Although this work is entitled "Companion for the Shell Collector", it is not intended to illustrate just any dead sea-shells. This intention was not present when this book was written. Rather, I wanted to show just a little part of the great biological diversity of marine shells from all oceans, including both tropical and cold-water species.
For this purpose I have used the WORLD REGISTER OF MARINE SPECIES (WORMS), which is an international basis of science. This includes the currently valid scientific names and systematics of our recent marine species.
If after the publication of this book one or the other Latin genus name has changed, I ask for your indulgence. Unfortunately, taxonomists are constantly busy with revisions, so the allocation of scientific names should not be understood as a static structure.
If you try to get to know marine animals better in this way, you will quickly develop an extensive knowledge and understanding of the different families and species, their survival strategies, their way of acquiring food and how the species defend themselves against predators. And therein lies a much greater gain than the mere possession of a dead shell of a faded creature.
In addition, I have also mentioned now and then whether and how available species can be kept in an aquarium. And many of these experiences are my own, which I would like to share with the growing number of aquarists. Because to observe living animals in an aquarium means at the same time the chance to get to know and appreciate these animals better than by collecting dead shells. And this includes the hope that a worldwide community of nature-loving people will grow, which will start to lobby for these interesting animals and protect their habitats. Most of the species are now threatened, because humanity is growing and the living conditions for wild animals are steadily deteriorating. Various experts predict an unprecedented extinction of species, which could result in an estimated 30-40% of all known species falling victim! And this "only" through anthropogenic influences. Such as climate change, marine pollution and overfishing, to mention only the most important.
In addition, there are other shells of marine animals that are interesting for collectors and hobby biologists. These include brachiopods, sea urchins and starfish. And because a growing number of collectors have recently turned to these fields as well, I have integrated some of these interesting animals into the context of this work.
The internet offers us the great opportunity to establish and support international networks to stand up for the widely dwindling fauna of the one ocean together with many voices and supporters. In favour of an environment that is obviously damaged in many ways, whose creatures cry for salvation every day, but unfortunately mostly unheard by the most people...
Sven Erik Gehrmann, in spring 2021.
Do shell collectors and hobby-biologists need scientific knowledge about the field of molluscs? Of course not, would most people say. But on the other hand side it is matter of fact, that sea-shells are mostly traded under their scientific names. So it seems to be necessary, to know the scientific name of a sea-shell to avoid misunderstandings. The advantage is that all shell collectors around the whole world share one scientific language: Latin. So it is no problem to trade or to order sea-shells, even from countries on the other side of the globe. If all share the same knowledge base, all can profit personally from this scientific system. And in deed this is what the first scientists like Linne`, Lamarck, Leach or Montague had in mind, when they developed the first descriptions of plants and animals and published their knowledge in scientific magazines. Now everyone is allowed to describe a new species, if he recognizes the international scientific rules for that business. It is not necessary, to have studied biology, to do that business, and during the last decades hobby-biologists or other interested persons have discovered and, in some cases, even have described new species. So what hinders you?
The only thing you need is some basic knowledge of taxonomy and the anatomy of the species described. With the help of universities, you can also obtain descriptions of similar species and follow them. Then you should have the work checked by a scientific expert before you publish it in an appropriate journal. If there is already a genus for the new species, this should be adopted to prevent later revisions. The species name of a new species, on the other hand, can be freely chosen, but should be Latinised if possible and, above all, make sense. Well-chosen Latin names can often already provide a small concise description of the species, in which they present essential characteristics of the species in a condensed form. If a species is called "ruber", for example, then one already knows that it is red in colour. Or if it is called "cornutus", then we know that it is a species with horns. However, species names can also be given in honour of others by Latinising their surnames or first names. This gives rise to names such as "muelleri", "weinkauffi" etc... The disadvantage of this naming method, however, is that a name given in this way unfortunately hardly says anything about the creature described and its characteristics. Therefore, it is better to always focus on the subject being described.
Below is an example of how a mollusc can be sorted into the scientific "tree" of taxonomy. However, this "tree" should better be understood as a chain, because the Greek word taxon (plural taxa) literally means "link of a chain". In order to shed more light on this fact, the purple dye murex Bolinus brandaris, a common purple snail of the Mediterranean, has been depicted here together with the taxonomic "chain":
Classification: Biota (living beings)
Kingdom: Animalia (animals)
Phylum: Mollusca (Molluscs)
Class: Gastropoda (gastropods; literally = "stomach-footed creatures")
Subclass: Caenogastropoda (snails with shells)
Order: Neogastropoda (New Snails)
Superfamily: Muricoidea (Rock snails and others)
Family: Muricidae (Rock snails)
Subfamily: Muricinae (True rock snails)
Genus: Bolinus (Purple snails)
Species: brandaris (Purple dye murex)
During the last decades, the taxonomic system has been heavily revised. In the process, more and more parts were added to the taxonomic structure. Thus, unfortunately, the original matter became more and more complicated and intransparent. It may be that the taxonomists merely wanted to establish themselves as the "true" experts, but it may also be true that some additions made sense in order to better distinguish different families and species from each other. It is to be hoped that an objective truth will prevail here in the long run.
This picture shows a sculpture from the Herrenhäuser Gardens in Hanover. It is Aphrodite, the Hellenic divine of female beauty.
Bacchus, the god of wine and idleness.
Statues and shells
During the 16th and 17th centuries, the shells of tropical shells from the Caribbean and the Indian Ocean became popular among the aristocratic upper classes in Europe. Such shells were popularly integrated into gardens and buildings and signified a status symbol. At that time, such bowls were extremely expensive and were usually unaffordable for the non-aristocratic population. The shell-decorated walls shown here demonstrated the artistic understanding of the kings and queens of Hanover in Germany, who were related to the royal family in England and for some years even presided over both kingdoms simultaneously. If only this political union had lasted a few decades longer, Europe might have been spared some pointless wars. The photographs show typical buildings of the Rococo era from the Herrenhäuser Gardens in Hanover, the capital of Lower Saxony. After the Second World War, these historic buildings were restored and renovated, as most of them fell victim to Allied bombing. Every few years, the shells incorporated there also have to be renewed because their colours in particular inevitably fade under the influence of acid rain and the ultraviolet components of sunlight. So you can easily see here that the shell at the top right of the picture is a newer specimen, while the others are already somewhat older. The arrangement itself represents the Greek god Bacchus, who was known as the god of luxury and wine.
The Birth of Venus, Sandro Botticelli, painted anno 1485/1486.
The Birth of Venus
Sandro Botticelli painted this magnificent painting for Lorenzo de Medici, who was once one of the greatest patrons of the arts of his era. In truth, the painting does not show the birth of Venus, but rather the arrival of the new goddess on the Greek island of Cythera.
In contrast to the depiction of the goddess as a naked beauty, however, Venus was not understood as an ancient sex symbol. Rather, the goddess was seen as a symbol of a pure mind and wisdom.
The clothing of the other persons around the goddess is typical of the Renaissance. Fortunately for posterity, this work escaped the burning of images during the Reformation. During which various great works of art were publicly burned for religious fanaticism because they were considered obscene. This happened especially in Florence, where the monk Savanarola led a relentless religious regiment to avert divine punishment.
The original painting can still be admired today in the Uffizi Gallery in Florence, Italy. The painted oversized shell is very typical of Mediterranean marine fauna. It is the Great Pilgrim Mussel Pecten maximus, which is also an excellent delicacy. It should be added that the mussel owes its name to the fact that pilgrims actually used the empty shells to beg or to use as easily portable eating utensils. These shells were very practical because they were light and could be quickly stowed under the robe.
Of course, the best storage method for mollusc shells would be to store them in closed cabinets to protect their colours from the ultraviolet components of sunlight. However, this would also mean not having the collection in front of one's eyes. This "correct" way of storing would therefore mean the same boredom as collecting stamps! Therefore, it might be a good compromise to display parts of the collection in a showcase cabinet. One premise for this, however, is to avoid direct sunlight, which fades the colours of the bowls. The bowls themselves can be combined with elements such as small stones, other sea animals or even artificial decorations. In the display cabinet shown here, artificial stones and corals were used to represent a fictitious marine habitat - here a rocky coast. Of course, real sand from a beach would be a good element to showcase the shells of shells burrowing into it. Gravel and shill (fragments of small shells) are also suitable for depicting other types of seabed. The right mix of real and artificial components can convey a certain over-realism to the viewer, so that in the best-case scenario a child would ask if the sea creatures on display were still alive!
If you want to keep small and fragile shells permanently, you should store them in small plastic boxes to protect them from breakage, dust and sunlight, which could destroy their colours. These shell boxes should be kept in folders or in closed cupboards. Individual shells should first be identified and then labelled with small notes containing the Latin name, place of discovery or other important details. Large shell jars or setter boxes may appear decorative at first glance, but fragile thin shells in particular are not well kept here. In addition, dust and sunlight can affect the bowls in this way and quickly make them unsightly. They can also fall out of an open setter box and break. The best thing would be to secure the bowls in the seed tray by placing a pane of glass or plexiglass in front of them. This would indeed protect the bowls from breakage and dust, but they must still never be exposed to direct sunlight. In addition, one could simply place the setter box in a closed cabinet. For their part, one should sort the bowls according to family or origin, which could also be an aesthetic element for the collection.
Cone snails (Conidae) in a setter box. Presented like this, they either fade due to the sunlight or they might even fall out... However, such boxes are always a very decorative element in interior design.
These plastic boxes can be kept in cupboards or file cabinets. A very effective method to protect especially narrow, thin and easily breakable shells and to store them clearly sorted.
Such clam jars are a very unsafe method of storing clam shells, especially the thin and easily breakable shells....
Shells and the remains of marine animals can be discovered in a wide variety of places and circumstances. Some habitats are therefore briefly presented below. Some marine animals need the same living conditions throughout the year, which hardly change. Others have adapted to tidal changes, fluctuating salinities and temperatures and other living conditions. Some organisms trust their camouflage, while others have bright colours to convince their enemies of their inedibility or toxicity. The following pages therefore present some marine habitats to give you an idea of the circumstances and forces of nature that affect the inhabitants of these habitats.
The tropical mangrove belts could also be described as a buffer zone between sea and land. Mangroves are trees that can tolerate different salinities, mud, storms, heat, storm surges and high levels of ultraviolet radiation from sunlight. By spreading cuttings into the muddy areas around them or driving new shoots through the mud from creeping shoots, they can even contribute to land reclamation. And their strong roots can secure entire stretches of coastline against tropical cyclones. Destroying mangrove forests - especially for the construction of shrimp farms - means destroying an important natural shelter belt of tropical coasts. Integrating mangrove plants into a tropical reef aquarium is a good idea and serves biological water treatment. This is because the mangroves extract nitrates and phosphates from the aquarium system via their roots, which they also use as fertiliser for their own growth. However, if you do not want to see the roots in the aquarium, you should place the mangroves in a well-lit filter basin that is connected to the water circuit of the aquarium. Under natural conditions, mangrove roots serve as breeding grounds for many fish species. During the flood, larger predatory fish such as sharks and tarpon try to find prey among the mangroves, but they also take care of their own offspring among the impenetrable root networks.
The tropical mangrove belts provide shelter and refuge for fiddler and mangrove crabs, swimming crabs, oysters, snails, soft corals, hermit crabs, jellyfish and many other invertebrates. They protect their inhabitants from storms and break the powerful forces of the waves. All organisms that reside here also have a strong influence on the mangroves, because they produce detritus, the decomposition products of which the mangroves feed on. In addition, many different bird species also live in the mangrove forests, which otherwise could not live on the coasts without mangroves.
Seagrass beds are found in temperate climates as well as in the tropics and subtropics. Seagrasses are highly developed flowering plants and are not related to seaweeds and algae. Sea grasses anchor themselves with their strong roots, the so-called rhizomes, especially in muddy soils and thus make use of the many nutrients stored in them. However, this also means that seagrasses benefit greatly from the organic overfertilization of coastal zones caused by human influences. On the once coral reef-rich coasts of Kenya, for example, seagrasses have now almost completely replaced the reefs, which has also destroyed biodiversity. On the other hand, seagrass meadows offer refuge to a very unique fauna, such as crabs, shrimps, snails, pipefish, seahorses and many more. Few specialised molluscs can be found here, in particular some species of mermaid snails, mudflat snails or some species of mussels that like to settle among the rhizomes of the seagrass. Sometimes you can also discover cephalopods such as the octopus, which lurk here for small fish and crabs or which go about their breeding business here. On some coasts - such as the German coasts of the North Sea - the once large seagrass beds were permanently destroyed by human influences as early as the 1930s. A virus destroyed most of the seagrass plants, which had previously been so common that beds were stuffed with their dried leaves. Nowadays, only small relict stands of seagrass can be found here, which unfortunately represent only a tiny fraction of the original stands.
A lagoon could also be described as a marine lake that has been separated from the surrounding sea. In addition, lagoons can also develop between the beach and the often-offshore fringing reef, so that new animals constantly enter this zone from the sea through the influence of tides or storm surges. The lagoons themselves are usually quite shallow areas with sandy or muddy bottoms, which do not provide cover for many animals (with the exception of areas with seagrass growth). Because seabirds can prey particularly easily here, the animals living here must have successful survival strategies. For example, the spider snails of the genus Lambis have long spines and particularly thick shells. And if you turn them over, they defend themselves vigorously with their sharp, crescent-shaped lid, which also allows them to turn over again quickly. Other molluscs prefer mass to class. They appear in enormous numbers and produce millions of juveniles to compensate for the losses caused by predators. While still other species try to evade their enemies by burrowing into the substrate. Most of these species live on diatoms, organic waste or carrion of any kind, while only a few species are predatory. As growing populations have become rampant in tropical coastal areas during the last decades, lagoons have become particularly threatened refuges, as they are usually easily accessible and can be exploited and polluted without problems by local residents.
There are very different types of rocky coasts. There are rocks made of limestone, rocks of volcanic origin or sandstone. Rocks are often found in very exposed locations, and there are many different marine organisms that have adapted to make these settlement areas their own. Snails and mussels that have adapted to them can withstand the force of the oncoming waves, strong currents and many predators. Some are able to use the smallest crevices and cracks for themselves, while others are able to suck on the rocks, attach themselves with byssus threads, or even etch or drill holes in the rocks themselves. On the shells of the molluscs living here, in turn, algae or other invertebrates often settle. So you can often find barnacles, tubeworms, bryozoans and other interesting animals here. Hermit crabs in particular are often found in large numbers on rocky coasts because they profit from the empty shells of dead snails. These crabs, in turn, are an important food source for many fish, such as wrasses. And so this habitat is a richly laid table for many different marine animals. In addition, larger molluscs such as octopus and squid also like to hunt in this biotope, being able to imitate the uneven surface structures of the rocks with their bodies. Shell collectors can find a great variety of mollusc shells and sea urchins on rocky shores, especially during low tide in the many small tide pools.
A typical rocky bay on the island of Rhodes, which reveals strong plate tectonic faults of the ground and strong erosive forces of the sea.
Tropical coral reefs are created by the tiny polyps of stony corals. These polyps are only a few millimetres in size, but they have nevertheless created the largest structure in the animal kingdom, namely the Great Barrier Reef off Australia's coasts. Coral reefs are very complex ecosystems in which the smallest organisms often have the greatest importance for the entire system. For example, most corals live in symbiosis with microscopic algae called zooxanthellae, which live as symbiotic partners in the coral's tissue. These produce nutrients and oxygen for the coral and thus support the growth of the coral colonies. Furthermore, these symbiotic relationships are also known from giant clams and some echinoderms. This could be a perfect system if humans were not endangering it through marine pollution, over-exploitation of the reefs and the consequences of man-made global warming. In particular, excessive warming of the seawater poses a very serious threat to entire reefs, because if the temperature remains too high for too long, the corals are forced to shed their zooxanthellae. Because they then have to choose between two evils: If they keep their zooxanthellae, they produce too much oxygen and poison the corals. If, however, they reject all zooxanthellae, they are no longer viable without them, eventually bleaching out and dying of so-called "coral bleaching". In this way, entire ecosystems can perish within short periods of time, because without corals, the fish also disappear and a wasteland of bare coral skeletons remains. This phenomenon could be observed worldwide when the water temperature exceeded 30° Celsius for more than a month. If you manage to avoid using a car or travelling by air, you can also make a small contribution to the protection of tropical reefs this way! Coral reefs are home to a great variety of algae, invertebrates and fish. Everything belongs together through diverse interconnections, and we are challenged to avoid disturbing this delicate ecosystem as much as possible.
Wrecks provide excellent artificial settlement areas for numerous invertebrates. Especially in places on the seabed where sand or mud would otherwise make settlement impossible. Many wrecks - such as in particular the wrecks of aircraft and ships from World War 2 in the Indo-Pacific Coral Sea - have been colonised by so many corals and invertebrates within a few decades that they can hardly be recognised as being of unnatural origin. Contrast this with the fact that many wrecks are unfortunately also a latent danger to their new inhabitants, because they often contain chemicals, oil, toxins of all kinds or ammunition residues that are still sharp even after decades under water and could explode at any time. So over time, the substances stored here can enter the marine food chains via the invertebrates and thus make their way back to the people who fish their food out of the sea. Divers love to dive into the history or biodiversity of this habitat here. However, it should be said here that wreck diving is dangerous and not for beginners. Shipwrecks are often home to lobsters, conger eels, moray eels, large groupers, octopus, large cod and other predators that make their homes here. Nowadays, most shipwrecks are made of steel, which rusts after a while, making wrecks even more dangerous for divers, as steel can also break and then show sharp corners and burrs. This can cause serious injuries, which is particularly unpleasant during a dive.
Mussel beds are mostly found where mussels or oysters attach themselves to the substrate with their byssus threads. Where there are no hard substrates, they simply stick to each other and form firm settlement felts that can defy the strong current. Their byssus threads are difficult to tear and adhere to the substrate after only a few minutes. Mussels are often found in exposed places, such as on groynes or on wooden piles, where they fall dry at low tide. Mussel beds provide a habitat for many animals that would hardly have any cover without the mussels. Worms, snails, various crustaceans and starfish can be found here. Thus, mussels take over an ecological niche that corresponds to that of corals in tropical seas. Moreover, even dead mussels still make an important contribution to other animals, as they can also settle on their empty shells. The current then gradually grinds the shells of the mussels, creating sand and silicates. These are then drifted, forming new sandbanks. Mussel reefs also form the food base for numerous echinoderms as well as various species of crustaceans and fish. Without these reefs, biological diversity and productivity in the world's oceans would be considerably lower. Finally, it should be noted that larger mussel deposits can also be relevant for humans, as they serve as natural erosion and coastal protection.