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Related FAQs: Mat/Star Polyps, Polyps  2, Polyps 3, Polyp Identification, Polyp Behavior, Polyp Compatibility, Polyp Selection, Polyp Systems, Polyp Feeding, Polyp Disease, Polyp Reproduction/Propagation, Blue and Pipe Organ "Corals"

Related Articles: Pipe Organ "Coral"

/A Diversity of Aquatic Life

Stoloniferans; Clove, Star Polyps,
Pipe Organ Corals

By Bob Fenner

Clavulariid colony in captivity

            Star or Mat Polyps present a mixed bag for hobbyists; on the one hand, many are gorgeously beautiful; and the group is hardy, tolerant of vacillating conditions and easy to propagate. On the other hand, their propensity for growth, crowding out other sessile, sedentary life can be problematical; AND they can generate significant toxic materials if disturbed.

            As usual, the onus is upon you, the aquarist, to investigate the needs of these animals, provide basic husbandry, AND limit their expansion and possible mal-influence in your systems.

Detail on Taxonomy:

            Stolonifera is a suborder of soft corals (Order Alcyonacea); and in turn Octocorallians (Subclass Octocorallia), bearing tentacle arrangements in numbers, multiples of eight. There are eight currently recognized families of Stoloniferans, though the hobby only sees the Clavulariidae (Star Polyps) and Tubiporidae (Organ Pipe Coral)

Shown above, an open Clove Polyp and a closed Organ Pipe.

The “Star Polyps” are made up of individual polyps arising from a colonial stolon mass. Clavulariids have internal supportive spicules and Tubiporids are supported externally by a horny cuticle. Stoloniferans are found worldwide in shallow temperate to semi-temperate seas.

Stoloniferans on Parade! 
Clavulariids: Star, Palm, Tree…. Polyps

Pachyclavularia violacea. Green Star Polyps. Indo-Pacific. Grow as thick mats that may cover meters of bottom. Stolon has purple reddish color to which all polyps are joined. Photosynthetic. May grow quickly in your aquarium, crowding out desired livestock. Best to confine to individual rocks with a break in-between. Middle of polyps white to greenish, tentacles brownish to greenish. Pinnules on tentacles very small. Colony in Sipadan, Malaysia at right and below in N. Sulawesi, Indo.  The most commonly available aquarium species.

Genus Carijoa:

Carijoa riisei, perhaps a Coelogorgia... Cebu

Genus Clavularia (et al. Clavulariids): Individual polyps are encased in calyces (sing., calyx) of half to two inches in length. Tentacle enclosed by feathery pinnules, often side-branched. Occur in pinks, blues, white to cream, brown to yellow colors, at times with contrasting centers. Unlike pulsing soft corals (Family Xeniidae), Clavulariids can withdraw their tentacles completely. 

Clavularia sp. N. Sulawesi

Clavularia sp. Gulf of Aqaba, Red Sea.

Tubiporidae: Pipe Organ Coral:




 The genus Tubipora has four nominal species; though according to Veron, these all probably represent only one valid species, T. musica.; and to others... six, sixteen... Organ  pipe  coral is also a  massive  colonial  animal, readily  recognized  by  its blood-red  cemented  parallel  tubes interconnected  by  horizontal  platforms. As per the Subclass (Octocorallia) bearing,  Tubipora  polyps have eight  tentacles,  arrayed  like feathery palms when exposed. Organ Pipe "coral" is used extensively as ornament as curios and aquarium decor, and I can testify, is very often overlooked underwater for being what it is. /WA Corals:  massive colonies • corallum formed by a series of tubes ~ 3mm wide • polyps have eight feather-like tentacles • skeleton is bright red • can be common in the intertidal zone • member of the Alcyonacea (soft coral) • common name organ-pipe coral

In an aquarium at right, and below in the Red Sea.

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Compatibility: “Ya gotta keep ‘em separated”


Clove and Star Polyps can be aggressive chemically. This allelopathy expresses itself in the “doing poorly” of near sessile Cnidarians, though reciprocally, they’re immune to being toxified or stung by other corals.

 Best to keep them separated, ideally on their own rocky prominence, not near the viewing panels which they branch out to.

 Clavulariids are particularly toxic to Zoanthids, and should be placed well apart from each other.

 Most “coral sampling” fishes give Stoloniferans wide-berth; evidently anti-fish predation chemistry is involved.





Stocking, Selection:

            It’s easy enough to pick out healthy specimens of these species; good ones will be open during the day; without obvious dead spots amongst them. Note that they will move onto gravel and sand substrates as well as directly onto viewing panels. Again, it is best that they be restricted by regular pruning.

            The best specimens are those that have been reared locally; available as trades with other hobbyists as in at frag swaps, or through an intermediary stockist at your local fish store. These animals are proven to live in captive conditions, accepting foods, artificial light… If you must buy wild-collected stock, DO take care to observe it carefully ahead of purchase to assure it is healthy. Stoloniferans are capable of retracting their polyps completely (unlike Xeniids, Pulsing Corals), and will do so given negative stimulus; but all sections of a colony should be open and full if in good to go shape.

            All, and I mean without exception new purchases must be isolated, quarantined if you will, for a few to several weeks; to assure their health as well as give you a chance to assure there are no unwelcome hitchhikers that have accompanied them. After you’re certain these criteria have been met; my standard operating procedure is to utilize a process of introducing the new and established organisms chemically; over a period of days; by routinely scooping out a cup or so of water from the main, display tank and pouring this into the isolation system, and vice versa.



            Stoloniferans are great candidates for small, nano systems. As long as you can maintain optimized, stable conditions, they’re fine in volumes of a few gallons. Likewise they are not very lighting or circulation dependent. “Moderate” to higher intensity of both is fine for them.

            Star Polyps make for great bio-assay organisms; showing early signs of lack of iodide-ate, and trace elements. I am a huge fan of administering both on a regular, weekly basis, in conjunction with gravel-vacuuming, water change outs and topping off, adding all supplements first to the make-up water to ensure complete mixing. I will admit to being lax re actually measuring “iodine” concentration in ongoing set ups; and even being careful with its administration. Simply squirting in several drops has never proved to be trouble; and whatever format I’ve employed (Lugol’s, commercial preparation, my own mixed iodide-iodate) has proven to be non-measurable within a day or two of application.

            Calcium I keep in the higher three hundred to lower four hundred parts per million range; Magnesium at about three times the concentration; and I rely on quality synthetic salt mix, new water to supply Strontium and most all else in the way of macro- and micro- minerals. I do test for alkalinity and strive to keep this at 5-8 meq/liter. For large and valuable collections I utilize calcium reactors; for smaller volumes dual commercial or DIY preparations of ostensibly the same formulation.

            Vitamins, HUFAs, chemical feeds that include Iron, Nitrogen, Phosphorus and Potassium I supply through do-it-myself mashes of foods, as mentioned in the section below.


Foods, Feeding:

            Stoloniferans, like most Cnidarians, produce food photosynthetically via Zooxanthellae as well as consume small planktonic life. They require measurable N, P, K… nitrogen, phosphorus and potassium in their water, as well as periodic micro-plankton feedings; supplied via incidental fish feeding, a large, robust refugium or exogenously by your adding commercial or home-made preparations.

            There are some great shelf-available food products nowayears that one can simply defrost or make a solubilized mash of if dried, and add to the water column near your filter feeding livestock. I am a huge fan of isolating gear like internal pumps separate from ones that power water through particulate filter media. Using a timer to temporarily switch off the latter while being able to continue circulate the water in the system is valuable to move the bits of foods about to the open polyps while they’re feeding.

            Do it yourselfers might well enjoy making their own filter feeder foods. Personally I’ve found it more economical to get out and buy ingredients and put my own mashes together. My basic formula involves ocean-based organisms of small and not sizes: Including “white” fish fillet vs. dark/oily, small crustaceans like Cyclops, Mysids, Copepods; algae of human palatability and Ogo/Gracilaria, liquid vitamin product (children or adult is fine), HUFAs (Highly Unsaturated Fatty Acids (from mail-order or health food stores), and the standard “Poor Man’s Dupla Drops) formula available on line on the Aquatic Gardener, Krib and wiki websites, for ferrous, N, P, K and other essential nutrients.

            These I whip, frappe, blend together in a food processor, fill small zippered lock freezer bags (polythene) and freeze laying down flat. If the mash is intended to feed fishes as well as filter feeders I may use a bit of emulsifier to cause the mix to stick together in larger, more discrete clumps. For this my choice is alginate (which you may order on-line) rather than gelatins for human foods; as the latter can prove problematical used long term.


Diseases, Pests:

            It should be noted that Aluminum compounds employed in many phosphate removing media are toxic to Stoloniferans. Hair and other pest algae are detrimental to them as well; easily overgrowing and smothering their stolons.

            Stoloniferans are easy losers to more potent allelopathogenic Cnidarians. Coming too near many soft corals; particularly Sarcophytons; and the more-stinging stony corals like Oculinids, Galaxea will cause your Polyps to die back. In fact, IF prompted by stress period, the more toxic stinging-celled life in your system may produce copious negative chemical metabolites resulting in die-back even if they’re located distally from each other.

            The usual call to keep your systems optimized and stable; maintaining regular water changes, the assiduous use of chemical filtrants; and if it’s not too dear, the application of ozone, measure of reduction oxidation potential, will go a long way in ensuring the health of all your aquatic life.



            Stoloniferans reproduce in an assortment of ways. Daughter polyps may be exited from the edge of mats; some produce planulae larvae which brood on the surface of the colony.

Clove and Star polyps are the easiest of stinging-celled life to propagate; breaking off a piece, cutting the stolon off in sizable chunks (outside the aquarium, discarding the frag water) is a simple matter. Adhere, or band the stolon piece to a rock. I encourage a triple dosing of iodide-ate in this process; administered to the fragging recovery water, and again in the recovery (isolation) tank.


Personal Experiences with Star Polyps:

            Simple Pachyclavularia violacea, Green Star Polyps were amongst the earliest “corals” I had success keeping. Starting in the mid 1970’s, they were also about the only Cnidarians offered for sale and considered “hot” for Californian marine aquarists back then. Did they live? Did they grow! Well; yes; the batch I had took over the rock bommie I’d situated them on within a few months; then branched on over to the adjacent glass panel, then onto the crushed dolomite substrate. Was I surprised? Was I fretful? No; I was proud and delighted with ‘my reproducing’ this colony! Growth exceeded more than three centimeters per month!

            My delight and pride were short-lived however, once the GSPs had managed to spread to my other “true” (soft and hard) corals; smothering and killing them until I wielded my mighty chisel and chipped the two apart.

            But oh what fun to razor blade off a patch of these Star Polyps and hoof on over to local stores for sales and trading. In those early reefing years, most all locally cultured livestock (Caulerpa, Xeniids in particular) were high dollar trade-in items. But, alas, as with all easy to breed livestock, ready markets are quickly overwhelmed; saturated with hobbyists excess material. What to do? Look to other, newer varieties to add to the market!

Some keen examples currently include a gorgeous blue Clavulariid:





Clavularia sp. Blue Clavularia. Here at friend Rob Bray’s “House of Fins” store in Greenwich, Connecticut. A beauty and fast grower, as are most Stoloniferans.


Other Choices Abound!

As an avid diver, and long-term content provider in the scuba interest; I have MANY images of encounters with Clavulariids in the wild. I assure you that there are several (from the Middle English meaning “many”) species, varieties of Star and Clove Polyps that might well make it in time to the hobby market. Below; a tannish colony in Sipadan, Saba, Borneo, Malaysia; and below it a specimen in Southern Leyte in the Philippines.



            Stoloniferans, Clavulariids in particular, can make interesting and easily kept “corals” for beginning marine/reef aquarists; they are not-picky in terms of water quality, compared with stony and other soft coral groups. Indeed, some folks employ them as organic pollution/nutrient filters in their systems.

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The images in this table are linked to large (desktop size) copies. Click on "framed" images to go to the larger size.

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