That Fish Blog – Aquarium Advice and Information

Sharks hold a fascination for everyone, whether they inspire fear or admiration.  They are iconic creatures many of us automatically associate with oceans, reefs, beaches and aquariums.  Though I have to say I am not a supporter of most sharks being placed in home aquariums, the possibility and temptation presents itself too often to be ignored.  Perhaps the best option is to present readers with enough information on some more appropriate species, and to encourage interested parties to research before purchase, so that these beautiful creatures will be kept in captivity more successfully.

In the vast majority of cases, captive sharks are best kept and observed in large, public aquariums, or better yet, left in their native waters to thrive.  Most species are simply too large, too mobile, and too high maintenance for the home aquarist.  If you have a VERY large aquarium, more than adequate filtration, and the financial means to acquire and support them, there are a couple of species that are less demanding that I’d like to introduce.  These species are the most common in the trade, and may be kept successfully with the right care and housing.

Bamboo Sharks, Coral Catsharks, and Epaulettes

Bamboo Sharks (i.e. Banded Catsharks) are probably the most frequently offered type of shark in the aquarium trade.  Several species are seen, they are banded brown and tan, and may have spots when they mature. Those in stores are reasonably priced and are typically sold as young pups. Egg cases are also available, allowing you to observe the embryonic shark as it develops and hatches in captivity (usually in 3-6 months). Pups are about 6 inches long when they emerge.  These sharks are native to the Indo Pacific and have the potential to grow to about 3.5 feet in length.

Coral Catsharks are a little less frequent, but they have very attractive black, tan and white patterns.  They are true tropical reef sharks, and grow to just under 30 inches in length.  They are quite docile, but should not be underestimated.

Epaulettes are very attractive, too, but they are not seen often in the trade.  These sharks are also tropical, collected from Australia and the surrounding region.  They are usually pale brown in color with dark spots all over and an ocellated black spot just behind the gills.  They reach a size of a little over 3 feet and are usually more expensive that cat or bamboo sharks.

Horn Sharks

Horn Sharks are another common type imported for sale.  Also known as bullhead or pig head sharks, these have stout bodies, a short, blunt head, with ridges over the eyes, and a prominent spine on the front of each dorsal fin.  Most often California or Mexican Horn sharks (and once in a while Port Jackson Horn Sharks from Australia) are found in pet stores.  These sharks grow to about 3.5 feet at maturity.  They are found along sandy bottoms and in kelp beds along the western coast of California and Mexico to Central America. These sharks prefer cooler water than those above (a chiller may be required), and they tend to excavate rock and substrate. 

We have 2 resident Horn Sharks here in our Touch Tank.  They spend most of their time under the rock formations in the center of the tank, but become quick and active when they smell food.  With the cooler temps, large volume and heavy filtration in the display they have grown quite fat and happy.  We’ve even found several spiral-shaped egg cases in the past couple of years!  These sharks are quite docile, with a mouth full of teeth designed to crush more than to tear. 

To Be Avoided

Several other species are seen from time to time including Wobbegongs, Dogfish, Nurse Sharks, and other even less appropriate species.  These should not, in my opinion, be offered or purchased for home aquariums  due to their large potential size, and/or special requirements.

Keeping Sharks

Sharks and egg cases should NOT be placed in tanks of less than 180 gallons (preferably larger), and the tank should be well-established. Despite their small purchase size and relatively sedentary behavior, they grow quickly and need space to move freely and turn.  The larger the tank the better (think about 3 times or more the length of the sharks adult size), furnished with some minimal rock piles and a cave where the fish can retreat and rest.  You’ll also want to supply ample flow and filtration as well as a good protein skimmer.  Even if you feel that the tank you already have may be large enough for the baby shark, or that you’ll have time to upgrade to a larger tank when necessary, it would be best to have an established tank of adequate size and function before considering a shark.

These fish will prefer their salinity on the higher side to mimic sea water, and keep it constant.  They will require regular water changes to keep their conditions pristine.  A varied diet of meaty foods should be supplied, including but not limited to shrimp, clam, krill, squid, silversides, and others (fresh or frozen, not live).  These fish can be fed 2-3 times each week, but be careful not to over feed for the sake of the shark and the water quality.  Hand feeding should be avoided to prevent accidental bites (don’t underestimate their speed or agility!).  Other fish may be housed with these sharks, as long as they are of adequate size, but be observant as some fish tend to be notorious harassers of sharks. Bottom dwellers and invertebrates like crabs, shrimp, and urchins should be avoided as they may become casual meals.  Also be aware that sharks have acute sensitivity to metals and chemicals in medications, so if a problem arises, thorough research should be performed before adding any treatment to the tank.

When you’re ready and you have carefully considered purchasing a shark, look for healthy, well-adjusted specimens that are feeding well and are not emaciated.  Avoid sharks with visible parasites or that look sunken (though newly hatched pups take a little while to fatten up).  With the right care and set-up they can be interesting and long-lived pets. 

Thanks for reading, and please let us know if you have any comments or questions about sharks for a home aquarium.

Until next time,

Patty

Shark egg cases image referenced from wikipedia and originally posted by Jean from flickr by falashad
Epaulette Shark image referenced from wikipedia and originally posted from flickr by Jim Capaldi

Please welcome Sam Yost as a blogger on That Fish Blog.  Sam has recently been promoted to Fish Room Supervisor and will be graduating from Millersville University in December with a degree in Marine Biology. 

Hello, My name is Sam Yost.  Being a hobbyist and working with other hobbyists in the trade, I have grown to understand that  keeping good water quality is one of the most important parts of aquarium keeping. If your aquarium water quality is bad, and a regular maintenance schedule is not kept, your fish will not be healthy, or will not live to their full potential.

There are many things that can happen in a tank to degrade the water quality. One of the major problems in maintaining water quality is overfeeding.  By overfeeding, a lot of unused food ends up breaking down in the tank.  It can be difficult to tell when fish have had enough, especially if there are a lot of fish in the tank, but it may be best to underfeed instead of dumping copious amounts of food. When uneaten food breaks down in the tank, it can cause a spike in ammonia, nitrites or nitrates. This spike, even if it is small, can be deadly to fish.  It may also settle into the substrate, where it can break down and cause chemistry problems, fish illness and other problems down the line.

There are several things you can do to help alleviate these overfeeding/water quality issues.

Consider what your fish need. Different fish can require different types and sizes of food, and some may require more frequent feedings than others. Generally, fish should be fed food that is about the size of their eye or smaller, or foods that can be broken easily, like flakes, that they can easily take in.

The amount of food administered should be what they can consume with in a minute or so. It is better to feed your fish several small meals than one large meal. Generally in a community, small feedings in the morning, evening and night will work great!  By doing three small feedings, there is a smaller amount of food being wasted.

Small, frequent feedings are also more healthy for the fish.  They are not eating so much that they look bloated, and the food can be used more efficiently.

You can also minimize the amount of waste that is put in to the tank by rinsing frozen food. This action gets rid of excess preservatives that are used to keep the food fresh so they go down the drain instead of breaking down in the tank.

Finally, small frequent water changes to reduce nitrates and gravel siphoning after several days can remove any waste and decaying food from the substrate.  A good, regular maintenance schedule will allow you to keep the water pristine and give your fish the best possible water quality for long, happy, healthy lives!

Thanks,

Sam

Hi everyone, Jason here!  Reefs can be described in so many ways.  They have every color imaginable, and creatures different in such drastic ways all living in closely intertwined communities.  Some are the hunters and some are the prey.  You could explore the same section of the reef everyday and there is a decent chance of discovering something new, whether a new creature or a specific behavior that allows so many creatures to coexist in a specific area.  Reproducing these niches cause a rather difficult situation when trying to put these rare and exotic creatures into the confined area of a home aquarium. 

One of our more frequently sought after fish are the Dragonets.  We usually carry three or four different species of them.  The most common two are the Green Mandarin Dragonet (Synchiropus picturatus) and the Blue Mandarin Dragonet (Synchiropus splendidus).  These fish are extremely colorful and very entertaining to watch when placed in an adequate aquarium.

The Dragonets are a challenging fish to keep in the home aquarium.  It is not as much an issue of how hardy they are but rather their diet which can make them difficult to keep.  Unlike most fish available to the aquarium trade, they are not easily enticed to eat prepared foods, mostly because they do not recognize these processed items as food.  In the wild, they hunt small crustaceans called the copepods.  They usually require a tank that has been established for about a year, with at least 90 pounds of live rock to provide a population of copepods.  The naturally occurring copepods provide prey for the active hunting lifestyle of the dragonet.  Some aquarists try feeding live black worms in an attempt to wean them off of copepods with occasional success, but this will require regular purchase and maintenance of live black worms. This practice works for a short time, but ultimately, black worms do not contain enough nutrition to act as a substantial food source.  If it were not for their constant hunt for food and limited food source these fish might be easier to keep. 

If you are able to provide a sufficient copepod/amphipod population, Dragonets can do well in the aquarium with most other fish.  However, when it comes to being kept with other Dragonets there can be an issue (besides exausted food sources).  A pair consisting of a male and female will usually get along without aggression, but if you put two males in an aquarium (unless it is very large) they may fight, as they are very territorial.  You can differentiate between a male and a female by their size and the elongated dorsal fin.  The male will be more robust than the female, and he’ll have a long extension from the dorsal fin that the female lacks.  Dragonets have been known to breed in captivity, but there is usually an extremely low success rate.  The male and female will rise up into the water column side by side to release the eggs and sperm.  Typically, they are more likely to show this behavior under actinic lights which simulate dusk or dawn lighting. 

If you have the well established reef to sustain them, and you want a show-stopping little fish, a Dragonet may be the way to go! 

Until next time,

Jason

Hello everyone! This is Craig, just writing a short blog on a group of fish that seems to be seeing a swell in popularity within the aquarium hobby lately. The danios. Yes… the lowly, boring, indestructible danios. You might just be surprised at how diverse and beautiful this group of fish has now become within the hobby. Gone are the days when Zebra danios (Danio rerio) and Leopard danios (Danio rerio ‘frankei’)were the only choices for hardy danio species. With the influx of newly discovered freshwater fish from South East Asia, there are many new and colorful species of danio. Almost all of these new danios still hold that indestructible danio trait. Here are some of the newest species in the hobby:

Danio choprae – the Glowlight Danio
These fish are one of the smallest of danio species. Barely attaining a size of 2 inches, these little fish are very active and have been known to spawn in home aquaria! Their body is a beautiful gold with glowing orange stripe going down its side. You can also see some blue barring on the fish when they are very happy! Kept in groups of 10 or more, these little fish are really spectacular!

Danio sp. “Burma” – the Burma Danio
This is a relatively new discovery in the world of danios. A subtle, yet beautiful fish. The Burma Danio is another smaller species that has a wash of gold and green down its sides. These washes form very distinct green spots that are ringed in metallic gold! When these little fellows are kept in large schools of 10 or more, they swim in tight formations and swing from one side of the tank to the other. If you want to see what schooling fish are all about, this is your fish!

Danio kyathit – the Orange Fin Danio
The Orange Fin Danio may look like its cousin the Zebra Danio, but when placed in a planted aquarium with plenty of other Orange Fin Danios, this species will develop broad, reddish-orange stripes on its fins. To make things even more interesting, this fish comes in a striped or spotted color morph! Regardless of the morph you see, this fish makes a robust and hardy addition to any home aquaria.

Devario sp. “Giraffe” – the Giraffe Danio
A slightly larger species of danio, these 3 inch schooling fish boast an iridescent green and orange pattern to their sides that will remind you of a giraffe’s mottling. Very hardy and very rare! This species of danio is one of the most uncommon seen today and is already proving to be a beautiful and hardy fish. As with all danio species, these fish are lively and appreciate a well planted aquarium.

Laubuca dadiburjori – the Dadio
Hailing from India, this tiny danio reaches barely over an inch and is another rarity in the hobby. It has shown to be very hardy and even able to tolerate cooler water temperatures. The Dadio shows a more muted coloration and has a thin body with pale orange on the side and a thin blue stripe going through the orange. There is also a second color morph in which the blue stripe has three tiny little balls of blue spaced along the stripe. This is yet another species that will benefit from being kept with several of its own kind.

As you can see, there are some beautiful and interesting new species of danio that are just now making their way into the hobby. I, like most hobbyists, have overlooked the danios for years, but seeing the newer introductions, I have to say that they are indeed charming little fish that add life and even a little splash of color your aquarium. Even the old standards, the Zebra and Leopard danios, tend to take on new beauty now! Just remember, these spunky little fish will always do better in larger schools of 6 or more. Also, these guys love to eat, so a couple of small feedings per day will help to keep them in good shape. If you decide to get a handful of these little guys, enjoy!

Thanks,

Craig

Hey Fish Blog Followers! There are lots of different types of freshwater communities created by hobbyists. Some people choose a peaceful community of tetras and other small docile fish, while others opt for a tank populated with predators or other territorial species, often a fine balance between tolerance and aggression. Many aquariums are somewhere in between, referred to as semi-aggressive communities, which often include fish such as barbs, gouramis, large tetras and others that fit into the category.  Today I wanted to give a small introduction to several popular species of fish often purchased for these aquariums that may interest you.
 

Not Exactly Maneaters

Some of the most popular fish for the freshwater semi-aggressive community are the cyprinids known as sharks. These are not the cartilaginous carnivores as featured in movies or the Discovery Channel. These fish are found primarily in the waters of Southeast Asia and Thailand. There are several species that are often imported for use in the aquarium trade, and several species also referred to as sharks that are less common in the trade. Though from several different genera, these fish all have in common the pointed heads and large, curved dorsal fins that give them their misleading common names.

Though these fish lack teeth, as a general rule they are considered semi-aggressive, if not for the sizes they attain, then for the territoriality they often express as they mature. They are generally not suitable for tanks under 55 gallons (some not less than a 75 to 100 gallon tank) and should only be mixed with fish that can stand up to the potential for chasing and harassment that sharks can dish out (especially to their own kind). Smaller fish may eventually be seen as a snack as the fish grow. Sharks make bold and interesting additions to freshwater semi-aggressive communities, as long as the tank is of adequate size and the conditions in the tank suit their needs. Suitable tank mates for most include fish like barbs, catfish, large tetras, and other fish of similar temperament.

If you are considering the addition of a shark to your community, there are several things to keep in mind. As far as the set-up goes (besides having an adequately sized aquarium) be sure that you provide plenty of cover like wood, plants or rock formations so these fish can hide and fell secure when they feel the need. A tightly fitting lid is also highly recommended as they tend to be terrific jumpers, especially if startled. Most common sharks prefer well-aerated, clean water with temps between 74 and 81 degrees (F) and a pH maintained between 6.5 and 7.5. Sharks do not tend to be finicky eaters, readily accepting flakes, pellets and frozen, freeze-dried or live treats like bloodworms, tubiflex, glass worms, plankton, brine shrimp or other meaty tidbits.

Popular Species

There are several species of freshwater shark, and variants of these species, regularly available on the market that may be candidates for your semi-aggressive community.

Bala Sharks (Balantiocheilus melanopterus), also called Tricolor Sharks, are a popular variety with silvery scales and bold black edges on the fins and tail. Though attractive, this species tends to be rather skittish unless kept in small groups. These fish tend to be more shy and docile than many of the other sharks. Reaching a length of between 13 and 15 inches potentially, this species is best left to aquarists with tanks of at least 75 gallons or more for a single specimen, much larger if they are to be kept in the security of a small group.

Rainbow Sharks (Epalzeorhynchos frenatus) may be the best choice for most hobbyists, despite their tendency to become territorial and increasingly aggressive as they mature. Also known as the Ruby Shark or the Red-Finned Shark, this species grows to only about 6 inches and bears bright red fins that are quite attractive. Several variants have also been selectively bred to make things even more interesting, such as albinos and white-finned. These sharks should be kept as a single specimen in the community as they do not tend to tolerate others of their kind in the confines of an aquarium. Red-tail Sharks (Labeo bicolor) are similar in size and behavior to Rainbow Sharks, but lack the red fins and display a velvety black body and a red tail.

Other types of freshwater sharks include Black Sharks, Iridescent Sharks, Colombian Sharks, and others that are even more uncommonly seen in the trade. For various reasons, these species are typically not suitable for the average semi-aggressive community, and careful consideration should be taken before purchasing these species.

Black Sharks are attractive, but they grow rather quickly to about 30 inches in length, too large for most home aquariums. Iridescent Sharks are actually a type of catfish that also quickly grows from a 2 inch juvenile to lengths nearing 4 feet, another that should not be considered for the average home aquarium. Colombian Sharks are sleek and active catfish too, rounding out at about 10 inches, with huge appetites and a preference for brackish to marine conditions as they mature.

Thanks, hope this information is helpful!

Patty