, or Hox gene, which serves as a molecular architect and directs the building of bodies according to definite detailed plans.

Our annelid, the Christmas Tree worm, belongs to the class of marine worms called polychaetes (along with fireworms), subclass sedentaria (along with feather duster worms, because they once the larvae settle, they secrete a parchment-like calcareous tube and then never move from that location), family serpulidae (this means creeping and probably refers to the larval stage. When ready to settle down, the larva creeps around a potential home in search of a good place to dig in.)

Spirobranchus come in a variety of bright colors, each worm with two "trees" poking out from its tube. Most often, they burrow into living coral, although sometimes they'll live in a rock or sponge, and secrete their tube.

S. giganteus possesses a complete digestive system and has a well-developed closed circulatory system. Like other annelids, they possess well-developed nervous systems with a central brain. They have fully developed nephridia simple kidneys) used for excretion. When they reproduce, they simply shed their gametes (eggs and spermatozoa) straight into the water and leave fertilization to chance and cooperative currents.

Christmas tree worms eat by capturing food from the plankton. "Capturing" sounds a bit more active than it really is. When currents carry tiny plants and animals floating in the water into the radiole, the tentacles direct that particle to the worms mouth. They don't really hunt anything down. Filter feeders wait for the food to come to them. They have few, if any, natural predators and no commercial value aside from as fascinating aquarium animals so they aren't endangered or threatened in and of themselves. With loss of their preferred habitat--coral reefs--their numbers could possibly decline, but for now, we get to easily and readily enjoy these colorful organisms while snorkeling and diving in tropical and subtropical waters worldwide.

Enjoy, and Merry Christmas, Happy Hannukah, Happy Kwanzaa, Merry Solstice, and a happy 2013!

Happy Holidays everyone!

HARMFUL ALGAL BLOOMS AND YOU!

Harmful Algal Blooms (HABs) occur when usually harmless phytoplankton--microscopic or very small, photosynthetic marine organisms--reach high densities. Their numbers rapidly increase in a given area to the point where they go from harmless to hazardous.

The hazard they present can come from their anatomy, physiology or metabolism.

ANATOMY
Some diatoms, like those pictured below, have sharp spines that can cause fish to suffocate by getting lodged in their gills and causing acute inflammation. Some microscopic algae produce mucus, clogging gills and leading to fish's respiratory failure.

Fish with spiny diatoms in its gills.
(Image from www.bigelow.org)
 

The spiny diatom Corethron pennatum 
(image from www.phys.org)

PHYSIOLOGY AND METABOLISM
Some phytoplankton affect theorganisms that prey on them by interfering with feeding. The mucus the phytoplankton produce might make them unpalatable or indigestible. Others have such low nutritional value that the organisms that eat them actually starve to death!

Perhaps the most well-known HABs are those that produce toxic blooms. We commonly call those "red tides" although the water color isn't necessarily red, but can be yellow, green, or brown due to the sheer numbers of phytoplankton. Some of the algae that cause the color changes are capable of producing powerful toxins that are harmful or deadly to other species. The toxins may kill fish, injure marine invertebrates, and cause human illness or death from ingesting shellfish that have accumulated the toxin in their tissue. Some of the human illnesses from ingesting contaminated seafood include Amnesic Shellfish Poisoning (ASP), Diarrhetic Shellfish Poisoning (DSP), Neurotoxic Shellfish Poisoning (NSP), Paralytic Shellfish Poisoning (PSP), and Ciguaterra Fish Poisoning (CFP).

A "red tide" bloom.
          From The Baltic Sea Portal (Itameriportaali).

While phytoplankton use photosynthesis to create their food source and release oxygen into the environment, their high productivity and short lifespan means a high turnover of biomass---lots of dead microalgae. As those decompose, they quickly deplete all the oxygen in an area, resulting anoxia---low or no oxygen in the surrounding water. Their decomposition also results in the formation of toxic sulfides in the water. The lack of oxygen and production of sulfides creates a deadly scenario for most marine life that can lead to massive fish die-offs.

Fish die-off due to anoxic conditions from a HAB
(photo from G. Pitcher, via www.bigelow.org)

PREDATION
At least one species of phytoplankton, Pfiesteria piscicida, is actually a predator, killing and then feeding on fish in the waters they inhabit.

WHO CARES?

We all should. HABs affect everyone! They're a global threat to living resources, fishing, tourism, and human health because the number and intensity of these events appear to be increasing in many countries. In the last two decades, HABs are estimated to have caused as much as $1 billion in losses to coastal resources and communities (NOAA). Check HERE for more information on the socioeconomic impacts of HABs (WHOI).

Preventing and eliminating harmful algal blooms is no easy tasks. There are numerous factors that influence the formation, distribution and duration of blooms. It’s difficult to control one factor in the environment, let alone all factors for all algae in all locations. In addition, any action taken to prevent or to remove a bloom has consequences for the other organisms in the environment.

A combination of factors contribute to the development of HABs such as the presence of  nutrients, warm temperatures and lots of light. Rising ocean temperatures from climate change, increased nutrient run-off from land due to poor land-development practices and a loss of wetlands, and the break down of marine food chains due to overfishing all play roles and are all increasing, so we can most likely expect to see more and more HABs in the future. 

Researchers are constantly trying to gain a better understanding of HABs to help find ways to control their development and reduce their impacts. Early detection of their formation is critical to prevent impacts to human health by issuing fishery and beach closures in impacted areas. 

If that makes you feel helpless to do anything about HABs, you're NOT! You can help by asking state and local lawmakers to implement better land-use planning and wetland preservation to protect coastal water quality, learning the facts about climate change, and demanding good, research-based science, not hype, someone's political- or financial-gain, or fear, drive government decision-making.



FOR MORE ON HABS, CHECK OUT THESE SITES

• Bigelow Lab for Ocean Science  http://www.bigelow.org/edhab/help_hab.html
• Environmental Health, 2008. Impacts of climate variability and future climate change on harmful algal blooms and human health. http://www.biomedcentral.com/content/pdf/1476-069X-7-S2-S4.pdf
• Environmental Protection Agency http://www2.epa.gov/sites/production/files/documents/climatehabs.pdf
• National Oceanic and Atmospheric Administration, National Ocean Service  http://oceanservice.noaa.gov/education/lessons/bad_algae.html
• Texas A&M, Ocean World Online Textbook http://oceanworld.tamu.edu/resources/oceanography-book/harmfulagalblooms.htm
• Woods Hole Oceanographic Institute https://www.whoi.edu/redtide/home

JAWS, or Handling the Fear in Open-water Swimming

I love open-water swimming. Lakes, rivers, the ocean, it's both exhilarating and calming. I'd be lying if I said it's not a little bit frightening, too. While I don't do as much open-water swimming as I used to, when I was swimming Brewers Bay, from the UVI dock to Black Point and back regularly, a swim didn't pass where I didn't start humming Da-dum. Da-dum. Da-dum-da-dum-da-dum somewhere out in the middle of the bay.

Thanks Jaws.

Original movie poster from Jaws (1975)

Here's a post from "The Swimming Blog" that appeared in The Guardian not too long ago that had me giggling and nodding my head in commiseration with the author, Jenny Landrith.
Open-water Swimming: How do you handle the fear?

Now, during my once a year open-water swim on the Cooper River, I tend to "get in the zone" or what I've referred to in a previous blog post as "swimmer's bliss" by counting strokes. I play games to make the 2.4 miles pass faster: "No peaking until I've swum 100 strokes." Or, "Count how many strokes to the next buoy" then compare that to the number of strokes to the one after that. Those distractions can keep me occupied for most of the swim, but still, at some point it happens.

Da-dum. Da-dum. Da-dum-da-dum-da-dum

I'm not certain if it's fear or habit anymore. Maybe it's even become my way to deal with fear: do something silly like sing the Jaws theme.

How do you deal with your fear of the unknown?

Oh, Those Wild, Sexy Reef Fish!

WARNING: If you're easily offended by "unnatural" phenomenon like sex-changes this is NOT the post for you to read! It's all about the all-too-common occurrence on the reef of fish undergoing a sex change.

For the rest of you, read on. This is fascinating stuff!

Out in the real world, meaning the one we humans haven't artificially insulated ourselves from with technology, where the realities of life and death are governed by chemical and physical laws, animals must stick to a strict budget. It isn't a financial budget, but an energy budget that must be balanced. Every living organism, for its survival and the survival of the species, does whatever it takes to optimize energy use.

Energy In = Work to Survive 

Where:

Energy In = the number of useable calories an organism takes in, and

Work to Survive = using those calories for growth, finding food, shelter, defending your shelter, finding a mate, the process of mating, and repair of tissue damage or injury incurred from any of the above activities.

If you don't take enough energy in, you can't do all of the activities needed to survive. The whole point of survival in the animal kingdom is to reproduce. The more offspring you have, the more likely your genes are to survive through subsequent generations, thereby making you somewhat immortal.

As anyone on a budget can tell you, making sure that what you take in can cover all your expenses, you have to make some trade-offs. The more you spend on having fancy things and defending them, the less you have to wine and dine potential mates. But, without those accoutrements that announce your relative fitness, even your superiority, to prospective mates you won't get that opportunity.

No surprise that the perfect balance is different for males and females. In most species, females do the majority of the work in the offspring department. Whether they carry those embryos internally, or scatter them to the currents in the ocean, they still have the greater energy investment in egg production. Their eggs provide all the initial nutrition and organelles, as well as DNA, to the newly fertilized offspring. Sperm are packs of DNA and nothing more. It doesn't take much energy to make them.

This difference in energy expenditure for reproduction is one of the driving forces behind sexual dimorphism: differences in physical appearance between the males and females of a species. In particular, this accounts for size differences: When males have to protect territory or a harem from other males, spending energy to get bigger makes sense. When you can swim in, release lots of sperm, and leave, being small and quick is beneficial. Likewise, if a female produces many eggs, a far more energy intensive undertaking than sperm production, being large is beneficial.

Since "survival of the fittest" doesn't really mean not dying, but actually reproducing, "success" in the natural world means producing healthy offspring that go on to be successful themselves, the more offspring you produce, the better. If a female with a larger body cavity can produce more eggs per reproductive episode, and the more eggs produced increases her potential reproductive success, it's to her benefit to be a big female. Conversely, if larger males have greatly increased reproductive success (i.e. gain control of a harem), it would be beneficial to be a big male.

This is known as the size advantage model, developed by Ghiselin in 1969, that states "if an individual could significantly increase its reproductive success after reaching a certain size by being a different sex, it would be to their advantage to switch to that sex." And on the coral reef, they do!

Here are some of the brilliant reef fish that can change sex--sometimes in a matter of a few hours.

The Blueheaded Wrasse

The cleaner wrasse, Labroides dimidiatus. Typically, live in harems with a dominant male around cleaning stations. When the male is removed, the largest female becomes a functional male. The Blueheaded wrasse, Thalassoma bifasciatum, do not form harems, but the dominant or terminal males take temporary control of spawning sites. Removal of terminal males results in the largest females transforming.

 

Moonheaded Wrasse

When the largest female turns into a male, it is called Protogyny, Almost all the sex-changing species in the Caribbean are protogynous hermaphrodites, switching from females to males after reaching a certain size, age, or when the harem's male is removed. Some other examples are the parrotfish, Spanish hogfish, Holacanthus tricolor (the rock beauty angelfish), and some damselfish.

 

Rock Beauty

Clownfish in their anemone

Anemone fish, like the skunk anemonefish Amphiprion akallaopisos, and clownfish, like Nemo, are protandrous. They change from male to female. Anemonefish live in monogamous pairs composed of a large female and a smaller, functional male. The pair may share their anemone-home with other, small, stunted (not sexually developed) males (juveniles; all anemonefish are born male). When the female is removed, the functional male changes sex and the largest juvenile becomes a functional male. Snook (Centropomus undecimalis) are one of the few known Caribbean protandrous fish.

Some reef fish, like gobies, can actively change sex in either direction. This lets them maximize their genetic fitness under any environmental situation.

There are many amazing things in the natural world. We'd do well to study them, be amazed by them, and learn from them. Our lesson from these fish? Embrace change, especially when it benefits us!

For More Info on Sex Changing Fish:

DeLoach, Ned and Paul Humann (1999). Reef Fish Behavior: Florida, Caribbean, Bahamas. New World Publications, Inc. Jacksonville, FL. 359 pp.

Hendrickson, Robert (1984). The Ocean Almanac. Doubleday. New York, NY. 446 pp.

The National Audobon Society (1997). Field Guide to Tropical Marine Fishes: Caribbean, Gulf of Mexico, Florida, Bahamas, Bermuda. Alfred A. Knopf, Inc. New York, NY. 720 pp.

 

Rice, Aaron N. (undated). Physiology of Sex-Change in Reef Fish. Available at: http://www.bio.davidson.edu/Courses/anphys/1999/Rice/Rice.htm

 

A Herd of Turtles?

Most people are familiar with the nouns used to refer to collective groups of common terrestrial animals and birds: herd of cows, flock of birds, congress of baboons, litters of cats/kittens/puppies, to name a few. Everyone has also heard of schools of fish.

Here are a few more collective nouns to describe other marine and aquatic  animals (and no, it isn't a herd of turtles!):

A bale of turtles
A bed of clams or oysters
A gam, herd, school, or pod of whales
A herd or pod of seals (also a bob, colony, crash, harem, rookery, or spring of seals!)
A hover of trout
A knot of toads

A herd or pod of walruses
A pod or school of porpoises
A siege or shoal of herring
A shoal of bass (or of most fish species)
A smack of jellyfish

A pack of polar bears (sounds like the start of a tongue-twister, doesn't it?)
A seige or sedge of bitterns
A flight of cormorants
A glint of goldfish
A colony of gulls
A hedge, sedge, or seige of herons
A romp of otters (ottes also come in bevies, families, or rafts, but I like romp!)

A colony, cr`eche, huddle, parcel, or rookery of penguins
A congregation or wing of plovers
A run, school, or shoal of salmon
A shiver of shark

Mystery of the Fish Eye

If you're on Facebook you probably saw the picture of the giant bloody eyeball that washed up on a Florida beach a few weeks ago. Speculation on the source of the softball-sized eye ranged from the reasonable (giant squid or whale) to the unlikely (Big Foot).

Photo by Carli Segelson, Florida Fish and
Wildlife Conservation Commission

Based on the eye's color, size and structure, along with the presence of bone around it, scientists concluded the eye came from a swordfish. They also observed straight cuts around the perimeter, suggesting the eye had not been ripped out in some deepsea wrestling match but removed with a knife. Most likely, the eye was cut out and discarded by a fisherman. Was it a fisherman with a keen sense of humor who thought "won't this freak someone out?" as he tossed it overboard? We may never know.

Giant squid attacking a bait squid.
Photo from National Geographic.

Most people don't realize how big a swordfish or marlin eye can be because most of it is inside the head. As impressive as the eye's size is, it pales in comparison to the giant squid's dinnerplate-sized eye that comes in at 3 times the diameter of the swordfish orb. Scientists speculate the larger eye allows the squid to detect the shimmer of bioluminescent organisms in the dark of the ocean deep. The glitter of light could indicate the approach of the squid's only predator, the sperm whale.

Fish eyes, for the most part, work similar to our eyes. They have rods and cones, and light enters through a cornea and passing through the pupil to reach the lens. Most fish have a fixed pupil size, but cephalopods, like the giant squid, have a pupil that adjusts size and shape: it's w-shaped when contracted and round when fully dilated. There isn't much difference in refractive index between the water and the cornea--light passes in a straight line, no bending as it does when passing through air into our liquid-filled eyes. Human eyes are adapted to accomodate the differences in refraction between air and water and so are more concave than most fish eyes. That's why we need to wear a mask to see underwater, but fish don't.

Four-eyed fish, http://aha.miraclegreat.com/

 The four-eyed fish might just be the winner for the most unusual eyeballs in the aquatic world. These fish feed on terrestrial insects at the surface so they need to see underwater, where they live and in the air, where they feed. Their two eyes (yes, 4-eyes is a misnomer) are raised above the top of the head and divided in two different parts, allowing them to see below and above the water surface at the same time. The fish floats at the water surface with only the lower half of each eye underwater. The two halves are divided by a band of tissue and the eye has two pupils connected by part of the iris. The upper half of the eye is adapted for vision in air, the lower half for vision in water The lens of the eye also changes in thickness top to bottom to account for the different refractive indices of air versus water. The two pupils allow the 4-eyed fish to search for the food above the water while keeping an eye out for predators below the water at the same time. It also makes them really difficult to catch!

56' of Sea Serpent

What's the longest fish on record? The oarfish, Regalecus is the longest bony fish in the oceans today, holding the record of 17 meters (56') in length. Seems like something that big would have a hard time hiding, so why have most people never heard of or seen something that large?

Some sailors in the US Navy pose with a dead oarfish (1996; from Wikipedia)

Oarfish live at depths up to 3,280 feet (1,000 m), although they're more typically found at around 656 feet (200 m). They rarely venture to the surface unless they're injured or dying. Occasionally, one of these giant eely fish will be tossed onto a beach after a storm. Their eggs can be seen during spawning season from July to December in the northern hemisphere. They release the brightly coloured, buoyant eggs (up to 6 millimetres (0.24 in) across) which are incorporated into the zooplankton. The eggs hatch after about three weeks into highly active larvae that feed on other zooplankton.

Drawing of the sea serpent-like oarfish

With their long, tapering body, smooth silvery skin (they don't have scales), and red dorsal fin that runs from the eye down the entire length of the body, oarfish are the most likely source of tales of sea serpents. Their dorsal fin is composed of 400 rays, the first 10-12 of which are elongated and flow from the head like a mane. Their pelvic fins are also elongated and end in a fleshy tab. It was once believed they rowed themselves through the water with these pelvic fins, thus the name oarfish. They actually swim by undulating their long dorsal fin while keeping the body straight (as do sea horses). Similar to sea horses, oarfish have been observed swimming in a vertical position in what is believed to be a method used to search for prey.

 

A dead oarfish washed up on a beach in Perth, Australia

Oarfish are found in temperate to tropic seas, but as mentioned, they're rarely seen because of their preferred depth. In fact, the first time a swimming oarfish was caught on video was in 2001! You can see parts of that on this You-Tube video.

Oarfish have no teeth and feed on plankton, so they're no threat to humans, and humans are no threat to them since their mushy flesh isn't very tasty. Still, I might think twice about jumping into the water with a 56' long fish!!
 

Oarfish. Image from Wikipedia.

 

 

For more information on the oarfish, see:

 

Hendrickson, R. (1984). The Ocean Almanac. Doubleday, NY. 446 pp.

http://www.itsnature.org/sea/fish/oarfish/

http://www.seasky.org/deep-sea/oarfish.html

http://en.wikipedia.org/wiki/Oarfish

 

THE WONDERFUL WORLD OF SEA JELLIES!

I love sea jellies (commonly referred to as jellyfish, although they aren't fish at all.) My infatuation with these graceful, mesmerizing invertebrates started when I saw what looked like a cross between a flower and an anemone on the sandy bottom of Brewer's Bay in St. Thomas. I'd recently transferred to the College of the Virgin Islands and was snorkeling around the school's dock. The flower was beautiful with its green-gold petals undulating with the slight surge. I had to get a closer look! (Casseopia photo courtesy of Shyzaboy's Flickr photostream.)


As I was about to touch a petal, a hand grabbed my wrist. My ecology professor was snorkeling nearby and saw what I was about to do. He pulled me to the surface and said, "That's not a plant, it's a jellyfish."

Now I was even more fascinated so found out everything I could about Cassiopea xamachana, the "upside-down jellyfish." Three years later, I did my senior research project and independent study on Cassiopea, and have never lost my fascination with jellies.

Maybe my affinity for these creatures comes from our many shared traits: elegance, grace, soft and pliable, yet able to defend ourselves with nasty barbs.

OK, we only share one out of those five traits. I'll let you guess which. Whatever the reason for my interest in these floating sacs of jelly, I'm drawn to them and endlessly curious about the incredible variety found within the phylum Cnidaria-from the Greek word for nettle, as in the stinging plant.

The Cnidarians are broken into three classes: scyphozoans (true jellies), anthozoans (corals and anemones), and hydrozoans (colonial hydras and the Portuguese Man-of-war, not a true jelly.) While corals, anemones, and hydras are all very cool, it's the scyphozoans that really captured my heart and mind. Here are the three that I find most interesting.

Cassiopea xamachana, the upside-down mangrove jelly. My first jelly. The species name xamachana means Jamaican, so you're right to guess this is a predominantly Caribbean species. Not to cast aspersions on Jamaicans or other islanders, but these jellies have some island attitude. "It's hot down in the Caribbean mehson, we ain' wastin' energy doin' all that movin' aroung!" Instead of swimming upright, bell-up, tentacles-down in traditional jelly fashion, these guys find a comfy spot on the sandy or muddy bottom of calm lagoons or bays and kick back, upside down.

They've not only found a lazy-man approach to swimming (that is, they rarely do), but to eating, too. Inside the mesoglea (jelly) of Cassiopea live thousands of zooxanthellae: tiny, single-celled algae (dinoflagellates). They're what give Cassiopea their green-gold color. These little guys do what all plants do--they photosynthesize, creating sugar (food) from sunlight and carbon dioxide, and release oxygen in the process. This jelly-mon gets part of its food and oxygen from them.

The algae don't provide all of the food the jellies need, so they do still have to eat some. Like other jellies, Cassiopea capture unsuspecting prey that swims into their waving tentacles and lappets by paralyzing them with stinging cells (nematocysts). They then move the food to their mouths. That's right. Mouths. Cassiopea don't have a single mouth in the middle of a ring of oral arms like the rest of the jellies, but instead have mouths at the ends of each branch of their manubrium (the fancy jellyfish word for stomach)!

Is it any wonder I became so intrigued with these guys?

The object of my next jelly-infatuation is a hefty, Mediterranean species.

Cotylorhiza tuberculata, the fried-egg jelly. I first saw fried-egg jellies while sailing in the Aegean. They're one of the most common species of jelly in the Mediterranean, Agean and Adriatic. Their bell has a flattened region along the margin and a yellow-orange dome in the center giving it the appearance of a large fried egg when viewed from above. Like Cassiopea, this jelly hosts symbiotic zooxanthellae, but instead of having them throughout their bodies, they house them in round appendages between and around their oral arms. The purple-blue zooxanthellae filled balls give Cotylorhiza a festive, dressed-to-party look.

Like all jellies, Cotylorhiza have nematocysts and do sting. Reports vary on its intensity and impact on humans, ranging from "very mild" to "not dangerous." There are many reports (and pictures) of people handling them, including one of a researcher putting one on his head like a hat to demonstrate how little danger they pose. Since venom strength can vary from one animal to the next, and sensitivity can vary from person to person, I wouldn't recommend this, but I'd also be the first one to jump in and touch one.

What's really fascinating about the fried-egg jellies is that they are active swimmers. While most jellies can control over their movement through the contraction of the bell, they aren't strong swimmers and the currents and wind do most of the work. When aggregations of jellyfish "swarm" in a harbor, it's usually less because they wanted to stop there and more because the current or wind put them there. Fried egg jellies, though, actively move back and forth across harbors to be in the sunlight, probably to keep their zooxanthellae happy and productive.

Click HERE to see a great you-tube video of the fried-egg jelly swimming.

My final favorite jelly is Cyanea capillata, the lion's mane jelly. This jelly isn't one of my favorites because of its physiology, behavior, or appearance, but out of empathy. People judge it harshly based on a widely circulated picture that uses perspective to make it appear to be something it isn't. Haven't we all been judged quickly or falsely based on appearance?

I like to say that perception is NOT reality unless it's correct, and MISperception is just plain wrong. In the case of Cyanea, the misperception is about its size. Yes, the lion's mane jelly is the largest sea jelly in the world, but based on the image shown here--one that periodically makes its way around the Internet--this thing is a MONSTER! Even if that man next to it is 6' tall, the jelly is still more than twice his length. That would make this behemoth a whopping 15' across.

The truth is, even though the lion's mane jelly is the largest scyphozoan in the world's oceans, it only grows to about 6.5 feet (or 8' by some reports). Its tentacles can extend as far as 50 feet (or 100', depending on the source). Yes, its tentacles sting. But the toxin is far from "the most potent species of jellyfish" as reported on the National Geographic website. That honor remains with the box jelly (aka cubomedusa or sea wasp), the most venomous animal in the world. More than 5500 deaths have been attributed to box jellies since people started keeping records of that sort of thing in 1884. Cyanea's sting is said to be painful, but it's rarely fatal.

The lion's mane jelly only reaches the maximum of its size range in cold, northern waters of the Arctic, northern boreal seas, and North Atlantic. In the Atlantic, it can be found as far south as Florida. It's abundant enough in South Carolina waters that the SCDNR has a listing for them on their "Marine Organisms of SC" website, where they're noted as considerably smaller than 6-8' in diameter, and having a far from potent sting:

"The bell, measuring 6-8 inches (emphasis added), is saucer-shaped with reddish-brown oral arms and eight clusters of tentacles hanging underneath. Cyanea are generally considered moderate stingers. Symptoms are similar to those of the moon jelly but, usually more intense. Pain is relatively mild and often described as burning rather than stinging."

At least this jellies' notoriety resulted in some small bit of fame for the maligned creatures. A Cyanea sea jelly was the murder weapon in the Sherlock Holmes mystery "The Adventure of the Lion's Mane." The victim must have been highly sensitive, though, since most swimmers who encounter this giant jelly survive to tell the story themselves.

To read more about these fascinating creatures, take a look at these resources:

The Cephalopod Page http://www.thecephalopodpage.org/MarineInvertebrateZoology/Cassiopeaxamachana.html

Gowell, E. (2004). Amazing Jellies: Jewels of the Sea. A New England Aquarium Book. Bunker Hill Publishing, Piermont, NH. 48 pp.

Humann, Paul (1992). Reef Creature Identification: Florida Caribbean Bahamas. New World Publications, Inc., Jacksonville, FL. 320 pp.

Malawi Cichlids http://www.malawicichlidhomepage.com/other/cotylorhiza_tuberculata.html

SCDNR http://www.dnr.sc.gov/marine/pub/seascience/jellyfi.html

Walla Walla University, Rosario Beach Marine Laboratory web site http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Cnidaria/Class-Scyphozoa/Order-Semaeostomeae/Family-Cyaneidae/Cyanea_capillata.html

Photos from:
National Geographic at http://ocean.nationalgeographic.com/ocean/photos/colossal-sea-creatures/

NOAA

Shyzaboy's photostream on Flickr at: http://www.flickr.com/photos/shyzaboy/2628679420/

SCDNR at http://www.dnr.sc.gov/marine/pub/seascience/jellyfi.html