سمك رئوي كوينزلاندي

Australischer Lungenfisch im National Zoo & Aquarium in Canberra

Der Australische Lungenfisch (Neoceratodus forsteri), auch Djelleh, Barramunda, Burnett Salmon oder Queensland-Lungenfisch genannt, ist der einzige australische Vertreter der nur sechs rezente Arten umfassenden Unterklasse der Lungenfische. Er gilt als ursprünglichste Art aller heute vorkommenden Lungenfische. Die Lungenfische sind in der Fossilgeschichte aus der Zeit von vor 400 bis rund 230 Millionen Jahren mit einem großen Artenreichtum gut bekannt. Daher werden die Arten der drei rezenten Gattungen auch als lebende Fossilien bezeichnet. Der australische Lungenfisch wurde erst im Jahre 1870 entdeckt.

Vorkommen

Der Australische Lungenfisch kam ursprünglich nur in den Burnett und Mary River Flusssystemen im süd-östlichen Queensland, Australien vor. Er wurde jedoch später erfolgreich in mehreren benachbarten Flüssen angesiedelt, wie im Brisbane, Albert, Coomera und Stanley River und dem Enoggera Reservoir.

Dieser Lungenfisch lebt, im Gegensatz zu anderen Arten, in nicht völlig austrocknenden, langsam fließenden und stehenden Gewässern. Hier hilft ihm seine Lunge, die beim teilweisen Verdunsten des Wassers entstehenden sauerstoffarmen Bedingungen zu überleben. Bei gesteigerter Aktivität oder in Trockenzeiten, wenn die Sauerstoffversorgung über die Kiemen nicht mehr ausreicht, steigt er zweimal pro Stunde an die Oberfläche, um zu atmen. Das Geräusch beim Ausatmen erinnert an einen kleinen Blasebalg.

Beschreibung

Der oberseits braunolive, unterseits helle Fisch mit dem länglich-stämmigen Körper wird meist bis 90 cm, gelegentlich auch 1,75 m lang und bis 43 kg schwer. Im abgeflachten Kopf sitzen kleine Augen. Er hat muskulöse Brust- und Bauchflossenarme, mit denen er sich langsam über den Schlamm auf dem Gewässergrund bewegen kann. Der Ansatz der Rückenflosse liegt in der Mitte des Rückens; sie ist saumartig mit den Schwanz- und Afterflossen verwachsen. Er hat im Gegensatz zu den südamerikanischen und afrikanischen Lungenfischen sehr große, knochige Schuppen.

Wie alle Lungenfische kann der Australische Lungenfisch außer mit Kiemen auch mit einer Lunge atmen. Die Trennung des Blutkreislaufes in einen pulmonalen und einen Körperkreislauf ist bei dieser Art in weit höherem Maß erfolgt, als bei anderen Lungenfischen.^[1] Anders als die Arten der Lepidosireniformes, welche eine zweigeteilte Lunge ausbilden, entwickelt er nur eine einzige. Wie bei den anderen Arten der Lungenfische ist auch diese mit einem aufwendigen System von Scheidewänden in kleine atmungsaktive Kammern aufgeteilt. Außer zur Atmung dient bei dieser Art die Einzellunge aber zusätzlich zur Auftriebserzeugung. Entsprechend besitzt die Lunge der australischen Lungenfische auch keine so große Effizienz bei der Sauerstoffaufnahme, und als fakultativer Luftatmer bewohnt er Lebensräume mit einer viel geringeren Notwendigkeit zur Luftatmung als die obligaten Luftatmer der afrikanischen und südamerikanischen Lungenfische. Damit hat diese Art einen kleinen Schritt in Richtung eines regelbaren Auftriebsorgans getan.

Lebendes Fossil

Fossilien der Zahnplatten eines Lungenfisches, die von denen des rezenten Neoceratodus nicht unterscheidbar sind, sind in Sedimenten der Unterkreide im Norden von New South Wales ausgegraben worden.^[2] Diese Art hat also für mehr als 100 Millionen Jahre praktisch unverändert überlebt und ist damit vermutlich die älteste heute lebende Wirbeltier-Art.^[3] Die Gattung Neoceratodes ist nach den vorliegenden Daten Schwestergruppe zu einer gemeinsamen Klade aus dem afrikanischen Protopterus und der südamerikanischen Lepidosiren, damit kann das Alter der Stammlinie mindesten 110 Millionen, wahrscheinlich aber (unter Berücksichtigung fossiler Taxa) sogar 250 Millionen Jahre, an den Beginn der Trias zurückverfolgt werden.^[4]

Im Januar 2021 wurde erstmals die DNA-Sequenzierung des vollständigen Erbguts von Neoceratodus forsteri veröffentlicht. Demnach besitzt der australische Lungenfisch mit mehr als 43 Milliarden Basenpaaren (dies entspricht in etwa der 15-fachen Menge der Basenpaare in der menschlichen DNA) das bisher größte nachgewiesene Genom der gesamten Tierwelt.^[5] Zudem wurde gezeigt, dass Lungenfisch und Mensch einige weitgehend „baugleiche“ Gene besitzen, die zum Beispiel die Embryonalentwicklung der Lunge steuern; die Lungen des Menschen und der anderen Landwirbeltiere können daher der Studie zufolge entwicklungsgeschichtlich auf eine gemeinsame Herkunft von den Lungenfischen zurückgeführt werden.

• Holzschnitt von 1898, British Museum

• Schuppen in Höhe der Seitenlinie

• Konservierter Beckengürtel mit Bauchflossen

Ernährung

Der Fisch ist überwiegend nachtaktiv und ernährt sich von Fröschen, Kaulquappen, Fischen, Wirbellosen und Wasserpflanzen. Er kann mit Hilfe seiner Zahnplatten in beiden Kiefern auch harte Muscheln und Schnecken knacken.

Vermehrung

Laichzeit ist in Fließgewässern von August bis Dezember vor den sommerlichen Regenfällen, wenn die Wassertemperaturen über 20 °C steigen. Nach ausführlichem Balzverhalten wird paarweise zwischen Wasserpflanzen abgelaicht. Der Laich besteht aus gallertigen Klumpen mit großen Eiern und ähnelt Froschlaich. Die nach 3 bis 4 Wochen schlüpfenden Jungfische erinnern an Kaulquappen und atmen nur über Kiemen. Die Jungfische liegen oft seitlich auf dem Grund. Unter optimalen Bedingungen können sie 25 cm Länge im ersten halben Jahr erreichen, normalerweise sind sie aber deutlich kleiner.

Nutzung

Zurschaustellung eines gefangenen Exemplars (ca. 1905)

Der Fisch war ein beliebter Speisefisch, steht heute aber unter Naturschutz.

Bedrohung

Obwohl die Art aufgrund des heutigen Verbreitungsgebietes nicht akut gefährdet erscheint, ist sie streng geschützt.

Mit Dekret vom 6. Mai 2006 beschloss die Regierung des australischen Bundesstaates Queensland, einen Staudamm am Mary River zu errichten. Durch diesen Damm wären bedeutende Laichplätze der Spezies zerstört worden und die verbliebene Population gefährdet worden. Ende 2009 wurde das Projekt aufgrund solcher Überlegungen aufgegeben.

Literatur

• G. Allen, S. Midgley, M. Allen: Field Guide to the Freshwater Fishes of Australia. 2. Auflage. Western Australian Museum, Perth 2003, ISBN 0-7307-5486-3.
• Edwin Stephen Goodrich: Studies on the Structure and Development of Vertebrates. MacMillan & Co, London 1930.
• Alfred Romer: The Vertebrate Body. 1964.
• G. Lauder, K. Liem: The evolution and interrelationships of the actinopterygian fishes. In: Bulletin of The Museum of Comparative Zoology. Band 150, 1983, S. 95–197.
• G. Lauder, K. Liem: Patterns of diversity and evolution in ray-finned fishes. In: Fish Neurobiology. Band 1, 1983, S. 1–14.

Einzelbelege

1. ↑ Warren W. Burggren, Kjell Johansen: Circulation and respiration in lungfishes (Dipnoi). In: Journal of Morphology, Band 190, Nr. S1, 1986, S. 217–236.
2. ↑ A. Kemp and R. E. Molnar (1981): Neoceratodus forsteri from the Lower Cretaceous of New South Wales, Australia. Journal of Paleontology 55 (1): 211-217.
3. ↑ Amy R.Tims, Peter J. Unmack, Simon Y. W. Ho: A fossil-calibrated time-tree of all Australian freshwater fishes. Molecular Phylogenetics and Evolution, 20 April 2021, 107180, doi: 10.1016/j.ympev.2021.107180. S. 3.
4. ↑ Lionel Cavin and Anne Kemp (2011): The impact of fossils on the Evolutionary Distinctiveness and conservation status of the Australian lungfish. Biological Conservation 144: 3140–3142. doi:10.1016/j.biocon.2011.08.014
5. ↑ Axel Meyer et al.: Giant lungfish genome elucidates the conquest of land by vertebrates. In: Nature. Online-Veröffentlichung vom 18. Januar 2021, doi:10.1038/s41586-021-03198-8.
   Was das Genom des Lungenfischs über die Landeroberung der Wirbeltiere verrät. Auf: idw-online.de vom 18. Januar 2021.

The Australian lungfish (Neoceratodus forsteri), also known as the Queensland lungfish, Burnett salmon and barramunda, is the only surviving member of the family Neoceratodontidae. It is one of only six extant lungfish species in the world. Endemic to Australia,^[7] the Neoceratodontidae are an ancient family belonging to the class Sarcopterygii, or lobe-finned fishes.^[8]

Fossil records of this group date back 380 million years, around the time when the higher vertebrate classes were beginning to evolve.^[9] Fossils of lungfish almost identical to this species have been uncovered in northern New South Wales, indicating that Neoceratodus has remained virtually unchanged for well over 100 million years, making it a living fossil and one of the oldest living vertebrate genera on the planet.^[9]

It is one of six extant representatives of the ancient air-breathing Dipnoi (lungfishes) that flourished during the Devonian period (about 413–365 million years ago) and is the outgroup to all other members of this lineage.^[9][10] The five other freshwater lungfish species, four in Africa and one in South America, are very different morphologically from N. forsteri.^[9] The Queensland lungfish can live for several days out of the water, if it is kept moist, but will not survive total water depletion, unlike its African counterparts.^[7]

The small settlement of Ceratodus in the Wide Bay–Burnett region of Queensland derives its name from that of the Australian lungfish. The species was named, by Gerard Krefft, in honour of the squatter and politician William Forster.^[11]

Distribution and habitat

The Australian lungfish is native only to the Mary and Burnett River systems in south-eastern Queensland.^[18] It has been successfully distributed to other, more southerly rivers, including the Brisbane, Albert, Stanley, and Coomera Rivers, and the Enoggera Reservoir in the past century. The Australian lungfish has also been introduced to the Pine, Caboolture, and Condamine Rivers, but current survival and breeding success are unknown.^[7] Formerly widespread, at one time at least seven species of lungfish were in Australia.^[9]

This species lives in slow-flowing rivers and still water (including reservoirs) that have some aquatic vegetation on banks.^[19] It occurs over mud, sand, or gravel bottoms.^[9] Australian lungfish are commonly found in deep pools of 3–10 m (9.8–32.8 ft) depth^[20] and live in small groups under submerged logs, in dense banks of aquatic macrophytes, or in underwater caves formed by soil being washed away under tree roots on river banks. The lungfish is tolerant of cold, but prefers waters with temperatures in the range 15–25 °C (59–77 °F).^[21]

The Australian lungfish cannot survive complete desiccation of its habitat, but it can live out of water for several days if the surface of its skin is constantly moist. Unlike the African species, Protopterus, it does not survive dry seasons by secreting a mucous cocoon and burying itself in the mud.^[22]

The Australian lungfish is essentially a sedentary species, spending its life within a restricted area. Its home range rarely extends beyond a single pool or, occasionally, two adjacent pools. It does not follow a set migratory path, but may actively seek out suitable spawning habitats between July and December.^[23]

Description

Australian lungfish are olive-green to dull brown on the back, sides, tail, and fins, and pale yellow to orange on the underside.^[18] They have been described as having a reddish colouring on their sides which gets much brighter in the males during the breeding season. This colouration is the only obvious distinguishing sexual characteristic of the lungfish.^[24] They have stout elongated bodies and flattened heads with small eyes.^[9] The mouth is small and in a subterminal position.^[21] The lungfish can grow to a length of about 150 cm (4.9 ft), and a weight of 43 kg (95 lb).^[18] It is commonly found to be about 100 cm (3.3 ft) and 20 kg (44 lb) on average.^[9] Both sexes follow similar growth patterns, although the females grow to a slightly larger size.^[21] They are covered in slime when taken from the water.^[18]

The skeleton of the lungfish is partly bone and partly cartilage. The vertebrae are pure cartilage, while the ribs are hollow tubes filled with a cartilaginous substance.^[25] The body of the lungfish is covered with large, bony scales.^[9] Ten rows occur on each side, grading to small scales on the fins. The scales are each embedded in their own pockets, and overlap extensively, such that vulnerable areas of the body are covered by a thickness of at least four scales. Two unusually large and thick interlocking scales cover the back of the head where the bony skull is thin. Their cranial muscles (around the skull and jaw) follow similar patterns observed in other vertebrates, whereby the muscles tend to first develop from anterior to posterior, and from their region of origin toward insertion.^[26] They have powerful long paddle-shaped diphycercal tails.^[21][18] The pectoral fins are large, fleshy, and flipper-like. The pelvic fins are also fleshy and flipper-like and situated well back on the body. The dorsal fin commences in the middle of the back and is confluent with the caudal and anal fins.^[9]

The dentition of the lungfish is unusual: two incisors, restricted to the upper jaw, are flat, slightly bent, and denticulated on the hind margin. These are followed by dental plates on the upper and lower jaws.^[25]

Juveniles have different body proportions from mature adults. The head is rounder, the fins are smaller, and the trunk is more slender. Also, the brain is relatively larger and fills more of the cranial cavity in juveniles compared to adults.^[27] The mouth is initially terminal, but shifts back as the fish grows. The dorsal fin typically reaches to the back of the head in young juveniles, and gradually moves caudally until it only extends to the mid-dorsal region in adults. They show a gradual change in body form as they develop, but no metamorphosis is externally detectable and no obvious point occurs at which they can be termed adult.^[28] As a juvenile, the lungfish is distinctly mottled with a base colour of gold or olive-brown. Patches of intense dark pigment will persist long after the mottling has disappeared.^[21] Young lungfish are capable of rapid colour change in response to light, but this ability is gradually lost as the pigment becomes denser.^[24]

The lungfish is reputed to be sluggish and inactive, but it is capable of rapid escape movements using its strong tail.^[29] It is usually quiet and unresponsive by day, becoming more active in the late afternoon and evening.^[21]

Breathing

A Queensland lungfish in the Frankfurt Zoological Garden

A distinctive characteristic of the Australian lungfish is the presence of a single dorsal lung, used to supplement the oxygen supply through the gills.^[9] During times of excessive activity, drought, or high temperatures (when water becomes deoxygenated), or when prevailing conditions inhibit normal functioning of the gills, the lungfish can rise to the surface and swallow air into its lung.^[18] More frequent air breathing is correlated with periods of greater activity at night when it uses the lung as a supplementary organ of respiration.^[30]

Unlike the South American and African lungfishes, the Australian species has gills on all the first four gill arches, while the fifth arch bears a hemibranch. It is also the only facultative air breather lungfish species, only breathing air when oxygen in the water is not sufficient to meet their needs. The lung is a single long sac situated above and extending the length of the body cavity, and is formed by a ventral outgrowth of the gut. Internally, the lung is divided into two distinct lobes that interconnect along its length, compartmentalized by the infolding of the walls.^[31] Each compartment is further divided to form a spongy alveolar region. Blood capillaries run through this region close enough to the air space in the lung to enable gas exchange. Lungfish breathe in using a buccal force-pump similar to that of amphibians. The contraction of smooth muscles in the walls of the lung results in exhalation.^[32]

The sound of the lungfish exhaling air at the surface prior to inhaling a fresh breath has been compared to that made by a small bellows.^[9] Young lungfish come to the surface to breathe air when they are about 25 mm (0.98 in) long.^[21]

Reproduction and development

The Australian lungfish spawns and completes its entire lifecycle in freshwater systems.^[21] The age of first breeding is estimated to be 17 years for males and 22 years for females. Males typically become mature at 738–790 mm (29.1–31.1 in) and females at 814–854 mm (32.0–33.6 in).^[23] After an elaborate courtship, the lungfish spawn in pairs, depositing large adhesive eggs amongst aquatic plants.^[9] They spawn from August until November, before the spring rains, in flowing streams that are at least a metre deep.^[7]

Eggs are most abundant during September and October. The stimulus for spawning is believed to be day length. The lungfish is known to spawn both during the day and at night.^[33] The lungfish is selective in its choice of spawning sites. Eggs have been recorded on aquatic plants rooted in gravel and sand, slow- and fast-moving waters, in shade and in full sun, but never on aquatic plants covered with slimy algae, in stagnant water, or where loose debris was on the water's surface.^[24]

Contrary to its South American and African relatives, the Australian lungfish does not make a nest or guard or care for its eggs.^[33] When spawning does take place, the pair of fish will lie on their sides or become entwined. They usually deposit their eggs singly, occasionally in pairs, but very rarely in clusters. The male lungfish fertilizes each egg as it emerges, and the eggs are deposited in dense aquatic vegetation. The newly laid egg is hemispherical, delicate, heavily yolked, and enclosed in a single vitelline and triple jelly envelope.^[24] The egg about 3 mm (0.12 in) in diameter; with the jelly envelope, it has a total diameter of about 1 cm (0.39 in).^[28] The egg is sticky for a short while until silt and small aquatic organisms have covered it, but long enough for it to become attached to submerged vegetation. It is negatively buoyant, and if it falls to the lake or river bed, it is unlikely to survive to hatching.^[24]

The female has a large ovary and the potential to lay many eggs, but in the wild only produces a few hundreds of eggs, at most, during her lifetime. In captivity, 200 to 600 eggs have been laid in a single event. The lungfish does not necessarily spawn every year. A good spawning season occurs usually once every five years, regardless of environmental conditions.^[21]

The eggs and young are similar to those of frogs,^[18] but the offspring differ from both frogs and other lungfishes by the absence of external gills during early development. Within the egg, head structures and pigmentation start to appear by day 17. They hatch after three to four weeks, and resemble tadpoles.^[9] The young fish are slow-growing, reportedly reaching 27 mm (1.1 in) after 110 days, and about 60 mm (2.4 in) after 8 months.^[34] During the first week, it lies on its side, hiding in the weeds, and moving only when stimulated by touch. It will swim spontaneously, and often retreat back into the gelatinous envelope when disturbed. Newly hatched larvae develop a ciliary current over their skin and gill surfaces.^[33] This is believed to either provide respiratory exchange across the skin and gills without necessitating any movements of the jaw or brachial apparatus, or to keep the skin of the unprotected larvae free of debris, parasites, and predatory protozoans.^[35] Larvae are reported not to feed for two to three weeks while the yolk is still present. By the time the yolk is fully used, a spiral valve has developed in the intestine and the fish starts to feed. The young can grow about 50 mm (2.0 in) per month under optimal conditions.

The Australian lungfish has very complex courtship behaviour made up of three distinct phases. The first is the searching phase, when the fish will range over a large area, possibly searching for potential spawning sites.^[36] A pair of fish will perform circling movements at the surface of the water close to beds of aquatic plants. They breathe air more frequently and more noisily than normal, possibly reflecting a greater physiological requirement for oxygen. Individual fish have been observed to breathe air at regular intervals of about 20 minutes, with air breathing accompanied by a distinct loud burp made in the air. The noisy breathing may be a form of a mating call. The lungfish seem to do their noisy breathing in concert, even responding to each other, but never in close vicinity of where the eggs are laid.^[33]

The next phase involves behaviour, similar to "follow-the-leader", during which one fish, the male, shows interest in the female and nudges her with his snout. Up to eight individuals may be involved in follow-the-leader behaviour. The male lungfish may occasionally take a piece of aquatic plant into its mouth and wave it around.^[21] In the third phase, the fish dive together through aquatic vegetation, the male following the female and presumably shedding milt over the eggs.^[36]

Adults have a high survival rate and are long-lived (at least 20–25 years). An Australian lungfish named "Granddad" at the Shedd Aquarium in Chicago was the oldest living fish in any Aquarium, and was already an adult when he was first placed on display in 1933; Granddad was estimated to be at least in his eighties, and possibly over one-hundred, at the time of his death on February 5, 2017.^[37]

The Australian lungfish has an unusually large karyotype, very large chromosomes and cells, and a high nuclear DNA content relative to other vertebrates, but less than what is reported for other lungfishes. In spite of this, it displays low genetic diversity between populations from the Mary, Burnett, and Brisbane catchments.^[21] This low level of genetic variation could be attributed to population "bottlenecks" associated with periods of range contraction, probably during the Pleistocene, and in recent times during the periods of episodic or prolonged drought that are known to reduce some reaches of these river systems.^[10]

Diet and feeding habits

The Australian lungfish is primarily nocturnal, and is essentially carnivorous. In captivity, it will feed on frogs, earthworms, pieces of meat, and pelleted food.^[7] In the wild, its prey includes frogs, tadpoles, fishes, a variety of invertebrates, and plant material.^[9] No quantitative dietary data are available, but anecdotal observations clearly indicate the diet of the lungfish changes with development. This is proven to be correlated with a change in dentition.

Lungfish larvae are bottom feeders. They eat micro-crustaceans and small Tubifex worms, occasionally supplementing their diets with filamentous algae. Soft foods such as worms and plants are partially crushed with a few quick bites and then swallowed. In the adult lungfish, movement of the prey in and out of the mouth is accompanied by strong adduction of the jaws. This crushing mechanism is coupled with hydraulic transport of the food, achieved by movements of the hyoid apparatus, to position the prey within the oral cavity.^[38] The Queensland lungfish exhibits the most primitive version of these biomechanical feeding adaptations and behaviors.

Conservation status

Although the status of the Australian lungfish is secure, it is a protected species under the Queensland Fish and Oyster Act of 1914 and capture in the wild is strictly prohibited.^[9] It was placed on the CITES list in 1977. The lungfish is currently protected from fishing, and collection for education or research purposes requires a permit in Queensland, under the Fisheries Act of 1994, and from the Commonwealth Government. It is included on the list of "vulnerable" species, as studies have failed to show it meets the criteria needed to be considered a threatened or endangered species.^[21]

Human activities currently threaten the Australian lungfish, particularly water development. It is potentially at risk in much of its core distribution in the Burnett and Mary Rivers, as 26% of these river systems are presently impounded by weirs and dams. Barriers to movement and altered flow regimens downstream of dams for irrigation purposes could lead to the disruption of existing population structure and cause even more loss of genetic variation.^[10] Researcher Anne Kemp has documented the decline of lungfish in many reservoirs and river systems due to lack of recruitment caused by dams.^[39][40][41]

Australian lungfish can be very fast-growing, yet with a delayed first breeding age. For a long-lived species with naturally low mortality rates, successful spawning and juvenile recruitment is not essential every year and may only occur irregularly in medium to long cycles, even in natural environments.^[42] The length of these cycles could easily mask the potentially deleterious impacts on recruitment for many years. Additionally, large adults could remain common for decades and give no indication of a declining population in the longer term.^[21]

The Mozambique mouth brooder, or tilapia, has been declared a noxious and threatening alien species to the lungfish in Queensland.

Recent events

Proposed 2006 damming projects on both the Mary and Burnett rivers^[43] threatened the habitat of the remaining lungfish. The dams would have changed the flow of the rivers, eliminating the slow, shallow areas the fish need for spawning. Scientists worldwide became involved in saving the habitat for these lungfish, citing their evolutionary importance.^[44] As of January 2022, the world's oldest living aquarium fish is a 90-year-old named Methuselah. At 4 feet long and 40 pounds, the lungfish resides at the California Academy of Sciences' Steinhart Aquarium in San Francisco. Methuselah inherited the title from Granddad. Granddad, another Australian lungfish, died at the age of 109 at Chicago's Shedd Aquarium in 2017.^[45]

Relationship with humans

In a 2021 FlyLife article, Karl Brandt proposed the Australian lungfish as the inspiration for Gurangatch, the legendary reptile fish from Gandangara mythology.^[46]

See also

• Gerard Krefft and Neoceratodus forsteri

Footnotes

References

• Allen, Gerald R. (1989). Freshwater Fishes of Australia. T.F.H. Publications.
• Clarke, William Branwhite (1871), "Ceratodus Forsteri" (a poem), pp.89-90 in Intercolonial Exhibition , The Industrial Progress of New South Wales: Being a Report of the Intercolonial Exhibition of 1870, at Sydney; Together with a Variety of Papers Illustrative of the Industrial Resources of the Colony, Sydney: Thomas Richards, Government Printer.
• Heaton, J.H. (1879), "Krefft, Johann Louis Gerhard", pp.108-109 in J.H. Heaton, Australian Dictionary of Dates and Men of the Time: Containing the History of Australasia from 1542 to May, 1879, Sydney: George Robertson.
• Krefft, G. (1870a), "To the Editor of the Herald", The Sydney Morning Herald, (Tuesday, 18 January 1870), p.5.
• Krefft, G. (1870b), "Ceratodus Forsteri (Letter to the Editor)", The Sydney Morning Herald, (Thursday, 9 June 1870), p.3.
• O’Connor, D. (1896) "Report on Preservation of Ceratodus", Proceedings of the Royal Society of Queensland, Vol.12, (1897), pp.101-102: Letter to the President and Council of the Royal Society of Queensland, dated 7 September 1896; read before the Society on 12 September 1896.

Aŭstralia pulmofiŝo (Neoceratodus forsteri) estas specio en la subklaso pulmofiŝoj (dipnoj), sola reprezentanto de la familio Ceratodontidae. Ĝi estas granda ŝlimbruna fiŝo, kiu povas kreski eĉ ĝis 1,7 metroj. Ĝi havas bone evoluintajn parajn naĝilojn, kies pediklo estas skvam-kovrita. La korpaj skvamoj estas grandaj. Por enpreni oksigenon ĝi uzas kaj brankojn kaj neparan pulmon. La pulmon ĝi utiligas, se la oksigenenhavo de la akvo forte malpliiĝas.

Ĝi frajas – sen fari nestojn – rekte inter plantojn. La junfiŝoj ne havas eksterajn brankojn.

Ĝi vivas en la orient-aŭstralia Queensland, nur en akvoj, kiuj ne sekiĝas eĉ dum somero. En du riveroj ĝi estas praa (la riveroj Burnett kaj Mary), en kelkaj aliaj enkondukita. Oni faris digon en la rivero Burnett (2005) kaj oni planas novan en la Mary, kio povas endanĝerigi la vivlokon de ĉi tiu vivanta fosilio.

Oni trovis fosiliojn de antaŭ pli ol 100 milionoj da jaroj, tute similajn al la aŭstralia pulmofiŝo, kio markas la fiŝon kiel unu el la plej aĝaj specioj de vertebruloj.

El pez pulmonado de Queensland (Neoceratodus forsteri) es una especie de pez de la familia Ceratodontidae endémica de Australia, y considerada como fósil viviente ya que se han hallado restos fósiles de este grupo de hace 380 millones de años en la región australiana de Nueva Gales del Sur. También se le conoce como pez pulmonado australiano, barramunda y salmón de Burnett.

Hallazgo y distribución

El pez fue descrito en el año 1870 por el herpetólogo australiano Johann Ludwig Gerard Krefft. Su distribución se limita a varios ríos del estado australiano de Queensland.

Hábitat

Es una especie de pez pulmonado que habita en las cuevas submarinas, troncos sumergidos y en general en las aguas lentas con vegetación acuática en profundidades de entre 3 y 10 metros. Se alimenta de batracios, pequeños crustáceos y lombrices.

Características

Neoceratodus forsteri, debido a sus caracteres (grandes escamas, forma del cuerpo y aletas en forma de paleta), se asemeja más al pez pulmonado “arquetípico” extinto que a los otros linajes existentes. Por el contrario, el pez pulmonado africano (Protopterus) y el sudamericano (Lepidosiren) han simplificado sus aletas en finos filamentos y han perdido casi por completo sus escamas. Por ello, el análisis del genoma de N. forsteri ha contribuido a una mejor comprensión de las preadaptaciones que permitieron la transición de los vertebrados del agua a la tierra.^[1]​

Genoma

N. forsteri posee el genoma animal más grande conocido, con un tamaño estimado de 37 Gb (hasta 14 veces mayor que el genoma humano).^[1]​ El gran tamaño de este genoma se atribuye principalmente a la presencia de grandes regiones intergénicas e intrones con alto contenido repetitivo. El intrón más grande de su genoma es de 5,8 Mb, situado en el gen dmbt1 y, el tamaño medio del intrón, de 50 kb. Este tamaño medio de los intrones es considerablemente superior al de los humanos (con una media de 6 kb). En total, los intrones del genoma de N. forsteri comprenden aproximadamente 8 Gb, suponiendo el 21% del total.^[1]​

Diversos estudios han revelado que el genoma de N. forsteri experimentó dos eventos importantes de expansión. Gran parte del crecimiento reciente es debido a los elementos nucleares largos intercalados o LINEs que, junto con otros elementos transponibles, podrían estar detrás de la aparición de funciones génicas novedosas. Estos elementos permanecen activos por lo que el genoma del pez pulmonado continúa expandiéndose actualmente.^[1]​ Es destacable, por otro lado, que las proporciones de las principales clases de elementos transponibles presentes en el genoma del pez pulmonado se asemejan más a las de los tetrápodos que a las de los peces.^[1]​

Genómica comparativa

Neoceratodus forsteri presenta 17 macrocromosomas y 10 microcromosomas. Mediante un estudio de genómica comparativa, se ha comprobado que estos macrocromosomas mantienen la sintenia con otros cromosomas de vertebrados. Por otro lado, los microcromosomas mantienen una antigua homología conservada con el cariotipo de vertebrados ancestrales. Esto confirma que los peces pulmonados ocupan una posición evolutiva clave.^[1]​

Preadaptaciones para la vida terrestre

La evolución de los pulmones

Al igual que los vertebrados terrestres, los peces pulmonados adultos respiran aire a través de pulmones, un hecho que requirió de ciertas innovaciones evolutivas. En este sentido, el genoma de Neoceratodus forsteri muestra una expansión de la familia de genes de la proteína surfactante B pulmonar.^[1]​ Estos agentes tensoactivos forman parte de la mezcla de lipoproteínas que recubren la superficie pulmonar, asegurando su función adecuada. La expansión de esos genes ha alcanzado en los peces pulmonados unos valores típicos de los tetrápodos, siendo de dos a tres veces mayores que en los peces cartilaginosos y óseos. Por otro lado, en el pulmón en desarrollo de N. forsteri se ha observado una alta expresión del gen shh que codifica un regulador del desarrollo pulmonar.^[2]​

De esta forma, ambas adquisiciones evolutivas habrían tenido una gran relevancia en la adaptación a la respiración de aire, permitiendo la evolución de los pulmones. Cabe destacar que el pulmón de N. forsteri se desarrolla de una forma notablemente similar a la observada en el caso de los anfibios.^[3]​

El olfato y la evolución del órgano vomeronasal

El genoma de Neoceratodus forsteri muestra una reducción en los receptores para la detección de olores en el agua. Por el contrario, se ha detectado una expansión en los receptores que permiten la detección de olores en el aire, los cuales son bastante limitados en los peces, así como una notable expansión de la familia de genes del receptor vomeronasal (especialmente de los genes V2R).^[1]​ El órgano vomeronasal, asociado a la recepción de feromonas, está presente en la mayoría de los tetrápodos^[4]​^[5]​ por lo que podría ser una innovación que surgió en la transición del agua a la tierra.

Las aletas lobuladas y la evolución de la locomoción terrestre

Los peces sarcopterigios presentan aletas lobuladas ramificadas distalmente, formando dígitos adecuados para la locomoción sobre sustrato. El análisis del genoma de Neoceratodus forsteri permitió esclarecer cómo se ha producido la adquisición de estas aletas lobuladas y la evolución de las aletas a las extremidades.^[1]​ Se han identificado hasta 31 elementos enhancers o potenciadores de extremidades en tetrápodos altamente conservados, que se relacionan con la emergencia de estas aletas lobuladas en los peces pulmonados. Concretamente, el enhancer hs72, que impulsa la expresión autopodal en tetrápodos, se asocia al gen sall1.^[6]​ Este gen se expresa fuertemente en los embriones de N. forsteri con un patrón de expresión similar al observado en el caso de los tetrápodos.^[7]​ Por otro lado, el genoma de N. forsteri presenta cuatro clusters génicos hox (hoxa, hoxb, hoxc y hoxd) que comprenden 43 genes. Si bien la expresión de los genes hoxc en aletas o extremidades se había observado previamente solo para mamíferos, relacionados con el lecho ungueal,^[8]​ se ha visto la expresión de hoxc13 en la aleta distal de Neoceratodus durante su desarrollo embrionario. Esto indica una ganancia temprana de la expresión de hoxc13 en sarcopterigios, que en tetrápodos permitió modelar elementos de las extremidades dérmicas (uñas, pezuñas, garras).^[1]​ Por tanto, hoxc13 y sall1, pudieron facilitar la transición de las aletas a las extremidades y, con ello, la colonización de la tierra.^[1]​

Referencias

Bibliografía

• Sistema Integrado de Información Taxonómica. «Neoceratodus forsteri (TSN 161037)» (en inglés).
• "Neoceratodus forsteri". En FishBase (Rainer Froese y Daniel Pauly, eds.). Consultada en junio de 2015. N.p.: FishBase, 2015.
• Allen, Gerald R. (1989). Freshwater Fishes of Australia. T.F.H. Publications.

Neoceratodus forsteri arrain birikaduna da. Arrainen barruko Sarcopterygii klasean sailkatzen da eta, egun, bere genero, familia eta ordenako kide bakarra da, hau da, monotipikoa. Fosil bizidun hau Australiako endemismoa da.^[2]

Erreferentziak

Australiankeuhkokala eli käärmekala (Neoceratodus forsteri) on Australian Queenslandin Burnett- ja Mary-joissa luonnonvaraisena elävä 100–150 cm pitkä keuhkokala. Sitä on siirretty myös muihin lähijokiin, mm. Brisbane-jokeen.

Australiankeuhkokala on sukunsa, heimonsa (Ceratodontidae) ja lahkonsa (Ceratodontiformes) ainoa laji, ainoa australialainen keuhkokalalaji, ja yksi kaikkiaan kuudesta tunnetusta keuhkokalojen alaluokan lajista. Australiankeuhkokala on elävä fossiili, sillä täysin samanlaisina pidettyjen kalojen fossiileita tunnetaan 100 miljoonan vuoden takaa.

Laji elää hitaasti virtaavien jokien syvännepaikoissa muta-, hiekka- tai sorapohjilla. Joen kuivuessa se voi pysytellä hengissä vähähappisissa lammikoissa, kun se 30–60 minuutin välein nousee pintaan hengittämään happea keuhkoillaan. Toisin kuin eräät muut keuhkokalat se ei kuitenkaan kestä koko lammikon kuivumista. − Normaalioloissa se kuitenkin hengittää kiduksilla.

Australiankeuhkokala on pääasiallisesti peto, joka saalistaa sammakoita ja niiden toukkia sekä selkärangattomia eläimiä, mutta ilmeisesti joskus myös syö kasvisravintoa.

Lähteet

• Native Fish Australia: Australian lungfish

Aiheesta muualla

• Neoceratodus forsteri (peilipalvelin) FishBase. Froese, R. & Pauly, D. (toim.). (englanniksi)
• Species in the genus Neoceratodus. FishBase. Froese, R. & Pauly, D. (toim.). (englanniksi)
• Family Ceratodontidae FishBase. Froese, R. & Pauly, D. (toim.). (englanniksi)
• Order Summary for Ceratodontiformes (peilipalvelin) FishBase. Froese, R. & Pauly, D. (toim.). (englanniksi)

Le dipneuste d'Australie (Neoceratodus forsteri) est également connu sous le nom de saumon du Burnett ou Barramunda. Ce seul représentant de la famille des Neoceratodontidae et du genre Neoceratodus est à la fois le plus rare des dipneustes actuels et celui qui présente le plus de ressemblances morphologiques avec les espèces fossiles de Dipnoi. Il possède également le génome animal le plus long connu avec 43 milliards de paires de bases^[1].

Répartition

On le trouve principalement dans les fleuves Burnett River et Mary River au Queensland, où il est protégé, mais des tentatives ont été déployées pour l'acclimater ailleurs.

L'espèce est menacée à cause de la construction et des projets de barrages sur les rivières du Queensland.

Description

De grandes écailles recouvrent le corps, les nageoires associées par paire ont toujours leur base de chair en forme de lobe, mais les nageoires dorsales et anales forment une seule membrane continue autour de l'extrémité postérieure du corps. Dans les eaux très oxygénées, cette espèce pratique la respiration branchiale. Le poumon unique, située au-dessus de l'œsophage, est relié latéralement à celui-ci par un tube. Par sa position et sa forme, ce poumon ressemble plutôt à une vessie natatoire, avec cette différence que la paroi du poumon est constituée d'un tissu absorbant. Cette espèce atteint normalement une longueur de 90 cm, mais on a noté des spécimens deux fois plus longs. À la différence des autres dipneustes, il supporte moins bien le manque d'oxygène et est incapable d'estiver dans un cocon de boue pour résister à la sécheresse, comme le peuvent par exemple les dipneustes africains.

Notes et références

Australska dvodihalica (baramunda, lat. Neoceratodus forsteri) je vrsta ribe dvodihalice iz porodice Neoceratodontidae, reda Sarcopterygii. Ovo je riba dna koja je nastanjena u sistemu rijeka Burnett i Mary River u australskoj državi Queensland. Maksimalno naraste do 170 centimetara i 40 kilograma težine. Grabežljivac je koji se hrani žabama, punoglavcima, ribama, crvima, puževima, ali i vodenim biljem kao i voćem palog sa stabala koja rastu uz potoke.

Steinhart Aquarium u San Franciscu posjedovao je jedan primjerak dužine jednog metra, teškog 20 kilograma i star preko 65 godina^[1].

Prvi ga je opisao Krefft (1870).

Izvori

• N. forsteri

• N. forsteri

• N. forsteri

Neoceratodus forsteri(Krefft, 1870) è un pesce polmonato unico membro del genere Neoceratodus e della famiglia Neoceratodontidae, endemico di una ristretta zona del Queensland (Australia).

Distribuzione e habitat

N. forsteri è endemico di due fiumi del Queensland meridionale (nordest dell'Australia): il Burnett e il Mary. È stato introdotto con successo in altri corsi d'acqua del Queensland meridionale. Vive nelle buche più profonde dei fiumi, con acque ferme o quasi e fondali da fangosi a ghiaiosi^[1].

Descrizione

Questo pesce ha un aspetto diverso dagli altri Dipnoi attualmente viventi che hanno corpo anguilliforme, scaglie piccole e pinne pari filiformi. N. forsteri ha corpo allungato ma massiccio con testa conica appiattita frontalmente ed occhi e bocca piccoli. La pinna dorsale, la pinna caudale e la pinna anale sono unite. La pinna dorsale ha origine a metà del dorso. Le pinne pari sono pinne lobate e carnose, inserite in posizione ventrale; le pinne pettorali sono subito sotto la testa, le pinne ventrali sono invece inserite molto indietro. Le scaglie sono grandi e rigide. La taglia massima è di 170 cm per 40 kg di peso; la misura comune è di circa un metro^[1].

Biologia

È un animale piuttosto pigro, con abitudini notturne. Essendo dotato di un polmone funzionante è in grado di respirare aria atmosferica come ausilio alla respirazione branchiale. Al contrario degli altri Dipnoi attuali non è però in grado di vivere fuor d'acqua e la respirazione polmonare è solamente ausiliaria a quella branchiale. Può vivere più di 65 anni^[1]. Il più vecchio esemplare conosciuto in acquario ha circa 90 anni, ed è ospitato dal 1938 nello Steinhart Aquarium di San Francisco^[2].

Alimentazione

Individua le prede nel sedimento grazie agli elettrorecettori di cui è dotato. Si ciba di pesci, chiocciole, rane, girini, gamberetti, lombrichi, materiale vegetale e frutti^[1].

Conservazione

È inserito nella tabella II della CITES ed è dunque proibito il commercio di questa specie^[3]. È inoltre tutelato dalla legge australiana^[1].

Evoluzione

Si tratta di un cosiddetto "fossile vivente", l'analisi di reperti fossili dimostra che il suo aspetto non è praticamente cambiato da almeno 380 milioni di anni^[1]. Il genere fossile più affine è Ceratodus.

Note

Australinė dvikvėpė arba baramunda,^[1] ceratodas^[2] (lot. Neoceratodus forsteri) – vienintelė šiuo metu gyvenanti australinių dvikvėpių šeimos ir vienaplaučių dvikvėpių būrio rūšis. Tai endeminė Australijos rūšis. Naujajame Pietų Velse rastos fosilijos, beveik identiškos šiai rūšiai, rodo, kad rūšis beveik nepasikeitė per pastaruosius 100 mln. m.^[3] Australinė dvikvėpė yra primityviausia iš 6 dabartinių dvikvėpių žuvų. Gyvena lėtai tekančiose upėse ir stovinčiuose vandenyse. Plėšri. Keletą dienų gali išgyventi be vandens, jei aplinka pakankamai drėgna, jog neišdžiūtų žuvies oda, tačiau skirtingai nuo dviplaučių dvikvėpių negali išgyventi visiško gyvenamojo vandens telkinio išdžiūvimo.

Nuorodos

Šis straipsnis apie zoologiją yra nebaigtas. Jūs galite prisidėti prie Vikipedijos papildydami šį straipsnį.

Vienplaušzivjveidīgās (Ceratodontoidei) ir ragzobzivjveidīgo kārtas (Ceratodontiformes) apakškārta.^[1] Šīs apakškārtas pārstāvjus raksturo nepāra plaušas un biseriālas pāra spuras ar labi attīstītām daivām.

Morfoloģija

Ķermenis vārpstveida. To klāj lielas kaula zvīņas. Ķermeņa priekšējo daļu klāj segkauli: clavicula, cleitrum un posttemporale. Smadzeņu kapsulu veido skrimslis ar nelieliem pārkaulojumiem; biseriālā arhipterīgija tipa endokrānijs. Sekundāro žokļu nav. Zobu plātnītēm ir nedaudzas biezas viegli grubuļainas ķemmītes. Ass skeletā var būt nelieli pārkaulojumi. Ir labi attīstītas pāra biseriālās spuras.

Plauša ir viena ar vāji izteiktu šūnainu iekšējo sieniņu. Žaunas ir labi attīstītas. Arteriālā konusa vārstules ir līdzīgas kā ganoīdzivīm. Olnīca nenoslēgta. Attīstība bez pārvēršanās. Aiz kloākas ir divi paritoneālie atvērumi.

Izplatība

Ragzobzivjveidīgo apakškārtas pārstāvji ir zināmi no apakštriasa nogulumiem. Domājams, ka tās nodalījās no aizvēsturiskajām zivīm jau devona perioda beigās. Mezozoja ērā tās bija sastopamas visās kontinentālajās ūdenstilpnēs. Mūsdienās ir sastopama tikai viena suga — Austrālijas ragzobe (Neoceratodus forsteri), kas ir izplatīta nelielā Austrālijas ziemeļaustrumu daļā.

Sistemātika

• Vienplaušzivjveidīgo zivju apakškārta (Ceratodontoidei)

  Ragzobju dzimta (Neoceratodontidae) Miles, 1977

  Ģints: Ragzobes (Neoceratodus) Castelnau, 1876

  Suga: Austrālijas ragzobe (Neoceratodus forsteri) Krefft, 1870

  Suga: † Neoceratodus africanus Haug 1905

  Suga: † Neoceratodus tuberculatus Tabaste 1870

  Suga: † Neoceratodus denticulatus

  Suga: † Neoceratodus eyrensis

  Ģints: † Mioceratodus Kemp, 1992

  Suga: † Mioceratodus anemosyrus Kemp, 1992

  Suga: † Mioceratodus gregoryi White, 1925

  Dzimta: Ceratodontidae

  Ģints: † Ceratodus Agassiz, 1838

  Suga: † Ceratodus latissimus Agassiz, 1838

  Suga: † Ceratodus nargun

  Suga: † Ceratodus humei Priem, 1914

  Suga: † Ceratodus sturii Teller, 1891

  Ģints: † Metaceratodus Chapman, 1914

  Suga: † Metaceratodus wollastoni Chapman, 1914

  Suga: † Metaceratodus ellioti Kemp, 1997

  Suga: † Metaceratodus palmeri Krefft, 1874

  Suga: † Metaceratodus bonei Kemp, 1997

  Ģints: † Microceratodus Teixeira, 1954

  Suga: † Microceratodus angolensis Teixeira, 1949

(†) — izmirušu zivju grupa.

Atsauces

De Australische longvis (Neoceratodus forsteri) is een longvis.

Kenmerken

Deze vissen hebben een brede en zware romp met een geleidelijk versmalde staartvin. De gepaarde vinnen zijn peddelvormig en niet draadvormig. Rug- en aarsvin lopen vloeiend over in de staartvin. Deze soort kan 180 cm worden met een gewicht tot 45 kg. De gespecialiseerde zwemblaas wordt gebruikt als enkelvoudige long, waarmee het dier zuurstof opneemt als hij naar het wateroppervlak moet komen om lucht te happen. Als het water zuurstofarm is, kan het dier niet meer ademen via zijn kieuwen.

Leefwijze

Het leeft van kleine visjes, kikkers, kikkervisjes en slakken, die tussen stevige tandplaten worden vermalen. Door veranderingen in het ecosysteem zijn ze bedreigd.

Verspreiding en leefgebied

Deze zoetwatervis komt voor in Australië, met name in het zuidoosten van Queensland.

De ogen

Onderzoek uit 2007 heeft aangetoond dat de Australische longvis vier soorten kegeltjes in het oog heeft, en daarmee meer kleuren kan zien dan bijvoorbeeld mensen, die drie soorten kegeltjes hebben.^[2][3]

• David Burnie (2001) - Animals, Dorling Kindersley Limited, London. ISBN 90-18-01564-4 (naar het Nederlands vertaald door Jaap Bouwman en Henk J. Nieuwenkamp).

Rogoząb australijski^[2], barramunda^[3], rogoząb^[3], barramundi^[4] (Neoceratodus forsteri) – najbardziej pierwotny gatunek ryby dwudysznej, jedyny współcześnie żyjący przedstawiciel rodziny rogozębowatych (Ceratodontidae).

Zasięg występowania

W zapisie kopalnym były szeroko rozsiedlone. Obecny zasięg występowania tego gatunku obejmuje rzeki Burnet i Mary – stan Queensland w Australii. Rogoząb zasiedla wody stojące i wolno płynące.

Budowa

Ciało nieznacznie ścieśnione, dobrze rozwinięte płetwy piersiowe i brzuszne, przypominające nieco łapy, łuski duże i cienkie. Płuco pojedyncze, prymitywne, powstało z przekształconego pęcherza pławnego. Duże okazy dochodzą do 2 m długości i osiągają masę kilkudziesięciu kilogramów.

Biologia i ekologia

W okresie suszy, gdy rzeki i zbiorniki wysychają, rogoząb oddycha powietrzem atmosferycznym, płuco częściowo przejmuje funkcje skrzeli, umożliwiając zwierzęciu przetrwanie w błotnistych zatokach i większych kałużach. Nie zapada w stan estywacji. Dorosłe okazy żywią się mięczakami i rybami, młode osobniki jedzą glony.

Rozmnażanie

Gatunek jajorodny. Tarło odbywa we wrześniu–październiku. Duża i kleista ikra podobna jest do skrzeku płazów.

Znaczenie gospodarcze

Gatunek o niewielkim, lokalnym znaczeniu gospodarczym.

Przypisy

Bibliografia

1. Neoceratodus forsteri. (ang.) w: Froese, R. & D. Pauly. FishBase. World Wide Web electronic publication. www.fishbase.org [dostęp 9 lutego 2009]
2. Mały słownik zoologiczny: ryby. Warszawa: Wiedza Powszechna, 1976.
3. Włodzimierz Załachowski: Ryby. Warszawa: Wydawnictwo Naukowe PWN, 1997. ISBN 83-01-12286-2.

O Peixe-pulmonado-australiano (Neoceratodus forsteri) é um peixe pulmonado, nativo dos rios do estado de Queensland na Austrália.^[1] Atinge até 150 cm de comprimento e é um peixe carnívoro, que se alimenta de pequenos peixes, batráquios, girinos e invertebrados.

Referências

Australiensisk lungfisk (Neoceratodus forsteri)^[2] är en art av lungfiskar som först beskrevs av Johann Ludwig Gerard Krefft 1870. Australiensisk lungfisk är den enda nu levande arten i släktet Neoceratodus och i familjen Neoceratodontidae.^[3][4] Inga underarter finns listade.^[3]

Arten förekommer endemisk i södra Queensland i Australien. Det ursprungliga utbredningsområdet var floderna Burnett och Mary. Senare introducerades australiensisk lungfisk i andra floder i samma region.^[3]

Bildgalleri

Källor

1. ^ Paxton, J.R., D.F. Hoese, G.R. Allen and J.E. Hanley (1989) Pisces. Petromyzontidae to Carangidae., Zoological Catalogue of Australia, Vol. 7. Australian Government Publishing Service, Canberra, 665 p.
2. ^ [a b] Allen, G.R. (1989) Freshwater fishes of Australia., T.F.H. Publications, Inc., Neptune City, New Jersey.
3. ^ [a b c] Bisby F.A., Roskov Y.R., Orrell T.M., Nicolson D., Paglinawan L.E., Bailly N., Kirk P.M., Bourgoin T., Baillargeon G., Ouvrard D. (red.) (13 april 2011). ”Species 2000 & ITIS Catalogue of Life: 2011 Annual Checklist.”. Species 2000: Reading, UK. http://www.catalogueoflife.org/annual-checklist/2011/search/all/key/neoceratodus+forsteri/match/1. Läst 24 september 2012.
4. ^ FishBase. Froese R. & Pauly D. (eds), 2011-06-14

Externa länkar

• Wikimedia Commons har media som rör Neoceratodus forsteri.
  Bilder & media
• Wikispecies har information om Neoceratodus forsteri.
  Artförteckning

Denna artikel om lobfeniga fiskar saknar väsentlig information. Du kan hjälpa till genom att tillföra sådan.

• 1 Спосіб життя
• 2 Розмноження
• 3 Використання
• 4 Посилання

Cá phổi Queensland, tên khoa học Neoceratodus forsteri, là một loài cá phổi. Nó là thành viên duy nhất còn sót lại của họ Ceratodontidae và bộ Ceratodontiformes. Đây là một trong những chỉ có sáu loài loài cá phổi còn tồn tại trên thế giới. Đặc hữu của Úc, Ceratodontidae là một họ cổ thuộc phân lớp Sarcopterygii.

Niên đại hóa thạch của ngày này nhóm trở lại 380 triệu năm, khoảng thời gian khi các lớp động vật có xương sống cao hơn đã bắt đầu phát triển. Hóa thạch của loài cá phổi gần giống như loài này đã được phát hiện ở miền bắc New South Wales, cho rằng Neoceratodus đã hầu như vẫn không thay đổi cho hơn 100 triệu năm, làm cho nó một hóa thạch sống và một trong các chi động vật có xương sống sống lâu đời nhất trên hành tinh.

Hình ảnh

Chú thích

Tham khảo

• Dữ liệu liên quan tới Neoceratodus forsteri tại Wikispecies
• Phương tiện liên quan tới Neoceratodus forsteri tại Wikimedia Commons
• Allen, Gerald R. (1989). Freshwater Fishes of Australia. T.F.H. Publications.
• Neoceratodus forsteri (TSN 161037) tại Hệ thống Thông tin Phân loại Tích hợp (ITIS).
• Thông tin "Neoceratodus forsteri" trên FishBase, chủ biên Ranier Froese và Daniel Pauly. Phiên bản tháng 10 năm 2005.

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• 7 Литература

昆士兰肺鱼（学名:Neoceratodus forsteri），是澳洲肺鱼科澳洲肺鱼属的单型种。长达一米，最大可达1.5米，鳞片大，只有一个鳔，胸鳍和腹鳍有力。只生活在澳大利亚昆士兰州，所以也叫昆士兰肺鱼或澳洲肺鱼。比非洲肺鱼更原始，不能长期干旱。

需要注意的是，英語“barramundi”一詞可指多種大型有鱗的淡水魚類，雖然包括肺魚，但通常餐桌上爲鱸形總目的尖吻鱸（或稱盲鰽，學名 Lates calcarifer）。而昆士蘭肺魚爲受CITES保護的易危物種，在澳大利亞禁止捕撈，僅在有澳大利亞聯邦及昆士蘭州許可的情況下允許以敎學和科硏目的的採集，而將食用的barramundi譯爲“澳洲肺魚”爲誤譯。

参考文献

オーストラリアハイギョ (学名：Neoceratodus forsteri ) は、肉鰭綱に属する肺魚の一種。オーストラリアハイギョ目オーストラリアハイギョ科に属する唯一の現生種とされている。属名をそのままカタカナ化した、ネオケラトドゥス、ネオセラトドゥス、ネオセラトダスなどの呼称で呼ばれることもある。他の肺魚よりも原始的な特徴をよく残している。

分布[編集]

オーストラリア・クイーンズランド州南東部のメアリー川・バーネット川水系にのみ生き残っている^[1]。しかし近年では本種の保護のために他の河川域への移植が盛んに行われており、いくつかの事例では導入に成功している^[2]。

形態[編集]

体長約1.5mほど。鱗は大きく、背鰭・尾鰭・尻鰭はとぎれずに一続きの大きな鰭を形成している。胸鰭と腹鰭は筋肉質で内部に支持骨を持つ。支持骨の数よりも鰭をふちどっている鰭条の数の方が多い。アフリカ産肺魚の肺が2室あって腹側に位置しているのに対し、オーストラリアハイギョの肺は部分的にしか2室に分かれておらず、消化管の背側に位置する^[2]。

生態[編集]

肉食性で、小型魚類^[2]・カエル^[2]・エビなどを捕食する。ただし、水生植物を食べるという報告もある^[3]。プロトプテルス等とは異なり空気呼吸に対する適応が低く、酸素補給の多くをエラ呼吸に頼っている^[4]。そのため干ばつ等には弱く、空気中ではすぐに死んでしまう。繁殖は冬である8月に行われる。求愛行動はオスがメスをつつくというもので、浅い水域の水草が茂った中にメスが卵を産み受精される。親は卵を保護しない^[2]。

発見史[編集]

1869年、シドニーにて博物館研究員をしていた生物学者のジェラード・クレフトは入植者によってその肉の色と味から「バーネット鮭」と呼ばれている魚のことを聞いた。その魚に興味を持ったジェラードは、報告者の家畜業者ウィリアム・フォースターにその魚をぜひとも送ってくれるように頼んだ。クイーンズランドに帰ったフォースターからほどなくして塩漬けにした数匹のバーネット鮭が届いた^[5]。種々の特徴からクレフトはこの魚が中生代の Ceratodus の生き残りであると考え、種小名をフォースターに献名して Ceratodus forsteri として記載した^[5]。後に本種は新設された Neoceratodus 属に移動された。

脚注[編集]

出典[編集]

1. ^ 動物大百科13 p133
2. ^ ^{a b c d e} 動物大百科13 p134
3. ^ 井田斉　他、『小学館の図鑑NEO・魚』、小学館、2003年、p25
4. ^ 動物大百科13 p135
5. ^ ^{a b} 世界動物発見史 p400

参考文献[編集]

• 井田斉　他、『小学館の図鑑NEO・魚』、小学館、2003年、p25
• K.E. バニスター編　『動物大百科 13 魚類』　平凡社　1987 ISBN 4-582-54513-0
• H.ヴェント　『世界動物発見史』　平凡社　1988 ISBN 4582515037

関連項目[編集]

• 古代魚

오스트레일리아폐어 또는 호주폐어(Neoceratodus forsteri)는 육기어강에 속하는 폐어류의 일종이다. 케라토두스목(Ceratodontiformes), 오스트레일리아폐어과(Neoceratodontidae 또는 Ceratodontidae), 오스트레일리아폐어속(Neoceratodus)의 유일한 현생종이다. "네오케라토두스 포르스테리"라는 이름으로도 불린다. 다른 폐어류보다 원시적인 특징을 잘 남기고 있다. 전세계의 현존하는 6종의 폐어류 중의 하나이다.알비노 종은 중국과 일본에 대량으로 수입 되고있다.

분포

오스트레일리아 퀸즐랜드주 남동부의 메리 강과 버넷 강 수계에만 유일하게 서식하고 있다.^[1] 그러나 근래에는 이 종의 보호를 위해 다른 하천 지역에 대한 이식이 활발히 이루어지고 있으며 몇몇 사례에서는 도입에 성공했다.

각주