That Fish Blog – Aquarium Advice and Information

Please welcome back Eileen with another excellent post.

What do you call the fizzy, carbonated drinks sold in cans and bottles and out of vending machines by companies like Coca-Cola and Pepsi? Soda? Pop? Cola?

What about the athletic shoes made by companies like Nike and Reebok? Sneakers? Trainers? Tennis shoes?

Or, more importantly for aquarists like us, what type of fish was “Dory” in the Disney movie Finding Nemo? If you say Blue Tang, Hippo Tang, Palette Tang, Regal Tang, Flagtail Surgeonfish, or Pacific Blue Surgeonfish, you aren’t wrong.

Just like people from different areas can’t agree on what to call their drinks or shoes, aquarists have lots of different opinions on what to call the fish and invertebrates in our aquariums. These “common names” are just nicknames that we as hobbyists use to identify the animals that we keep. So how do we know that we’re all talking about the same fish when we talk to other hobbyists that might even come from another country or speak another language? Do we pull out a portable DVD player and point to the screen every time?

Enter the Binominal Nomenclature System…the dreaded “scientific names” that we see written in italics in every aquarium guide and identification book we read. No matter what language we speak or what part of the world we are from, every picture of that bright blue fish with the black markings and yellow tail will undoubtedly say the same thing under it….Paracanthus hepatus. Understanding how this system works and how we can use it to our benefit is helpful to every level of aquarist.

A Brief History

This system of classifying and naming every plant and animal discovered started with a family of scientists in the 16th century but didn’t truly begin to gain in popularity and use until a 18th century Swedish botanist by the name of Carolus Linnaeus began to assign a two-part name to every plant, animal or mineral that was discovered. The names were created based on the animals appearance or behavior as they observed it at the time. Even now, some of Linnaeus’s original classifications still stand even though many have been amended as knowledge about the organisms has increased.

One things that hasn’t changed is the Latin Linnaeus used to start his naming system. Latin was already a dead language by the time Linnaeus started using it. No one spoke it in everyday life and only those who were educated in universities had a working knowledge of it. This unpopularity and relative uselessness of the language was what actually made it perfect for scientific use. Using a language that wasn’t used every day means that it won’t change a whole lot. Think back to any classic English works that you might remember like Shakespeare and then think back to a magazine or newspaper that you read last week (or like this blog you’re reading right now, for that matter). Do they sound the same? Language changes and evolves through time but using a language that essentially hasn’t been used since the time of Caesar and the gladiators means that it isn’t going to go through a whole lot more evolving. Latin is also not a national language of any country around the world, then or now, so it is more likely to be accepted by everyone while if the naming system was based on a specific country’s national language, any countries who aren’t too fond of that nation aren’t as likely to use and accept it.

How It Works

Every creature on Earth is classified into one of 3 Kingdoms – Bacteria, Archaea, and Eukarya (this last Kingdom was adopted in the 1990s to combine four other Kingdoms -Animalia, Plantae, Fungi, and Protista). From there, the classifications are broken down further into a Phylum, Class, Order, Family, Genus and Species. Aquarists and hobbyists primarily use the last of these ranks – Family, Genus, and Species – so that is what we’ll focus on here.

The Family is one of the first ranks where it usually becomes obvious that all the fish in the group are all related. In some of the higher ranks, the similarities may be so vague that it might be hard to tell how two things are related just by looking at them. A Family (usually ending in -ae, by the way) would include all of the fish we commonly know as Tangs or Surgeonfish, for example, although we can still see that a Yellow Tang (Zebrasoma flavescens) is visibly different in body shape from a Hippo Tang (Paracanthurus hepatus). We can tell that if we have a fish with a scalpel-like spine at the base of its tail, a generally teardrop-shaped body, a mouth designed for algae grazing and a flattened body is probably in the Family Acanthuridae with other tangs and Surgeonfish, even if we don’t know yet if it is in the genus Zebrasoma, Acanthurus, Paracanthurus, or Naso.

After the Family, the genus (“genera” in the plural form) is the next level of classification and where we start getting very specific about the identification of an organism as it applied to the aquarium hobby. The genus is the first part of the two-word scientific name. In Rhinecanthus aculeauts, most commonly known as the Picasso Triggerfish, “Rhinecanthus” is the name of the genus which also includes the Bursa Trigger, Huma Huma Trigger, and Rectangle Trigger. At this level, we still can’t point to a fish and know exactly what it is from the genus it is in, but aquarists can typically make some important generalizations about a fish by becoming familiar with the genera commonly available in the aquarium trade. By looking at the genus of a triggerfish, we can usually tell if it is probably going to be a super-aggressive powerhouse (Balistes, Balistoides, Rhinecanthus) or if it will be a more docile, Reef-safe addition (Xanthichthys, Melichthys, Odonus). Genera can lead to some confusion however; as our knowledge of organisms grows, the genus classification is the most likely level to change. This is especially seen in African cichlids. Genera are being added and modified regularly as fish that were once thought of as color variations of the same fish are being classified as new species altogether.

Check back on Wednesday for the conclusion of Eileen’s article.

Welcome back Brandon Moyer for Wednesday’s post.

Many aquarists are familiar with varying forms of symbiosis.  The most popular example I can give is that of the clownfish hosting in an anemone, providing the anemone with food and in return receiving protection from predators.  There are several different types of symbiosis, but both parties do not always benefit from these close relationships.

You may not be familiar with one creature that forms a symbiotic relationship with humans.  This relationship is considered parasitism, and we receive the poor end of the deal.  The species is called Vandellia cirrhosa, or candiru.  These fish live in the Amazon River basin, grow to about three inches in length, and prey on other species of fish.  They can detect the waste excreted by other fishes gills and follow the trail to find their prey.  Rather than eating the fish, they use barbs on their gill covers, or opercula, to wedge themselves under the opercula of their victim.  They then bite into an artery in the gills and drink the fishes blood.  They can completely gorge themselves with blood in as little as thirty seconds!

What makes the candiru even more horrifying is that their ability to detect waste from other fish also allows them to detect human waste, more specifically urine.  They have been known to follow the trail of urine of those who relieve themselves in the water and actually swim up the victims urethra!  If that doesn’t make you cringe, once in the urethra they are unable to turn around, and because of their spines they cannot back themselves out.  They eventually die in the urethra while the victim experiences swelling and obviously extreme pain.  The only way to remove the fish is through surgery. 

I hope you have enjoyed my first article on symbiosis.  Make sure to wear a bathing suit if you are ever swimming in South America.  Look for another blog on pistol shrimp and goby mutualism and pearlfish and sea cucumber parasitism.

Welcome back Cory Shank with an article on aquarium fish availability.

Throughout the year, the availability of certain aquarium fish and invertebrates can change for what seems to be no reason at all. It may be for a few days to a week or even a few weeks extending into months. There are many reasons for absence of your favorite aquarium resident, but the one most overlooked is the weather.

One must remember that almost every aquarium inhabitant has begun their journey from the rivers, lakes, and oceans from where they reside. Now if the fish or invertebrate is either tank raised or tank bred, then obviously they have not traveled that far, but for the most part everything is collected from the wild. The weather is quite variable, especially in the tropics, season to season. This is where most of the marine organisms are collected. The largest interruptions from the Caribbean to the Indo-Pacfic regions are during the hurricane season. The Caribbean tends to be more vulnerable to tropical systems than the Indo-Pacific regions, mainly because of the size difference.

Hurricanes, tropical storms, and even tropical depressions and waves cause an increase in wind, generating larger ocean swells, which can wreak havoc in shallow collection areas. Obviously during a hurricane divers can not enter the water and collect fish, but one storm can delay collection for up to a week or even longer. As seen with Hurricane Ike, 2 days prior to the storm, there were waves and tides above the norm, nearly a thousand miles from the storm, affecting the entire Gulf of Mexico and parts of the Caribbean. After the storm passes, collection depends on how fast the water clarity increases, this can take a few more days to happen. Looking at this situation, the collection for one area can be shut down for a full week. This increases the demand for certain organisms, making the availability for the following week extremely high, which leads to a less than healthy fill rate for orders for the orders following a storm. The Caribbean has been highly vulnerable this year, with a few storms passing through major collection areas of Scarlet Reef and Blue Leg Hermit Crabs, along with Royal Grammas, and Peppermint Shrimp.

Hurricanes are not the only culprit: excessively warm or cold water can affect availability. Organisms will move from shallow regions to deeper zones to escape a time of warmer water. This can also be a seasonal migration, affecting availability for a longer term. El Nino and La Nina can lead to big changes in global water temperatures. In such extreme events such as the 1997-98 El Nino event, populations can be severely impacted. Responsible marine fish and invertebrate collectors will either halt or decrease collection significantly in order to help the population rebound.

Weather can also play a role after the fish have been collected. After collection, the organisms will be sent to the wholesaler’s facility. In order for the organisms to arrive safe and in good health at your local pet store, the weather along the route must be taken into consideration. The time of transport relies heavily on how the fast the airlines can get the fish to their final destination. A heat wave can destroy an entire shipment if it were to be delayed by even a few hours. The same goes for extremely cold weather in parts of the country. The shipment, if delayed, could become frozen if the heat packs fail or run out.

So the next time you can’t find your favorite fish at the store, think about where it is coming from and what the weather is like in its hometown!

Thanks Cory,

Until Next Time,

Dave

Patty here,

There are many snail species available for the marine aquarium hobby, and many of them are beneficial to the aquarium as they perform specific duties aiding in the health and up-keep of the tank. Popular types include ceriths and nassarius, great for sand bed stirring and clean-up, and various Turbo species and other algae eaters like astreas and trochus. For the most part, the majority of the snails you find in shops are there for your aquarium’s benefit. There are also many types of snails for sale that may not be a benefit such as predatory snails, and yet others that may find their way into your reef by hitchhiking on or in live rock or corals that you introduce. I want to introduce some naughty snails, and some really naughty snails you can watch out for to avoid potential issues they may present.

Murex Snails
There are several species of Murex snails that may hitch on rock or collected specimens. Most murex snails are characterized by rough spines or knobs on the shell. They are shaped more like conchs, but are usually rather stout. These are predator snails, and will prey on clams and other bivalves, starfish, and other snails. Some species drill through the shells of their victim to eat the flesh inside the shell. Better safe than sorry with murex snails, remove them to an iso tank or species tank if you want to watch them, they will feed on meaty frozen tidbits if live prey is unavailable.
Tulip Snails, Fasciolaria sp.
Tulip Snails are beautiful creatures, with stunningly banded, smooth shells and a deep pink or red body. These snails are unfortunately carnivores, so they cannot be kept with beneficial snails like turbos and astreas unless you want them to be eaten. They will also prey on bivalves, so no clams, scallops, oysters, or fun little mussles will be around for long if you introduce one of these to your reef either. Tulips are nonetheless offered periodically for sale. They can be kept in the right tank, and are enormously entertaining, but consider their diet before purchasing one. They will feed on bits of frozen mussel, clam, and other meaty foods in the absence of live prey, and can get along with fish and crustaceans that can move away from them.
Flamingo Tongue, Cyphoma sp.
Though these little snails are very pretty, they are not reef safe as they feed only on gorgonians. If you find that one has hitch-hiked on a new specimen, which is not necessarily uncommon, it should be removed from your main reef. They are beautiful specimens, however, for a small species tank. If you have large gorgonian colonies, small pieces can be clipped and place into the species tank to feed the snail.
Black Limpets, Scutus unguis
Most limpet snails are safe and even beneficial in reef aquaria. The Black Limpet will eat algae but also has a tendency to feed on coral tissue, so if seen in a reef, it should be promptly removed before it is able to proliferate. This is a very cool snail, its delicate black mantle may appear to you to be a sea slug, but its white shell is cloaked by the ebony mantel. If you should come across one in your reef, the first challenge is to dislodge it from the rock, which is not an easy task. You may need to remove the rock itself, which may be placed in a small species tank for observation and enjoyment.
Sundial Snails, Helicanthus variegatus
Sundial snails are small button-shaped snails, kind of flat, with a spiraling, checkered shell. The operculum is shaped like a cone. These snails are most commonly seen on Zoanthid polyps, their primary food source. Obviously, these snails can be detrimental to polyp colonies and they should be removed from your reef if you come across them. They hide well amongst polyps and rock, so be sure to keep an eye out, especially when introducing new colonies.
Conchs and Cowries
Just an additional note, there are lots of different cowries and conchs offered in the trade today, and they are some of the most interesting snails you can find. Be responsible as aquarists, and be sure to find out about any species you’re interested in before purchasing them. Most species are safe and functional, but others with size and diet in mind may only be appropriate for large, non-reef homes. Some Cowries can grow to 4 inches or so, and though reef safe, they can easily topple rock and corals in their travels. The Egg Cowry only dines on soft corals. As for Conchs, most offered are marvelous sand sifters like our burrowing conch, but many conchs can grow to be very large and thus disruptive in smaller tanks and tanks with limited sand bed area. Crown conchs, Queen conchs, and many others are omnivores and may prey on bivalves if algae and other foodstuffs are scarce, so be aware of the needs of the snail you purchase.

Until next blog,

Patty

Frank Indiviglio here with an introduction to Echinoderms.

Sea stars, or starfishes, are perhaps the most familiar of the Echinoderms (a phylum containing over 7,000 marine species), and many adapt well to aquarium life.  Most people are quite surprised to realize that they are active, interesting predators that routinely exhibit a wide variety of behaviors in the aquarium.  Many are also useful scavengers, but all are predatory in nature and, depending upon the species, will consume mollusks, coral polyps and other sedentary invertebrates.

Red-knobbed Sea Star, Protoreaster lincki
When picturing a sea star, many people think of the simple reddish-orange animal so often seen as a dried curio in beachfront shops.  However, many are fantastic in appearance and coloration.  The Red-knobbed Sea Star, with brick-red dorsal spines set off against a dazzling white background, is a case in point.

Native to the Indo-Pacific region, this perennial aquarium favorite reaches a length of 12 inches and is capable of consuming quite large mollusks.  It is best fed by placing a piece of clam, scallop or mussel directly below the body, although it is quite active and capable of finding food on its own.

Although sea stars are quite adept at sensing and locating food, they respond more slowly than do most fish.  Therefore, they will usually remain hungry in a mixed-species tank unless care is taken to see that food is placed directly below each animal.

Brittle Stars
Brittle stars bring the word “bizarre” to mind instantly, even to those well acquainted with the sea’s curiosities.  They react very quickly to the scent of food, and their long, slender arms thrash wildly about as they begin to explore.  It is quite a sight to see a tank housing several of these normally sessile creatures suddenly come to life – the many sinuous arms seem to take on a life of their own, yet the animals glide unerringly toward the source of the odor that aroused them.

Brittle stars are harmless to most other creatures and are extremely valuable scavengers.  Perpetually hungry, their thin arms can get into the tiniest of crevices between coral heads and other places where bits of uneaten food might otherwise go unnoticed.

Sea Urchins
These slow-moving, spiny invertebrates are often encountered in tide pools, and are worldwide in distribution.  The spines of all are effective weapons, and many secrete venoms that are as yet not well-studied.  Hot-water baths seem to assist in alleviating the sting caused by most species, but handle all with extreme care.

With over 800 species identified to date, urchin enthusiasts have much to celebrate.  Many unusual species are commercially available, including the Long-spined Sea Urchin, Diadem antillarum and the Pencil Urchin, Heterocentrotus mammillatus. Both feed primarily upon algae, but will also consume bits of fish and shrimp.  The Long-spined Urchin is armed with extremely sharp spines, much to the chagrin of bathers in tropical waters.  The Pencil Urchin is well named – its spines, less numerous than those of other urchins, are very thick and blunt-ended.

Wave your hand above a captive or wild sea urchin and you will likely be surprised at how quickly the seemingly inert beast responds.  A shadow or object passing overhead is viewed by an urchin as a predator, and all the spines are oriented to face the threat.  Although parrot fish, sea otters and wolf fish are adept at clipping off urchin spines or turning the animals over to expose the soft underbody, the defense is, in general, foolproof.

Despite their slow-moving ways, sea urchins are quite active and seem bent on getting into every possible nook and cranny in their aquarium.  Be sure to check that they do not wedge themselves too tightly into small corners, or tumble backwards into coral and become stuck.

I’ll cover individual species in depth in future articles.  Until then, please write in with your questions and comments.  Thanks, Frank.

You can read more about sea urchins, sea stars and their relatives at:
http://tolweb.org/tree?group=Echinodermata&contgroup=Deuterostomia