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Though the saying goes that God favors the insects called
Beetles (Order Coleoptera), having made so many species of them; I’d
choose worms of various phyla in their stead. Indeed, some fifteen
of thirty five phyla of living animals are worms according to Wiki.
By some estimates there may be more species of "worms" than
insects! Some groups are largely unknown to aquarists, others are
considered undesirable (most flatworms, flukes, tapeworms…); and a
few of benefit or use, including the subjects of this article.
Featherduster Worms; What Are They?
Featherdusters are members of the the segmented worms, phylum
Annelida. This group includes the earthworms of fishing bait fame,
these being classed as Oligochaetes (“few bristles”). Annelids also
comprise the Polychaetes (“many bristles”) as many a hapless
aquarists can relate to have been poked but good.
Polychaetes in turn are subdivided into two principal groups; the
Errantia (“moving”), and Sedentaria (non-moving) species; comprising
the Bristleworms and Featherduster Tubeworms respectively. All told
there are some 12,000 or so described species of Polychaetes, with
some species being VERY populous in places in the wild; some are
used as human food, and in places there are species that make up a
large percentage of pelagic filter feeding species diets; including
large Manta Rays.
Polychaete Annelids are divided into two
sub-classes:
Some Prominent Featherduster Species:
We’ll just mention the most common, hobbyist-available members of
two families:
Family Sabellidae: Fanworms.
Non-calcareous tubes produced that they live in, feed from. Fanworms
are filter feeders that can retract their tentacular crowns when
alerted. Often found attached to dead coral, or in sediment with
part of tube exposed. Sabellids are collected most often in
"polluted" harbors in mud/muck for the ornamental aquatics market.
Many aquarists don't have similar environments (!) to house their
Featherdusters... high nutrient, plankton levels... Another reason
why these animals are best placed in "old" well-established systems,
with ooze about, refugium sumps.
Genus Anamobaea:
Genus Bispira:
Genus Sabellastarte:
Family Serpulidae: Calcareous Tubeworms.
Produce white, calcareous tubes, often with longitudinal ridges,
thickening and, spines. The shape, size of cover (operculum) is
often useful in determining species.
Genus Filograna:
Genus
Pomatostegus:
Genus Protula:
Genus
Spirobranchus:
The tentacular crown of Featherduster worms is composed of feather
like radioles. This is about all one can see that registers as
“live” of these animals; and this structure serves several purposes;
chiefly respiration and feeding. Such an important organ, and
so exposed, the tentacles themselves are often the major source of
injury and resultant reason for loss of the animal. There is more
about this structure below in the section on feeding.
Compatibility:
Featherdusters themselves get along with all other macroscopic reef
life; not stinging, eating, chemically competing with any other
biota. Unfortunately the reverse is not the same; with some fish
groups in particular pulling on their heads at times. The usual
suspects of Triggerfishes, large wrasses and big puffers or
filefishes, along with some Butterflyfishes and Angels are suspects;
and large clumsy animals like Eels and Urchins can work them woe as
well as omnivorous crabs.
Selection:
For soft bodied Sabellids, you should carefully examine the tube
body to assure it is not torn or overly beat, especially around the
open end. Hard-bodied (Serpulids) tubeworms should similarly be
looked over for breaks in their tube channels. Beyond this is
looking at soft tubed varieties to assure their blind end is intact
(not torn open), and for calcareous species, that their covers and
openings aren’t badly broken.
As with many invertebrate animal groups, it is important to avoid
lifting these worms into the air, too-often causing air entrapment
in their tubes. Instead, substrate dwelling and boring varieties
should be bagged underwater.
A thick substrate (four or more inches) of small diameter calcareous
material, with some organic inclusion is ideal for supporting
Featherduster husbandry. This mix serves to bolster alkalinity as
well as fostering the growth of useful food materials.
Water quality conditions should mimic a large-established reef
system. Steady, near natural seawater specific gravity; tropical
temperature; with a dearth, but still measurable nitrate and
phosphate concentration.
Lighting is unimportant to where you situate your Featherdusters,
but current and elevation are. Soft and hard-tube species
(Sabellids) can be placed amongst rock et al. that will serve to
anchor them, or buried in soft sand, embedded/boring tubeworms
(Serpulids) are likewise best placed near the bottom (as opposed to
higher in the water column) to benefit from higher concentration of
foods there as well as dispersed circulation.
Water movement is critically important to these animals. Current
should not be direct, but serve to move water under their crowns
continuously. Experiment with your powerheads, internal pumps,
discharges to ascertain whether this is so.
Foods/Feeding/Nutrition:
Featherduster worms are ciliary-suspension-mucus filter feeders on
very small plankton, organic particles and bacteria. Though it’s
hard to see without magnification each radiole (“feather”) of the
crown of your Featherduster has a small central groove. This groove
serves to sort and transport food items to the mouth, body of the
worm further down the tube. Tiny particulate food items are caught
up in sticky mucus the worm produces and transported down the
collective food tube.
Understanding how the animal feeds is critical to your being able to
feed it, keep it alive; as food particles are processed on the basis
of size alone. Too big particles are flicked out before reaching
this area, medium ones are incorporated into the tube itself, and
suitably small materials are brushed along via cilia and ingested.
Like corals and other reef life, both carbohydrates and protein are
required to keep life going. Providing these nutrients is not as
easy as blasting a turkey baster or pouring in some liquid
invertebrate food occasionally however. Tubeworms need nearly
continuous quantities/densities of high quality phytoplankton, and
bacteria sized particles (under two micrometers) to thrive. This
food is taken from the underside of their tentacular feathers, not
the top; and so needs to be in suspension, being circulated for them
to take it up. I am a huge fan of the use of simple timers to
temporarily suspend the operation of skimmers and mechanical
filtration for tens of minutes after pulsing in particulate foods;
allowing the recirculation system to move food items about without
their immediate removal.
There are few systems with enough endogenous food material to
support Featherduster worms; thus exogenous additions of cultures
need to be supplied to assure adequate nutrition is supplied;
otherwise these animals wane, shrink and die. Having a large,
well-established refugium, better with mud/muck incorporated as a
substrate is helpful, but you will still have to supply food from
cultures outside the system.
Culture of these algae is really not a big deal; in fact, it can be
quite fun. A starter population of Nannochloropsis et al. can be
purchased from your LFS or ordered online from outfits like AlgaGen
and LiveAquaria (.coms); this can be extended by simple culture in
glass or plastic jars, made up seawater and dilute fertilizer
addition.
Again, I warn you regarding the use of too-large food items, as well
as “juice” of clams et al. and the too often “pollution in a bottle”
which are commercial liquid/bottled invertebrate foods.
Sources of Mortality:
Though not much is known re pathogenic disease of Tubeworms, the
reasons for their common loss are. Most all die too soon from a
combination of trauma and starvation; both before (during
collection, holding, shipping) and after landing in their ultimate
and penultimate permanent settings.
So; what can you do to optimize your chances of returning and
preserving health of these Sedentariate Polychaetes? It may not
appear obvious, though it should, that picking out better specimens
is the key to initial success, placing them in suitable
circumstances, providing foods of use frequently and not introducing
predators for longer-term.
Don’t lose your head! If your worm ceases to show its crown, or even
loses it, don’t necessarily give it up as gone. These worms do
regenerate this tentacular process, and at times this can take weeks
to complete. I urge patience here. Through all-too common starvation
these worms will toss off their crowns and regenerate successively
smaller ones. As you might assume, this does not go on forever. A
less large regenerated crown should serve notice that your animal is
not getting sufficient nutrition. Cloze:
Worms are not all gross! Featherdusters, Sedentariate Polychaetes
are worthy specialized reef additions. Given sufficient
outside-provided fodder they can live for years in captivity;
starved; they might last a few months. Other than providing enough
useful food, initially selecting good specimens and placing them in
propitious circumstances is requisite for keeping these animals
long-term.
Bibliography/Further Reading:
Calfo, Anthony & Fenner, Robert, 2003. Reef Invertebrates.
WetWebMedia
Hoff, Frank. & Terry Snell, 2007. Plankton Culture Manual, 6th
ed. Florida Aqua Farms, Inc.
Shimek, Ron, 2008. The inside story on Featherdusters.
Aquarium Fish Int’l. 6/08
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