The "good" the "bad" and the "Ugly!" And where aquarists are concerned, we see all three! We can add them purposely to our aquariums, or they can sneak in on live rock, live sand, or on and inside coral animals. And there are so many different kinds that I could probably spend the rest of my life researching them, however, I'll stick to what is and can be of interest to marine aquarists. To help decipher those of interest, I've attempted to place them into their proper "Phylum's." Each Phylum will have a description of its family members and why they are of interest. Keep in mind I'm a hobbyist, not a scientist, and therefore its terminology will be quite non-technical.
There are about 15,000 segmented members in this phylum, with many of major interest to marine hobbyists, especially those with lots of live rock and deep sandbeds. In fact, this phylum contains very good examples of the good, bad, and ugly, with all in the Class Polychaeta. It contains over 10,000 described species, mostly marine, and has over 80 families.
As for those we add because of their beauty and interest, they fall into the Order Sabellida, and the Families Sabellidae and Serpulidae or what is generally referred to as 'ornamental worms,' i.e., feather dusters. Many of these worms are classified according to their mode of existence, such as tubeworms/fan-worms.
In fact, all Polychaetes are usually called 'bristleworms' since they have hair-like projections along their sides, even our beloved fanworms. These hairs are often used for locomotion, yet some dispense a toxin, such as coral eating fireworms (the bad and ugly guys) in the Genera Hermodice and Eunice. Yet, even some of the bad and ugly ones have some value in healthy reef tanks, which is discussed below.
Sabellida worms, commonly called Feather Dusters, construct a leathery tube, sometimes up to 12 inches (30 cm) in length, from which they extend a single crown of multicolored feather-like filaments. In the wild, they are usually found buried in sand, not adhered to rocks. Their tubes are constructed of sand, detritus, mucus, and other bits of sediment. It is better to locate these worms near the bottom of the aquarium where this material is more plentiful. The fact that particulate matter is higher near the bottom of the aquarium and that they are not photosynthetic animals, are other good reasons to place them in this area.
They use their slime-coated filaments/tentacles or "feathers" as some call them, for respiration and to collect suspended particulate matter/plankton. The collected matter is then drawn towards the mouth area at the center of the tentacle ring. Solutions containing phytoplankton and/or zooplankton (rotifers) are recommended. These feeding solutions should be applied near and under the crown of feathers so it can normally be drawn up and to the beating cilia on the feathers. It should be noted these tiny hair-like extensions generate the current that draws the food supply into the feather-like head of the animal. Dispensing the feeding solution above the animal may cause the animal to retract with most of the feeding solution going to waste.
Feather dusters may lose their crown of "feathers" for many reasons, some being: poor water quality; being disturbed too often; or, lack of a sufficient amount of food. This does not mean they are dead as most will grow their feathers back in a month or so. If the head returns and is smaller, this is an indication the food supply is inadequate. Could be if this happens again and the head comes back again smaller, the tubeworm will die. Always wait a couple of months and if no reappearance occurs, feel the tube for the worm body inside. If there is some movement inside the tube, put it back and be patient for another month.
When it comes to keeping any of the ornamental type worms, predators like triggerfish, wrasses, angelfish, most shrimp, and the arrow crab will not make suitable tankmates.
Unlike the Sabellida Feather Duster worms, Serpulida worms form a rigid limestone tube. The Spirobranchus giganteus species is common in the Caribbean and a subspecies is found in the Central Pacific to the Red Sea. Their radioles or "feathers" form two spirals, each separated with a hardened operculum, a trapdoor-like device. There are several whorls of feathers in each crown. Their tentacles radiate from a central stem area with the largest near the base of the crown, narrowing to a point at the tip. Hence the name "Christmas-Tree." These colorful, yellow, red, white, blue, purple, green, pink, and combinations of, tube worms may have a crown up to 1 inch (2.5 cm) or slightly larger.
They are found in colonies attached to live rock. Those coming from the Gulf of Mexico and the Caribbean are the largest, having radioles about 1 inch (2.5 cm) in height. They do not exist in a symbiotic relationship with other corals as do the Indo-Pacific variety (Tullock, 1997). They may be kept in lower light and water movement than the Indo-Pacific variety.
As for those coming from the Indo-Pacific area, the Christmas Tree "worms" have a symbiotic relationship with live heads of Porites coral. It is thought the worms derive nutrition from the coral mucus (Wilkens, 1990). They require strong water movement and excellent lighting to maintain the Porites coral. Their radioles average a 0.5 inch (1.2 cm) in height.
As an added note, they reproduce sexually, as there are separate males and females. The males release sperm into the surrounding waters and if sensed by a female ready to spawn, she releases eggs. Embryos develop into a swimming larva within a few days. Ongoing culture is extremely difficult, as phytoplankton is needed for further development and I do not know of this yet occurring in captivity.
Also of interest is the tropical species' Neodexospirs' and Vermiliopsis pygidalis, which are the very tiny (2 mm) circular white hard-shelled feather dusters that appear in shaded areas, such as on pump bodies, live rock, and aquarium side panels. They are suspension feeders and often found in great numbers on these type surfaces.
And, last but not least, there's another very small family member, about 3 mm, and more snake-like in appearance that often shows up under live rock. They, probably Vermilliopsis and/or Microprotula spp., are elongated with a very delicate tube-like structure. These 'squiggly' shaped worms are detritus feeders.
There are actually eight described species in the Spirobranchus genus and one, possibly two undescribed species. Three are from the Caribbean and five are from the Indo-Pacific. Most can only be differentiated by the shape/form of the operculum (Vincent Hargreaves, pers. com.). S. giganteus, S. incrassatus, and, S. spinosus hail from the Caribbean. S. corniculatus, S. gaymardi, S. paumotanus, S. nigranucha, and S. gardineri hail from the Indo-Pacific Ocean.
The worms in this family are called 'Scaleworms' and are generally found under stones in intertidal and subtidal zones. These broad flattened worms have a row of bristles on both sides of their body and reach a length of about 1 inch (2.5 cm). Probably those in the genus Lepidonotus are of most interest as they may arrive on live rock from the Indo-Pacific Ocean. They are basically scavengers, feeding on dead organic matter
As for the ones that get added without our knowledge and fall into the category of 'bad guys' those in this family are commonly called bristle worms or fire worms. They generally arrive as a hitchhiker in some hole in live rock and/or in the calcareous areas of some corals. There are two mentioned here, with one being a very good scavenger of dead organic matter (Eurythoe complanata) and the other (Hermodice carunculata) a scavenger of anything it can get! Both have poisonous setae or hair-like spines along its sides, which are very brittle and can easily break off and cause a painful experience if you pick one up without gloves.
Should you ever be unfortunate enough to get stuck by these bad guys, I suggest the following - dry the area by directing air from a fan or blower over the area. Do not under any circumstances wipe the area dry. Once dry, use tape such as masking, duct, or clear cellophane tape to 'blot' the area. This should allow the bristles sticking in your skin to stick to the sticky side of the tape, hopefully removing most of them. Repeat as needed. Then dab the area with rubbing alcohol or vinegar. Or try a mixture of 1 part household ammonia to 10 parts water or sprinkle a meat tenderizer on the area. This helps denature the toxin and provides a reduction in the burning sensation. When the area appears to be free of bristles and is dry, apply an over the counter antibiotic ointment. If there's lingering pain or swelling, consult a physician.
Keep in mind both of these worms can multiply quite rapidly when there is a ready supply of food. Aquarists that overfeed are inviting them to reproduce and they can do so quickly via asexual reproduction. They can also, via "fragmentation", divide themselves up into new worms. Any type of food will be quickly consumed by these worms and the more food there is, the more worms. Fortunately most of those seen in aquaria are the species Eurythoe complanata, which if small, are not a threat as would be the Hermodice carunculata species.
As for ridding the aquarium of these scavengers, suggest only removing the larger ones as they may damage or kill some corals, anemones, and clams. The smaller ones, less than 1 or 2 inches (2.5 - 5 cm) should not be a problem and may serve as a food supply for the Banded Coral Shrimp, Arrow Crab, Dottyback Pseudochromis dutoiti/fridmani, and/or the Flame Hawk. In fact, I've even seen a Tubastraea polyp swallow a fire worm that crawled onto it while it was open.
If they do become large and noticeable, it is time to bait them out. Since they are nocturnal creatures, they feed mostly at night unless real hungry! Take a whiffle ball and insert a piece of defrosted shrimp/fish flesh and wrap the ball loosely with a lot of fishing line. Use enough fishing line so the worm has some difficulty in finding its way through it to get to the bait in the center of the ball. Place the ball, weighted with a small weight, on top of a large net at the bottom of the aquarium late in the evening. Early, "very" early next morning, the worms should be intertwined/feeding on the bait. Simply grab the handle of the net and lift the whole affair out of the aquarium.
Another fairly good method in removing these pests is using a short length, about 10 inches, of PVC pipe. Drill some holes near each end, place a piece of defrosted shrimp flesh in the center of the pipe and fill each end of the pipe with Eheim Ehfifix media. This course plastic media makes it slightly difficult for the worm to make its way to the center bait. Once there, the worm feeds and grows fatter and will find it extremely difficult to get out if you have used the right amount of this plastic media. By lifting out the length of pipe early in the morning and pushing a rod through the pipe, any worms inside can easily be extracted. There are also small traps used for trapping fish and/or unwanted crabs. They can also be baited and used to capture these pests. The following two bright orange worms with white bristles along their sides are some of the worst examples and should be carefully removed when larger than an inch or two (2 - 5 cm).
These large bristle "Nereis" worms, sometimes reaching sixteen inches (40 cm), are major predators and nocturnal feeders. They burrow and do not live in a tube. Unfortunately they also burrow into soft corals and damage or kill them. Natural predators include the Harlequin Tuskfish (Choerdon fasciatus) and Green Bird Wrasse (Gomphosus varius). Removing these worms when seen with a large tweezers is highly recommended.
Paddle-worms are by far the largest order of polychaetes, with some species getting physically quite large. However, those in the Genus Eulalia are fairly small, i.e., less than 5 inches (12 cm) and can make fairly good hunters of other worms and very small crustaceans (copepods/amphipods) in reef tanks. Easily identified by their fleshy paddle-like projections along each side of the body. May or may not be something you want in your reef tank, however, anything much larger than a few inches should be removed. Take note, they will quickly multiply in tanks that are overfed.
Earthworm in appearance, and somewhat similar in size, however, not as docile! These worms have a proboscis that is armed with snake-like fangs with each fang having a poison gland at its base. The venom is used for subduing its prey or fending off its predators.
Commonly mistaken for the Thread Worm or Spaghetti Worm which has numerous thread-like filaments/tentacles. However, this creature has only two thread-like filaments/tentacles/legs, which are used to push water through a net-like structure that filters out suspended matter. These worms are generally up to 2 inches (5 cm) in length including the two tentacles (palps). They are thought to be in the Genus Phyllochaetopterus and conceal themselves in parchment-like tubes and are generally found in sand or rock crevices. Their body remains hidden inside its tube, yet these two thread-like filaments are quite visible. They are basically harmless suspension feeders and actually a valuable addition to any aquarium. Can also be seen in the publication: The Modern Coral Reef Aquarium, by Svein Fosså & Alf Nilsen ISBN#3-928819-29-1, page 181.
Commonly called the Thread Worm or Spaghetti Worm. Most of these worms usually conceal themselves in the sand or a crevice in the rock, and live inside a chitonous tube surrounded by grains of sand. Their body remains hidden inside its tube, yet numerous thread-like filaments are fed out into the surrounding water to trap food. Very small food particles/detritus stick to the filaments where cilia on its thread-like tentacles draw particles of matter to its mouth. They are basically harmless detritivores and interesting to watch. Found both in the Indo-Pacific Ocean and Caribbean and are valuable additions to most sandbeds.
Eunice worms are large predatory nocturnal feeding bristle worms sometimes reaching 16 inches (40 cm) in aquaria and much more in the wild. They burrow, and do not live in a tube. Unfortunately they also burrow into stony corals and damage or kill them. They also will feed on small fishes and invertebrate. Natural predators include the Harlequin Tuskfish (Choerdon fasciatus) and Green Bird Wrasse (Gomphosus varius). Removing these worms when seen with a large tweezers is highly recommended.
Generally called the "Clam" worm, this is a long orange colored worm that is active during the night and feeds mainly on mollusks, e.g., snails and clams. Can drill small holes through the sides of Tridacna shells and kill the clam. Can also secrete mucus around small clams and suffocate them, then devour their tissue. If you notice either a hole through the side of your Tridacna clam, or the unexplained death of snails in your aquarium, you should view your aquarium during very early morning hours with a small flashlight to see whether these worms are the cause. Bait them out as described above using defrosted clam/mussel meat or try to remove the rock they are living in.
Generally called "Peanut Worms" these non-segmented worms consist of about 300 species, and are somewhat U-shaped or sausage-shaped. Their body is usually covered with bumps, small spines, warts, or tubercules, which provide some protection from larger predators. Some bore into calcareous rock, while others burrow into sand or mud. The mouth area on the end of its body is usually surrounded with ciliated tentacles, which are used to capture suspended organic matter, detritus, and/or algae. These worms range in size from very tiny, a few millimeters, to about 20 inches (50 cm) in length. They arrive on/in live rock and are not harmful to the environment or its inhabitants and may serve as a foodstuff for larger crustaceans.
The rock living sipunculans generally tunnel into rock, and/or live in previously drilled holes. The end that protrudes has a small group of tentacles that is used to 'mop' the surface of rock and collect algal cells and detritus. Since this mouth-like extension, called the "introvert" can be extended quite far, it can clean fairly large areas of the rock surface without the worm leaving the safety of its hole. Those sand dwelling sipunculans appear more feather-duster-like and are suspension feeders, and there are also crevice dwelling sipunculans also.
There are about 15,000+ species, with about 10,000 of them being considered a parasitic type creature to fish and invertebrate, such as flukes, tapeworms and the tiny flatworms that occasionally infest corals in our aquariums.
Many flat worms can easily be mistaken for nudibranchs, as their color and body shape is quite similar. However, most are paper-thin oval shaped, can move quite rapidly, and do not have external gills. They 'glide' on a secreted coating of mucus and if disturbed, can swim away in with an undulating motion. These hermaphrodites have both male and female organs and can also regenerate from body fragments. They are carnivorous predators and generally feed upon colonial ascidians, making them almost impossible to maintain in closed systems. Occasionally they arrive on the bottom of live rock, and are infrequently seen after that.
Of major interest to aquarists is the flat worm called 'Planaria' and actually is not among what is considered 'parasitic' flat worms. The ones I've seen, Convolutriloba retrogemma, look like reddish-brown freckles with a forked tail and slightly rounded top. They are about the size of a freckle (.25 inch - 2 - 5 mm) and can rapidly increase in number to the point where they may cover an entire coral specimen. Mushroom and leather corals seem to be a favorite gathering place. They are thought to be harmless (Sprung, 2000) yet unsightly, however, they will suck out body fluids containing zooxanthellae. When in great numbers they can also block light from reaching photosynthetic animals. Click on the following to see examples of these pests Notoplana tremellaris "Planaria on Coral" and "Planaria Size."
When there is an abundance of them and if possible, remove the infected specimen and give it a five to ten second freshwater dip. Almost all the flatworms will drop off and any remaining can be gently brushed off. Caution, not all corals can withstand a freshwater dip.
Since these worms are photosynthetic, they are attracted to light. Placing a lamp near the aquarium at night will attract them in huge numbers making it easy to siphon out the majority of them very early the next morning. The reduced number may give other biological control methods a better chance at bringing their numbers under control.
As for biological controls, the Banded Goby, Amblygobius phalaena, is said to eat this flatworm. Also, Wrasses, e.g., the Sixline Wrasse Pseudocheilinus hexataenia, Leopard Wrasse (Macropharyngodon meleagris), and Yellow Wrasse Halichoeres chrysus. Also some Anthias are thought to be an efficient consumer of this pest, as are Peppermint Shrimp (Lysmata wurdemanni) and also those in the Lysmata genus. In fact, the Mandarin fish (Synchiropus splendidus) has cleared up the problem in some of my past reef systems. Also, the Sea Slug/Nudibranchs in the genus 'Chelidonura' are believed to be a very good consumer, although very short-lived slugs. Also, scooter blennies and hawkfishes may consume them.
There is also some thought these flat worms can rapidly go away due to some biological clock, lack of foodstuffs or a biological competitor. Also, there's some thought the over use of iodine supplements, which flat worms may concentrate in their internal fluids, may lend itself to promoting their proliferation.
There is some thought that killing these flat worms, such as Convolutriloba retrogemma in large numbers could present a toxic condition in the closed system by stripping its oxygen in the degradation of large numbers of these pest flat worms and in the release of iodine in some format, as they harbor iodine in their tissues. Increased water flow and improved protein skimming is also helpful. Recently, (2003) a product from Salifert called Flatworm Exit has been said by some aquarists to safely reduce the population of these pests without harm to other invertebrate. Caution is advised.
Because it would serve no useful purpose to proved detailed information about these creatures, I've decided to simply provide photos of several of these creatures so as to help identify them should they show up in your aquarium.
Ribbon worms are slender unsegmented, mostly nocturnal worms, and range in size from very small to several yards. They occasionally show up on live rock, and usually do well in systems with a deep sandbed, however, they are not to be trusted with very small fish and invertebrates.
These very tiny crawling worms, mostly less than a few millimeters in length, live in mud and sand, and are a member of the meiofauna found in healthy substrates/sandbeds. They look like very small somewhat flattened crustaceans and have a tail used for steering through their burrows. Most are a dull yellowish-brown in color and feed upon organic debris. A valuable addition to sandbeds. Other drawings/sketches of such worms can be seen in the book "Encyclopedia of Marine Invertebrate," Edited by Jerry G. Wells, ISBN #0-87666-495-8, page 179, or "Marine Life" by David & Jennifer George, ISBN #0-4471-05675-8, page 47.
These very tiny crawling worms, sometimes called 'Jaw Worms' are mostly less than a millimeter in length and live in mud and sand. They are a member of the meiofauna found in healthy substrates/sandbeds. Their body is covered in cilia and their mouth area has jaws that proceed the entry into the gut. They feed upon bacteria, fungi, and tiny algae cells. Those that live in anaerobic areas are believed to get their oxygen from nitrite and nitrate. A valuable addition to all sandbed aquariums.
These very tiny crawling worms, sometimes called 'Hair Bellies' because their cilia is located on the belly side, are mostly less than two millimeters in length and live in mud and sand. They are a member of the meiofauna found in healthy substrates/sandbeds. They have a gliding motion and a sticky substance used to adhere to substrate particles. They feed upon bacteria and tiny alga cells. Those that live in anaerobic areas are believed to get their oxygen from nitrite and nitrate. A valuable addition to all sandbed aquariums. Drawings of such worms can also be seen in the book "Marine Life" by David & Jennifer George, ISBN #0-4471-05675-8, page 47 or "The Complete Book Of The Marine Aquarium" by Vincent B. Hargreaves, ISBN # 1-84065-351-5, page 235.
There are many different nematodes in existence, with many being parasitic and causing problems in humans and plants. However, those in aquarium substrates, in the Class Adenophorea, feed on algae, diatoms, bacteria, various organic matter and are considered important recyclers of sandbed organic matter. These unsegmented, round, elongated, translucent crawling worms are generally called 'Round Worms' because their body is snake-like in shape, and are mostly less than three millimeters in length. They are part of the meiofauna found in healthy substrates/sandbeds and a valuable addition to all sandbed aquariums. Photographs of such worms can also be seen in the book "The Complete Book of the Marine Aquarium" by Vincent B. Hargreaves, ISBN # 1-84065-351-5, page 235.
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