Category Archives: Saltwater Aquariums
Feed SubscriptionInvasive Species: Volitan Lionfish
Environmental responsibility is not something that most people think about when they are purchasing fish or plants for their aquarium, but it should be. Responsible ownership is vital to the long term availability of non-indigenous livestock. Unwanted fish and plants should never be released into the wild. In recent years there have been far too many stories about invasive plants and animals ravaging local ecosystems, with the blame being placed upon negligent or uneducated aquarium owners.
Believe it! 15 years later, the existence of Lionfish is not only documented, but they are growing in number, and becoming a major problem. NOAA has documented specimens ranging from Florida to New York. Some divers have reported hundreds on the offshore wrecks of the Carolinas. Lionfish are voracious predators, with little who prey on them. These invasive predators have the potential to destroy these sensitive ecosystems.
I hope that has given you something to think about, until next blog.
Dave
Spongeblog Squarepants
Sponges are animals? Believe it or don’t. Most of us are familiar with the dried colorless varieties that populate the kitchens and bathrooms of the world, or worse, the cellulose fakers that our children believe dwell in pineapples at the bottom of the ocean. But that’s not what sponges are at all. To me, they are some of the most fascinating and fun sea creatures. Fun? Well, they may not actually do anything, but in the home aquarium, they are “fun” in the aspect that they are beautiful and challenging to keep. They are remarkably adaptive, and if purchased healthy many not only survive in reef tanks, but can grow well and reproduce.
“Sponge” refers to the animals classified in the phylum Porifera; which means loosely “bearer of pores”. The first type of sponges that most aquarists encounter in their aquariums belong to the class Calcarea. These little guys are the tiny little sponges you’ll find in your sump, on the standpipes, and bopping around in the bio-tower or skimmer output. They are about the size of a large grain of rice with a fine, funnel-like extension at one end. They don’t hurt anything, so if you are new at this, don’t be alarmed.
Those sponges most commonly sold in the trade as ornamental sponges belong to the class Demospongiae. They are variable in form and color – from branching blue to orange paddles, to yellow or red balls. Others in this group that are not sold, but most reefers see in their aquarium are amorphous, encrusting species in colors of white, yellow, pink or black.
Sponges are one of the most primitive animals in the sea, yet are far more complex than most hobbyists are aware. All sponges differ from other marine invertebrates in that they have no true tissues or organs. Their structure is made up of silica based spicules and/or collagenous spongin. Most sponges are constant filter feeders with little need for lighting. To feed, sponges pump an incredible amount of water through their bodies. The uni-directional flow allows the sponge to absorb fine food particles (most not larger than 1.5 micron!) and release wastes back into the water column. It’s nutrition by diffusion, Cool Thing #1! As the sponge grows, it will modify its surface and cavities to optimize the water flow around and through it. For this reason, once a sponge settles in a spot in your aquarium, it is best not to move it.
Not all sponges are obligate filter feeders. There is a group of calcareous sponges, like my current favorite, the blue finger sponge, which are moderately photosynthetic (due to symbiotic cyanobacteria) as well as filter feeders. Use high light, high water flow, and don’t forget your calcium!
A note about purchasing sponges; Do not ever EVER remove them from the water. If you remove them, air bubbles become trapped in the body cavities and there is no way to purge the air so those cells will die. When buying, look for uniformity, no transparent or fuzzy spots. Don’t buy sponges with necrotic tissue, unless you are brave and willing to eat the cost, as many retailers will not guarantee sponges. If the sponge is new, and it was exposed in shipping, it may not show dead tissue for a while. If after a few days you see some of your new sponge dying, just cut off the bad spot. Sponges have remarkable regenerative abilities due to Cool Thing #2: Totipotent Cells. Think Stem Cells. These cells can revert to any type of cell needed to ensure the regeneration of the sponge.
I feel I should include Cool Thing #3 even though it’s not really related to the hobby but it’s cool nonetheless: Sponges are one of the most chemically rich resources identified to date. They’re packed full of biochemicals that are currently the basis of the majority of new pharmaceutical research. Products from anti-inflamitories to anti-cancer agents have been derived from sponges. But that’s a different blog.
I hope I’ve manage to convince you of the hidden charm and FUN of poriferans, and I encourage aquarists who want to attempt keeping sponges to research them further and to go ahead and try them out!
Species Profile: Anglerfish
Canister Filters for Saltwater
A customer recently asked me a question about using a canister filter on their saltwater aquarium. The customer had read on Reef Central that you should not use a canister filter on a saltwater aquarium, especially on a reef aquarium. That they do not work well, and will cause high nitrates.
This is a topic that you will see differing opinions on. The problem with canister filters is not that they don’t work on saltwater or reef aquariums, they work very well. Any biological filter is going to produce nitrate on a closed aquarium system, it is the natural end product of the nitrogen cycle.
This is why many reef tank owners will remove the bio balls from their wet dry filters, or run their systems on a sump only set up, in an effort to reduce nitrate production. This is why some people are of the opinion that canister filters should not be used on a reef tank. You can get away with this approach if you have a sufficient amount of live rock and substrate in your aquarium to act as your biological filter. In fact, live rock is an excellent source of nitrifying bacteria, and will function as a very efficient biological filter in an aquarium with enough rock. Most reef set ups will work well without a dedicated biological filter, so long as the biological load is not too high, and you are using a good protein skimmer. This method is often referred to as a “Berlin” style aquarium (lots of live rock, good water movement, heavy protein skimming, and no biological filter). Canister filters can still be used on reef tanks, they can be used as additional biological filters in heavily stocked tanks, and can easily be used for whatever chemical filtration media you may want to use.
Saltwater fish only tanks are a different story; in most cases you will need a biological filter to handle the fish waste and biological load, even if your tank has live rock in it. You will also want to have a mechanical filter on a saltwater fish tank, especially if you have large fish in your tank. Most canister filters give you the ability to operate them in different ways. You can use them for biological, mechanical or chemical filtration as needed.
Nitrate is going to be produced in any set up, some more than others. My best advice is to use as much filtration as your aquarium demands. Ammonia and Nitrite should be near zero in an established aquarium, if you are detecting either, chances are your aquariums biological filter is insufficient. Nitrate levels will creep up slowly over time in any system, so whatever filtration method you employ, you still need to monitor your water chemistry. Water changes will remove nitrate from your aquarium, so as long as you are testing your water, and performing regular water changes, nitrates should not be a problem.
Speaking canister filters, here’s a video my staff created to help aquarists set up a canister filter on their aquarium. Canister Filter Video
Thanks,
Dave