Moon Jellyfish

Moon Jellyfish

Author:  James Murray

Illustrations: by Moloud Mazaheri

Common name: Moon Jellyfish

Scientific name: Aurelia labiata

Size range: 25-40cm (9,8-15.8in)

Identifying Features: The Moon Jellyfish (Aurelia labiata) ranges from 25 to 40 cm (9.8 to 15.8 in) in diameter and can be easily recognized by the four horseshoe-shaped rings on its bell. A. labiata is not perfectly circular, but has multiple ridges around its bell between its rhopalia. It also has four oral arms leading up to its mouth and many short tentacles all around its bell. A. labiata may be confused with A. aurita, a closely related species found along the eastern Atlantic coast of Northern Europe and the western Atlantic coast of North America in New England and Eastern Canada.

Habitat: Moon jellyfish are found along the west coast of North America all the way from southern Alaska to southern California and as far out into the open ocean as Hawaii. Moon Jellyfish can be found up to 1000m (3280ft) below sea level in waters ranging from -6 to 31 degrees celsius; but often float near the surface, especially in bays and harbours. In the summer and through autumn, moon jelly fish are found in dense aggregations.

Food:  A. labiata feeds mainly on zooplankton such as mollusks, crustaceans, fish eggs, and other small jellies. The plankton is caught on the mucus lining the bell of the jelly and is moved by cilia to the bell margin. From here, tentacles help funnel the food into the manubrium and stomach pouches at the top center of the bell.  The food is then transported through a system of canals that can be seen in the video. When starved, the moon jellyfish can shrink dramatically in size while still retaining functionality.

Predators: The main predators of the Moon Jellyfish include the Rockfish, sea birds, turtles, and other cnidarians including the Lion’s Mane jellyfish (Cyanea capillata) and the Fried Egg jellyfish (Phacellophora camtschatica). The Moon jellyfish’s only hope to avoid predators is to sting them with the nematocysts on its tentacles, but these are only effective on small creatures.

Life Cycle: A. labiata  reproduce through internal fertilization. Males hold sperm filaments on their oral arms during mating season and these sperm are picked up by females. Sperm is carried to the females gastric pouch by cilliary currents. The female hold the fertilized eggs, which appear as grey clumps on the manubrium. The zygotes of A. labiata are brooded on the jelly’s manubrium in tear-drop shaped clumps. Eventually they are shaken off and continue their development after attaching to a substrate. Polyps usually strobilate in early spring, and the young medusa, called ephyra, mature very quickly. The adults spawn, and die by mid-summer or early fall; however, in certain places medusae are present all year.



Photography by Ali Isles

Illustrations by Moloud Mazaheri

Video by D. Young

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Brooding Anemone

Brooding Anemone

By Maeve Leduc

Common name: Brooding Anemone

Scientific name: Epiactis prolifera

Size range: up to 5cm diameter, does not often exceed 3cm height


Identifying Features: Brooding anemone are often brown to greenish brown, and more rarely almost green, blue, red, pink or purple. One may see baby anemone brooding off the base of a full grown adult which grow up to 5cm in diameter and 3cm tall. Oral disk often marked with radiating white lines, along with the pedal disk and column. On the anterior end, or top of the body you will find the mouth and stinging tentacles.

Habitat: One can find Brooding anemone in subtidal zones, rock benches, surge channels, near crustose coralline algae and other places where they won’t be carried away by disturbances in the sea. They may also be found on leaves of eelgrass which you will see in the picture, although to find red or pink Brooding anemone on eelgrass is rare. Most anemones will spend their whole lives in one place, but if desired they can hitch a ride on hermit or decorator crabs.

Food: Anemones on crabs is a great example of mutualism, while the anemone is protecting the crab and getting a free ride, they can also pick up bits and pieces of food from their messy eating habits. Otherwise, they mainly feed on crustaceans like shrimp and krill. They capture their prey with their stinging tentacles, paralyzing the creature with their thousands of stinging cells located in their stalk and tentacles. Then the Brooding anemone slowly moves the prey down to their mouth where they devour it whole.

Predators: Not many animals will try to feed on Brooding anemones because they attach themselves to their location with their suctioned tube feet and their tentacles and stalk are filled with thousands of stinging cells. But the nudibranches prevail, they’re not only immune to their stinging cells but they can actually take them for their own defense after digesting the anemone. To avoid being seen or easily attacked the anemone will contract at the tiniest threatening disturbance.

Life Cycle: Brooding anemones are hermaphroditic creatures. Their eggs are fertilized in the digestive cavity, and once hatched will swim down to the base of the parent and attach themselves there until they’re big enough to go off on their own and feed themselves.

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Pacific Sea Nettle

Common name: Pacific Sea Nettle

Authors: Stephanie Hurst & Chelsea Dinh

Scientific name: Chrysaora fuscescens

Size range: Between 10 to 15 feet in length.


Identifying features:

The Pacific Sea Nettle has a bell with a diameter of approximately 17.7 inches (45 cm), and arms which range between 12 to 15 feet (3.6 to 4.8 m) in length; this cnidarian has 24 flowing feather-like tentacles, and four oral arms. Regarding unique markings, the Sea Nettle’s bell’s overall color ranges between yellow to maroon, and may also have sporadic stripes strewn across the surface.

Habitat:

This Sea Nettle lives widespread across the Pacific Ocean, but can range from Alaska to the Philippines; lingering near the surface of the waters during the winter, and in the depths of the sea in the spring/summer. Occasionally the Sea nettle becomes a way of transportation for young cancer crabs, and larvae which adhere to the top of the Sea Nettle, hitching a ride to a more favorable spot.

Predators:

The main predators of the Pacific Sea Nettle are Sea Turtles and the Ocean Sunfish. To defend against a threat, minor or large, the Sea Nettle stings whatever comes in contact with its tentacles.

Life Cycle:

The Pacific Sea Nettle reproduces externally, where the eggs then hatch in the open waters of the ocean where they adhere to an area of the ocean floor. The “larvae” then develop in to a “polyp” through an asexual process, where miniature medusas form in to a plant-like structure; the medusas later bud off in to the open waters, where they continue to develop in to adult Sea Nettles.

Aquarium Photos and video by Stephanie Hurst and Chelsea Dinh

Wild Photos and video by D. Young

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Orange Sea Pen

Orange Sea Pen

Author:  Marissa Toner

Common name: Orange Sea Pen

Scientific name: Ptilosarcus gurneyi

Size range: up to 48cm (19 inches) tall


Habitat
Sea Pens are completely underwater animals so you won’t find them in any waters under 10 meters at least.  They prefer deep water and are usually found at depths that range from 45 to 225ft. They burrow their stalks into the mud or substrate on the sea floor, but for the first part of their life after fertilization they actually float in the water before planting themselves in the sea floor. Sea Pens can often be found in abundance in harbors, sheltered areas close to shore off in deeper waters but they are located all over the world! They can be found in the Pacific and Indian oceans, or in Europe and Mediterranean.

Life Cycle
Sea Pens are made up of colonies of polyps that are separate sexes. Some of the polyps are male and some are female. Fertilization takes place outside the Sea Pen.  The eggs and sperm are released and meet in the water. Once the egg is fertilized it will develop into a larva which will actually float in the water for a short time before rooting into the seafloor. They can grow very old; more than 100 years and the age can be indicated by growth rings (much like a tree).

Description
Sea Pens are given their name based on their shape: named after old style writing quills the Sea Pen lives up to its name. It is shaped very much like a feather. Its long and slender (made from the primary polyp) and has feather-like branches (made up from the secondary polyps). They stand upright and occur in a variety of colours but most are orange.

Feeding Habits
Sea Pens have limited ways to feed considering how they maneuver themselves into the sand and are permanently stuck there.  They feed through passive predation catching food such as zooplankton with the tentacles of their polyps.  As a result their main way to adsorb nutrition is through this form of suspension feeding.

Predators
The main predators of the sea star are nudibranch’s and sea stars. The types of nudibranch’s that attack the Sea Pen are Armina loveni, Tritonia festiva and Hermissenda crassicornis. The Armina Loveni are specialized for hunting the Sea Pen. Other Predators of the Sea Pen are prawn trawlers and dredgers, because as mentioned before they can be found in man-made harbors as well as along the ocean floor just where these prawn trawlers would be. To protect themselves they will burrow into the dirt or force water out of themselves.

Behavior
Sea pens have very limited ways of protecting and expressing themselves but they do have a few technique. First of all when threatened they can push water out and burrow into the sand to protect themselves. One odd thing they can do though is project a luminescent green liquid if they are disturbed!

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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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