Lion’s Mane Jellyfish

Lion’s Mane Jellyfish

Author: Jamie Lenihan

Common name: Lion’s Mane Jellyfish

Scientific Name: Cyanea capillata


Identifying Features:

The Lion’s Mane jellyfish is one of the most easily identifiable varieties of jellyfish. At first glance, you can often recognize one of these jellies by their very large bell size and tentacle length, reaching up to 3 metres in diameter and 130 metres respectively. Depending on their environment, these jellies will grow to different scales: those found in lower latitudes will tend to be smaller, usually only up to a 50cm bell diameter and less than 5 metre tentacle span, while those in Alaska and arctic waters will far more frequently grow to monstrous sizes. A key feature of the Lion’s Mane Jellyfish is the thick red ‘mane’ of tentacles extending from the bell of the creature. These sticky tentacles extend from the centre of the bell, separate from the dull and silver arms that attach to the outer bell. The bell itself is divided into eight distinct regions in a similar fashion to a peeled orange. The jellyfish travels through bell pulsations that propel it forward. The greatest factor in their movement is, however, the ocean current and tides.

Habitat:

The Lion’s Mane habitat ranges all the way from the 50°N latitude in the Pacific and Atlantic Oceans upwards to the Arctic Ocean and surrounding cold waters. These jellyfish prefer to live near the surface of the ocean and rarely travel past 15 metres deep. During most of their lives, the jellyfish will live in the open ocean; it is here that the jelly shares a symbiotic relationship with many other creatures. The jelly gives protection to the smaller organisms as well as providing some of its leftover food. Near the end of its life, the Lion’s Mane Jellyfish drifts towards more sheltered bays and inlets (see the photo below of the beached Lion’s Mane). This is usually a result of their larger size being more naturally affected by current, and not solely by choice.  Even when it is washed up on shore the Lion’s Mane can still have active cnidocytes (stinging cells) and should not be handled.

Food and Predators:

Animals that feed on the Lion’s Mane Jellyfish include other jellyfish, large fish, seabirds, and sea turtles – in particular the Leatherback sea turtle. The Leatherback feeds almost entirely on this particular jelly during the summer, particularly in Eastern Canada. Very large Lion’s Mane Jellyfish, such as those in the far north, have very few predators due to their large size; they are seen as ‘not worth the effort’, as their plethora of stinging tentacles makes eating them a challenge. For their own diet, these jellyfish consume mostly very small creatures such as tiny fish, zooplankton, ctenophores, and moon jellyfish. This is done by catching the prey with its netted tentacles.

Life Cycle:

The life cycle of the Lion’s Mane Jellyfish, along with other jellies, is quite remarkable. These jellies have four stages of development over the course of their one year lifespan. The female jellyfish will ferry its fertilized eggs on its tentacles, where they develop into a larval form. Once old enough, the eggs are deposited onto a rock or hard surface. It is here where they develop into a polyp stage. It is through asexual reproduction that these polyps form ‘stacks’ of tiny creatures, known as ephyraes, that break off to later grow into the medusa stage – a full size Lion’s Mane Jellyfish.

Photos by Adam ‘Abcdave’ Davidson (abcdave.deviantart.com) and D. Young (Beached Lion’s Mane)

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Catablema Nodulosa

Scientific name: Catablema nodulosa

Author: Erin Henley

Size:  up to 20mm wide.

Identifying features: This species has a very distinct bell in the shape of a ball.


Catablema nodulosa is a relatively newly discovered jelly fish in the class Hydrozoa.  It is easily identified by its large round gelatinous bell on top. They have 8, 16, or 32 tentacles. C. nodulosa do not have any ocelli. Their stomachs are attached to the bottom of the bell and also have radial canals with frilly lips. The stomach colour can vary from golden-brown to salmon pink similar to the gonads.

C. nodulosa is usually found in Puget Sound and B.C. and north to the Aleutian Islands and the Bering Sea.  Though they reside in the upper 100 meters large numbers are quite common near the surface of the water in bays in the late spring.   This species is known to be a voracious predator for ctenophores (comb jellies) and hydromedusae. Hydroids of this species have never been identified.

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Fried Egg Jelly

Fried Egg Jellyfish

Author:  Rebecca Wilkinson

Common name: Fried Egg Jellyfish

Scientific name: Phacellophora Camtschatica


Identifying Features:  The Fried Egg Jellyfish gets its name from its appearance. Its bell, measuring up to 60cm (24 inches) across, is white or light yellow.  It has a yellow center circle (referred to as a gonadal mass), making it look like a fried egg against the whitish bell. Inside it’s bell there are 16 large lobes with smaller lobes inside containing 25 clusters of folded tentacles. The smaller ones are often colourless or an opaque white. The Fried Egg Jellyfish moves in slow pulses.

Habitat: P. Camtschatica can be found worldwide in temperate oceans. It alternates between benthic(lowest level of the ocean) and pelagic(region far from shore and ocean floor) stages depending on its reproductive cycle. Most people would be familiar with the medusa stage of the jellyfish when it’s swimming close to docks or the shore near the surface of the water. These jellies have been studied mostly at Monterey Bay Aquarium.

Food:  Fried Egg Jellyfish eat gelatinous zooplankton, smaller jellyfish and little crabs. Their tentacles can be 10 to 20 feet long.  They discharge their stingers in a harpoon like motion after being coiled in capsules filled with a “stinging” fluid.   The stinging apparatus is called a nematocyst and it is in a specialized cell called a cnidocyte. Smalls crabs often ride on the Fried Egg Jellyfishes bell and steal food from it.  According to Wrobel and Mills (2003) it only has a mild sting.

Predators:  The green turtle is one of the well-known predators of the Fried Egg Jellyfish, but unfortunately their numbers are declining, leaving more jellies.

Lifecycle:  The Fried Egg Jellyfish sexually reproduce in the medusa stage of life which is the stage that looks like a typical jellyfish.  After the eggs are released from females and sperm from the males, the resulting fertilized eggs turn into a larva that eventually settles onto docks or the ocean floor.  They develop into small polyps.  The polyps will begin dividing asexually and will end up looking like a stack of bottle caps. The top individual on the stack detaches, now being called an ephyra, to float away and continues to grow into an adult medusa.

Photo by D. Young

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Cross Jellyfish

Cross Jellyfish

Authors: Kelsey Baker and Danielle Boutcher

Common name: the Cross Jellyfish

Scientific name: Mitrocoma cellularia

Size range: to 90mm in diameter.


Identifying features

The Cross Jellyfish (Mitrocoma cellularia) may grow to 90mm in diameter.  They have up to 340 tentacles that are very thin and flexible and do not contain obvious rings or clusters of cnidocytes. They have a small stomach and from it extends a manubrium with four long frilly lips. They have a transparent bell with four white internal canals that make a distinct “X” shape which they are named after. A narrow bioluminescent band circles the edge of the body from which the hundreds of white tentacles originate and they can glow with a blue-green coloured light.   These jelly fish belong to the class Hydrozoa and contain a thin vellum on the inside of their bell that allows them to swim relatively fast.

Habitat

The Cross Jellyfish lives in coastal waters, near the shore of the Pacific Ocean from Alaska to central California. They may be found from 6m to 1600m deep. They prefer low light levels, a temperature range of 2 to15oC, and a salinity of 33ppt.

Food

Cross Jellyfish tend to eat zooplankton and it has been suggested that they may find their food by smell. They capture the plankton in their tentacles around the bell.  Smaller individuals have been observed in our classroom aquarium to then fold the bell over to place the food into their mouth.  Once the food is in the mouth they take the food into the manubrium and then into the four stomach pouches that radiate outwards – that is why the inside of the jellyfish might turn orange after they eat freshly hatched brine shrimp in captivity.  Interestingly they require wild food to be bioluminescent and will not glow in captivity when fed other food types.

Predators

The Cross Jellyfish avoids getting eaten by predators through camouflage since the transparency of the bell makes them a little invisible. They get eaten by other kinds of jellyfish, and are parasitized by larvae of peachia (a sea anemone) and also pelagic amphipods.

The Jellyfish Life Cycle

In general the jellyfish life cycle begins with males and females releasing sperm and eggs into the water. In the water the sperm fertilizes the eggs producing diploid zygotes. The zygotes grow into a ciliated larva. Then the larva swims around looking to attach to a hard surface and then develops into a polyp. The polyp, called a strobila, then reproduces asexually. The strobila looks like a stack of bottle caps and the new jellyfish called ephyra bud off the top of the pile to become free swimming individuals. These then grow into adult medusas.

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