Á safninu eru til sýnis fulltrúar þriggja íslenskra landspendýrategunda, þ.e. refa minka og hagamúsa. Alls finnast sex tegundir spendýra villtar á Íslandi, en það eru auk framataldra tegunda, hreindýr, húsamýs og brúnrottur. Einungis refurinn er upprunalegur, aðrar hafa flust hingað með manninum.
Uppstoppaður útselsbrimill og beinagrind úr háhyrningi eru fulltrúar íslenskra sjávarspendýra, en auk þess á stofan nokkuð af hvalabeinum sem alla jafna eru ekki til sýnis. Talsvert sýningarefni er að auki um hvali og lifnaðarhætti þeirra.
Hér að neðan er fjallað sérstaklega um hvern hóp þeirra spendýra sem finnast villt á Íslandi og umhverfis það.
Molluscs (Mollusca) are a very large and diverse phylum of invertebrates. There are about 85.000 living species. They range in size from 1 mm up to 14 m, in the case of the colossal squid (Mesonychoteuthis hamiltoni). Some species are permanently attached to the seabed while others are fast moving creatures, travelling at the speed 40 km per hour.
Molluscs are comprised of seven different classes: Monoplacophora (near extinct), Polyplacophora (few species), Cephalopoda (few species), Gastropoda (species rich), Bivalvia (species rich), Scaphopoda (few species) and Aplacophora (few species).
In Iceland, roughly 300 species of living molluscs are known. Previously, the most accessible species were commonly used as bait for fish. Many clams can get extremely old, such as the Icelandic cyprine Arctica islandica (kufskel), that often lives to an age of 150 years and may reach over 500 years, thereby reaching the highest age known to any animal.
A diverse collection of molluscs is on display at Kópavogur Natural History Museum. The centerpiece of the museum is Jón Bogason’s mollusc museum, which is one of the most complete collections of shells and molluscs in the country.
About 200 Icelandic species and over 1,300 foreign species are listed in Jón Bogason’s shellfish collection. In addition, the museum has received smaller private collections as a gift. The complete registration of the shellfish museum is ongoing and is well advanced. It is expected that species lists will be available in PDF format before long.
Molluscs or shellfish (Mollusca) are a fairly large group of animals that all have in common that they live in a house that they build around themselves from lime and form one of the groups of the animal kingdom. This calcium is formed by cells in the skin layer, (mantle) that lies under the shell. As the animals grow, they increase their size along the way, and you can often tell the age of some species by annual rings in the shell, where summer growth is much greater than winter growth. About 50,000 species are considered to be alive today, and this is the second largest group in the animal kingdom after Arthropoda. The mollusc phylum consists of seven groups, which are: Shellfish, Horns, Snails, Clams, Shells, Clams and Squids.
Snails or cochlea (Gastropoda), make up the largest group of molluscs (35,000 species). These animals have a single shell that is usually twisted up and forms a spiral. Can the animal pull itself into the shell and some can close behind it with a special valve. The animals sit on a so-called foot, which they use to attach themselves to the substrate and move with it. In front of the shell, the animal stretches a somewhat defined head, which often bears both eyes and feelers.
These animals mainly feed in two ways, on the one hand they scrape algae from the substrate they sit on with a toothed tongue called a radula. Others form mouths that they can stretch out. Are they mainly scavengers or predators and then use their trunk to suck up the entrails of other animals, e.g. shells.
Gastropods include about 80% of living molluscs. The shell will typically be formed in a spiral. They move by creeping on a sucker-like foot and eat by rasping food with a tongue-like mouthpart called radula, armed with small teeth. Size ranges between 1 and 1.000 mm.
World: ~70.000 species. Iceland: ~200 species.
Clams or shells (Bivalvia), form a house of two shells that are mirror images of each other. They are connected together at the so-called nose with a ligament made of protein. Where the shells meet at the nose is called a hinge and it is toothed so that the teeth on each shell fit together and prevent the shells from sliding apart. The animals then have one or two muscles that are used to fold the shells together and close the house. Like cochleae, many shells also have a foot that they can extend out of their shell to move. There are also many people who know the whiskers that some species produce (e.g. mussels) and which they use to attach themselves to a substrate such as e.g. stones
As with snails, there are two main methods of foraging, on the one hand, it involves filtering various particles that can be carried from the sea current that the animals form through the shell, or particles are filtered from the muddy bottom in which the animals burrow. It is always bifid hairs on the gills of the animals that create this stream of water through the shell. The particles that enter the shell then cling to the mucus layer on the surface of the gills and are then carried to the mouth by the movements of bivalve hairs. However, various species have suckers that they can use to reach other animals they feed on.
Bivalves, unlike other molluscs, have a shell consisting of two parts called valves, hinged together. The shells protect the animal. Size ranges between 2 and 1.000 mm.
World: ~15.000 species. Iceland: ~100 species.
Two groups of molluscs are quite similar in appearance, but rather few species, namely the Nakkvar (Polyplacophora) and Skeljungar (Monoplacophora). They are similar to snails in many ways, such as having a rather wide foot under them, which they use to attach themselves to the substrate. The toothed tongue, radula is found in both of these groups and they feed by scraping algae and bacteria from the substrate they crawl on. Clams have a single shell similar to cochleas but never form a spiral like they do, the arrangement of the internal organs is quite different from that found in cochleas. On the other hand, the shell is divided into 7 plates that lie over the animal. These animals are all rather small shells around 3 cm, but the shells go up to 40 cm in length.
Aplacophora are a very small group of animals that are considered molluscs. They have been found in many parts of the sea down to a depth of 9000 meters. They are otherwise very primitive in appearance, more like worms, and the main characteristics of molluscs are not seen on these animals, however there are other characteristics that correspond to the characteristics found on other molluscs, e.g. radula found in some species of carapace. Their main diet seems to be carnivores such as corals and anemones.
Among cephalopods are the largest, fastest, and most intelligent of all invertebrates. Cuttlefish and squids have two long tentacles and eight short arms which they use mainly in feeding. They can move very fast by squirting water out of the mantle cavity. They have large brains and well developed eyes. In most cephalopods the external shell is absent, but there is an internal shell structure in most species. Size varies from few cm up to 15 m.
World: ~800 species. Iceland: 15–20 species.
Horns (Scaphopoda) is the sixth class that will be mentioned here. These are animals that live in a very simple shell, which is a pipe that tapers back at one end like a barnacle. The largest of these shells will be around 15 cm (Dentalium vernedei, a species found in Japan) and the smallest around 4 cm. About 350 species are known, all of which are found in the sea. The body of these animals is relatively long and they have a foot that they use to dig into the sand or clay bottom where they lie with their heads down. It is rather spherical and has a mouth opening. Feelers with a ball on the end are also around the mouth and they are a kind of fishing tool where various particles cling to a layer of mucus on their surface. The animals can then pull the feelers to their mouths and next the particles clinging to them. Horns do not have gills like the largest groups of molluscs have for breathing, but it takes place through the cells of the mantle.
Echinoderms (Echinodermata) are a large phylum of strictly marine invertebrates, living mostly on the seabed in relatively shallow waters (<200 m). Their skeleton is made of plates of calcium carbonate (CaCO³) and they usually are covered with spines. They have tube feet by which they are able to move along. The body is usually structured in five-sided, radial symmetry. The echinoderms include the starfish (Asteroidea, krossfiskar), brittlestars (ophiuroids, sæstjörnur), sea urchins (Echinoidea, ígulker), and sea cucumbers (Holothuroidea, sæbjúgu).
World: 7.000 species. Iceland: 150
Main sources: Verdenshavens conkylier, a handbook for shell collectors. Court: S. Peter Dance. Ed. Lademann Forlagsaktieselskab 1978. The Hamlin Guide to shells of the world. Authors: A. P. H. Oliver and James Nicholls. Ed. The Hamlyn Publishing Group Limited 1980. Shellfish flag of Iceland: l. Clams in the sea, II. Snails with a shell. Author: Ingimar Óskarsson. Ed. Prentsmidjan Leiftur hf. 1982.