Dreaming of Marines - Corals and Anemones
The Patel brothers’ 100-gallon marine aquarium had turned out to be a combined reef and fish tank containing a whole load of live rock,. This is possibly because many retail outlet in the UK tend to display all their marine livestock in mixed tanks. Their aquarium had many beautiful specimens of soft coral and anemones that were all doing well.
Soft Corals
The three species of soft coral in this tank, although contrastingly different in appearance are all from the Alcyoniidae family and are all found in the coral reefs of the Indian and Pacific Oceans. The colony of leather finger corals, a Sinularia sp., placed high on the rocks to be close to the light sources was one of the early additions to this tank. This particular specimen has long slender fingers and fleshy arms both of which were cream coloured. Sinularia sp. are monomorphic having just one type of polyp, the autozooids that ingest food, which are dark brown in colour from which tentacles were almost always visible.
The three species of soft coral in this tank, although contrastingly different in appearance are all from the Alcyoniidae family and are all found in the coral reefs of the Indian and Pacific Oceans. The colony of leather finger corals, a Sinularia sp., placed high on the rocks to be close to the light sources was one of the early additions to this tank. This particular specimen has long slender fingers and fleshy arms both of which were cream coloured. Sinularia sp. are monomorphic having just one type of polyp, the autozooids that ingest food, which are dark brown in colour from which tentacles were almost always visible.
The Sinularia sp. colony grew at a remarkable rate, obviously very happy with the conditions and its location in the tank. It was growing so well that the colony was split in two and placed at the top corners of the aquarium, where they now form independent colonies. The splitting was easily done using a large sharp pair of scissors. The detached piece was stuck to a large rock using super glue. Following this procedure, the finger coral lost a lot of its colour taking on a lighter bleached appearance
Within four to six weeks though, the two finger coral colonies had recovered its natural colour again. Many of the smaller fish such as the damsels swim near the finger coral without actually spending too much time there. The only fish that seem to spend some time around this soft coral were a young pair of Amphiprion ocellaris, the False Clownfish, especially when they were first introduced. The tentacles of finger corals do have nematocysts with various toxins with which to paralyze tiny prey, but these toxins were obviously not harming the clowns.
A second Sinularia species placed high up in this tank was S. dura, which is flat shaped with no finger like extensions and has only a few polyps sparsely spaced. This specimen of S. dura is brownish-beige in colour and did have a couple of smaller sisters attached when first bought. The colony did not extend in number but just grew in size. S. dura is often referred to as Lobophytum crassum in older books. Natural reproduction incudes budding from the base but pieces cut from the body are easy to propagate. The fish in this aquarium were not generally seen to frequent this coral
A huge toadstool leather coral, Sarcophyton sp. belonging to the Alcyoniidae family, occupies centre stage at the top end of the aquarium between the two colonies of finger corals. This particular species has a short main stalk and a large convoluted capitum that is densely covered in autozooid polyps, which often opened out to display tentacles. Sarsophyton sp. are dimorphic also having smaller, less obvious polyps on the capitum surface called siphonozooid for transport of water round the animal. This pale brown soft coral had also grown quickly and was obviously happy in its location.
Sarsophyton sp. can be propagated by cutting of pieces which are glued to pieces of rock. However, this does destroy the beautiful shape of the toadstool, which the Patel brothers have no intention of doing. The Brilliant Red hawkfish often spends long periods perched on the edge of the edges of the toadstool coral, surveying the goings on in the aquarium as it waits for its next meal. At one time, a young pair of False Clownfish also used the Toadstool coral as a temporary base in their early days in the tank, hovering in characteristic style just above the polyps.
Mushroom anemones
Two large dark greenish-brown mushroom anemones, Discosoma species, occupied separate rocks half way down the tank. These mushroom anemones in the Patels’ aquarium, which often expand so that they are sometimes 6 inches in diameter, had grown considerably over a period of 18 months but had not expanded to form a colony and had remained as single specimens. These anemones have marginal tentacles that are short and un-branched, while the tentacles on the disc, which are clearly visible, are finer and branched. Sometimes, if the light was right, it is possible to observe about a dozen or so equally spaced rows of paler green polyps extending from the oval shaped mouth to the edge of the anemone.
Two large dark greenish-brown mushroom anemones, Discosoma species, occupied separate rocks half way down the tank. These mushroom anemones in the Patels’ aquarium, which often expand so that they are sometimes 6 inches in diameter, had grown considerably over a period of 18 months but had not expanded to form a colony and had remained as single specimens. These anemones have marginal tentacles that are short and un-branched, while the tentacles on the disc, which are clearly visible, are finer and branched. Sometimes, if the light was right, it is possible to observe about a dozen or so equally spaced rows of paler green polyps extending from the oval shaped mouth to the edge of the anemone.
Occasionally, these mushroom anemones would assume a wide funnel shape, but would soon spread out flat on the rock surface. Propagation takes place naturally by budding where new polyp forms at the base of an old one or by division of a polyp into two after formation of a new mouth. A Sebae Clownfish uses the centrally placed mushroom anemone as one of its bases, hovering just above the anemone, before moving on to its second home in a H. crispa. The Sebae Clownfish is obviously immune to the stinging nematocysts on the short tentacles of the mushroom anemone.
Colonial anemones
There are two species of colonial anemones in this tank. One colony of button polyps, possibly a Palythoa sp., has cream coloured stalks and greenish brown discs with striations across the surface, surrounded with some fifty four quite short marginal tentacles. Several daughter button polyps have been produced giving rise to a spreading colony. These attached to the rock alongside, but not necessarily touching their parents, suggesting that the polyps were putting out special root-like runners called stolons from which new buds appeared. There is no evidence of a gelatinous mat called the coenenchyme between the polyps.
There are two species of colonial anemones in this tank. One colony of button polyps, possibly a Palythoa sp., has cream coloured stalks and greenish brown discs with striations across the surface, surrounded with some fifty four quite short marginal tentacles. Several daughter button polyps have been produced giving rise to a spreading colony. These attached to the rock alongside, but not necessarily touching their parents, suggesting that the polyps were putting out special root-like runners called stolons from which new buds appeared. There is no evidence of a gelatinous mat called the coenenchyme between the polyps.
A second faster growing colony of Zoanthus sp. that has greenish yellow stalks, discs and some thirty six long tentacles round each disc added colour and motion as the tentacles sway in the current in the tank. These polyps are growing more densely and sometimes appear to be one large animal, especially when all the tentacles are fully extended, rather than a large numbers of closely growing polyps. This species is able to completely retract its tentacle and disc, leaving just the stalk showing. None of the fish in the tank appear to closely associate with these colonial anemones, although the yellow tang occasionally picks at some tit bit, possibly algae from the polyps.
Heteractis Anemones
Surprisingly, this aquarium is also home to three different species of true anemones, all from the same genus Heteractis, in the Stichodactylidae family. These are H. aurora, H. crispa and H. magnifica all of which have a wide spread distribution in the reefs of the Indo-Pacific. The H. aurora, commonly known as Sand anemone, Beaded Sea anemone or Glass pearl anemone because of the beaded appearance of its tentacles, occupies a spot mid-way up in the tank. In the wild this anemone is buried in the sand with just the disc and tentacles sticking out. The disc and tentacles of this particular specimen are a pale brownish violet and since it was always laid out flat, I never got to see its column colour. None of the clownfish associate with the Beaded Sea anemone.
Surprisingly, this aquarium is also home to three different species of true anemones, all from the same genus Heteractis, in the Stichodactylidae family. These are H. aurora, H. crispa and H. magnifica all of which have a wide spread distribution in the reefs of the Indo-Pacific. The H. aurora, commonly known as Sand anemone, Beaded Sea anemone or Glass pearl anemone because of the beaded appearance of its tentacles, occupies a spot mid-way up in the tank. In the wild this anemone is buried in the sand with just the disc and tentacles sticking out. The disc and tentacles of this particular specimen are a pale brownish violet and since it was always laid out flat, I never got to see its column colour. None of the clownfish associate with the Beaded Sea anemone.
The anemone, H. crispa, in this aquarium has a brownish-green disc and tentacles. The tentacles, which could be completely retracted, were sometimes quite short but longer on other days and tend to appear more along the outer rim of the anemone, leaving the center usually clear. Having spent a year mid way up the aquarium on a rock, the Leather anemone suddenly decided to move to the coral sand bottom, placing half its extended column, which was cream coloured, on the glass surface. In the wild, several clownfish species, but not the Sebae Clownfish, associate with the Leather anemone. Here in the aquarium, with no other choice when it was introduced, the Sebae Clownfish took up part-time residence in the Leather anemone, spending the rest of its time on a mushroom anemone.
A Magnificent sea anemone, H. magnifica. and its two Clark's Clownfish, Amphiprion clarkii, occupy a position near the bottom right hand corner of the tank, having moved there by itself from a position higher up in the tank. Attached firmly to a rock, the Magnificent Sea Anemone opens up and extends its long tentacles sometimes occupying a cubed foot of volume. This Magnificent Sea Anemone has a pink coloured column and greenish brown tentacles that are variable in length and inflation status depending on its mood and also the time of day. This Magnificent Sea anemone always has a columnar appearance unlike the other two Heteractis species in this tank which prefer to open out fully like a plate. The two Clark’s clownfish, particularly the larger female spend all its time either in the vicinity off or in the anemone, impervious to its stinging nematocysts.
Harmony
With such a collection of soft corals, mushroom anemones, colonial anemones and true anemones, one might expect trouble in this tank, especially as some of the anemones are mobile. Moreover, all these creatures secrete mucus which contain highly potent neurotoxin. The filtration systems, the protein skimmer and the water changes obviously reduce or remove any harmful substances. Hence, for the most part so far there has been harmony in this tank, perhaps because there is still some space between the animals.
With such a collection of soft corals, mushroom anemones, colonial anemones and true anemones, one might expect trouble in this tank, especially as some of the anemones are mobile. Moreover, all these creatures secrete mucus which contain highly potent neurotoxin. The filtration systems, the protein skimmer and the water changes obviously reduce or remove any harmful substances. Hence, for the most part so far there has been harmony in this tank, perhaps because there is still some space between the animals.
Although the Toadstool coral is in fairly close proximity to the S. dura
specimen, neither has suffered any ill effects, although it might be
advisable to put more distance between the two. The only aggression came
from the Magnificent Sea anemone, which was stinging a mushroom anemone
that was living above it, causing the edges of the mushroom to shrivel
up. Moving the rock holding the mushroom anemone
to another location out of reach of the Magnificent Sea Anemone solved
the problem, with the mushroom making a full recovery within a few
weeks.
Lighting and Feeding
All the marine invertebrates, from soft corals to anemones, host the symbiotic algae, Zooxanthellae sp., within their bodies. These algae are known to provide a large part of the nutritional requirements of their host by sharing their food products formed during photosynthesis. For photosynthesis to occur light and carbon dioxide are necessary. The lighting for this tank is provided by two 15000 K metal halide bulbs as well as an actinic blue tube and a moonlight tube, all controlled by timers with an 12 hour lighting cycle. There is also some natural light that reaches the tank from a window, although direct sunlight does not actually fall on the tank. These light sources appear to be adequate, since all the corals and anemones are doing well.
All the marine invertebrates, from soft corals to anemones, host the symbiotic algae, Zooxanthellae sp., within their bodies. These algae are known to provide a large part of the nutritional requirements of their host by sharing their food products formed during photosynthesis. For photosynthesis to occur light and carbon dioxide are necessary. The lighting for this tank is provided by two 15000 K metal halide bulbs as well as an actinic blue tube and a moonlight tube, all controlled by timers with an 12 hour lighting cycle. There is also some natural light that reaches the tank from a window, although direct sunlight does not actually fall on the tank. These light sources appear to be adequate, since all the corals and anemones are doing well.
In addition to the photosynthetic products provided by the symbiotic algae, most of these animals benefit from feedings of micro-plankton and thawed newly hatched brine shrimp, which they can capture with their tentacles. These feedings, which are given about twice a week, are apparently particularly important for the colonial anemones. The Magnificent Sea Anemone also takes larger foods that are provided by the Clark’s clownfish that grabbs food, which is dumped on the anemone, while the other Heteractis species do not have this service but still do well.
The Marine Dream lives on!
The Marine Dream lives on!