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).