Sea Creatures & Me

Because my friends are not reefkeepers—and most have never had an aquarium of any kind—I feel like I need to provide a glossary of some sort so they won’t bounce off unfamiliar words and phrases. To a limited extent I’ll explain a few concepts here as well. Since I’m a beginner and this blog documents my beginnings, my definitions and explanations may not be precise. I’ll make corrections and additions as necessary. This is not meant to be comprehensive. There are plenty of sites out there with more and better information than you can find here. This is, as I said, for my friends so they will be able to have some understanding of my little experiment.

Salty Slang: Getting Oriented to Reef-speak

Words in bold are found elsewhere in the glossary.

LFS common slang for “local fish store”.

nanoreef a small salt water tank. There’s no firm number of how small “small” is, but most people consider a salt water tank of 20, 25, 29 gallons or below to be a nanoreef.

picoreef a very, very, small salt water reef tank. Usually refers to the extreme end of nanoreefs, 5 gallon tanks might be “pico”, but 2.5 gallon tanks—or even smaller—would certainly be considered picoreefs.

biotope a biotope refers to an ecological area and the things living in it. The grass beds where seahorses live in the wild are a biotope, so are the coral reefs, etc. In marine aquaria biotope usually refers to a tank in which all the life forms are from the same geographical area and would be found living together in nature. A piece of live rock is a natural biotope.

hitchhikers common slang for life that comes on live rock. Usually doesn’t refer to algae, but invertebrate life forms such as worms, anemones, sea stars, zoanthids, shrimp, crabs, etc.

Live rock: cured and uncured Live rock consists of rock or concrete that has been immersed in sea water and populated by the organisms living there, from beneficial bacteria on up to invertebrates. Most often it is “natural” rock harvested from locations like Fiji, Marshall Islands, Tonga, etc., but it may also refer to aqua-cultured rock that consists of manmade pieces immersed in the sea, and allowed to be populated by the native organisms. When it’s pulled from the water and shipped, many of the organisms, both large and small, die off. “Uncured” rock has a lot of dead organisms on it. People cure rocks by different methods, but basically curing consists of scrubbing off the dead organisms with a brush, putting the rock back into salt water with good current and letting the situation on the rock stabliize, so that things stop dying and eventually start growing back. When the die-off is complete and the rock is starting to look healthy again it is said to be “cured live rock”. A lot of organisms don’t survive the curing process—low light, no food—any better than they survived shipment. Only the hardy survive. Some of the hitchhikers on live rock are beneficial, some are benign and a few are troublesome. Among the beneficial organisms are anaerobic bacteria which help with the nitrogen cycle.

nitrogen cycle refers to the process by which bacteria convert toxic substances to less toxic substances. Waste from food, fish, invertebrates, microorganism dying, etc. produces ammonia which is toxic. Nitrosomas bacteria (assorted species) break down the ammonia and convert it to nitrite, which is less toxic, but still not good. More nitrosomas bacteria convert the nitrite to nitrate which is less toxic still. In freshwater tanks this is as far as it goes; nitrate must be removed/decreased by regular water changes. In salt water tanks with live rock anerobic bacteria that live in the rock (and also in the substrate to some extent) convert nitrate into nitrogen gas in a process called denitrification. This helps control the nitrates, though some water changes are still necessary unless the bioload on the tank is extremely low. (Usually there is more nitrate produced than can be eliminated naturally.)

cycling the tank a new tank doesn’t have a big healthy population of denitrifying bacteria. It takes time to grow a colony sufficient to keep the ammonia and nitrite levels at zero. Cycling the tank refers to putting a small amount of fish, food, live rock, etc. into the tank and letting it run, while monitoring the ammonia, nitrite, nitrate levels and doing water changes to prevent the toxicity from killing the fish (if a fish is used).

bacteria: the good, the bad and the nasty (cyanobacteria) The good bacteria are the denitrifying bacteria mention above. Bad and nasty bacteria is the cyanobacteria, sometimes called algae, which is a misnomer. It’s not algae though it can spread fast and cover rockwork, glass and organisms. Descriptions of cyanobacteria usually have the adjectives “slimy” and “mucous” in them. It’s color can vary from red to brown to green (based on what I’ve read about it).

red tide refers to a type of “bloom” or rapid multiplication of some types of dinoflagellates. The extensive rapid multiplication of these dinoflagellates will choke out other marine organisms in the area by producting toxins. Red or reddish brown is a common color of massed “bloom” when it occurs, hence the name “red tide”.

dinoflagellates are a type of plankton, being a small free-floating marine organism. They are not strictly speaking considered “algae” these days though “algae bloom” is still a common term used to describe red tide. Dinoflagellates are considered to be neither plant nor animal and are contained in the Kingdom Protista.

diatoms are usually a microscopic single-celled algae, with a cell structure made of silicon. Consequently they tend to be hard, not “grassy” like other algaes.

algae: macro, symbiotic, nuisance, coralline Coralline algae is usually the hard pink, purple or red algae that is found on live rock (and occasionally aquarium glass). Symbiotic algae is called zoonxanthellae and is explained below. Nuisance algae comprises a vast number of algae species which thrives in the presence of lots of nutrient and lack of herbivores. Algae can overrun a reef (or reef aquarium!) choking out the invertebrates living them. Macroalgae is larger than regular algaes which can become a nuisance. It’s generally considered to be beneficial because it sucks up excess nutrients that promote the rapid growth of other algaes, less easier to contain. Macroalgae must be kept in check in an aquarium, too. Kelp and common seaweed are macroalgaes.

zooxanthellae symbiotic algae that lives within the tissues of coral as well as some other marine organisms (like the mantles of clams). Corals (and other creatures) take these algaes into their tissues, incorporate them and then use the energy they produce from photosynthesis. Sometimes when corals are diseased or stressed they will expell their zooxanthelllae. This is called “a bleaching event” or “bleaching”. Without the symbiotic algae the coral will rapidly decline and die. Corals with zoonxanthellae get most of their “food” from the zooxanthellae, though they do feed on plankton as well.

light OK, this is way too complex for me to expound upon, especially since I’m no expert. I will say this, however, light is extremely important in a reef aquarium because many of the organisms will have zooxanthellae and therefore will need a certain number of hours of high quality light. Actinic lighting is a bluish lighting meant to simulate the light waves that reach marine organism at lower depths. As light waves pass through water certain colors get filtered out as the water gets deeper. Compact flourescent lights (which may include daylight bulbs and actinic bulbs) as well as metal halide lights are commonly used to insure reef organisms with zooxanthellae get enough light. There are also “moon” or “lunar” lights available that simulate moonlight under the ocean, so that a reefkeeper with a sufficiently sophisticated lighting system can simulate nature as closely as possible. Although corals can be propagated by fragmentation (aka “fragging“), they also reproduce sexually in the ocean—and the light cycle, including moonlight, are crucial for this. Lunar lighting in an aquarium may not just make the corals feel more “at home”; it may also serve to put them “in the mood”.

substrate the rocks, gravel, sand, silt, etc that are on the bottom. On earth it’s called “the ground” or “dirt”; on the moon it’s called “regolith”; in aquariums it’s called “substrate”.

benthic refers to things living in the substrate.

pelagic free floating in the water, living in the water column.

the water column this is an odd term; it’s not a “column” at all, but merely refers to the water in the tank, around the reef, etc.

plankton This is the general term for small (even microscopic) organisms found suspended in the water column in the open ocean. (One source I checked considered jellyfish to be planktonic, because it drifts with the currents). Plankton may consist of algae, bacteria, and animals like larvae or small critters like parasites and other tiny marine animals that live in the ocean waters.

zooplankton This refers to the plankton comprised of small animals.

phytoplankton This refers to plankton comprised of algaes.

glass anemones Small, prolific, nuisance anemones in the genus Aiptasia which will overrun a tank, stinging and killing pretty much anything in their path as they multiply. They are difficult to eradicate because, like so many weeds, if you pull them up and even a teeny piece is left it will regrow from that—and any other stray pieces. There are a few species that will eat Aiptasia. There’s a nudibranch that only eats Aiptasia. Which is great except for the fact that it will starve to death once it eradicates the population. The Copperband Butterfly fish will also munch on it, but it’s not a good choice for all aquariums. The most popular, easy to keep, inexpensive and readily available Aiptasia predator is the Peppermint Shrimp. Even so, it’s far better not to find any glass anemone hitchikers on new live rock than to deal with the continual struggle against them afterward.

clean up crew colloquial phrase aquarists use to describe an assortment of creatures whose function is to “clean up” the tank. They are algae-eaters and detrivores. Sometimes an assortment of these inverts are sold together as a set. “Clean up crews” typically include snails and may include cleaner shrimp, peppermint shrimp, hermit crabs, and even bristleworms!

box filter a small square or rectangular box layered with filter floss and carbon which sits inside the tank on the substrate. Air is pumped in by an external pump attached to an airline tube. The rising bubbles draw the water current up through the layers, providing physical filtration (trapping particles), chemical filtration (activated carbon acts as a purifier), and biological filtration (nitrosomas bacteria live in the floss, see nitrogen cycle). This type of filter used to be common, but has now largely been replaced by easier to maintain external filters which don’t take up space in the tank and make the tank look unnatural or cluttered. Box filters are still used in small aquaria like hospital tanks and grow-out tanks with small fry (baby fish). Box filters are sometimes called “corner filters” or “internal filters”.

airstone not a stone, but a small porous piece of synthetic material which is fitted with a connector so that a piece of airline tubing can be attached to one end of it. Air is then pumped into the airstone which acts as a diffuser, breaking the air into microbubbles (coarse or fine, depending on the airstone). This aerates the water in the tank and provides a current as the bubbles travel up, break the surface and displace water.

protein skimmer pulls excess nutrient out of the tank–or perhaps I should say “pulls nutrient out of the tank”. It’s not a filter in the same sense that a box filter, power filters, undergravel filters are. It’s part of a filtration system. The protein molecules are worked into a froth and bind themselves to air bubbles which rise to the top of the tube and the waste is collected in a plastic cup which you empty regularly. The use of protein skimmers allows aquarists to feed highly nutritious food (more nutritious than what they’d get in the wild) in a closed system (eg the tank) without polluting the tank and killing everyone in it. Pulling nutrient out of the tank also helps control nuisance algae. Besides food, nutrient is also the byproducts of reproduction in the tank: spores, eggs, etc. and microorganisms living and multiplying on the live rock.

nutrient everything in the tank is potentially nutrient. (It’s that whole food chain thing.) What is usually meant by “nutrient” is “food”. It’s also the by products when food breaks down either with or without passing through the digestive tract of some organism. Most of the nutrient is still in the waste after it has been consumed–and will eventually dissolve into the water or be reprocessed by benthic organisms. All the nutrient (“food”) you ever put into your tank stays there unless you remove it by water changes, filtration, protein skimming or “exporting nutrient” which is a way of saying: removing algae, trimming back macroalgae, fragging (removing bits of coral) etc.

frag or fragging from “fragment”. In the plant world this is “propagation”. Fragging is like taking a cutting and rooting it or dividing clumps of plants when you repot them. Invertebrates are animals; they don’t have roots, but you can divide clumps or take pieces of them and attach them to another bit of rock. If the frag is removed from the tank, this constitutes “exporting nutrient” (see nutrient) whether you dispose of the piece of invert that’s grown too big by growing it in a separate tank, giving it to a friend, or chunking it in the trash.

captive raised the opposite of being captured in the wild (the ocean). Most fish and invertebrates in salt water aquaria are removed from their natural habitat and shipped to a distributor who sells them to your LFS. Many commercially available corals are aquacultured, that is, raised from frags which were at some point way back, wild caught. (Corals do reproduce sexually, but as I understand it, this is more difficult to achieve in captivity and not as commercially viable as fragging.) Anemonefish (e.g. clownfish) like “Nemo” are one of the few types of fish that are raised successfullly commercially. There’s no reason anyone should buy a wild-caught clownfish these days. There are several fish and some types of seahorses that are captive raised. Some fish don’t spawn in captivity or do spawn, but there’s a problem raising the fry successfully. Anemonefish are by no means the only captive raised marine fishes, but they are at present the most common. Most salt water fishes are not captive raised. By contrast, most freshwater fishes are commercially raised, not wild caught.