Friday, October 31, 2014

Nothing is cooler than seeing a dolphin jump out of the water or ride along in front of a boat. Dolphins have been popularized within the last few decades as being very social mammals not only within their pods, but towards humans as well. And not only are they awesome, but they're super smart as week. But are they really…?

Dolphin jumping out of water, Dolphin Research Center

Dolphins have showed off their intelligence in both their natural habitats and in captivity. Their large brain capacity at first seems to be the cause of this intelligence, but there are many skeptics that don't think they're as smart as they seem. Some researchers believe that dolphins have only developed large brains in order to help them retain body heat- it has title to do with higher cognitive functions. Even though many believe dolphins are smarter than many other mammals due to their advanced behaviors, these researchers believe that they aren't that special. For example, pigeons and octopi have been able to complete some of the same tasks that dolphins can. But hey, that doesn't mean that this one guy's view is correct and they aren't awesome anyway.

This doesn't mean that dolphins aren't smart, because they are; I mean they're definitely not as smart as us, but they're a few steps up compared to some other organisms. Dolphins have shown off their creativity in both the wild and captivity. They are known to be able to mimic other dolphins as well as they trainers. These guys are highly developed in this area, as they repeat behaviors that yield some sort of reward. This can be anything from jumping out of the water, painting, or even solving puzzles set up to them by their trainers. They are then able to pass down these behaviors to another dolphin, showing that they do have high levels of intelligence.

Dolphin painting at Dolphin Research Center, Meghan Pentak

Another behavior they display is when they hunt, as they are very social mammals. Dolphins often swim in large groups and then surround the fish, forming a barrier in which they can't escape. Some other dolphins have been known to push the fish into shallow waters, trapping them as they have no other way to go. Another hunting technique is to use mud rings, in which an individual dolphin will chase down fish and trap them by using their tails to kick up mud, forming a ring of mud around their prey.

Dolphins jumping at Dolphin Research Center, Meghan Pentak

But besides this, dolphins are also known to have fun! In the wild they have been seen playing games of catch by tossing fish and turtles back and forth, as well as them playing tag with one another. Another really awesome thing that they do is riding whales! Dolphins have created a game out of swimming onto a whales nose, which then breaches. The dolphin will slide all the way down the whale and back into the water, repeating this game over and over. So between dolphins being able to understand commands, having creative hunting techniques, and being able to have fun, how can you say dolphins aren't smart?

Sunday, October 26, 2014

The biggest struggle I have as a fish owner is knowing whether a fish is a dude or a girl, so I can give them a name of the correct gender. Sometimes it's pretty easy to tell the difference since many species have a more colorful male and a less colorful female. Other types of sea creatures are a little more difficult to tell apart. This is due to the fact that many different types of fish tend to be hermaphrodites. But what exactly is a hermaphrodite? It's an animal that is born with reproductive organs of both sexes. Tis is known as a simultaneous hermaphrodite. However, in many other species, individuals are born as one gender and are later able to switch sexes. There are two types of sequential hermaphrodites: protandrous and protogynous. 

In simultaneous hermaphroditism individuals are born with both male and female reproductive organs. This type of hermaphrodite is usually found in the deepest, darkest parts of the ocean, although there are a few exceptions. Since it's pretty vast down there, it's not every day you run into a potential mate. This means that both individuals can end up producing offspring, yielding this type of hermaphroditism beneficial to these fish. One example of a fish displaying simultaneous hermaphroditism is the salmon.


Those that are protandrous hermaphrodites are born male but are later able to change into a female. Examples of fish that are protandrous are clownfish, moray eels, and damsels. In most cases you will find a group of two large fish and a bunch of smaller ones. The larger fish are sexually mature and are a reproducing male and female, while the smaller fish actually lack gonads altogether. When a female dies or leaves the group, the large male will then become the reproducing female and the next largest male will take over his place. Basically, the movie Finding Nemo us now ruined.

My clownfish: Nemo, Meghan Pentak

My eel: Snowball, Meghan Pentak

The other type of sequential hermaphroditism is known as protogyny. Wrasses, gobies, angelfish, and groupers fall under this category. In this situation fish are born female and can later become male. Only once she has mated and produced eggs is the female able to turn into a male. These fish are found in groups called harems which are made up of one male and several females. In nature the male is the larger of the two, with the female being smaller and less colorful. When the male dies one of the female will turn into a male and take his place.

My green bird wrasse: Nick Ricci (don't mind the puffer fish), Meghan Pentak

My eibli angelfish: Poseidon, Meghan Pentak

So in conclusion, if I assumed my fish were guys when I named them, did I name them correctly? Or did I give some girls some guy names...

Sunday, October 19, 2014

One of the cutest mammals of the sea has to be the manatee, which happens to be an endangered species. With three different species of manatees currently known to exist, I'm going to focus on the West Indian manatees which tend to live in the warm ocean and river waters of Florida and surrounding areas. These guys spend most of their time in the ocean but are also known to populate brackish waters of rivers and areas with only freshwater. When they aren't in Florida during the winter months, they are known to migrate north during the summer months. Sea cows are known to grow up to ten feet long and weigh in as much as 1200 pounds. Many of them tend to travel in groups, but some like to live a solitary life… Like the one that showed up in New York!

Manatees are indeed mammals, meaning that they must breathe air if they want to keep on living. Normally they just chill underwater, but every so often they come back up to the surface to breathe. They can hold their breath for up to twenty minutes, but are usually up every few minutes. Although they usually don't travel fast (they average around five miles per hour) some manatees can reach speeds up to twenty miles per hour! But since they are pretty slow, they get a nice coating of algae on them, as they provide the perfect environment for algae growth.

Manatee in Mexico, Meghan Pentak

These chubby guys are really good at three things: eating (up to 15% of their weight a day!), sleeping, and swimming… Although there's a fourth thing I've realized they're pretty good at. They will spend up to half of their day sleeping and another seven hours eating. These sea cows are mainly herbivores, eating the vegetation they find along their travels. Manatees will eat both submerged and floating plants, and on occasion they will snack upon small fish and invertebrates. When I played with manatees in Mexico I noticed some of their favorite treats were lettuce, broccoli, and carrots. Although it's stated that they're intelligent, these guys were nothing compared to dolphins- the only tricks they knew were how to roll over and open their nostrils… And pass gas. Their fourth talent. And yeah, I said that. When swimming with them you would just see bubbles come up from their backend pretty frequently. Maybe that's why they're referred to as sea cows… 


Manatee eating Broccoli, Meghan Pentak

Although manatees are very docile and have no known natural predators, this species is endangered. With only 4,831 of these guys left in the wild as of January 2014, it's important to take the time and learn how to protect them. Once the subject of hunting as a result of their hides, oils, and bones, there are now laws in place to protect this mammal. Under the Marine Mammal Protection Act of 1972 and the Endangered Species Act of 1973, it is now illegal to harass, hunt, capture, or kill any marine mammal. The West Indian Manatees in particular are also protected by the Florida Manatee Sanctuary Act of 1978. Even though all of these laws are in place to protect manatees, they are often still in danger in their natural habitats. The main cause of injury to sea cows is boats. Since they are very slow moving and tend to stay towards the surface, they are often cut by propellors and hit by vessels. They are also known to have died by other causes such as: being crushed by canal locks, ingesting fishing hooks and litter, and being caught in lines and nets. So how do we make sure they stay protected and don't die out?

Manatee in Mexico, Meghan Pentak

When boating is it crucial to stay in deeper, less vegetated areas when possible, as manatees tend to swim in more shallow areas that are more vegetated. Also, just use your eyes and look out for them, and actually pay attention to speed zone signs- they're there for a reason. An easy thing to do is just pick up your trash; don't let any litter get into the water, where it may be ingested by a marine mammal. And if you do see a manatee when you're in the water, don't attempt to feed or touch it. Even though they're awesome, docile creatures, they're still wild animals that should be left alone. Plus you're kind of breaking the no harassment law if you do touch them… 



Friday, October 10, 2014

Sea Creature Defense Mechanisms

The ocean is a pretty big and scary place. With the majority of Earth being covered by water, who knows what's out there? How do you protect yourself from these potentially huge and scary creatures? Well, many organisms that call the ocean home have developed amazing camouflage, learned how to travel in schools, developed toxins, and use their size to fend off predators. I know from first hand experience how some of these creatures protect themselves, and let's just say it's not pretty.

Some of the cutest and most interesting fish are barely spotted by the average person while snorkeling or diving: flounder. With both of their eyes on one side of their body, these little guys spend their days blending in flat against the ocean floor. They're able to adapt their coloring to match the sand that they're currently burying in, making them nearly invisible to their predators, as well as their prey when they're hunting. This camouflage is a result of the flounders vision and hormones that they have; if they aren't able to see their surroundings, then they aren't able to blend in. But look a little closer at the sea floor next time, and you might see two eyes looking right at you.


Flounder in Antigua, Meghan Pentak
Many fish have learned that swimming in large groups, known as schools, helps protect them from predators. By staying in a large group, it makes it harder for a predator to single out a certain fish and chase it. When alone, a single fish is much easier to catch and make into dinner. Schooling fish also have an easier job during their own hunts; with strength in numbers, they can search more efficiently. This also applies to defending their territory- the bigger they seem, the more likely other fish won't mess with them. These reasons are why many types of fish tend to swim in schools.


School of Sergeant Majors in Florida Keys, Meghan Pentak

Many different creatures of the sea utilize poison as a form of defense. Whether it be a tiny little anemone or large stingrays, these guys are able to protect themselves pretty well… So you'll probably want to avoid them if you see them. Although not always poisonous to humans, anemones can pack a punch to their predators, which are mainly fish and crustaceans. This neurotoxin stuns the organism that disturbs the anemone, and it's pulled into its mouth for digestion. Another type of sea creature that contains toxins is the stingray. This sea creature has poisonous barbs on its tail, which it utilizes as a defense mechanism. Although not usually a big threat to humans, this venom can be lethal if the barb penetrates a critical area of the body (rest in peace, Steve Irwin). Sea urchins also have spiny structures laced with venom that they use as a form of self defense. These stings occur as the spines or pedicellarines penetrate the skin and toxins are released. When stuck with their spines, humans usually experience severe pain and discomfort. And now onto one of my favorite little poisonous guys, or in my case gal: the spotted boxfish. I can't get over how cute they are- their little white polka dots and happy demeanor make them so adorable. But if they feel threatened or die they're not as cute… They emit toxins. More specifically, ostracitoxin. If emitted in a confined aquarium, it will most likely kill off any other organisms in it as well as themselves, as it's highly toxic. Thank goodness mine is the happiest fish ever.
Pink tip anemone in Antigua, Meghan Pentak

Stingray in Antigua, Meghan Pentak


Sea urchins in Mexico, Meghan Pentak                                               


My boxfish: Lumpy, Meghan Pentak


Another way to fend off larger predators is simply through size. Yes, I know super big sea creatures like sharks and whales have this form of defense, but so do some of the smaller guys. For example: pufferfish. Most pufferfish aren't that small, but they aren't that big either when you compare them to other fish in the ocean. But they are able to "puff up" when threatened by a predator. By inhaling a large amount of water, these fish are able to double in size, which usually fends off their predators as they don't want to deal with a larger fish. Along with puffing up, many types of pufferfish also have spikes that stick out when they inflate. These spikes add another form of protection, as many are also poisonous. This toxin is deadly to those who consume pufferfish, including humans. In the many years of having these types of fish, I've only seen one of them puff up. This happened when we were transferring him to a bigger tank, which he was apparently not happy about. He blew up to the size of a cantaloupe, and it was one of the funniest things ever. But don't worry, this act of puffing up doesn't cause much harm to the fish unless they fill up with air, in which they usually die. 


 
         
My pufferfish: Mrs. Puff, Meghan Pentak                     

     
My pufferfish with spines: Gilligan, Meghan Pentak

And finally, the ugliest form of self defense: expelling your internal organs and chemicals. Yeah, it's as disgusting as it sounds. Sea cucumbers are known to do this under high amounts of stress, and somehow I caused this to my little guy. Not only did he kill himself, but he wiped out all his tank mates in the process… Sorry, guys. When I noticed what happened, I had no idea what it was at first. All you could see was stringy, sticky goop coming out of my sea cucumber. It was disgusting. I was warned that this might happen, but I didn't think it actually would. Sea cucumbers are also able to eject just their organs, which they are able to regenerate; they can also get rid of all the water in their bodies, leaving them as small, hard things. So they don't die every time they do something weird like this. Why my guy committed suicide instead of just making a statement? I don't know. I just knew I was never getting a sea cucumber again.