family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
of fully aquatic
salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...
s commonly known as the giant salamanders. They include the largest living amphibians. The family is native to China, Japan, and the eastern United States. They constitute one of two living families within the
Cryptobranchoidea
The Cryptobranchoidea are a suborder of salamanders found in Asia, European Russia, and the United States. They are known as primitive salamanders, in contrast to Salamandroidea, the advanced salamanders. It has two living subdivisions, Cryptobra ...
, one of two main divisions of living salamanders, the other being the Asiatic salamanders belonging to the family Hynobiidae.
The largest species are in the genus ''
Andrias
''Andrias'' is a genus of giant salamanders. It includes the largest salamanders in the world, with ''A. japonicus'' reaching a length of , and ''A. sligoi'' reaching . While extant species are only known from East Asia, several extinct species i ...
,'' native to east Asia''.'' The
South China giant salamander
The South China giant salamander (''Andrias sligoi'') may be the largest species of salamander and the largest amphibian in the world. It is Endemism, endemic to southern China, mainly in the Pearl River (China), Pearl River basin south of the Na ...
(''Andrias sligoi''), can reach a length of .Andrias davidianus AmphibiaWeb: Information on amphibian biology and conservation. 2012. Berkeley, California: AmphibiaWeb. Retrieved 13 December 2012. The
Japanese giant salamander
The Japanese giant salamander (''Andrias japonicus'') is a species of fully aquatic giant salamander endemic to Japan. With a length of up to ,crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...
s, and has been known to live for more than 50 years in captivity.Andrias japonicus AmphibiaWeb: Information on amphibian biology and conservation. 2012. Berkeley, California: AmphibiaWeb. Retrieved 13 December 2012.
The
hellbender
The hellbender (''Cryptobranchus alleganiensis''), also known as the hellbender salamander, is a species of aquatic giant salamander endemic to the eastern and central United States. It is the largest salamander in North America. A member of the ...
(''Cryptobranchus alleganiensis'') inhabits the eastern United States and is the only member of the genus ''Cryptobranchus''.
Taxonomy
The family name is from the
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
''krypto'' ("hidden"), and ''branch'' ("gill"), which refer to how the members absorb oxygen through capillaries of their side-frills, which function as gills.
Clade Pancryptobrancha (Cryptobranchidae + Ukrainurus)
* Genus †''
Ukrainurus
''Ukrainurus'' is an extinct genus of pancryptobranchan urodelan known from the Miocene of Grytsiv locality, Ukraine. It contains a single species
In biology, a species is the basic unit of classification and a taxonomic rank of an org ...
'' Ukraine,
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
** †''
Ukrainurus hypsognathus
''Ukrainurus'' is an extinct genus of pancryptobranchan urodelan known from the Miocene of Grytsiv locality, Ukraine. It contains a single species
In biology, a species is the basic unit of classification and a taxonomic rank of an org ...
''
* Genus †''
Chunerpeton
''Chunerpeton tianyiensis'' is an extinct species of salamander from the Late Jurassic Daohugou Beds in Ningcheng County, Nei Mongol (Inner Mongolia), China. It is the only species classified under the genus ''Chunerpeton''. It was a small anima ...
?'' China, Middle Jurassic
** †''
Chunerpeton tianyiensis
''Chunerpeton tianyiensis'' is an extinct species of salamander from the Late Jurassic Daohugou Beds in Ningcheng County, Nei Mongol (Inner Mongolia), China. It is the only species classified under the genus ''Chunerpeton''. It was a small anima ...
''
*Family Cryptobranchidae
** Genus ''Cryptobranchus'' (hellbenders)
*** †''
Cryptobranchus saskatchewanensis
The hellbender (''Cryptobranchus alleganiensis''), also known as the hellbender salamander, is a species of aquatic giant salamander endemic to the eastern and central United States. It is the largest salamander in North America. A member of th ...
?''
Ravenscrag Formation
The Ravenscrag Formation is a stratigraphic unit of early Paleocene age in the Western Canada Sedimentary Basin. It was named for the settlement of Ravenscrag, Saskatchewan, and was first described from outcrops at Ravenscrag Butte near the Fr ...
, Canada,
Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...
*** ''
Cryptobranchus alleganiensis
The hellbender (''Cryptobranchus alleganiensis''), also known as the hellbender salamander, is a species of aquatic giant salamander endemic to the eastern and central United States. It is the largest salamander in North America. A member of t ...
'' (
hellbender
The hellbender (''Cryptobranchus alleganiensis''), also known as the hellbender salamander, is a species of aquatic giant salamander endemic to the eastern and central United States. It is the largest salamander in North America. A member of the ...
)
** Genus ''
Andrias
''Andrias'' is a genus of giant salamanders. It includes the largest salamanders in the world, with ''A. japonicus'' reaching a length of , and ''A. sligoi'' reaching . While extant species are only known from East Asia, several extinct species i ...
'' (Asian giant salamanders; sometimes classified among the ''Cryptobranchus'')
***''
Andrias davidianus
The Chinese giant salamander (''Andrias davidianus'') is one of the largest salamanders and one of the largest amphibians in the world.Chinese giant salamander
The Chinese giant salamander (''Andrias davidianus'') is one of the largest salamanders and one of the largest amphibians in the world.Simplified Chinese
Simplification, Simplify, or Simplified may refer to:
Mathematics
Simplification is the process of replacing a mathematical expression by an equivalent one, that is simpler (usually shorter), for example
* Simplification of algebraic expressions, ...
: ;
pinyin
Hanyu Pinyin (), often shortened to just pinyin, is the official romanization system for Standard Chinese, Standard Mandarin Chinese in China, and to some extent, in Singapore and Malaysia. It is often used to teach Mandarin, normally writte ...
: ') (may actually be a
species complex
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
South China giant salamander
The South China giant salamander (''Andrias sligoi'') may be the largest species of salamander and the largest amphibian in the world. It is Endemism, endemic to southern China, mainly in the Pearl River (China), Pearl River basin south of the Na ...
)
***''
Andrias japonicus
The Japanese giant salamander (''Andrias japonicus'') is a species of fully aquatic giant salamander endemic to Japan. With a length of up to ,Japanese giant salamander
The Japanese giant salamander (''Andrias japonicus'') is a species of fully aquatic giant salamander endemic to Japan. With a length of up to ,Andrias jiangxiensis'' ( Jiangxi giant salamander)
*** †''
Andrias matthewi
''Andrias matthewi'', or Matthew's giant salamander, is an extinct species of giant salamander from the Miocene of North America. It belongs to the genus ''Andrias'', which contains the living Asian giant salamanders. It is the largest salamande ...
'' North America, Miocene
*** †''
Andrias scheuchzeri
''Andrias scheuchzeri'' is an extinct species of giant salamander belonging to the genus ''Andrias'', which also contains the closely related living Asian giant salamanders. It is known from Oligocene to Pliocene aged deposits primarily from Ce ...
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Eoscapherpeton
''Eoscapherpeton'' is an extinct genus of giant salamander, known from the Late Cretaceous of Central Asia. Fossils have been found in the Cenomanian aged Khodzhakul Formation and Dzharakuduk Formation, Turonian aged Bissekty Formation and the C ...
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campani ...
)
**Genus †''
Aviturus
The Cryptobranchidae are a family of fully aquatic salamanders commonly known as the giant salamanders. They include the largest living amphibians. The family is native to China, Japan, and the eastern United States. They constitute one of two l ...
'' Mongolia, Paleocene
*** †''
Aviturus exsecratus
The Cryptobranchidae are a family of fully aquatic salamanders commonly known as the giant salamanders. They include the largest living amphibians. The family is native to China, Japan, and the eastern United States. They constitute one of two l ...
''
** Genus †''
Ulanurus
The Cryptobranchidae are a family of fully aquatic salamanders commonly known as the giant salamanders. They include the largest living amphibians. The family is native to China, Japan, and the eastern United States. They constitute one of two l ...
Zaissanurus
The Cryptobranchidae are a family of fully aquatic salamanders commonly known as the giant salamanders. They include the largest living amphibians. The family is native to China, Japan, and the eastern United States. They constitute one of two l ...
Zaissanurus beliajevae
The Cryptobranchidae are a family of fully aquatic salamanders commonly known as the giant salamanders. They include the largest living amphibians. The family is native to China, Japan, and the eastern United States. They constitute one of two l ...
''
Fossil record
Extant species in the family Cryptobranchidae are the modern-day members of a lineage that extends back tens millions of years. The oldest known fossils of cryptobranchoids are known from the Middle Jurassic of China. ''
Chunerpeton
''Chunerpeton tianyiensis'' is an extinct species of salamander from the Late Jurassic Daohugou Beds in Ningcheng County, Nei Mongol (Inner Mongolia), China. It is the only species classified under the genus ''Chunerpeton''. It was a small anima ...
'' from the Middle Jurassic of China has been suggested to represent the oldest known cryptobranchid. However, some studies have found it to be a more basal cryptobranchoid not more closely related to Cryptobranchidae than to
Hynobiidae
The Asiatic salamanders (family Hynobiidae) are primitive salamanders found all over Asia, and in European Russia. They are closely related to the giant salamanders (family Cryptobranchidae), with which they form the suborder Cryptobranchoidea. ...
. The next oldest cryptobranchid is ''
Eoscapherpeton
''Eoscapherpeton'' is an extinct genus of giant salamander, known from the Late Cretaceous of Central Asia. Fossils have been found in the Cenomanian aged Khodzhakul Formation and Dzharakuduk Formation, Turonian aged Bissekty Formation and the C ...
'', known from numerous
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...
deposits in Central Asia, which is suggested to represent a
stem-group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...
to modern cryptobranchids. Modern crown group representatives appear during the
Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...
.
As the fossil record for the Cryptobranchidae shows an Asian origin for the family, how these salamanders made it to the eastern US has been a point of scientific interest. Research has indicated a dispersal via
land bridge
In biogeography, a land bridge is an isthmus or wider land connection between otherwise separate areas, over which animals and plants are able to cross and colonize new lands. A land bridge can be created by marine regression, in which sea leve ...
, with waves of
adaptive radiation
In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic int ...
seeming to have swept the Americas from north to south.
In 1726, the Swiss physician
Johann Jakob Scheuchzer
Johann Jakob Scheuchzer (2 August 1672 – 23 June 1733) was a Swiss scholar born at Zürich.
Herbarium deluvianum
Zürich, Zwingli-Platz ( Grossmünster) : Former home of Konrad von Mure († 1280) and the house, where Johann Jakob Scheuch ...
described a fossil as ''Homo diluvii testis'' (
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
: Evidence of a
diluvian
A flood myth or a deluge myth is a myth in which a great flood, usually sent by a deity or deities, destroys civilization, often in an act of divine retribution. Parallels are often drawn between the flood waters of these myths and the primae ...
human), believing it to be the remains of a human being who drowned in the biblical
flood
A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrol ...
. The
Teylers Museum
Teylers Museum () is an art, natural history, and science museum in Haarlem, Netherlands. Established in 1778, Teylers Museum was founded as a centre for contemporary art and science. The historic centre of the museum is the neoclassical Oval R ...
Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...
, bought the fossil in 1802, where it is still exhibited. In 1812, the fossil was examined by Georges Cuvier, who recognized that it was not human. After being identified as a salamander, it was renamed ''
Salamandra
''Salamandra'' is a genus of seven species of salamanders localized in central and southern Europe, Northern Africa, and western Asia.
List of species
References
External links
Salamandraat Fauna Europaea
*
Salamandraat Animal Diversity W ...
scheuchzeri'' by Holl in 1831. The
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
''Andrias'' was coined six years later by Tschudi. In doing so, both the genus, ''Andrias'' (which means "image of man"), and the specific name, ''scheuchzeri'', ended up honouring Scheuchzer and his beliefs. It and the extant ''A. davidianus'' cannot be mutually distinguished, and the latter, only described in 1871, is therefore sometimes considered a synonym of the former.
Description
Cryptobranchids are large
salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...
s, with large folds of skin along their flanks. These help increase the animals' surface area, allowing them to absorb more oxygen from the water. They have four toes on the fore limbs, and five on the hind limbs. They have paedomorphic traits, meaning their metamorphosis from the larval stage is incomplete, so the adults retain gill slits (although they also have lungs), and lack eyelids. They have a stout body with a heavy, laterally compressed tail. They have bad eyesight. They can reach a length of , though most are considerably smaller today.
Distribution and habitat
In Japan, their natural habitats are threatened by dam-building. Ramps and staircases have been added to some dams to allow them to move upstream to areas where they spawn.
"Giant Salamanders Helped to Spawn" 31 December 2009. National Geographic Society. Retrieved 13 December 2012.
Behavior
A Japanese giant salamander lived for 52 years in captivity.
Feeding
The Chinese giant salamander eats aquatic insects, fish, frogs, crabs, and shrimp. They hunt mainly at night. As they have poor eyesight, they use sensory nodes on their heads and bodies to detect minute changes in water pressure, enabling them to find their prey.
Reproduction
During mating season, the salamanders travel upstream, where the female lays two strings of over 200 eggs each. Lacking the stereotypical courtship behaviors found in other species, the male fertilizes the eggs externally by releasing his sperm onto them, and then guards them for at least three months, until they hatch. Tail fanning also occurs in order to increase the oxygen supply for the eggs. At this point, the larvae live off their noticeable stored fat until ready to hunt. Once ready, they hunt as a group rather than individually.
Scientists at
Hiroshima City Asa Zoological Park
is a zoo in Hiroshima, Japan.
Overview
Asa Zoological Park opened in 1971 in Asakita-ku, Hiroshima as the 62nd zoo in Japan. The gross area of the zoo is 49.6 ha. There are about 170 varieties of animals including giraffes, lions, black rhino ...
in Japan have recently discovered the male salamander will spawn with more than one female in his den. Only large males can occupy and guard a den. They guard the den against other males and sexually inactive females. Those that are sexually active are welcomed. On occasion, the male "den master" will also allow a second male (smaller male salamanders, named "satellite males", who do not have their own den) into the den; the reason for this is unclear.Okada, Sumio, Yukihiro Fukuda, and Mizuki K. Takahashi. "Paternal care behaviors of Japanese giant salamander Andrias japonicus in natural populations." Journal of ethology 33.1 (2015): 1-7.