Watching the great documentaries that, occasionally, are offered on television, or resting to browse books of underwater images, we often have the impression that the Marine Environment is a beautiful picture, a huge photo in which you can meet, simply diving into it, a large number of fascinating and curious creatures of many colors, always there, waiting for our curious eyes (and lenses!) to direct their glances on them. Actually, the Sixth Continent is more like a stage on which a wonderful performance is taking place, some kind of an unstoppable play in which, without a break, many players take turns putting up their own, colorful daily life.

All this, in effect, means that the "actors"-or to better define them- the inhabitants of the sea, are not always easy to spot: sometimes because their activities are bound to particular times or conditions, other times because we are trying to deal with inconspicuous organisms that may even prefer to remain well hidden and protected from dangers.

So how is it possible to take pictures of all those wonderful and strange creatures that populate the seas? How is it possible to be always in the right place at the right time? And how is it possible to get so close to the fish to be able to picture their eyes and their skin? Again, how is it possible to trace and identify the refuges where the “shyest” inhabitants of the sea use to spend their days or hide from predators?

All these questions are interesting, and important, and the answers lie in a concept already quoted into the Insight "Talking About Underwater Photography": in two words, Marine Biology!

I don’t want to get into a long lecture about what are the methods or approaches to use to come up to the study of this discipline, or what were the ones I used to delve into the world of this fascinating science, I just want to give you some practical examples, so that you can understand the importance of drop below the surface of the sea aware and prepared.

So let’s try to discover, throughout some examples, how the specific knowledge of the sea and of its inhabitants and their habits, can help us to meet and take pictures of the fascinating “people of the Blue”.

Let's start by imagining to swim along a colorful drop-off, full of life and colorful corals of many different forms. We are at a quite-shallow depth, let’s consider in within 20 meters; suddenly we notice an expanse of a rather-dull-and-opaque pink colored soft corals: so dull and seemingly “out of place” among all the color that surrounds them, that they would hardly stimulate our curiosity . Well, although naturally inclined to ignore them, we really should pause to "take a look" between the branches of this soft coral, as it is one of the favourite habitats of the beautiful Bristletail filefish (Acreichthys tomentosus), which often finds shelter within the intricate twine formed by the "branches" of this lithophytum, escaping from predators, as well as from the eyes and the lenses of the divers!
 

With this first example, we touched two points that can be considered particularly important for the study of biology, the first is about the habitat of the different organisms, in other words the depth and substrates on which fish, shrimp, invertebrates, (...), use to be available, from which the importance of learning to observe everything that surrounds us under water, so we can easily identify which are the best sites to spot the animals that we are looking for. The second important point that we have came through is definitely one of the leitmotifs of the marine environment: the mimicry. In fact, the file fish that we talked about just few lines above, prefers habitats in which it is easy for him to go unnoticed, sometimes even adapting the color of his “coat” to the color of the substrate on which it is located.

I referred to mimicry as one of the leitmotifs of marine biology and, in fact, many animals use this system to defend against predators (or to try to be invisible to their quarries!). So let’s see another example of how this innate ability of the animals can save some pleasant surprises for divers and photographers who have fully understood his importance and mechanisms.

Let's go back swimming through the colorful riff of the previous example. After a while, we meet a large madrepore, surrounded by some sponges of a color standing between red and brown, topped by some colorful crinoids, fascinating organisms, similar to flowers gently moving their petals following the flow of the current; belonging to the starfish family, they are in fact very similar to them for conformation, distinguishing from them especially by the lack of rigidity in their arms. The curiosity and wonder that arise from the sight of these animals, naturally lead to take a closer look and it is easy, at least for a keen and well-trained eye, to meet squat lobsters, shrimps and small gobies that, assuming a color similar to the one of the crinoid in which they are established, often rising another important leitmotif of underwater life: the symbiosis (we are going to talk about this topic just few lines below). After have carefully " peeked " near the core of the crinoid and , with a little luck, have spotted one of the animals mentioned above, it is important to broaden our perspective because, often, among the swaying arms of the crinoids, especially among those most long and far from the core, find shelter, perfectly disguised, the ghost pipe fishes

Here’s how with the appropriate knowledges, leading you to recognize a habitat, together with the awareness of the mimetic capability of the animal you are looking for, where we would never have tried to look for this animal, we can find a Solenostomus paradoxus that, following the gait of the long arms of the crinoid, is peeping among the colors, observing the world around keeping a low profile.
 

We have talked a lot about substrates, so far, but, no doubt, incompletely. We have considered soft corals, madrepore, sea fans, sponges, (...), simply as "benchmarks" to find out the inhabitants of the sea, but do not forget that in any good photograph, an attractive background plays a key role. Again, the knowledge of the organisms (and thus also of the corals) comes to rescue us. Take for example a goby standing at the base of a sea fan. If you want to photograph it, you would have a very nice and curious fish, placed on a rather smooth and flat background, somehow aesthetically less charming than a shiny soft coral, than a whip coral or than a madrepore. However, in presence of a fair amount of current, sea fan polyps are open, making the background more attractive, allowing us to watch a breathtakingly beautiful scenery.
 

Obviously it would be unreasonable to expect that the goby remains at our disposal, awaiting the arrival of the current, but we can certainly take into account the fact that, in presence of it, coral polyps open to feed themselves so we will able both to take wide-angle pictures where polyps are open, and to use these as “wallpapers” for beautiful macro photographs: if it is true that the fish we are talking about will not remain still, waiting for the polyps to open for us, it is equally true that recognized a particular habitat, we have good chance to meet others like them and so being able to create the image that we had envisioned!

Let’s now change environment and move to a sandy-ground. We are carrying out a so-called Muck Dive on a sandy shallows. In this situation, the great camouflage ability of the animals comes back, and we constantly have to confront what looks like a grayish-white expanse of nothingness. In fact, this monochrome carpet, hides a multitude of animals and organisms, usually (but not always) limited in size, with a great ability to camouflage.

Proceeding with an expert and conscious eye (paying attention to move the fins only the bare minimum and keeping them lifted compared to the rest of the body, not to raise sand and sediments) , we identify several shrimp, some juveniles stadium of larger fish and also a good number of " critters " (from " creatures " , it is a term used to refer to the entire range of animals so rare, and peculiar , which often turn out to be among the favourite subjects in the macro underwater photography); between these, we meet a beautiful specimen of Pegasus fish ( Eurypegasus draconis ). As often happens when dealing with critters, it is not unusual for some people to wonder how one can define " beautiful " an animal as "strange" and not colored. Once again, biology comes in our help to solve this question, and to enable us to see a new wonder of nature: as a beautiful lotus flower that is born from the mud , much like the Pegasus fish, opening his lateral fins, very similar to wings, he discovers a beautiful color shades of purple, blended by the transparency of the " wings" !
 

We have seen some interesting examples of how the study and in-depth knowledge of the sea and its inhabitants can help us, but until now we were on a "fertile ground", in other words we referred to situations where we were diving in places known to be populated by interesting "characters."

We are well aware that, unfortunately, not all dives are like that: sometimes we find ourselves diving into barely-populated spots, in which it seems to have nothing to do but enjoying the feeling of being underwater; even in this cases, the biology can help us enormously. To understand how, I decided to tell you something actually happened a few years ago.

We were in Saudi Arabia. After two wonderful morning dives, the sea began to mount and the weather was turning considerably worse. We looked for a sheltered place, somewhere to easily moor in, maybe even taking a third dive and spending a quiet and safe night . Unfortunately, the only site which could satisfy these requirements, close enough to be reached before the weather and the sea turn to worse conditions, it appeared as a shallow lagoon with very little water turnover. Despite the conditions were not the best, we decided to dive and, just as we expected, the bottom turned out to be a low maze of rocks and dead corals, brushed only by few small seaweeds and certainly devoid of any appeal. With the exception of a fortuitous encounter with a crocodile fish, it really seemed that we would have hardly find something interesting.

All of a sudden, while we were almost on our way back to the boat, we have identified a number of sandy clearings among the rocks, with a rather particular conformation and with the presence of some small dunes that have caught our attention. From our position they seemed, in fact, nothing more than empty areas in the sand, but the location and the structure of the small dunes left no doubts: we were sure to have found a small colony of gobies. We were not aware of the kind, but, no doubts, they  would have been matched by the usual pair of shrimp (here we are again: symbiosis, in this case between a goby that is responsible for ensuring the safety of two shrimp, warning them of possible dangers, while they keep stable and clean the “longhouse”).

Once in proximity of the clearings, quickly reached by few fins strokes, not only have we found exactly what we expected but, with our great surprise, we found ourselves in front of a colony of brightly colored gobies of considerable size, called Cryptocentrus coeruleopunctatus.
 

In this regard, I open a small parenthesis. I mentioned how, many animals, follow well-defined habits and “time-tables”. In the case described above, we arrived near this small colony, exactly within the best time to observe the activities of this unusual team, if we had reached the site on a different time, we would have found the gobies, but we would have hardly been able to observe the intense activity of the shrimps, since the best time to meet these animals well exposed and shrimps in the middle of their work is located approximately in the second half of the afternoon, before the dusk begins to dye the red lights.
 

Here we are, at the end of the article. We have seen how the knowledge of the animals, of their habits and of their habitats can be useful in any occasion; we could go on and on with examples, some as the result of the study of biology books, other fruits of researches in the field, of personal experience and observation and…even of some loss! The advice is to keep your eyes wide open, and he never claim to see everything, otherwise you may not see anything!

I close with a final, brief idea: we dealed mostly with macro photography, but be careful: biology comes in our help in every situation and, for example, to know that large pelagic fishes are attracted and intrigued (although unsettled sometimes) by the sound of the bubbles and by the presence of humans (especially if supported by calm and serenity vibrations), means that, moving along a wall facing the open sea, we have take a look every now and then in the blue behind us. Sometimes nothing happens, other times...