That Fish Blog – Aquarium Advice and Information

Eileen here. A lot of people who come into our store see fish like our lionfish and scorpionfish and ask if they are poisonous. The answer? Technically, no. They’re venomous.

People also see warnings on some cucumbers, Sea Apples and Boxfish that they are poisonous and wonder if they might get a painful bite or sting. The answer? Probably not.  They’re poisonous.

So, what’s the difference that makes the lionfish venomous but the boxfish poisonous? The key is all in how the toxin is delivered. The term “toxin” simply means a harmful substance produced naturally by an organisms and is used for both venomous and poisonous animals. Venomous animals inject their toxin into their target using spines (lionfish, stonefish, rabbitfish), teeth (sea snakes, Blue Ring Octopus), or specialized stinging cells known as nematocysts (jellyfish, anemones, some corals). Some of these animals use their venom to hunt; jellyfish and anemones paralize whatever prey is unfortunate enough to end up in their tentacles before they draw the prey to their mouth. Others like the lionfish and rabbitfish only rely on their venomous spines as defense against being preyed upon themselves. This venom can range from very mild as in the case of anemones to fatal. The Blue Ring Octopus is one of the most toxic animals on the planet and has no known antivenom. People who are sensitive to bee stings are much more likely to have a severe reaction to common venomous animals in the aquarium trade like lionfish and anemones.

Poisonous animals like boxfish, puffers or sea cucumbers, on the other hand, rely on their target absorbing the toxin. This can happen across any membrane – through the skin or gills, in the stomach or digestive tract, even in the lungs. Poison is used almost exclusively as a defense mechanism. Puffers and boxfish have special toxin in their bodies – usually the liver, ovaries and skin – that they can release when they are stressed to hopefully deter any possible predators. Unfortunately, in a closed system like an aquarium, this toxin can eliminate an entire tank – including the puffer or boxfish itself. Some groupers like the Clown Grouper also have a similar toxin in their slime coat. Cucumbers, especially the large Sea Apples, can also poison a tank if they are stressed, picked on or dying. These animals can be deadly in an aquarium but aren’t much of a threat to aquarists; if in doubt, use gloves when handling any of these animals, especially with any open wounds or cuts.

Whether venomous or poisonous, harmful or peaceful, the keywhen dealing with any animals is knowing what they are capable of and how to handle them properly. Being able recognise when an animal is stressed or how it defends itself is important in knowing how to keep that animal, its tankmates and yourself safe and happy.

Dave here. Recently we’ve been getting some new items in at TFP worth taking a look at, so I thought I’d take Wednesday’s post and give an overview of a few of them.

1 . Frag Racks from EShopps

As our recent frag swap can attest (take a look here), lots of folks are fragging these days. These new racks are really inexpensive, and ridiculously handy at keeping the little guys going, even within your main tank. They attach with magnets too rather than crappy suction cups. The clear-ness is great too because it doesn’t obsruct the view of your tank all that much. They’re available in corner and straight versions too. Check them out online, or stop by the retail store. Our main frag tank has one installed.

2. Fluval E-Series Aquarium Heaters

Haven’t actually had a chance to try one of these out yet, but the reviews have been nothing but favorable. Anyone who’s ever had a heater breakdown and ruin your tank, or accidently broke the sleeve on your tank wall, will be impressed by the Fluval Es. Each one uses an LCD display to report the temperature, and actually uses a color coded system to alert you when the temperature fluctuates plus or minus 2 degrees. A fish guard keeps the sleeve away from tank walls and your fish. Temperature sets to the nearest .5 of a degree to for more specialized jobs. Basically, they’re the Rolls-Royce’s of aquarium heaters at this point. Take a look at the Fluval E Series heaters here.

3. Instant Ocean Salt in the 200 gal – Pro Sized Box

Ok, I’ll admit, sometimes having the empty salt bucket around for water changes and stuff is pretty handy, but Instant Ocean’s new ProSized Salt-in-a-box helps save waste/make things more green/Save the Planet…all that stuff. Cardboard is way more biodegadeable and friendly than the oil-rich plastics processing that takes place with the good ol’ 160 gal bucket, so as a reef enthusiast, it seems like the way to go. Each box has 4, 50-gal bags so you can actually dump it into your old salt bucket. Take a look at Instant Ocean Salt-in-a-box here.

Anyway, these are just of the few of the cool things coming into ThatFishPlace.com. For a l ist of all of our new Aquarium Items, click here.

Until next time,

Dave

Melissa here. Well, summer is just ahead and I was thinking about what I had done past summers for amusement. One particular mini-vacation popped into my mind. I found myself in Emerald Island, North Carolina after a summer class had ended. When my parents and I arrived at the beach I walked up and down the beach for hours identifying things I remembered seeing in my class. I found one particularly unusual jellyfish. Looking at the jellyfish laying on the sand the bright blue with purple caught my eye. Definitely didn’t remember seeing any of those. I thought it was cool so I scooped it up in the bucket I had been carrying. I wanted to take it back to my car to identify what kind of jellyfish I had found. Before identifying it i wanted to clean off some of the sand. I assumed that it had been on the beach for a while and was probably dead. I was trying to be careful since I knew most jellyfish could still sting many hours after they washed up on the beach. As I was attempting to wash the sand off a few of the tentacles must have sneaked out of the bucket and brushed up against my foot and across my hand. I didn’t feel anything right away. When I started walking back to the car I felt something burning across my foot and hand. Sure enough, when I looked down there were bright red streak marks becoming visible. Once I got back to the car my hand and foot felt like they were on fire. I got my field guide and was shocked to see that I had found a Portuguese Man O’ War. In big bold letters under the name it said, “DO NOT TOUCH, DO NOT COLLECT”. Immediately I thought, “O crap, what have I gotten myself into?” I knew I had to tell my parents in case it got worse and they have to find me a hospital. I grabbed a bottle if ice from the cooler in the car and headed back to find mom to let her know I had a slight little problem. When I told her what had happened and showed her the red streaks, lets just say she was less than thrilled. She told me that we were keeping the “creature” in case I had to go to the hospital. I guess she wanted the blob as proof of what stung me since she had no idea what it was. After 4 hours or so it still stung and burned. By this point there was also some minor swelling. The only thing that helped a little was keeping my foot and hand iced. Around noon the next day the red streaks were still visible but it didn’t hurt anymore. I guess I was lucky that is all the reaction I got since I am allergic to bee stings.

If anyone else has any interesting beach encounters I would love to hear about them!

Image referenced from Wikipedia commons.

Please welcome our newest contributor, marine biologist in-training  Jason Tschudy with a little insight on some marine eels.

Eels.  Beautiful creatures that inspire fascination in many, fear in others, in many cases, a little of both.  These mysterious creatures make for a great focal point in a display aquarium.  There are quite a few species sold for the aquarium trade, but some are better suited for the aquarium than others.

Take the Snowflake Moray (Echidna nebulosa) for example.  It is one of the most attractive and readily available eels in the hobby.  These eels will eat crustaceans and small fish, and they can grow to about 36″ in length. The Snowflake Moray can generally be kept with other fish, things of moderate size like lionfish and angels won’t have a problem living with a Snowflake Moray. 

The Black Edged Moray (Gymnothorax saxicola) is another smaller species that can be a good fit for many aquariums.  It has diet and behavior similar to the Snowflake, and as with any eel it can get a bit aggressive when food is present.  They can be kept in a reef tank, but may predate any crustaceans in the tank. 

For those who like to go all out and have some extra cash lying around, the Dragon Moray (Enchelycore pardalis) is the eel for you.  They are considered the “holy grail” of eels by many aquarium enthusiasts.  They are extremely attractive, but pretty rare to the hobby.  These eels eat fish, but will happily eat shrimp, clam, and other foods in the aquarium too.  They grow to about 36 inches, so they’ll need a large tank, a nice cave to hide in, and a clean, well-maintained tank.

Generally a 75 gallon tank is big enough for the smaller species, but a larger tank is always recommended.  Most of the common eels found for the aquarium will grow between two and four feet long, though there are some, like the Green Moray (up to 8 ft) that can reach several feet. Larger species should only be housed in the largest of tanks, and it is important to know as much as you can about the species you’re considering –  how big a species can get, how much space it needs, dietary needs, and to be prepared before considering an eel for the home aquarium.

We get a lot of really cool stuff in our fish room.  After years and years of seeing the same goodies each week, I love that we get new and interesting species from areas not previously collected from. New crabs, corals, shrimp, fish and other inverts arrive to us each week, but I have to say I’m particularly drawn to the various Sea Hares that show up. I mean, what’s not to like?  These are the equivalent of a cute and fuzzy bunny for your home aquarium!  But they’re more than just an adorable face.  These amazing little guys can play a big role in controlling pesky algae.

The Sea Hares consist of nine genera of family Aplysiidae.  Species of these various genera range in size from under an inch to over 27 inches in length! They are found around the world in temperate and tropical waters. They earned the common name Sea hare for their loose resemblance to a sitting hare or rabbit.  The rolled, erect rhinophores on their heads give these lovely little slugs the silhouette of ears, and their bodies are rather bulbous.  Most species have a thin calcified internal plate or shell in the small mantle cavity to protect the gill and heart.  The cavity is usually covered by variable skin flaps called parapodial flaps.  While most species slide along on their slippery belly, some use their large flaps to “swim” or glide through the water.  Sea Hares are hermaphroditic and may produce clusters, strings, or spirals of eggs in a healthy aquarium.

Sea Hares are all herbivores, feeding on different algaes and cyanobacteria, and making them great workers in a reef or rocky tank.  They may congregate in shallow waters in large numbers when food is abundant. These creatures have a keen sense of smell, (facilitated by their chemoreceptive rhinophores) which allows them to seek out appropriate food in sediments and rock.  They are variable in color and skin texture, but often exhibit a color, texture, or pattern that allows them to blend with the algae they eat.  This camouflage helps to protect them from predators while they lazily graze. Though they look slow, these guys are cleaning machines with big mouths and big appetites!

If the camouflage does not deter predators, these gastropods have a unique secondary defense.  When disturbed, stressed or harassed, they have the ability to release ink from glands in the cavity.  The ink may be white or colored purple or red, and it serves as a noxious smoke screen, deterring predators and allowing the hare to slip away in the confusion.  Their skin also contains other toxins making them unpalatable to predators.

When considering Sea Hares for your aquarium, keep several things in mind.  First and foremost, consider the size of the species you’re interested in.  You’ll need plenty of room and food (algae) for the one you choose, and some species like the Caribbean Dolibrifera are more suited for smaller or delicately arranged tanks.  As for any addition, keep the water quality pristine and be sure not to house sea hares with fish that may pick at or agitate them to prevent inking pollution on the tank. This is more a concern in a small aquarium where the ink would be less diluted should it occur.  Food may be supplemented with live macro algaes and spirulina or sheet algae if your natural algae growth can’t keep up with their appetites.  Sea Hares are rather slow, but heavy and may dislodge loose rock or coral, especially large species in close quarters.

In the right environment, you won’t be disappointed when you add sea hares to your tank. They’re a joy to watch, and a big help if you have nuisance algae.  Choose your chubby new pet with your needs and their’s in mind, and you’re in for a rewarding experience.