Behind the scenes - part 1

Taking care of many different marine animals can be very challenging.  But the staff here at the Fundy Discovery Aquarium soon develops a routine. For the next few blog posts, I will discuss what goes on behind the scenes and what it takes to maintain aquarium creatures 365 days a year.

We typically have around 15 different species of fish on display and lots of invertebrates such as lobsters, crabs, snails, seastars, sea cucumbers and urchins, mussels, scallops, sea slugs, and anemones. Many of those invertebrates are filter feeders, which mean they filter the ocean water and keep plankton for food.  This is why we have seawater pumped right into the touchpool, in order to have a fresh supply of plankton. But most others need to eat either bits of meat or marine plants. The prickly sea urchins and the small periwinkles are the ones that require a fresh supply of seaweed, although few people know that lobsters need to get their “salad” every now and then.

For all others, we typically thaw a number of herring in order to cut them into chunks.  The lobsters and larger fish such as the halibut and sea ravens need whole fish or halves, but for everything else, we need to cut the fish into 1-inch thick morsels. The crabs in the touchpool eagerly grab a piece by the claws, and shred the meat using their mandibles near the mouth. Fish such as ocean pouts and sculpins swallow their food whole. Some species like cunners can tear pieces off a larger bit using very sharp teeth.

But so much more needs to be done. Stay tuned for the next post!

Coconut crabs

Last week, we have received two new species  of hermit crabs: the electric blue hermit crab (Calcinus elegans) and the Halloween hermit crab (Ciliopagurus strigatus). We are still looking for two more to complete the Hermit crab from around the world exhibit. Next to their tanks at the Fundy Discovery Aquarium, you will also notice a panel telling the story of the coconut crab (Birgus latro).  At a maximum of 9lbs (4 kg), and over 16 inches (40 cm) long, I find this species very fascinating, as it is the largest land arthropod, and some say the largest land invertebrate in the world! However, this hermit crab is especially interesting because of its life cycle: it does not always behave like a hermit crab.

After mating on land, females carry their eggs under their abdomen until the eggs are ready to hatch. She then moves into the shallow ocean water, usually at high tide, to release the eggs that will then hatch in the water. The microscopic larvae float around for 3 to 4 weeks, after which they settle at the bottom and find an empty snail shell to live in, just like any other hermit crabs. They live underwater, sometimes coming out on land, and eventually choose to live permanently on  land, where they find empty broken coconut shells as an alternative to snail shells. They lose their ability to breath underwater, and their abdomen hardens. When they become adults, they no longer need an extra shell for protection, and they live like any other land crab. Coconut crabs can live 40 or 60 years. Coconut crabs live in the Indian Ocean and the central Pacific Ocean, where coconut palms grow. When living on land, they dig burrows in sand or loose soil.

A couple of months ago, our coordinator, Jim Cornall, went to visit a public aquarium in Tennessee and they a coconut crab on display (see photo). They come in beautiful colors like blue or bright orange. Quite amazing!

New Hermit crabs at the Fundy Discovery Aquarium

Come and warm yourself in front of our tropical tanks this winter. We are excited to announce a brand new display at the Fundy Discovery Aquarium: tropical species of hermit crabs. We have chosen some marine species from around the world, and we have one land hermit crab that comes from the Caribbean.

Why tropical species? Well, it is well known that we have hermit crabs here in the Bay of Fundy,  but it is a treat to be able to compare them with other species. Do they have similar features? Do they live the same way? The display is right next to our touchpool, that houses the popular Acadian hermit crab (Pagurus acadianus), so you can see them all on one floor and discover the differences between them.

Let me introduce you to some of them. The first ones that we acquired were the land hermits. We had to set up a terrarium with a substrate of sand, small gravel and soil, with plenty of branches for them to climb on. The Caribbean Hermit crab (Coenobita clypeatus) is a nocturnal species, so we do not see a lot of movement during the day. Rather, I tend to see evidence of their behaviors when  I come in the morning; a shell has been moved to a different corner, tracks in the sand have changed, food has been nibbled at... These crabs come out when the heat is not as intensive, and  they enjoy a very high humidity level. They will feed on anything vegetable and animal, like greens, fruits, fish, and even tropical fish food.

Like all hermit crabs, they are constantly in search of new and better gastropod shells to live in, so even though the two hermits that we currently have came in with good sized shells, they immediately investigated the spare ones I had put in the terrarium. One of them adopted a new shell on the very first night last week. This morning, it looks like the two may have switched shells once again. Hence the importance of keeping a good supply of spare ones around their habitat.

It will be a challenge to care for the new species, but it will be a very good learning experience. This week, we are set to receive two more species, both marine, the electric blue hermit crab (Calcinus elegans) and the Halloween hermit crab (Ciliopagurus strigatus).

Creature Feature: Lined Seahorse

The Lined Seahorse (Hippocampus erectus), also known as the Northern Seahorse or Spotted Seahorse, is one of the larger species of its kind and is easily distinguishable by its colouring pattern of dark lines on a light background.  The seahorse is an interesting looking fish because of its resemblance to a knight on a chess board. From its horse-like head to its prehensile tail it does not resemble many peoples’ idea of what a fish looks like.  Rings of rectangular bony plates have replaced scales on the Lined seahorse and one of the most distinguishing features is the kangaroo-like pouch that the males of the species have.  They use this pouch during reproduction; the female seahorse will deposit from 250 to 650 eggs into this brood pouch where they will be fertilised and incubated until the babies are developed enough to swim freely on their own. Once they have matured to this point the male will make sharp movements bending back and forth to expel the young from the brood pouch. When they are born they are exact miniatures of adult seahorses at about a size of approximately 1.5cm.  The seahorse will reach its maximum length of 12.5cm in 8 to 10 months.  The Lined seahorse may live up to 4 or 5 years.

It is also important to note that seahorses are currently in danger of being wiped out due to their use in traditional Chinese medicine and their use as novelty items for personal aquariums and tourist products.  Here at the Huntsman Marine Science Centre, we hope to create a Lined Seahorse exhibit and to help offset the depletion of these interesting creatures; a breeding program as well.  To learn more about these creatures and how you can help please visit http://huntsmanmarine.ca/subcontents.php?id=16&sid=60 .

 

Adult Lined or Northern Seahorse.

 

 

Diagram of both the male and female Hippocampus erectus.

 

 

Newly hatched seahorses.

Creature Feature: Double Crested Cormorant

The Double Crested Cormorant (Phalacrocorax auritus), is a member of the cormorant family of seabirds and is a common visitor to the Bay of Fundy.  This cormorant is a larger bird and ranges in size from 70-90 cm long with all black plumage, except during mating season when it gains a double crest of black and white feathers.  It has a patch of yellow-orange skin near its bill, which is long and fairly narrow with a hooked end.  These fishing birds are commonly seen standing on docks, tree limbs or rocks with their wings out-stretched to dry.  They are a solid, heavy-boned bird built for diving in the water, in search of fish.  They fly in v-shaped patterns and can be found in many areas of North America.

 

 

Here a Double Crested Cormorant dries his wings after fishing.

 

 

 

Double Crested Cormorants are a solidly built bird that rides low in the water while swimming.

 

 

A close-up of the yellow-orange skin patch and hooked beak.

 

 

click here to hear the  Double Crested Cormorant Sound

Creature Feature: Fin Whale

Fin Whales (Balaenoptera physalus), also sometimes referred to as the Finback whale or common rorqual, is the second largest whale in the world, second only to the Blue whale. The Fin whale can weigh up to 80 tones and stretch up to 26 meters long.  It has a v-shaped head with asymmetrical colouring.  The left jaw is dark coloured, usually grey and the right side is white. The rest of the whale is usually white on the ventral side and dark coloured on the dorsal side. The Fin whale has a very stream-lined body with a tall dorsal fin rising at a shallow angle about two-thirds of the way along the back.  It is part of the rorqual family of whales and therefore has distinctive throat grooves.  These horizontally running grooves allow the whale to open its mouth very wide in order to take in large amounts of water which it then pushes back out through the numerous, large baleen plates hanging in its jaw, to filter out the plankton, krill and small schooling fish that make up its diet. 

The Fin whale lives in social groups of 2 to 7 individuals as well as being often seen feeding near other groups of whales such as the Humpback or Minke whales.  The only non human predator of the Fin whale is the Killer whale or Orca.  Female Fin whales are mature at around 7 to 12 years, while males mature slightly faster at 6 to 12 years. A female Fin whale will give birth to a live calf after 11 to 12 months gestation.  The calf is approximately 6 meters long and 2 tones when it is born.  Fin whales are believed to live as long as 90 years.  Another interesting fact is that in some rare cases Fin whales have been known to breed with Blue whales as a few hybrids, believed to be sterile, have been located.

 

Fin Whale surfacing.

 

 

Diagram of the Fin Whale. (courtesy of EnchantedLearning.com)

 

 

 

Pictures showing the way in which the rorqual grooves allow for expansion of the mouth.

Marine Moment - Dulse

Dulse (Palmaria palmate), also known as red dulse or sea lettuce, is from the red algae family. Dulse is made up of a thallus comprised of several separate leaflets or bunches of leaves attached to a short stipe or stem.  The leathery blades or leaves branch off to look almost like fingers. It can be many colors from a rose color to a deep red/purple.  You will find dulse attached to rocks, pebbles or even other seaweeds from the mid to low intertidal zone and up to depths of 3m.  Dulse is a very high source of potassium and is a popular snack food on the east coast.  While dulse can be consumed as soon as it is harvested, most often it is dried in the sun and sometimes powdered for use in other food products. 

One location where dulse is harvested is Grand Manan Island; where it is a large part of the local economy.  In order to harvest the dulse, people go out at low tide and snip the dulse from its stipe, leaving the holdfast, which is similar to a land plant’s roots.  They leave the holdfast intact so that the dulse may re-grow and continue to be harvested.  Grand Manan Island is said to have some of the most flavorful dulse in the world due to its environmental growing conditions. Yum!

One way to eat Dulse is fresh, as in a salad.

 

 

The most common way is to eat it sundried like a chip.

 

It is also used in flake or powder form in sauces.

Creature Feature: Purple Sun Star

The Purple Sun star (Solaster endeca), also known as the Northern Sun Star or Smooth Sun Star is one of the few sea stars to have more than 5 legs. It may have anywhere from 7 to 14 arms, which gives it its ‘sun’ like appearance.  The colour of this sun star ranges from pale yellow to purple and even red although the purple colour seems to be most common in this area.  It is a larger sea star and may be up to 40 cm across.  It is found mainly in the subtidal zone and up to depths of 320 meters or more but very rarely, it may be found in the low intertidal area.  This species of sea star feeds mainly on sea cucumbers, other sea stars, molluscs and sea urchins.

 

 

A Purple Sun Star under examination in the lab.

 

This one was pulled up in the scallop drag aboard the Fundy Spray.

 

 

Two vastly different-sized sun stars.

Creature Feature: Northern Rock Barnacle

The Northern Rock Barnacle (Semibalanus balanoides) also known as the common rock barnacle is found fastened to rocks in the low intertidal zone to the shallower waters of the subtidal area.  This is the most commonly found barnacle in this area and can be identified by its rough grayish white shell.  It does not have a calcareous base as some other barnacles do. 

The barnacle is an arthropod and a crustacean, meaning it is related to crabs and lobsters.  It does not have a hard exoskeleton so must build a shell around itself for protection. It is the only crustacean that is stationary for its entire life.  Once the barnacle is finished with its planktonic larval stage, it will glue itself head down onto a rock substrate where it will create the shell around itself. It will not move from this spot for its entire life cycle.

Rock barnacles are hermaphroditic (both male and female).  They reproduce sexually but do not release their eggs and sperm into the open water; rather their fertilization is internal wherein one barnacle acts as the male and will reach to another barnacle that will act as the female and accept the sperm and brood the eggs within their shell. Once the eggs are hatched they will be released into the water.  A single adult barnacle may release up to 10,000 larvae into the water.  When these larvae settle, they may chose something other than rocks to attach to, such as the hulls of boats, lobsterpots and even slow moving or fairly stationary creatures such as Horse mussels.  The cement they secrete to attach themselves to things is very strong and currently being studied for possible use in dental applications.

 

Diagram of the internal anatomy of the Rock barnacle; though note the Northern Rock Barnacle does not have a calcerous disk on the bottom.

 

Colony of rock barnacles. Note the gastropod; Dogwinkles are known to feed quite frequently on barnacles.



 

                                            

 

Creature Feature - Northern Horsemussel

The Northern Horse mussel (Modiolus modiolus) is found subtidally, sometimes buried in gravel or rocks. It uses byssal threads to attach itself to various substrates like it smaller cousin the Blue Mussel. It is larger than the commercially grown Blue mussel and can grow up to 15cm long and live anywhere from 20 to 100 years. The Horse Mussel is a suspension feeder, which is similar to filter feeding but instead of actively drawing water into itself, the Horse mussel feeds on whatever happens to flow through. The Horse mussel is preyed upon by lobsters, crabs, sea ducks and some marine mammals. These bivalves are edible but are not as popular as the smaller Blue mussel.

 

 

 

The Horse Mussel.

 

 

 In its natural habitat.


Inside of the Horse Mussel; note the byssal threads in the middle, the gill beside and the mantle below.
 

Creature Feature - Waved Whelk

Today's featured animal is the Waved Whelk (Buccinum undatum). The Waved whelk is of the phylum mollusca and class gastropoda. This particular whelk makes its home on rocky or gravel substrates with the young living in tide pools, while the older Waved whelks prefer deep water. The shell of the Waved whelk is unique in that is has both axial and spiral ridges, giving it the easily identifiable 'waved' appearance. These whelks are mainly carnivorous and feed on polychaete worms and bivalves. The Waved whelk can force the shell of a bivalve open by using the edge of its own shell or it may also bore a hole into the shell and suck out the inside. The Waved whelk is also known as a scavenger, and will eat dead fish or bait from lobster traps that it can detect from a considerable distance using olfaction. The siphon that is used to direct water over its gills also acts as a sensory organ. The Waved whelk is preyed upon by sea starts, and in Europe is commercially fished. This whelk can live up to 10 years and reach a size of 14cm high.

 

The Waved Whelk; note the siphon protruding from the front.

 

A diagram of the Waved Whelk.

Happy Halloween!

Happy Halloween from the Huntsman Marine Science Centre. We hope that everyone stays safe tonight and that the weather left over from Hurricane Sandy lets up in order to enjoy some fun Halloween activities.
In the ocean there are many places that are still being explored or have not yet been explored. Scientists are discovering new weird and wonderful things all the time.  Here are some new somewhat spooky discoveries that have been made in the depths of the ocean, in only the last decade!

Halloween at the Huntsman

On Saturday we welcomed all kinds of ghosts, goblins, princesses and even an garden gnome to the Huntsman for our annual Halloween haunt.  A great time was had by all, as the children were led on a journey through the aquarium by our very own mermaid!  The children had to solve various mysteries and puzzles in order to find their way to our party room for games and refreshments.  It was a great night and I cannot wait until the next one! To keep updated on all the events happening at the Huntsman visit http://www.huntsmanmarine.ca/events.php

 

Getting ready to wrap some mummies!

 

Enjoying the refreshments and the games.

 

Our mermaid, Janie, getting in on the mummy wrapping fun!

 

A well wrapped mummy.

 

Our Phantom of the Aquarium, Genny.

 

More games!

 

 

The Phantom likes to play too!

ECS Day 3

Today is the last day that the students from ECS in Montreal will be here at the Huntsman.  The students began the day with a field trip to Pottery Creek where they took note of and marked the invasive species; green crabs.  This is done a few times a year in order to keep track of the population of this species and also to monitor its movements.  This data is important, as it gives us an idea of how far and how quickly this particular invasive species has spread.  Before lunch the students created artwork of different sea life for our Colour Spectrum Mural which is on display in the lower level of the aquarium.  This afternoon the students will be studying the feeding rate of barnacles and how it is affected by temperature change.

 

In order to find the green crabs, the students and their teachers, looked under rocks and seaweed.

 

Some of the data collected from Pottery Creek.  Note that there are many more male crabs than female.

 

As the tide came in some areas of the beach became inaccesable.

 

Here students bearing crabs converge on Tracey so that she may mark and record the data.

 

Looking under the rocks is sometimes a team effort.

 

This particular crab, marked with a smiley face, might not be happy to see you if you can catch him again.

ECS Day Two

Today the students from E.C.S. started the morning on the beach near the Bar Road looking for worm specimens.  The students spent the time digging for the worms by first identifying the areas of the beach most likely inhabited by the worms.  After the students finished collecting their samples, it was back to the lab to create a dichotomous key to help with the classification of each species.  While in the lab the students looked at blood worms, clam worms, trumpet worms and a few others.
This afternoon the students will be going aboard the Quoddy Link in hopes of catching a glimpse of some fascinating marine mammals; whales and seals.

 

The students head out on to the beach on a sunny but chilly morning.

 

The students lost no time in getting down to business; digging worms!

 

It is very important to break apart the dirt so you do not miss any possible specimens.

 

The students worked in groups of 2 or 3 to look for the worms.

 

Here is a nice example of one of the specimens found.

 

Checking the shovel and the ground below will ensure that all worms are accounted for.

 

A Clam Worm.

 

The students are back in the lab to classify the different worms they collected.

 

The Acorn Worm.

 

More Clam worms.

Watch how these Blood Worms move!