| The Top Ten Cnidarians |
Jellyfish, corals and anemones are already pretty damn weird, so what happens when mother nature goes
off the deep end and decides they still aren't weird enough? As brainless, tentacled blobs of slime go, these
guys are the most unusual; the brainlessest, tentacledest, blobbiest blobs in the sea!
off the deep end and decides they still aren't weird enough? As brainless, tentacled blobs of slime go, these
guys are the most unusual; the brainlessest, tentacledest, blobbiest blobs in the sea!
| #10 - Actinoscyphia - The Fly Trap Anemone |
Meals can be few and far between in the deep sea abyss, and this unique anemone doesn't take any
chances. Its sticky, stinging tentacles line a folded maw like the leaves of its namesake, snapping shut over
victims who could have struggled free from a more conventional anemone. If this sounds familiar, you may
have previously read about the deep ocean's carnivorous tunicates. If attacked, the fly-trap anemone
releases a bioluminescent slime into the water, which may serve to attract the attention of even bigger
predators - the anemone's enemy's enemies.
chances. Its sticky, stinging tentacles line a folded maw like the leaves of its namesake, snapping shut over
victims who could have struggled free from a more conventional anemone. If this sounds familiar, you may
have previously read about the deep ocean's carnivorous tunicates. If attacked, the fly-trap anemone
releases a bioluminescent slime into the water, which may serve to attract the attention of even bigger
predators - the anemone's enemy's enemies.
| #9 - Stauromedusae - The Stalked Jellies |
Tiny jellyfish that abandoned swimming, the Stauromedusae have an adhesive stalk growing from the center
of the bell, which they use to attach "head"-first to solid surfaces and pretend to be anemones, trapping
whatever drifts by. If they need to move, they may roll or "somersault" in a darling inchworm-like manner or
release their stalk and ride the current. Many species prefer to attach themselves to particular seaweeds,
colored to blend in with marine foliage.
of the bell, which they use to attach "head"-first to solid surfaces and pretend to be anemones, trapping
whatever drifts by. If they need to move, they may roll or "somersault" in a darling inchworm-like manner or
release their stalk and ride the current. Many species prefer to attach themselves to particular seaweeds,
colored to blend in with marine foliage.
| #8 - Stygiomedusa gigantea |
Rarely seen by man, very little is known about this deep-sea titan. Lacking the fringe tentacles of normal
jellyfish, it instead has abnormally large, sheet-like oral arms over twenty feet in length, billowing from a bell
more then a meter across. Though harmless to man, there is something incredibly intimidating about such a
huge, dark and unusual jelly drifting through the lightless deep. Celebrated horror writer H.P. Lovecraft
suffered a phobia of marine invertebrates quite evident in his works, and were he alive to see photos like
these, I could only imagine the effects on his already-fragile sanity.
jellyfish, it instead has abnormally large, sheet-like oral arms over twenty feet in length, billowing from a bell
more then a meter across. Though harmless to man, there is something incredibly intimidating about such a
huge, dark and unusual jelly drifting through the lightless deep. Celebrated horror writer H.P. Lovecraft
suffered a phobia of marine invertebrates quite evident in his works, and were he alive to see photos like
these, I could only imagine the effects on his already-fragile sanity.
| #7 - Deepstaria enigmatica |
Another deep-sea spook with no tentacles, the mysterious Deepstaria simply swallows up prey in its
enormous, sheet-like bell, which may take a recognizable jellyfish-like shape or warp into a nondescript glob
in the water's current. Strangely, every single member of this species ever observed has been home to a
single Anuropus, an isopod crustacean. Whether the two animals benefit one another is not known, though
the isopod seems to feed on Deepstaria's tissues.
enormous, sheet-like bell, which may take a recognizable jellyfish-like shape or warp into a nondescript glob
in the water's current. Strangely, every single member of this species ever observed has been home to a
single Anuropus, an isopod crustacean. Whether the two animals benefit one another is not known, though
the isopod seems to feed on Deepstaria's tissues.
| Image credits: MBARI |
| #6 - Cassiopeia - The Upside-down Jellies |
Many species of jellyfish feed entirely via the photosynthesis of symbiotic algae cultivated in their own
tissues, sustaining themselves off no more than sunlight. Of all these solar-powered jellies, the Cassiopeia
seem to take it the farthest, spending most of their lives lying upside-down on the sea bed, still constantly
pumping their bell to avoid floating away - imagine someone who walks face-first into a wall and just keeps
walking without going anywhere. This ridiculous behavior not only gives the jelly's algae garden maximum sun
exposure, but makes it more difficult for predators to sneak around the stinging tentacles and attack the main
body. Upside-down jellies often congregate in large numbers, forming group "gardens" to protect one
another.
tissues, sustaining themselves off no more than sunlight. Of all these solar-powered jellies, the Cassiopeia
seem to take it the farthest, spending most of their lives lying upside-down on the sea bed, still constantly
pumping their bell to avoid floating away - imagine someone who walks face-first into a wall and just keeps
walking without going anywhere. This ridiculous behavior not only gives the jelly's algae garden maximum sun
exposure, but makes it more difficult for predators to sneak around the stinging tentacles and attack the main
body. Upside-down jellies often congregate in large numbers, forming group "gardens" to protect one
another.
| #5 - Turritopsis nutricula - the Highlander of jellyfish |
Less than half an inch in length with a fairly conventional anatomy, this tiny Hydroid (not truly a "jellyfish" as
most sources call it) boasts a fantastic gift unheard of in most of the animal kingdom: biological immortality.
While it can certainly be killed like an ordinary Cnidarian, it does not have to age and die like one, but can
simply revert back to its immature polyp stage and begin life all over again. This commonly used photo
actually portrays a different, but identical-looking species in the same family. It is not currently known if this
species - or any other species - share nutricula's special trick.
most sources call it) boasts a fantastic gift unheard of in most of the animal kingdom: biological immortality.
While it can certainly be killed like an ordinary Cnidarian, it does not have to age and die like one, but can
simply revert back to its immature polyp stage and begin life all over again. This commonly used photo
actually portrays a different, but identical-looking species in the same family. It is not currently known if this
species - or any other species - share nutricula's special trick.
| #4 - Edwardsiella lineata |
One of the only truly parasitic Cnidaria, these anemones spend their larval stage buried in the body of a
Ctenophore or "comb jelly" (not related to the Cnidaria), stealing food straight from the host's gut. After
leaving their host, they may seek out another or mature into more typical, carnivorous anemones.
Ctenophore or "comb jelly" (not related to the Cnidaria), stealing food straight from the host's gut. After
leaving their host, they may seek out another or mature into more typical, carnivorous anemones.
| #3 - Anthopleura elegantissima - the anemone military |
| #2 - Epizoanthus paguricola |
As the tide rises, the colony sends small "scouts" to expand its borders, protected by larger "warrior"
anemones who stretch out their bodies and inflate their stinging tentacles. Special tentacles called
"acrorhagi" are used exclusively to attack other anemones, and leave behind stinging "peels" which necrotize
anemone tissue. As the colony spreads out, their numbers are filled back in by specialized reproducers, who
stay put and replicate while the warriors are keeping them safe.
Despite their aggressive ways, these anemonazis are another Cnidarian fed by little more than symbiotic
algae, using their stingers primarily for their epic territorial disputes.
anemones who stretch out their bodies and inflate their stinging tentacles. Special tentacles called
"acrorhagi" are used exclusively to attack other anemones, and leave behind stinging "peels" which necrotize
anemone tissue. As the colony spreads out, their numbers are filled back in by specialized reproducers, who
stay put and replicate while the warriors are keeping them safe.
Despite their aggressive ways, these anemonazis are another Cnidarian fed by little more than symbiotic
algae, using their stingers primarily for their epic territorial disputes.
Faced with the problem of where to actually grow in the sludge of the deep-sea floor, this abyssal Anthozoan
(neither anemone nor coral, but what is known as a Zoanthid) devotes its swimming larval stage to tracking
down a snail shell and rapidly overtaking it. Its goal is not to ride the back of a snail, but to eventually be
carried by a hermit crab, which gains even better protection from the stinging tentacles than it ever would
from an ordinary snail shell.
(neither anemone nor coral, but what is known as a Zoanthid) devotes its swimming larval stage to tracking
down a snail shell and rapidly overtaking it. Its goal is not to ride the back of a snail, but to eventually be
carried by a hermit crab, which gains even better protection from the stinging tentacles than it ever would
from an ordinary snail shell.
Many creatures of the sea - especially the dark abyss - employ
"aggressive mimicry," meaning that parts of their bodies function as
tasty-looking lures to attract prey. Viperfish, gulper eels, cephalopods
and the famous anglerfish are all examples of aggressive mimics, but no
cnidarian had ever been observed "fishing" in this manner until the
discovery of Erenna in 2003.
This worm-shaped siphonophore is guided by a chain of swimming
polyps (left in the above photo) with rows of feeding, reproductive and
stinging polyps trailing behind. Its stinging appendages end in luminous
red organs which closely resemble tiny copepod crustaceans, even
twitching in the water as though "swimming." After Erenna's discovery, it
became apparent that many other deep-sea siphonophores may also
employ lures to attract hungry fish - tactics we never expected from these
brainless invertebrates.
"aggressive mimicry," meaning that parts of their bodies function as
tasty-looking lures to attract prey. Viperfish, gulper eels, cephalopods
and the famous anglerfish are all examples of aggressive mimics, but no
cnidarian had ever been observed "fishing" in this manner until the
discovery of Erenna in 2003.
This worm-shaped siphonophore is guided by a chain of swimming
polyps (left in the above photo) with rows of feeding, reproductive and
stinging polyps trailing behind. Its stinging appendages end in luminous
red organs which closely resemble tiny copepod crustaceans, even
twitching in the water as though "swimming." After Erenna's discovery, it
became apparent that many other deep-sea siphonophores may also
employ lures to attract hungry fish - tactics we never expected from these
brainless invertebrates.
| Image credit: MBARI |
Another large jelly, Tiburonia Granrojo or "big red," was long mistaken for juvenile gigantea until its
recognition as a distinct species in the 2000's. It, too, has only oral arms, without stinging tentacles, and
grows three feet across.
recognition as a distinct species in the 2000's. It, too, has only oral arms, without stinging tentacles, and
grows three feet across.
| #1 - Erenna - the gelatinous fisherman |
| Photos by Steven Haddock |
| an unidentified deep-sea jellyfish |
| written by Jonathan Wojcik |
This "aggregating" anemone may appear fairly typical on the outside, but engages in some of the most
complex and violent behavior of all anemonekind. Constantly cloning itself, it builds a massive colony of
genetically identical anemones who show extreme hostility towards any genetically dissimilar anemone,
resulting in brutal turf wars between rival clone-armies. Why, you could almost call them clone wars.
complex and violent behavior of all anemonekind. Constantly cloning itself, it builds a massive colony of
genetically identical anemones who show extreme hostility towards any genetically dissimilar anemone,
resulting in brutal turf wars between rival clone-armies. Why, you could almost call them clone wars.