Fish

Kópavogur Natural History Museum has a small collection of stuffed fish, as well as live fish in marine and freshwater aquariums. These are three freshwater aquariums, the largest one about 1800 liters, and two sea aquariums. Each aquarium has a specific theme going on. In the largest cage, conditions in a lake with a lava bottom are simulated, and there you can e.g. see char varieties from Þingvallavatn (murta and dwarf char). The hornbills get a whole cage for themselves and there you can e.g. observe the evolution process of the hinges as they protect certain areas with great hardness.

In the aquarium you can see crabs, manatees and sprint fish (skerja catfish), roe eel fry and many other things that can be found in beach pools or in the shallow water. The fourth aquarium simulates a shallow pond with a mud bottom and associated vegetation. There, the focus is on small animals in fresh water, e.g. water tit, well clock, water bobber, etc.

The aquariums are the part of the museum that attracts the most attention of visitors. They are constantly changing and we strive to have the most diverse animals in them at any given time. The museum’s employees, together with helpers and well-wishers, have taken care of the animals.

Below you will find information about the fish that are on display at Kópavogur Natural History Museum, as well as some others from the diverse range of fish that live in the waters around Iceland. A very small overview is given of each group to which the artefacts belong and then the artefact itself is discussed.

Fishes (Pisces) were the first backboned animals to appear on earth. There are three major groups of living fishes; jawless fishes (Cyclostomata), cartilaginous fishes (Chondrichthyes) and bony fishes (Osteichthyes).

The jawless fishes are the most primitive group and first appeared about 500 million years ago. Jawless fishes have no scales, jaws or paired fins. There are ~90 species world-wide. Icelandic waters: 2 species.

Cartilaginous fishes, including sharks and skates, have well developed jaws, teeth of bone, paired fins, ctenoid cales and cartilaginous skeleton. World: ~810 species. Iceland: ~33 species.

Bony fishes have calcified skeleton, well developed jaws, and usually scales. World: ~25,000 species. Iceland: ~300 species.

Atlantic cod | Gadus morhua

The cod is abundant in the North Atlantic Ocean. It is comprised of different subpopulations that live in different areas. The subpopulations vary in size and shape and age of maturity. The main spawning grounds in Icelandic waters are off the south coast. The cod spawns in open water in March and April, and the fertilised eggs drift clockwise along the western coast. In 15–20 days the fry hatches from the egg. The yolk sac lasts for several days, at which time the fry must start feeding, mainly eating microscopic algae and invertebrates. Soon after hatching the fry becomes benthic. At 50 cm length the cod feeds largely on capelin.

The cod reaches maturity at 4–9 years of age and 50–100 cm. It returns to the spawning ground and will spawn every year after that. The cod can get as old as 25 years. It is a very fertile species, a 100 cm long female may spawn about 4.3 million eggs in a single spawning season. The sea, however, is a dangerous place with a lot of hungry mouths of different kinds. The estimated mortality of eggs and drifting fry is 90–95%.

Adult size: Up to 180 cm in Icelandic waters

Saithe / Pollock | Pollachius virens (Gadidae)

Benthic and pelagic N-Atlantic species. It is commonly found down to 250 m depth all around Iceland. Omnivorous and feeds among other things on euphausiids, Capelin and squid. The Saithe can get up to 30 years old and more than 1.3 m long. Reaches sexual majority 4–7 years old. Spawns along the South and West coast of Iceland in January–March. 

Redfish | Sebastes norvegicus (Scorpaenidae)

The Redfish is one of five related species found in Icelandic oceans. Found in most densities near the edge of the continental shelf, at 100–400 m depth it may be found down to 1000 m depth. Small redfish feed on zooplankton such as euphausiids, calanoids, chaetognaths and fish fry. Larger fish feed on other fish species such as cod and herring, but also on shrimps and other crustaceans.

The Redfish is among the rare fish species that doesn’t spawn eggs but releases its offspring’s as fry. Growth is very slow and sexual majority is reached at the age of 12–15 years, at the length of 35 cm and weight of 800 g. The fish may reach the length of 100 cm and weight of 12–15 kg. 

Red bream | Beryx decadactylus

Deep sea or benthic species, mostly found in the Mediterranean and Northeast Atlantic Ocean. Rather uncommon in Iceland but have been caught in midwater trawls at 200–600 m depth in the ocean south and west of Iceland. Feeds on crustaceans, small fish and squid.

Adult size: 60 cm.

Atlantic footballfish | Himantolophus groenlandicus (Himantolophidae)

Mid- to deep-sea fish found in all oceans at 1,000–3,000 m depth. Fish of this genus usually have big head and mouth and a modified fin ray on the head, with a bioluminescent lure for attracting prey in the pitch-black depths of the ocean – sometimes referred to as a “fishing rod”.

The male of the Atlantic football fish is only 5 cm long, dwarfed by the female which can grow ten times larger. The males are free living and not parasitic on the female, as is commonly seen in related species.

Adult female size: 60 cm. Adult male size: 4–6 cm.

Krøyer's deep sea angler fish | Ceratias holboelli (Ceratiidae)

Mid- to deep-sea fish found in all oceans at depth of 120–1000 m. Here, the specialization towards live in the deep-sea habitat is taken to some extremes, as this species both has a fishing rod with a bioluminescent lure to attract pray, and parasitic dwarf males to simplify the search for compatible partner in the vast depths of the open ocean.

Sexually mature males seek out females and permanently attach to them. The males even lose the ability to feed, which the female counterbalances by sharing the bloodstream with the male. Each female may carry more than one of those 5 cm long dwarf males and does so, as long as both live.

Adult female size: 1–1.3 m. Adult male size: 4–6 cm.

Atlantic salmon | Salmo salar

The Salmon is a so-called anadromous fish. That means that the fish switches between fresh water and sea and spawns in fresh water. Catadromous fish such as the eel, have this the other way around and spawn in the sea. 

The salmon lives in the river where it hatches from egg for 2–5 years, or until 10–15 cm long, then swims downstream to the sea during spring. In the ocean, the Salmon feeds on fish and crustaceans in the pelagic zone and does so until sexual maturity is reached. Then the salmon returns to the river where it hatched, using its exceptional sense of smell for navigation, where spawning occurs in the autumn. 

Afterwards the fish are quite spent and most die in the river, although some manage to return to the sea. Those who survive quickly regain their strength and may return next autumn for a second spawn.  

Because the salmons spawn in their home rivers, special stocks or morphs have evolved that are adapted to the particular conditions of each home river. The rivers differ in chemistry, temperature, current velocity and productivity. These factors have various effects on the salmon, such as timing of migration, and age and size of maturity.

Adult size: 50–100 cm.

Sjaldséðir flækingsfiskar

Blákarpi (Polyprion americanus)
Þessi fiskur er mikill flækingur. Hann hrygnir í Miðjarðarhafi en flækist um mest allt Atlanshaf og finnst frá yfirborði niður á 1000 m dýpi. Þessi fiskur líkist helst karfa, ef ekki væri liturinn sem er grá-brúnleitur með hvítann jaðar á sporðblöðku.

Göltur (Neocyttus helgae)
Sérkennilega vaxinn fiskur sem finnst á um 800 – 1200 metra dýpi. Afar hávaxinn og þunnur með gróft hreistur og með áberandi gadda fremst í bak- og kviðuggum. Hefur fundist á grálúðuslóð hér við land. 

Hveljusogfiskur (Careproctus reinhardti)
Þessi fiskur er líka kallaður “barbapabbi” vegan litarins og útlitsins. Hveljusogfiskur er bleikur að lit, umlukinn glærri, hlaupkenndri hvelju og afar viðkvæmur. Á þessari síðu eru ýmsar upplýsingar um þennan sérkennilega fisk.

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Rauðserkur (Beryx decadactylus) Serkjaætt (Berycidae) 
Rauðserkur er mjög sjaldgæfur flækingur við Ísland. Aðalheimkynni hans eru í vestanverðu Miðjarðarhafi og Norðaustur-Atlantshafi. Rauðserkir eru af ættbálki serkja (Berycomorphi) og skyldir búrfiskum (Trachichthyidae), ennisfiskum (Caristiidae), silfrum (Diretmidae) og fleiri fiskiættum.
Þekking á líffræði rauðserkja er almennt lítil. Hér við land hafa þeir veiðst nokkrum sinnum á 200–600 m dýpi á miðunum út af Suðausturlandi og vestur um land, allt að Halamiðum norðvestur af Vestfjörðum.

Svarthveðnir (Centrolopus niger)
Svartur að lit með áberandi stóran sporð og lítinn kjaft. Þessi fiskur hefur fundist í flestum heimshöfum. Lítið er vitað um lífssögu þessa fisks nema það að hann lifir á smágerðri og mjúkri fæðu (smáfiskum, svifi og marglittum). Á þessum vef má finna töluverðar upplýsingar um þennan fisk.

Sæsteinsuga (Petromyzon marinus) Haustið 2003 veiddu skipsverjar á Páli Jónssyni GK-7 undarlega skepnu á Vestfjarðamiðum. Um var að ræða sæsteinsugu, sem fest hafði sig á belg. Meira um þessa skrítnu skepnu.

Main sources:

Icelandic fish, description and analysis of all Icelandic species. Author: Gunnar Jónsson. Ed. Macro 1992.
Fish in rivers and lakes. Author: Guðni Guðbergsson and Þórólfur Antonsson. Ed. Land Conservancy 1996.

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