By Floor Anthoni (2006)
www.seafriends.org.nz/images/jelly.htm
The transparent jellyfish of our oceans are a photographer's delight,
like the translucent dress of a bride in summer. But capturing these veils
of grace in their most wondrous appearance is not easy, as it depends on
circumstance. For best results one needs a sunny day with a blue sky, and
tranquil clear water. Such moments are not of our choosing, as jellyfish
prefer more turbid waters which are richer in food. Jellyfish are also
easily damaged by entanglement with plants and rocks, and they are a chosen
target for many kinds of fish who eat their gonads out.
Jellyfish are found in all oceans as they are free to roam between
these. But even though there are few species in the world's oceans, they
are difficult to identify. Some jellyfish are but the flowering stage of
a sessile organism like a hydroid but fortunately, most of these are rather
small. For the larger jellyfish, their flowering or reproductive phase
is very small, like a hydroid, and often attached to the undersides of
overhanging rock walls.
Jellyfish belong to the flower animals that have stinging cells. For
a diver they can become a mine field, as these stinging cells are located
on long fishing lines that can extend over several metres. Photographing
a stinging variety often ends up in being stung, the price of a daring
shot.
f012430: the moon jelly or earlobe jelly is one of the most
common and widely spread jellyfish. It does not sting as it does not 'fish'
for food with long stingy lines. Instead its short tentacles act like brooms,
brushing food onto its many mouths in its skirts. Aurelia sp.
f012434: jellyfish seek out the shallows below the wave-torn
zone, where zoo plankton abounds. But this creates problems for the photographer.
The earlobes contain the animal's eggs, a target for fish. Aurelia sp.
Beautiful light on Aequorea
f026811: from the centre of an Aequorea jellyfish
hangs a flower-like mouth on a stalk. This jellyfish does not have trailing
lines but mops food particles onto its mouth, with each contraction of
the bell.
f026809: beautiful sun rays and rippled water. Jellyfish
somehow know how deep they are, perhaps due to the wave movement. In the
case of ruffled water,t hey stay deeper down. Aequorea sp.
f026810: unidentified jellyfish swimming towards the sun.
Aequorea
sp.
f029609: A small jellyfish with a simple bell underneath
which hangs a translucid bag with the mouth parts. It has withdrawn its
tentacles. (Aequoria victoria?)
f045335: Aequorea shown with its tentacles extended.
Chrysaora reflections
f035436: the sea nettle (Chrysaora sp.? ) is one of
the most beautiful of jellyfish as it has colour, long skirts and very
long fishing lines. In this photo the clouds are visible, low in the blue
sky, which created a pleasant effect.
f035433: sea nettle and its reflection in oily calm water.
Somehow these animals can see, because this one was constantly attracted
to the photographer. For an unruffled surface, one needs to hold one's
breath for a long time.
f035419: a sea nettle swimming gracefully upward.
f035427: sea nettle and its surface reflection.
f029605: the mildly stinging plagusia jellyfish (Plagusia
noctiluca) has a pink body and spots on its bell. Four graceful skirts
contain its many feeding mouths. Long tentacles
f029503: a mine field of young plagusia jellyfish nearly
always results in a few stings.
f029525: once jellyfish die, some float up towards the surface
where they may be swept into a tranquil corner of the shore.
f045228: a thick raft of dying and dead jellyfish. It is
surprising how fast such a mess disappears, either by the breaking force
of waves or by decomposing bacteria.
f003724: the lion mane jelly (Cyanea capillata) can
grow very large, larger than a car tyre. The dark patch underneath contain
its millions of eggs, portend of a jellyfish plague.
f033522: jellyfish reproduce through an intermediate polyp
stage, seen here attached to the rock. A patch of only a few hands wide
can give birth to tens of thousands of new jellyfish and a plague is born.
See indepth/jellyfish.htm
IMG_0147: massive lion mane jellies washed up on a beach
near Auckland.
IMG0141: Most of what you see is egg mass, millions of
eggs.
f047012: jellyfish need zooplankton, lots of it. So it was
rather surprising to find this crested jelly (Cephea cephea) swimming
in water of over 40m visibility near Niue. But these animals have plant
cells on board, enabling them to live from sun light.
f047009: a crested jellyfish in a gin-clear sea around Niue
Island. Unfortunately the day was heavily overcast.
Salps and comb jellies
f038705: this x-wing sea gooseberry is not like the others
as it can unfold four delicate wings and two long whips with which it propels
itself (Mnemiopsis sp.?)
f038635: delicate four-winged sea gooseberry.
f046117: surface reflection of a sea gooseberry. For a photo
like this one needs a calm surface and a small strobe placed forward of
the camera.
f046106: a large gooseberry like this 10cm zeppelin, propels
itself with whipping hairs along its eight ribs, here seen as bright lines.
These jellyfish are predators, hunting for surprisingly large prey. They
are very agile and move with purpose even though they cannot see.
f046112: reflection of a sea gooseberry at the moment it
touched the surface.
f038701: a baby giant salp has an outlet opening on one side
(on right) and many openings all over. Consisting of many filtering animals
that pump water from the outside in, it propels itself like a rocket, but
more slowly. These salps can grow to a length of 7m with a 60cm opening.
Their skins feel hard and spiky but they can't sting.
f048430: a sea gooseberry catching zooplankton at night.
It can open a fairly large 'mouth' or catch bag to catch large zooplankton
animals with.
f028007: some seasquirt families are not attached to a rock
but rather to one another, forming rafts that are propelled by their exhaust
water flow. In this variety, the fragile squirts are arranged in interconnecting
rosettes, their orange gonads in the centres.
