The Secret Lives of Sea Stars

Where is their mouth? How do they move? Why does the animal care team call them sea stars and not starfish? Learn a few basics and discover how different sea stars can be with aquarist Bethany H. #cleaquarium #natureiscurious

Today we’re going to talk about sea stars. The reason we call them sea stars and not starfish most of the time is because they’re not actually fish. They’re in a group called echinoderms, which means spiny skin. Other echinoderms include sea urchins and sea cucumbers, so it’s a big group of invertebrate animals.

We have several different species here at the Aquarium. We will start by looking at the Bahama sea stars that live in the Aquarium’s Invertebrate Pool.  They have a bottom surface where you can see their mouths are right there in the middle. They also have rows of tube feet coming out in every direction. Those tube feet end in little suction cups, so that’s how this particular sea star is sticking to the acrylic.  Sea stars also have a back surface with little spikes all over it.

The way sea stars move and breathe are really pretty interesting. Both of those work a lot on what is called a water vascular system. You might think of vascular blood vessels. While these guys do have a couple of blood vessels, most of their circulatory system is done with just sea water. That sea water can move their tube feet in and out.

Because we disturbed him, this sea star might decide that this is no longer where he wants to be and start moving very slowly across the acrylic. He’s going to do that by sticking out each tube foot and pulling himself along. Sea stars tend to look like they’re just gliding because their arms aren’t actually moving, just their tube feet. They’re really slow. Their average speed is about six inches a minute. The fastest sea star there is can move about nine feet a minute, which is still quite a bit slower than your walking speed.

Sea stars also use that water vascular system to breathe by sticking little papulae or little hair-like projections out of their backs. All those little white specks in between the big bumps are papulae that are all pulled in right now. Again, sea stars can use hydrostatic pressure inside to move those in and out. When those papulae are sticking out they create a lot of surface area for gas exchange with the water. Then that will circulate through the sea water inside their body to move it all throughout all of their tissues.

This central little dot or light area you can see here is called the madreporite. That’s a big word for something sea stars can open or close to determine how much water is inside of them.

The leather and the pink star in our Coastal Arch exhibit look a lot furrier with all of the papulae out. These are some cold water species. Sea stars do live in different climates all over the world. There are many different species. Most of them have five arms, although there are a few exceptions. 

All sea stars can move their arms independently a little bit, but how much they do so is very much dependent on the species. These are all mottled sea stars and as sea stars go, they are probably some of the most flexible.

Author: Bethany H.

The Truth about the Red-Bellied Piranha

Are piranhas as fierce as they’re often made out to be in pop culture? Maggie H. dispels some of the myths and tells you how a President was responsible for their frightening reputation while feeding the red-bellied piranhas at the Greater Cleveland Aquarium.

Some people think is the red-bellied piranha is the scariest fish here at the Aquarium. Piranhas have gained a bad reputation for viciously devouring anything in their path within mere seconds, but are they actually as scary as everyone thinks they are? The short answer is no. These fish get a bad reputation in part because of some exaggerated claims made about them following one of Teddy Roosevelt’s expeditions to the Amazon. His guides showed him starving piranhas taking down a large animal in a short period of time. The widely circulated story from the President’s trip inspired a 1970s’ horror movie that only confirmed people’s suspicions that the piranha was a man-eating terror.

This is a gross misrepresentation of a beautiful and usually quite docile fish.

Piranhas are native to the Amazon River Basin where they struggle to survive changes to their habitat during the dry season. This land can go for months without rain at certain times of the year, reducing the piranhas’ normally large swimming areas to small, stagnant pools that are little bigger than puddles. These conditions make competition for food and resources fierce as the fish can go for a long time without a meal. So, if something falls in the water, the hungry fish will use their strong jaws and razor-sharp interlocking teeth to rip it apart as quickly as possible to get their fill.

They tend to travel in groups more for protection than to take down larger prey, but then end up stuck in these ever-shrinking pools together trying to fend off starvation.

So, while people tend to think of these fish as fearsome predators, they are actually very valuable to their ecosystem as scavengers. They are opportunistic feeders with a very varied diet. Although they might hunt for small fish insects and invertebrates, they also consume carrion and even plant matter. Piranhas have also been known to nip at the fins of some larger fish for sustenance. The red-bellied piranha at the Greater Cleveland Aquarium, eat a mix of fish shellfish and a special very nutritious gel diet.

While stories in the media have portrayed these fish as ferocious killers that should be feared, they are actually quite docile when well fed and will avoid conflict if possible. I hope I’ve debunked some of the myths surrounding these widely misunderstood creatures.

Make sure to check them out on your next visit to the Greater Cleveland Aquarium. We look forward to seeing you soon!  

Where to find @CLEaquarium: Tropical Forest Gallery

Author: Maggie H. 

Meet Your New Favorite Animals, the Surinam Toads @CLEAquarium

Aquarist Maggie H. feeds the Surinam toads (who shovel the meals in their mouths most adorably) and explains why she’s such a big fan of these unusual animals.

Hey guys! My name is Maggie and I’m an aquarist here at the Greater Cleveland Aquarium. Today I’m going to tell you a little bit about Surinam toads . Surinam toads are native to northern South America where they spend most of their time lying in wait in the bottoms of rivers, streams and ponds disguised as leaves. They are very still most of the day, blending in exceptionally well with their surroundings.

Even though their name implies they are toads, they’re actually frogs. They get that name due to their exceptionally bumpy and textured skin.

In the wild, these animals would eat a varied diet of small fish, crustaceans and worms. Here at the Greater Cleveland Aquarium they get a similar diet of earthworms, squid tentacles and fillets of freshwater fish. Their eyes are quite small, so to help them find food they have small, star-shaped sensory organs on each digit of their forelegs. Their strong, muscular back legs are used for swimming.

In addition to their odd appearance, reproduction for this species is also very unique. The toads locate each other using a loud, metallic-sounding clicking noise. Once a male and female find each other,  amplexus, or a spawning ritual, will begin. The toads will do a series of movements in the water column that culminates with the female laying anywhere from 60 to 100 eggs which the male then fertilizes and presses into a thick pad of skin on her back. There they will develop for several months before her babies swim out fully formed and able to provide for themselves.

The toads and I are looking forward to seeing you at the Greater Cleveland Aquarium soon.

Where to Find @CLEAquarium: Tropical Forest Gallery

Author: Maggie H.

Get to Know the Longnose Gar @CLEAquarium

The Greater Cleveland Aquarium’s Ohio Lakes & Rivers Gallery highlights animals native to this region and it’s where you’ll find several longnose gar. Watch aquarist Laura B. feed them whole, small trout while she tells you more about these distinctive fish. #natureiscurious

Hi! I’m Laura and I’m an aquarist here at the Greater Cleveland Aquarium and today I’m feeding some of our native species in the gamefish exhibit. In fact, right now I’m going to feed the longnose gar .

Longnose gar get their name from their elongated jaws, which have needle-like snouts. They have rows of cone-shaped teeth on the top and bottom of those jaws that help them trap small fish, insects and crustaceans. Today they’ll be eating whole, small trout.

The longnose gar have a very wide distribution. They’re found all throughout the Midwest and Eastern United States. They’re found in areas with vegetation and downed trees. They have gills, but they’re also able to breathe air which makes them able to adapt to low oxygen environments. They’ve been found in brackish water in coastal areas.

Gar are pretty special because they don’t have typical scales like normal fish. They have what are known as ganoid scales, which have serrated edges and don’t overlap like an average fish you might see. Full-grown adult gar are what are known as apex predators. That means that there are very few species that will prey on them. The only two predators really are alligators and humans. They will live to be about 15 to 25 years old. Typically they’ll be 2- to 3-feet long but they have been known to grow up to be 6 feet long and 55 pounds.

Personally, I think the gar are very interesting. Their fossils go back 100 million years, which is absolutely fascinating. I think they’re underrated. They’re very pretty. They have those dark patches that kind of help them blend in with their surroundings and that long body shape, which is pretty unique of all the species found in this region.

Where to Find @CLEAquarium: Ohio Lakes & Rivers Gallery

Author: Laura B.

5 Things I Learned about Horseshoe Crabs

Horseshoe crabs get their name from a rounded carapace, or exoskeleton, that’s u-shaped like a horse’s shoe. They have jointed legs, a hard shell, an exoskeleton and a segmented body, but they don’t have antennae or a jaw. These arthropods are more closely related to spiders or scorpions than they are to what we think of as true crabs, and they are really fascinating (and important) creatures. Here are just a few reasons why:

1. Tracing the ancestry of these invertebrates would result in a massive family tree. Horseshoe crabs have been around for hundreds of millions of years, even longer than the dinosaurs!
   
2. It might not be fine dining, but it gets the job done. A horseshoe crab’s diet consists of sea worms, mollusks and crustaceans. Because horseshoe crabs don’t have jaws or teeth, they’ll break up food between their legs before pushing it into their mouths. Like birds, a gizzard further grinds that food down. Any undigested bone or shell particles are regurgitated.
   
3. Their spiky telsons are nothing to fear. They look like barbs or stingers, but those tails are actually pretty fragile. Horseshoe crabs use them to dig, to steer and to right themselves after swimming upside down or being flipped by a wave.
   
4. Horseshoe crabs are slow growers. And because that hard exoskeleton doesn’t grow with them, they regularly develop new, slightly larger shells and shed their old ones. It’s a process called molting.  They’ll do this 16 to 17 times before they reach full adult size.
   
5. They’re very important animals. Not only do horseshoe crabs play a big role in their ecosystems—providing a source of food for migratory seabirds, sea turtles, alligators and even sharks—but they are also important to human health. Because their blue, copper-based blood quickly clumps up in the presence of bacterial toxins, it can be used to test for contamination in things like injectable drugs, surgical implants and medical equipment.

While there are synthetic alternatives in development, today pharmaceutical companies developing COVID-19 vaccines are using horseshoe crab blood to test for potential bacterial contamination. Pretty amazing, right? Don’t miss these little lifesavers in the Coastal Boardwalk Gallery the next time you visit the Greater Cleveland Aquarium.

Author: Samantha F.