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.


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.


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

Author:  Marissa Toner

Common name: Orange Sea Pen

Scientific name: Ptilosarcus gurneyi

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

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).

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.

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.

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

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.


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 ( and D. Young (Beached Lion’s Mane)

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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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