Pharyngeal Jaws and Green Moray Eels

April 20, 2016

Species Highlights

Did you know that there are animals at the Greater Cleveland Aquarium that have more than one jaw? Moray eels have been known to have a second jaw, or pharyngeal jaw. The aquarium is home to several moray eels, many of which you can find in the Shark Exhibit swimming right along with the sharks and other fish.

Green moray eels are a pretty amazing animal, full of secrets. Just about ten years ago researchers discovered that these curious animals actually have a second jaw. This jaw, known as a pharyngeal jaw, is how they are able to eat. Most fish use suction to swallow. They expand their mouths to create negative pressure. This negative pressure causes water and prey to rush into their mouths allowing them to swallow their prey. Moray eels do not have this ability. Instead, they lie in wait in caves and crevices for their prey to swim by. They then burst out and grab their prey with their oral, or first set, of jaws. Their pharyngeal jaws then move forward to grip it. They can then move these jaws backwards to swallow their prey whole. They typically eat fish, shrimp, squid, crabs and octopus.

Another secret that green moray eels have is that they are actually brown! Their bodies are covered with thick yellow mucus that gives them their vibrant green color. This mucus protects the eels from parasites and infectious bacteria.

Green moray eels are found along the western Atlantic and into the Gulf of Mexico. They’re frequently found in the Bahamas and the Caribbean and been found as far south as Brazil. When full grown they can get to be 8 feet long and weigh as much as 65 pounds. Green moray eels have few natural predators once they reach full size, although smaller eels must look out for sharks and other large predators.

Next time you are at the aquarium make sure you look for the green moray eels. They are nocturnal in nature so they tend to spend a lot of the day hiding in the rocky structures around the exhibit. You’ll see their heads and part of their bodies sticking out. However, we often see them swimming around throughout the day. They even like to visit the divers when we are in the exhibit. Also, be sure to visit the aquarium on a Sunday, Tuesday or Thursday at 3:30 to watch the shark feed! The eels are often seen coming over for a snack as well. Look fast! Maybe you’ll just catch that pharyngeal jaw in action!

Symbiotic Relationships

March 2, 2016

Written by Greater Cleveland Aquarium

Symbiotic relationships occur all around us every day. They are quite simply relationships between two different species where at least one species benefits. There are three main types of symbiotic relationships: mutualism, commensalism and parasitism. Let’s focus today on mutualism, or a relationship where both organisms benefit from each other. The Greater Cleveland Aquarium has multiple examples of this happy relationship!

Let’s start out by taking a journey into our live coral exhibit, because that happens to be the site of not one, but TWO mutualistic symbiotic relationship. Both involve (you guessed it) coral! The first one involves a very famous movie star that goes by the name of Nemo. Now most people associate the clown anemonefish with anemones, hence the name. However, in this particular exhibit, the anemonefish has a relationship with a type of coral known as Ricordea florida, which doesn’t actually have a common name. This coral protects the anemonefish with its stinging tentacles, which the anemonefish are immune to because of a protective mucous coating. In return, the anemonefish gives protection to the coral by being aggressive and fighting away other fish that might otherwise prey on the coral. Also, the coral can feed on bits of food from the anemonefish’s meal. Everyone wins.

Coral play a role in our Aquarium in multiple mutualistic symbiotic relationships. The next one we’ll look at is the connection between coral and zooxanthellae. Zooxanthellae, if you’ve never heard of them, are plant-like microscopic algae that live within the tissues of coral. The coral, once again, offer a protected home with their stinging tentacles. The zooxanthellae also receive the compounds necessary for photosynthesis from the coral, which is why coral need clear, low-turbulent waters to grow in, so the sunlight can reach them. Once photosynthesis is complete, the zooxanthellae transfer up to 90% of the products to the coral, which include oxygen and carbohydrates. The most fun and beneficial part for us humans is that the zooxanthellae provide the coral with the many different vibrant colors that are seen on coral reefs.

Our next relationship takes place in our stingray touch pool where there’s an interaction between our stingrays and the cleaner wrasse. While a stingray is resting on the bottom, a cleaner wrasse will use that opportunity to swim up and start the process. The cleaner wrasse, as its name suggests, cleans the stingray of dead skin and parasites, essentially getting an easy meal. The stingrays stay clean while the wrasse stay full! In the wild, the stingrays would also be a form of protection for the wrasse but that isn’t an issue in our friendly touch pool. Be sure to look carefully for these cleaner wrasse. Not every guest notices them.

Our last symbiotic relationship covers one that pertains to us humans directly. One of the newer exhibits at the Greater Cleveland Aquarium is the invertebrate touch pool, which is home to many different invertebrates, including cleaner shrimp. In the wild, these shrimp would receive their food by removing external parasites and old skin from eels, groupers and other fish. Here at the Aquarium though, guests can walk up and place their fingers in the water for a free mini-manicure! The cleaner shrimp hop right on your fingers and start cleaning away. Now hopefully we don’t have any external parasites, but old skin we surely have – so that makes a great meal for the shrimp.

Do you SEA the resemblance?

March 1, 2016

Species Highlights

Written by Greater Cleveland Aquarium

Do you SEA the resemblance?

The Greater Cleveland Aquarium is home to quite a variety of interesting aquatic life from all different parts of the world. With a touch of so many different places here, you’re bound to run into some pretty interesting looking little guys. Let’s call this one, celebrity doppelgangers for fish.

1. Dog Face Puffer – Dog

Imagine if a dog was stuck inside a fish body because that’s basically what makes up our friend, the Dog Face Puffer. He’s a native of the Pacific and calls our Indo-Pacific gallery his humble abode. The Dog Face Puffer gets its name from its appearance, and I bet you can guess why – he looks fairly similar to a canine! Oddly enough, Puffer fish have been known to have personalities similar to dogs. However, the Dog Face Puffer doesn’t have teeth like his furry friends, but instead has a fused beak-like structure, which it uses to crush its food.

2. Raccoon Butterflyfish – Racoon

Sounds like a weird combination, right? However, the combination of the traits from these two very different animals actually creates a beautiful aquatic creature. This fish gets its name from its highly recognizable mask over its eyes, nearly identical to that of a raccoon. Its beautiful yellow coloring and shape resemble a butterfly. This remarkable combination makes for an awesome addition to the Tropical Reef of the GCA.

3. Pterois aka Lionfish – Lion

This fish is given its name due to its venomous fins that create a look similar to the mane of a lion. The Pterois is found mostly in the Indo-Pacific, and can be found there within the Greater Cleveland Aquarium. If attacked or threatened, the fish will deliver a potent venom through it’s needle-like dorsal fins. The sting from this act is extremely painful to humans, sometimes resulting in nausea or breathing difficulties, but is rarely fatal.

4. Red Terror Cichlid – Tigers

He’s got the eye of the tiger, and you’re gonna hear him roar! Well, maybe more like blow bubbles, but you get the point. The Red Terror Cichlid typically sports a beautiful orange color with black stripes – similar to a wild tiger. These fish tend to be territorial a similar characteristic of tigers. It can generally be found along the banks of rivers hiding under brush. You can visit our Red Terror Cichlid in our Lakes and Rivers of the World gallery.

Be sure to look out for these amazing aquatic creatures on your next visit to the aquarium! You never know what resemblances you might see!