Posts
Contents:
- Introduction
- About the Author
- Various disclaimers and copyright information
- The bristleworm Factsheet
- What is a bristleworm?
- Sedentary bristleworms.
- Errant bristleworms.
- The Bad Boys.
- The Fireworm (additions welcomed).
- What is a bristleworm?
- The Bristleworm FAQ
So you've set up a reef tank, with lots of live rock, corals, and fish. You sit back to admire your work, when a strange centipede-like creature suddenly crawls out from under a rock. What is it? Is it dangerous? Should it be killed? How? Is it Bleach-and-Boil time?
Relax.
The cavalry is here with some answers - I give you the Bristleworm Factsheet and Frequently Asked Questions. Everything you've ever wanted to know about bristleworms, and then some.
At the time of writing this I'm a biology student, specializing in marine evertebrate systematics, at Stockholm University. I work at the Molecular Systematics Laboratory at the National Museum of Natural History in Stockholm, under Dr Ulf Jondelius, one of the worlds foremost authorities on flatworms. Aquariums are my hobby, and I've some 20 years experience in the field, 10 years with reef tanks.
Contacting the author with questions/suggestions/bug reports: email to:
ev-michael@nrm.se or (preferably) radharc@karkis.canit.se
VARIOUS DISCLAIMERS AND COPYRIGHT INFORMATION:
Legal stuff: This text is (c) Mike Noreen, but may be freely reproduced for non-profit purposes as long as it is not altered in any way and the authors name is not removed. Commercial use of this text (ie in publications) require the written consent of the author.
Disclaimer: This text is as accurate as I could make it without making it _too_ big, but I'm only human and there will be errors in it. I am not responsible for any actions or losses or altered mental states resulting from the reading of this text or following advice given in it.
1. What is a bristleworm? The phylum Annelida (ringworms) is divided into three classes: the Oligochaeta (earthworms and allies (ie tubifex)), the Hirudinea (leeches), and the Polychaeta (bristleworms). By far the biggest class is the polychaetes, with over 8000 species in at least 80 families - and more species are described every year. Almost all polychaetes live in the sea, although a few live in freshwater or in moist soil. They are extremely diverse, ranging in length from 1mm to in excess of two meters, and are abundant in all biotopes in all seas around the world. Together with crustaceans they play a role reminiscent of that of insects on land, making up the lower levels of the foodweb. Several species, mainly of errant polychaetes, are used as fishing bait (ie the sand/lugworm).
From an aquarists point of view, for purposes of identification, bristleworms can be crudely divided into errant and sedentary species (please note that this is not systematically correct. This division does not in any way reflect relationship, but is purely utilitarian).
Sedentary bristleworms stay in one place, are typically tube-builders and feed by filtering microplankton with their often brightly coloured retractable tentacle crowns. Common in our tanks are for example Peacock worms pertaining to the family Sabellidae.
Errant bristleworms actively move about in search of food, which may be other small vertebrates, algae, corals or almost any organic matter depending on species. Errant bristleworms usually resemble centipedes in general appearance, and have strong jaws.
Bristleworms normally reproduce sexually, usually with planktonic larvae. Only about 30 out of 8000 species reproduce asexually by fission.
These guys are common and usually welcome inhabitants in reef tanks. Roughly they can be divided into two different types: those with fan-like feeding apparatuses and those with tentacle-like feeding apparatuses (again not a systematically correct division, but useful for identification). They all feed on small organic particles and detritus, and are totally harmless to other inhabitants in the tank.
- Sedentary with fan-like feeding apparatus:
- Peacock worms (any species belonging to the family
Sabellidae). Recognisable by their soft, leathery, tubes made
of mud or sandgrains and mucus. Worms of this family are often
sold in pet shops. They require good quality water to thrive, but
are not photosynthetic. They occasionally scare their owners by
shedding their brightly coloured crown of tentacles - don't
worry, it grows back. However, if the worm leaves its tube
it's dying and should be removed (and water parameters should
be checked). They sometimes reproduce in aquaria, but not so
to become a problem.
- Christmas tree worms and allies (several families, ie
Spirorbidae, Serpulidae). Very similar to Peacock worms, but
living in limestone tubes and sometimes burrowing in
limestone (the familiar Fan worms of living rock). Of
particular interest are the Serpulidae and Spirorbidae
families, which may have sudden population explosions in the
tank. Serpulids are bigger than Spirorbids, and live in
irregularly shaped tubes, while the Spirorbid tubes are
small, white, tightly coiled spirals (spiral less than 1cm,
often just a few mm, from side to side).
They may proliferate to the point that they become a minor
nuisance, clogging tubing and covering the glass, but usually
these explosions are over as quickly as they started, presumably
because the worms deplete the microplankton of the aquarium.
- Sedentary with tentacle-like feeding apparatus:
- Common in reef tanks are the Spaghetti worms and Sand Mason
worms belonging to the family Terebellidae. They hide their
bodies (which are quite large) in cracks in or under stones,
and all that's visible are the numerous, often 30cm long,
narrow, flattened, u-shaped, translucent tentacles. The tentacles
work as conveyor belts, bringing detritus to the worm on which
it feeds.
- Other extremely common but rarely noticed worms belong to the
family Spionidae; they are small, burrow in limestone (and snail
shells), and all that's visible of them are two short tentacles.
Here we find a bunch of worms sometimes difficult to even identify as worms.
The problematic ones in tanks. They are ugly, move in an unnerving manner, can pack nasty poisonous bites and/or poisonous bristles, and may eat things the aquarist would not like them to eat. In general appearance they resemble centipedes (although the 'legs' are not true legs, and they are not related to centipedes), and are always present in all tanks with live rock or live sand. They are of varying colour, size and disposition, and a great number of families and even greater number of species are found in aquaria. It is very common for errant polychaetes to be opportunists - eating algae, scavenging, or killing small evertebrates as opportunity presents itself. Despite their omnivorous habits the vast majority of species are totally harmless in a reef tank. A very few species may however cause problems.
Errant bristleworms cause problems in two ways: either by becoming so big that they can attack things they normally would not be able to harm (ie fish or aquarists fingers), or by being predators/parasites on valuable inhabitants in the aquarium.
- Bad because of size: Basically a bristleworm larger than, say, two-three inches can deliver painful bites, and conceivably kill fish, shrimp etc. Some species also have poisonous bites, and although I've never heard of anyone dying of bristleworm-bite, there's no doubt they could seriously inconvenience a sensitive person (normally a bite from a poisonous species, ie a Glycera, is comparable to the sting of a wasp). Use caution (and/or tweezers) when dealing with a large worm.
- Bad because it's a specialized predator/parasite: Actually very few bristleworms are parasites, and none on vertebrates, so the fish are safe (except from very large very hungry predatory worms). Some species do eat corals, and may cause problems. The most known coral-eating species is the Fireworm.
additions welcomed)
The Fireworms are a group of coral-eating worms from the Caribbean, common in shallow waters. In general appearance a fireworm is fat, fatter than an earthworm, reddish-brown, with prominent tufts of white-to-green bristles. They can multiply rapidly, and can in a short time kill all corals in a tank. They have got their names from having poisoned bristles, which cause skin irritation. Handle with care. Various methods have been suggested to remove Fireworms. These include: commercially sold traps, mechanical removal with tweezers, putting something tasty (ie shrimp meat) in old nylon stockings in the tank overnight. The worms become entangled in the nylon, and can be removed in the morning. If I sound somewhat vague on fireworms, that's because I've never even seen an actual fireworm.
BRISTLEWORM FREQUENTLY ASKED QUESTIONS:
Q: My peacock worm has left it's tube. What's happening?
A: It's dying. Remove it before it rots. Its death may be a sign of poor
water quality.
Q: My peacock worm has lost its head! Is it dying?
A: No. It's just shed its old worn tentacle crown. A new crown will grow
back.
Q: How much light does my peacock/christmas tree/fan worm require?
A: None. It's a filter feeder - it's not photosynthetic.
Q: How should I place my peacock/christmas tree/fan worm?
A: They like moderate current. They dislike too strong current.
Q: I've found this centipede-like worm in my tank - is it dangerous?!
A: With 99.9% probability not, unless it's more than 2-3 inches in length
OR very fat, reddish brown, with white or greenish bristles, and there's
live rock from he Gulf/Caribbean in the tank. Remember: there are ALWAYS
bristleworms in ALL tanks with live rock, and they're nearly always
harmless.
Q: I've got one/several 'bad' bristleworms in the tank - how do I kill
it/them?
A: Four ways:
- Get a commercial bristleworm trap. Not all work well.
- Pluck them out/cut them in two with tweezers. If divided in
two it will NOT grow back into two worms, although the head
end MAY sometimes grow a new tail.
- Put something tasty, ie shrimp or mussel meat, in a nylon
stocking, and place on the bottom of the tank over night.
Bristleworms who try to eat the meat become entangled in the
nylon, and can be disposed of in the morning.
- Get a bristleworm predator, ie an Arrow crab. Problem is
that they don't know that you want to keep some bristleworms,
like the Peacock/Christmas tree worms, but eat all worms.
Q: Why not kill the worms by boiling the live rock, or with copper
sulphate, or with fresh water, or with bleach?
A: Because all of the above are guaranteed to kill the beneficial bacteria
in the live rock which are the reason one uses live rock to begin with.
You might as well throw the live rock/sand away as try the above. Chemical
control of bristleworms is basically only an option in fish-only tanks.
Q: What's this hard, white, organism that's growing on the glass of the
tank?
A: If it's a tightly coiled spiral its the tube of a Spirorbid, else
probably a Serpulid, bristleworm. Harmless filter feeders, but may go
through population explosions. Usually they disappear as the tank ages.
Q: There's weird _long_ translucent tentacles coming out of my live rock!
What is it?
A: It's the tentacles of a detritus-feeding Terebellid bristleworm, aka
Spaghetti worm. Totally harmless, quite long-lived (several years), and
extremely ugly, even for a bristleworm, should you ever see the actual worm
(which may well be the size of your thumb!).
Q: There's lots of small parasitic bristleworms all over my soft corals!
A: Take out the coral, and mechanically remove all the worms by carefully
scrubbing the coral in salt water. Repeat as necessary.
Q: My tank has been set up for several years, and I've now found
bristleworms. Should I be worried?
A: No. If they've caused no damage after a year, chances are they never
will.
HTML'ized for RTO Features by Todd Zebert.
No comments:
Post a Comment