Invertebrates Guide

Invertebrates Guide needs because sometimes its difficult to keep invertebrates in an aquarium: on the one hand, they are very sensitive to the quality of the water, which must be as faultless as possible, and, on the other, feeding them is complicated, particularly in the case of sponges, Coelenterates, anemones, and corals. It is also important to consider the compatibility of invertebrates, not only with each other but also with fish as invertebrates are the favorite meal of some fish! For all these reasons, the best option is a specialist tank, which will provide a spectacle just as fascinating as that of a fish aquarium, although those fish which can cohabit with invertebrates represent a logical complement to this type of aquarium.

The invertebrates which are most robust and easiest to acclimatize can reproduce in captivity (especially some species of anemones), but success in this area requires a solid background in saltwater aquariums on the part of the hobbyist.

Nevertheless, some saltwater aquarists hesitate to cross the threshold from fish to invertebrates, on the grounds both of cost and risk. However, these days there is a craze for this type of aquarium, but you must not get carried away: it is not feasible to reconstitute a coral reef, although it is possible to achieve satisfying results, both in terms of ecological equilibrium and an engrossing spectacle.

The Aquarium
The bigger it is, the easier it is to acclimatize the invertebrates. Do not consider a tank of under 300 liters for a medium-sized anemone, accompanied by its clown fish. A volume of 400-500 liters is the absolute minimum for a tank containing several species of invertebrates. A maximum height of 50 cm is recommended to allow the light to penetrate, as well as making it easier for the aquarist to intervene. It makes sense anyway to install as large a tank as possible, as your enthusiasm for these creatures is bound to grow.

Lowering the pH in a Saltwater Aquarium

Water
This must be stirred vigorously: use a pump with an outflow equal to at least five times, and up to ten times, that of the volume of the aquarium. Do not forget that the water in an invertebrate tank will never be as agitated as in a natural setting. The water must be very clear, to facilitate the penetration of light. It is therefore vital to have good mechanical filtration, possibly in conjunction with an air pump. Invertebrates are extremely sensitive to nitrates (NO3-).

A box filter is indispensable, and its volume must equal at least 10% that of the aquarium. It must be pointed out, however, that tanks containing true corals, or madreporites, which form reefs can sometimes work well without this type of filter.

In order to facilitate the operation and reduce the burden of the filter, thus increasing its efficacy, put the protein skimmer in its first section. As a complement to these techniques, you are strongly advised to perform partial water changes, at a rate of around 10% of the volume, once a week. It is advisable to change the water the day after the weekly feeding session, as this will help to reduce pollution. The specific gravity of the water must be around 1.024, although it can go up to 1.026.

Light
This is extremely important, both as regards quantity and quality. Apart from the aesthetic effect, lighting serves to enhance the development of Zooxanthellae, the micro-algae which live in the animals' tissues and contribute to their equilibrium.

If the water is less than 50 cm deep, use fluorescent tubes as day lighting, in conjunction with a blue tube. Deeper water requires powerful HQI lamps, again combined with a blue tube. The lighting must be strong (around 1 W per liter of water) and should be left on for about 13 hours every day. UV lamps are not recommended for invertebrates.

The Substrate
Fine-grained soils are to be avoided, a size of 2-5 mm being perfect. The bed must be calcareous and comprise sand made from corals and marine algae, which can be complemented by crushed oyster shells to guarantee a moderate supply of calcium carbonate.

The Decor
This serves as a support for some animals. Create an aquascape in tiers or with steps, and place the species on it according to their need for light. This is easy to do with artificial materials, and the decor can be finished off with dead coral and rocks.

Vegetation
Plants release substances that have a beneficial effect on invertebrates, although as yet we still know relatively little about the mechanism of this process. Use algae of the Caulerpa genus, but do not allow them to become too dense. In addition, remain on the lookout for the growth of certain filamentous algae, as there is a danger that they might smother some sponges and delicate Coelenterates.

Acclimatizing Invertebrates
As the characteristics of invertebrates' native waters are radically different from those of the tank in which they will be placed, great care must be taken with respect to their acclimatization. The container in which the new arrival has been transported must be gradually filled with water from its future aquarium, to enable the invertebrate to slowly adapt before it is carefully transferred into its new habitat. The whole process takes about 1 hour. A quarantine period in an acclimatization tank is recommended. When handling invertebrates, be aware of the stinging capability of some species (such as anemones and madreporites).

Compatibility between Invertebrates and Marine Fish
Invertebrates cannot cohabit with just any fish, for a number of reasons. The first is that they are liable to become prey for carnivorous fish. Coelenterates are completely incompatible with angelfish (Pomacanthids), for example. Secondly, some lively and active fish, of over 10-15 cm in length, can jostle and disturb invertebrates in the aquarium.

Furthermore, the bigger and more active a fish, the more it excretes nitrogenous substances, leading to the accumulation of nitrates (NO3-), which are harmful to invertebrates. It is therefore best to avoid the presence of this type of fish. Too many fish produce the same result and the same degree of harm for invertebrates.

Finally, there is another problem when a sick fish has to be treated, particularly with substances containing metals, which are toxic for most invertebrates. Remember that it is always preferable to nurse a fish in a hospital aquarium.