That Fish Blog – Aquarium Advice and Information

Hello, Frank Indiviglio here.

The subjects of this article are often sold in pet stores as “curiosities” to be added to aquariums housing typical tropical fishes.  Unfortunately, due to their unique dietary requirements and feeding methods, none do well in such situations.  As most hobbyists are unaware of their fascinating behaviors, tanks are rarely set up solely for these creatures, and most perish in short order. 

I recently set up a tropical West Africa themed exhibit for a public aquarium, based on similar tanks I have maintained at home and at the Bronx Zoo.  It was a big hit and generated many inquiries from visitors who wished to have a similar aquarium in their homes. 

The aquarium I’ll describe here is similar to that exhibit.  It houses animals from the same region of Africa, and includes two of the pet trade’s most interesting and overlooked fishes, a social shrimp and an active, aquatic frog.  All follow different lifestyles and utilize unusual feeding methods, yet they co-exist very well.

General Considerations

The animals described below hail from West Africa, and all prefer heavily planted aquariums maintained at 78-80 F.  They are quite sensitive to water quality, so be sure to choose a filter that is of an appropriate size for your aquarium, but avoid strong currents (from the filter’s outflow) within the tank.  A comprehensive water test kit  should be used regularly to assure that pH is held between 6.8 and 7, and that the water is moderately soft (water softness is not a major concern, but is best monitored).

Due to the feeding habits of the elephant nose (see below) and the desirability of establishing a lush growth of plants, I suggest that you use Porous Clay Gravel as a substrate.

Peter’s Elephant Nose or Elephant-Nosed Fish, Gnathonemus petersi

This first recommended member of the aquarium is truly interesting in appearance and behavior.  It uses the greatly extended lower jaw from which its common name is drawn to root in the substrate for aquatic worms and insects, its main food source.  Organs near the tail discharge electrical impulses that allow the elephant nose to navigate, hunt and, according to recent research, to communicate (please see the article referenced below).

Feeding and Observing the Elephant Nose

The elephant nose is a confirmed live food specialist, and rarely feeds before nightfall…hence it is always out-competed for food when kept with swordtails, platys and other typical community fishes.  A heavy growth of live plants will encourage it to move about by day; Moonlight Bulbs  are great for use in observing nocturnal behavior. 

Although only small specimens are usually seen in the trade (adults do not ship well at all), the elephant nose can reach 10 inches in length – a group of adults foraging in a large aquarium is a very impressive sight.  Live blackworms can form the foundation of their diet, but you should endeavor to include live bloodworms, glassworms and other such invertebrates regularly.

Click: A Community Aquarium for Fishes, Shrimp and Frogs – West African Oddities – Part 2, to read the rest of this article.

Frank Indiviglio.

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.

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.

The Marine Bio staff That Fish Place gets a lot of questions about husbandry of fish and inverts in aquariums. When adding any new inhabitant to an aquarium we recommend researching the conditions, max size, and temperament of the species you are interested in to ensure that it will be a good fit for your tank and the other creatures you may already be keeping. And, as always, quarantining new additions in a separate aquarium is highly recommended.  If in doubt, we’re always here to answer any questions you may have so you and your aquarium continue to stay happy!

 One question recently submitted was from Al in New York:

 I’m going to be starting up my 55 gallon set-up with blue rams. My questions are what will make good tank mates? What water conditioners might I need? Should I use live plants, and if so which do you recommend? How many rams should I add?

 Marine Bio Responded:

There are several fish you can keep with rams. Lemon tetras in a school of 6-10 would be nice. Serpae tetras in a large school of 8 to 10, or Brilliant rasboras in a similar school would also work well. These are fish (introduced gradually) that I would start with once the tank is established. Rams should not be added to the tank for at least 2 to 3 months after the introduction of your first fish. So you can maybe start with 6 Serpaes or Brilliant rasboras, and let the tank run for with nothing else added until the cycle is complete.

During this time, you can certainly add plants if you wish, but do not add more fish. I am a proponent of live plants in aquariums. They make for a beautiful and healthy environment, and many fish will do very well in a planted tank that is similar to their native waters. Plants that you can add may include Rotala, Ruffled swords, Ozelot swords, dwarf sagittaria, and Bacopa. These are all nice plants to start with, and there are others you may prefer, it is all according to taste and the lighting and conditions you present. Just make sure you add Flourish Iron or a similar product to your tank to help your plants to stay healthy.  

After you cycle your tank with the tetras or rasboras, you can add some Corydoras Catfish in school of 5 or 6 to help keep the bottom clean. Some smaller pleco species may also be considered.  Rubbernose plecos, for example, are great algae eaters in planted aquariums, as are Bristlnose and Medusa plecos. Gold nugget plecos and Queen Arabesque plecos would also work, and they are really attractive. When you are ready to add rams, I would think a small group of 5 or 6 would work out great for you, maybe 1-2 males and the rest females.

Water conditions? Well, rams prefer warm, soft water. So you want your temperature to be in the range of 80 to 82 degrees, and your pH should be around 6.5 to 6.8. You may need a buffer to maintain the keep the water at this pH and there are several available to choose from and keep on hand for water changes and maintenance including Seachem Discus Buffer.