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109-474: Triturus is a genus of newts comprising the crested and the marbled newts , which are found from Great Britain through most of continental Europe to westernmost Siberia , Anatolia , and the Caspian Sea region. Their English names refer to their appearance: marbled newts have a green–black colour pattern, while the males of crested newts, which are dark brown with a yellow or orange underside, develop

218-431: A 6 mm jelly capsule, which distinguishes them from eggs of other co-existing newt species that are smaller and darker-coloured. A genetic particularity in the genus causes 50% of the embryos to die: their development is arrested when they do not possess two different variants of chromosome 1 (i.e., when they are homozygous for that chromosome). Larvae hatch after two to five weeks, depending largely on temperature. In

327-564: A brief time interval between 11.5 and 8   mya: First, the Balkan–Asian group (the Anatolian, Balkan and southern crested newt) branched off from the other crested newts, probably in a vicariance event caused by the separation of the Balkan and Anatolian land masses. The origin of current-day species is not fully understood so far, but one hypothesis suggests that ecological differences, notably in

436-461: A complex ranking but it is not a species complex. In most cases, a species complex is a monophyletic group of species with a common ancestor, but there are exceptions. It may represent an early stage after speciation in which the species were separated for a long time period without evolving morphological differences. Hybrid speciation can be a component in the evolution of a species complex. Species complexes are ubiquitous and are identified by

545-405: A conspicuous jagged seam on their back and tail during their breeding phase. Crested and marbled newts live and breed in vegetation-rich ponds or similar aquatic habitats for two to six months and usually spend the rest of the year in shady, protection-rich land habitats close to their breeding sites. Males court females with a ritualised display , ending in the deposition of a spermatophore that

654-405: A group of closely related species that live in the same habitat. As informal taxonomic ranks , species group , species aggregate , macrospecies , and superspecies are also in use. Two or more taxa that were once considered conspecific (of the same species) may later be subdivided into infraspecific taxa (taxa within a species, such as bacterial strains or plant varieties ), which may be

763-476: A landscape that offers cover, invertebrate prey and humidity. The precise requirements of most species are still poorly known, as the newts are much more difficult to detect and observe on land. Deciduous woodlands or groves are in general preferred, but conifer woods are also accepted, especially in the far northern and southern ranges. The southern marbled newt is typically found in Mediterranean oak forests. In

872-643: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

981-621: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

1090-500: A mean of roughly 4% for the northern crested newt, which is comparable to other newts. In unfavourable conditions, larvae may delay their development and overwinter in water, although this seems to be less common than in the small-bodied newts. Paedomophic adults, retaining their gills and staying aquatic, have occasionally been observed in several crested newt species. Crested and marbled newts are found in Eurasia, from Great Britain and

1199-489: A milky substance. A complex courting ritual performed underwater characterises the crested and marbled newts. Males are territorial and use leks , or courtship arenas, small patches of clear ground where they display and attract females. When they encounter other males, they use the same postures as described below for courting to impress their counterpart. Occasionally, they even bite each other; marbled newts seem more aggressive than crested newts. Males also frequently disturb

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1308-473: A range of other amphibians. Genus The composition of a genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of

1417-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

1526-407: A sign of ongoing or incipient speciation . Examples are ring species or species with subspecies , in which it is often unclear if they should be considered separate species. Several terms are used synonymously for a species complex, but some of them may also have slightly different or narrower meanings. In the nomenclature codes of zoology and bacteriology, no taxonomic ranks are defined at

1635-556: A species group share a range . A source from Iowa State University Department of Agronomy states that members of a species group usually have partially overlapping ranges but do not interbreed with one another. A Dictionary of Zoology ( Oxford University Press 1999) describes a species group as complex of related species that exist allopatrically and explains that the "grouping can often be supported by experimental crosses in which only certain pairs of species will produce hybrids ." The examples given below may support both uses of

1744-488: A stocky build and mainly terrestrial lifestyle, as today found in the marbled newts, to a slender body and a more aquatic lifestyle, as in the Danube crested newt. A 24-million-year-old fossil belonging to Triturus , perhaps a marbled newt, shows that the genus already existed at that time. A molecular clock study based on this and other fossils places the divergence between Triturus from Calotriton at around 39   mya in

1853-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

1962-508: A total length of between 10 and 16 cm (3.9 and 6.3 in), with some crested newts of up to 20 cm (8 in) described. Size depends on sex and the environment: females are slightly larger and have a proportionally longer tail than males in most species, and the Italian crested newt seems to be larger in colder parts of its range. Crested newts are dark brown, with black spots on the sides, and white stippling in some species. Their belly

2071-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

2180-402: Is actually at least three different species that diverged over 5 million years ago. Stabilizing selection has been invoked as a force maintaining similarity in species complexes, especially when they adapted to special environments (such as a host in the case of symbionts or extreme environments). This may constrain possible directions of evolution; in such cases, strongly divergent selection

2289-596: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

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2398-564: Is habitat loss. This concerns especially breeding sites, which are lost through the upscaling and intensification of agriculture, drainage, urban sprawl, and artificial flooding regimes (affecting in particular the Danube crested newt). Especially in the southern ranges, exploitation of groundwater and decreasing spring rain, possibly caused by global warming , threaten breeding ponds. Aquatic habitats are also degraded through pollution with agricultural pesticides and fertiliser. Introduction of crayfish and predatory fish threatens larval development;

2507-548: Is in general very effective as they are rapidly colonised when other habitats are nearby. In some cases, entire populations have been moved when threatened by development projects, but such translocations need to be carefully planned to be successful. Strict protection of the northern crested newt in the United Kingdom has created conflicts with local development projects; at the same time, the charismatic crested newts are seen as flagship species , whose conservation also benefits

2616-464: Is not straightforward, but most can be determined by a combination of body form, coloration, and male crest shape. The Anatolian, Balkan, and southern crested newt however are cryptic, morphologically indistinguishable species. Triturus newts occupy distinct geographical regions (see Distribution ), but hybrid forms occur at range borders between some species and have intermediate characteristics (see Hybridisation and introgression ). Based on

2725-480: Is not to be expected. Also, asexual reproduction, such as through apomixis in plants, may separate lineages without producing a great degree of morphological differentiation. A species complex is usually a group that has one common ancestor (a monophyletic group), but closer examination can sometimes disprove that. For example, yellow-spotted "fire salamanders" in the genus Salamandra , formerly all classified as one species S. salamandra , are not monophyletic:

2834-403: Is picked up by the female. After fertilisation, a female lays 200–400 eggs, folding them individually into leaves of water plants. Larvae develop over two to four months before metamorphosing into land-dwelling juveniles. Historically, most European newts were included in the genus, but taxonomists have split off the alpine newts ( Ichthyosaura ), the small-bodied newts ( Lissotriton ) and

2943-573: Is rare, supporting overall reproductive isolation . Backcrossing and introgression do however occur as shown by mitochondrial DNA analysis. In a case study in the Netherlands, genes of the introduced Italian crested newt were found to introgress into the gene pool of the native northern crested newt. The two marbled newt species can be found in proximity in a narrow area in central Portugal and Spain, but they usually breed in separate ponds, and individuals in that area could be clearly identified as one of

3052-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

3161-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

3270-435: Is yellow to orange with black blotches, forming a pattern characteristic for individuals. Females and juveniles of some species have a yellow line running down their back and tail. During breeding phase, crested newts change in appearance, most markedly the males. These develop a skin seam running along their back and tail; this crest is the namesake feature of the crested newts and can be up to 1.5 cm high and very jagged in

3379-553: The Apennine Mountains , the southern crested newt up to 2,000 m (6,600 ft) in the southern Caucasus, and the marbled newt up to around 2,100 m (6,900 ft) in central Spain. The closest relatives of the crested and marbled newts are the European brook newts ( Calotriton ). Phylogenomic analyses resolved the relationships within the genus Triturus : The crested and the marbled newts are sister groups , and within

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3488-484: The Azores . In the northern Balkans , four species of crested newt occur in close vicinity, and may sometimes even co-exist. Triturus species usually live at low elevation; the Danube crested newt for example is confined to lowlands up to 300 m (980 ft) above sea level. However, they do occur at higher altitudes towards the south of their range: the Italian crested newt is found up to 1,800 m (5,900 ft) in

3597-537: The Chinese sleeper has been a major concern in Eastern Europe. Exotic plants can also degrade habitats: the swamp stonecrop replaces natural vegetation and overshadows waterbodies in the United Kingdom, and its hard leaves are unsuitable for egg-laying to crested newts. Land habitats, equally important for newt populations, are lost through the replacement of natural forests by plantations or clear-cutting (especially in

3706-845: The Corsican fire salamander 's closest relative has been shown to be the entirely black Alpine salamander . In such cases, similarity has arisen from convergent evolution . Hybrid speciation can lead to unclear species boundaries through a process of reticulate evolution , in which species have two parent species as their most recent common ancestors . In such cases, the hybrid species may have intermediate characters, such as in Heliconius butterflies. Hybrid speciation has been observed in various species complexes, such as insects, fungi, and plants. In plants, hybridization often takes place through polyploidization , and hybrid plant species are called nothospecies . Sources differ on whether or not members of

3815-491: The EU habitats and species directive . As required by these frameworks, their capture, disturbance, killing or trade, as well as the destruction of their habitats, are prohibited in most European countries. The EU habitats directive is also the basis for the Natura 2000 protected areas, several of which have been designated for the crested newts. Habitat protection and management is seen as

3924-517: The Eocene , with an uncertainty range of 47 to 34   mya. Based on this estimation, authors have investigated diversification within the genus and related it to paleogeography : The crested and marbled newts split between 30 and 24   mya, and the two species of marbled newts have been separated for 4.7–6.8 million years. The crested newts are believed to have originated in the Balkans and radiated in

4033-479: The Galápagos Islands described by Charles Darwin . It has been suggested that cryptic species complexes are very common in the marine environment. That suggestion came before the detailed analysis of many systems using DNA sequence data but has been proven to be correct. The increased use of DNA sequence in the investigation of organismal diversity (also called phylogeography and DNA barcoding ) has led to

4142-570: The Iberian Peninsula in the west to West Siberia and the southern Caspian Sea region in the east, and reach north to central Fennoscandia . Overall, the species have contiguous, parapatric ranges; only the northern crested newt and the marbled newt occur sympatrically in western France, and the southern crested newt has a disjunct, allopatric distribution in Crimea , the Caucasus , and south of

4251-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

4360-799: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

4469-616: The banded newts ( Ommatotriton ) as separate genera. The closest relatives of Triturus are the European brook newts ( Calotriton ). Two species of marbled newts and seven species of crested newts are accepted, of which the Anatolian crested newt was only described in 2016. Their ranges are largely contiguous but where they do overlap, hybridisation may take place. Although not immediately threatened, crested and marbled newts suffer from population declines caused mainly by habitat loss and fragmentation . Both their aquatic breeding sites and

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4578-470: The grass snake , and mammals such as shrews , badgers and hedgehogs . They secrete the poison tetrodotoxin from their skin, albeit much less than for example the North American Pacific newts ( Taricha ). The bright yellow or orange underside of crested newts is a warning coloration which can be presented in case of perceived danger. In such a posture, the newts typically roll up and secrete

4687-886: The malaria vector genus of mosquito, Anopheles , the fungi causing cryptococcosis , and sister species of Bactrocera tryoni , or the Queensland fruit fly. That pest is indistinguishable from two sister species except that B. tryoni inflicts widespread, devastating damage to Australian fruit crops, but the sister species do not. When a species is found to be several phylogenetically distinct species, each typically has smaller distribution ranges and population sizes than had been reckoned. The different species can also differ in their ecology, such as by having different breeding strategies or habitat requirements, which must be taken into account for appropriate management. For example, giraffe populations and subspecies differ genetically to such an extent that they may be considered species. Although

4796-419: The nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

4905-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

5014-462: The Amazonian frog Eleutherodactylus ockendeni is actually at least three different species that diverged over 5 million years ago. A species flock may arise when a species penetrates a new geographical area and diversifies to occupy a variety of ecological niches , a process known as adaptive radiation . The first species flock to be recognized as such was the 13 species of Darwin's finches on

5123-501: The Caspian Sea. The northern crested newt is the most widespread species, while the others are confined to smaller regions, e.g. the southwestern Iberian Peninsula in the southern marbled newt, and the Danube basin and some of its tributaries in the Danube crested newt. The Italian crested newt ( T. carnifex ) has been introduced outside its native range in some European countries and

5232-648: The Italian crested newt) rice paddies. The Danube crested newt is more adapted to flowing water and often breeds in river margins, oxbow lakes or flooded marshland , where it frequently co-occurs with fish. Other newts that can be found in syntopy with Triturus species include the smooth , the palmate , the Carpathian , and the alpine newt . Adult newts begin moving to their breeding sites in spring when temperatures stay above 4–5 °C (39–41 °F). This usually occurs in March for most species, but can be much earlier in

5341-405: The absence of forests, other cover-rich habitats, as for example hedgerows , scrub , swampy meadows, or quarries , can be inhabited. Within such habitats, the newts use hiding places such as logs, bark, planks, stone walls, or small mammal burrows; several individuals may occupy such refuges at the same time. Since the newts in general stay very close to their aquatic breeding sites, the quality of

5450-408: The absence of suitable plants, the eggs may also be deposited on leaf litter, stones, or even plastic bags. In the northern crested newt, a female takes around five minutes for the deposition of one egg. Crested newt females usually lay around 200 eggs per season, while the marbled newt ( T. marmoratus ) can lay up to 400. Triturus embryos are usually light-coloured, 1.8–2 mm in diameter with

5559-525: The adaptation to an aquatic lifestyle, may have evolved between populations and led to parapatric speciation . Alternatively, the complex geological history of the Balkan peninsula may have further separated populations there, with subsequent allopatric speciation and the spread of species into their current ranges. At the onset of the Quaternary glacial cycles , around 2.6   mya, the extant Triturus species had already emerged. They were thus affected by

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5668-495: The back legs. Unlike smaller newts, Triturus larvae are mostly nektonic , swimming freely in the water column. Just before the transition to land, the larvae resorb their external gills; they can at this stage reach a size of 7 centimetres (2.8 in) in the larger species. Metamorphosis takes place two to four months after hatching, but the duration of all stages of larval development varies with temperature. Survival of larvae from hatching to metamorphosis has been estimated at

5777-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

5886-493: The books of Griffiths (1996) and Jehle et al. (2011), with additions from articles on recently recognised species. NRBV = number of rib-bearing vertebrae, values from Wielstra & Arntzen (2011). Triturus anatolicus , T. ivanbureschi and T. karelinii are cryptic species and have only been separated through genetic analysis. Like other newts, Triturus species develop in the water as larvae, and return to it each year for breeding. Adults spend one half to three quarters of

5995-413: The courting of other males and try to guide the female away from their rival. Pheromones are used to attract females, and once a male has found one he will pursue her and position himself in front of her. After this first orientation phase, courtship proceeds with display and spermatophore transfer . Courtship display serves to emphasise the male's body and crest size and to waft pheromones towards

6104-455: The cover-rich, natural landscapes upon which they depend during their terrestrial phase are affected. All species are legally protected in Europe, and some of their habitats have been designated as special reserves. The genus name Triturus was introduced in 1815 by the polymath Constantine Samuel Rafinesque , with the northern crested newt ( Triturus cristatus ) as type species . That species

6213-485: The crested newt (now full species); this index however sometimes leads to misidentifications. The number of rib -bearing vertebrae in the skeleton was shown to be a better species indicator. It ranges from 12 in the marbled newts to 16–17 in the Danube crested newt and is usually observed through radiography on dead or sedated specimens. The two marbled newts are readily distinguished by size and colouration. In contrast, separating crested newt species based on appearance

6322-496: The crested newts often collectively referred to as " T. cristatus superspecies ". The Balkan and the Anatolian crested newt, the most recent species formally described (2013 and 2016, respectively), were only recognised through genetic data ; together with the Southern crested newt, they form a cryptic species complex with no morphological differences known. Triturus is a genus of rather large-bodied newts. They typically have

6431-469: The crested newts, the Balkan–Asian group with T. anatolicus , T. karelinii and T. ivanbureschi is sister to the remaining species. The northern ( T. cristatus ) and the Danube crested newt ( T. dobrogicus ), as well as the Italian ( T. carnifex ) and the Macedonian crested newt ( T. macedonicus ), respectively, are sister species. These relationships suggest evolution from

6540-591: The cycles of expansion and retreat of cold, inhospitable regions, which shaped their distribution. A study using environmental niche modelling and phylogeography showed that during the Last Glacial Maximum , around 21,000 years ago, crested and marbled newts likely survived in warmer refugia mainly in southern Europe. From there, they recolonised the northern parts after glacial retreat. The study also showed that species range boundaries shifted, with some species replacing others during recolonisation, for example

6649-407: The discovery of a great many cryptic species complexes in all habitats. In the marine bryozoan Celleporella hyalina , detailed morphological analyses and mating compatibility tests between the isolates identified by DNA sequence analysis were used to confirm that these groups consisted of more than 10 ecologically distinct species, which had been diverging for many millions of years. Evidence from

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6758-671: The drawing of dividing lines between species can be inherently difficult . A species complex is typically considered as a group of close, but distinct species. Obviously, the concept is closely tied to the definition of a species. Modern biology understands a species as "separately evolving metapopulation lineage " but acknowledges that the criteria to delimit species may depend on the group studied. Thus, many traditionally defined species, based only on morphological similarity, have been found to be several distinct species when other criteria, such as genetic differentiation or reproductive isolation , are applied. A more restricted use applies

6867-821: The dry months of summer. Like other newts, Triturus species are carnivorous and feed mainly on invertebrates. During the land phase, prey include earthworms and other annelids , different insects , woodlice , and snails and slugs . During the breeding season, they prey on various aquatic invertebrates, and also tadpoles of other amphibians such as the common frog or common toad , and smaller newts. Larvae, depending on their size, eat small invertebrates and tadpoles, and also smaller larvae of their own species. The larvae are themselves eaten by various animals such as carnivorous invertebrates and water birds , and are especially vulnerable to predatory fish. Adults generally avoid predators through their hidden lifestyle but are sometimes eaten by herons and other birds, snakes such as

6976-433: The female touches his tail with her snout, he deposits a packet of sperm (a spermatophore ) on the ground. The ritual ends with the male guiding the female over the spermatophore, which she then takes up with her cloaca . In the southern marbled newt, courtship is somewhat different from the larger species in that it does not seem to involve male "cat buckles" and "whiplashes", but instead slower tail fanning and undulating of

7085-444: The female. A position characteristic for the large Triturus species is the "cat buckle", where the male's body is kinked and often rests only on the forelegs ("hand stand"). He will also lean towards the female ("lean-in"), rock his body, and flap his tail towards her, sometimes lashing it violently ("whiplash"). If the female shows interest, the ritual enters the third phase, where the male creeps away from her, his tail quivering. When

7194-424: The first days after hatching, they live on their remaining embryonic yolk supply and are not able to swim, but attach to plants or the egg capsule with two balancers, adhesive organs on their head. After this period, they begin to ingest small invertebrates, and actively forage about ten days after hatching. As in all salamanders and newts, forelimbs—already present as stumps at hatching—develop first, followed later by

7303-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

7412-727: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

7521-636: The genus is potentially susceptible to the highly pathogenic fungus Batrachochytrium salamandrivorans , introduced to Europe from Asia. The crested newts are listed in Berne Convention Appendix II as "strictly protected", and the marbled newts in Appendix III as "protected". They are also included in Annex II (species requiring designation of special areas of conservation; crested newts) and IV (species in need of strict protection; all species) of

7630-454: The genus with a considerable range overlap (in western France). In that area, they have patchy, mosaic-like distributions and in general prefer different habitats. When they do occur in the same breeding ponds, they can form hybrids, which have intermediate characteristics. Individuals resulting from the cross of a crested newt male with a marbled newt female had mistakenly been described as distinct species Triton blasii de l'Isle 1862 , and

7739-691: The genus: the small-bodied newts ( Lissotriton ), the banded newts ( Ommatotriton ), and the alpine newt ( Ichthyosaura ). The monophyly of the genus Triturus in the strict sense is supported by molecular data and synapomorphies such as a genetic defect causing 50% embryo mortality (see below, Egg deposition and development ). As of 2020, the genus contains seven species of crested newts and two species of marbled newts. Both groups were long considered as single species, Triturus cristatus and T. marmoratus , respectively. Substantial genetic differences between subspecies were, however, noted and eventually led to their recognition as full species, with

7848-424: The identification of cryptic species has led some to conclude that current estimates of global species richness are too low. Pests, species that cause diseases and their vectors, have direct importance for humans. When they are found to be cryptic species complexes, the ecology and the virulence of each of these species need to be re-evaluated to devise appropriate control strategies. Examples are cryptic species in

7957-628: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

8066-559: The level between subgenus and species, but the botanical code defines four ranks below subgenus (section, subsection, series, and subseries). Different informal taxonomic solutions have been used to indicate a species complex. Distinguishing close species within a complex requires the study of often very small differences. Morphological differences may be minute and visible only by the use of adapted methods, such as microscopy . However, distinct species sometimes have no morphological differences. In those cases, other characters, such as in

8175-751: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Cryptic 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 other, further blurring any distinctions. Terms that are sometimes used synonymously but have more precise meanings are cryptic species for two or more species hidden under one species name, sibling species for two (or more) species that are each other's closest relative, and species flock for

8284-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

8393-426: The most important element for the conservation of Triturus newts. This includes preservation of natural water bodies, reduction of fertiliser and pesticide use, control or eradication of introduced predatory fish, and the connection of habitats through sufficiently wide corridors of uncultivated land. A network of aquatic habitats in proximity is important to sustain populations, and the creation of new breeding ponds

8502-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

8611-589: The newts likely use a combination of cues including odour and the calls of other amphibians, and orientation by the night sky has been demonstrated in the marbled newt. Activity is highest on wet nights; the newts usually stay hidden during daytime. There is often an increase in activity in late summer and autumn, when the newts likely move closer to their breeding sites. Over most of their range, they hibernate in winter, using mainly subterranean hiding places, where many individuals will often congregate. In their southern range, they may instead sometimes aestivate during

8720-443: The northern crested newt. Another feature of males at breeding time is a silvery-white band along the sides of the tail. Marbled newts owe their name to their green–black, marbled colour pattern. In females, an orange-red line runs down back and tail. The crest of male marbled newts is smaller and fleshier than that of the crested newts and not indented, but marbled newt males also have a whitish tail band at breeding time. Apart from

8829-553: The northern crested newts have reached 17 years in the wild. The aquatic habitats preferred by the newts are stagnant, mid- to large-sized, unshaded water bodies with abundant underwater vegetation but without fish, which prey on larvae. Typical examples are larger ponds , which need not be of natural origin; indeed, most ponds inhabited by the northern crested newt in the UK are human-made. Examples of other suitable secondary habitats are ditches, channels, gravel pit lakes, garden ponds, or (in

8938-404: The northern range), and the conversion of structure-rich landscapes into uniform farmland. Their limited dispersal makes the newts especially vulnerable to fragmentation , i.e. the loss of connections for exchange between suitable habitats. High concentrations of road salt have been found to be lethal to crested newts. Other threats include illegal collection for pet trade, which concerns mainly

9047-479: The obvious colour differences between crested and marbled newts, species in the genus also have different body forms. They range from stocky with sturdy limbs in the Anatolian, Balkan and the southern crested newt as well as the marbled newts, to very slender with short legs in the Danube crested newt. These types were first noted by herpetologist Willy Wolterstorff , who used the ratio of forelimb length to distance between fore- and hindlimbs to distinguish subspecies of

9156-472: The only useful method. Different methods are used to analyse such genetic data, such as molecular phylogenetics or DNA barcoding . Such methods have greatly contributed to the discovery of cryptic species, including such emblematic species as the fly agaric , the water fleas , or the African elephants . Species forming a complex have typically diverged very recently from each other, which sometimes allows

9265-526: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

9374-427: The retracing of the process of speciation . Species with differentiated populations, such as ring species , are sometimes seen as an example of early, ongoing speciation: a species complex in formation. Nevertheless, similar but distinct species have sometimes been isolated for a long time without evolving differences, a phenomenon known as "morphological stasis". For example, the Amazonian frog Pristimantis ockendeni

9483-586: The reverse hybrids as Triton trouessarti Peracca 1886 . The first type is much rarer due to increased mortality of the larvae and consists only of males, while in the second, males have lower survival rates than females. Overall, viability is reduced in these hybrids and they rarely backcross with their parent species. Hybrids made up 3–7% of the adult populations in different studies. Other Triturus species only meet at narrow zones on their range borders. Hybridisation does occur in several of these contact zones, as shown by genetic data and intermediate forms, but

9592-459: The rigorous study of differences between individual species that uses minute morphological details, tests of reproductive isolation , or DNA -based methods, such as molecular phylogenetics and DNA barcoding . The existence of extremely similar species may cause local and global species diversity to be underestimated. The recognition of similar-but-distinct species is important for disease and pest control and in conservation biology although

9701-466: The same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but the French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or

9810-461: The same species. Where closely related species co-exist in sympatry , it is often a particular challenge to understand how the similar species persist without outcompeting each other. Niche partitioning is one mechanism invoked to explain that. Indeed, studies in some species complexes suggest that species divergence have gone in par with ecological differentiation, with species now preferring different microhabitats. Similar methods also found that

9919-408: The scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of a species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in

10028-485: The smaller newts of Lissotriton and Ichthyosaura , usually prefer the deeper parts of a water body, where they hide under vegetation. As with other newts, they occasionally have to move to the surface to breathe air. The aquatic phase serves not only for reproduction, but also offers the animals more abundant prey, and immature crested newts frequently return to the water in spring even if they do not breed. During their terrestrial phase, crested and marbled newts depend on

10137-503: The southern crested newt, and the northern crested newt in its eastern range. The possibility of hybridisation, especially in the crested newts, means that native species can be genetically polluted through the introduction of close species, as it is the case with the Italian crested newt introduced in the range of the northern crested newt. Warmer and wetter winters due to global warming may increase newt mortality by disturbing their hibernation and forcing them to expend more energy. Finally,

10246-416: The southern marbled newt are considered " near threatened " because populations have declined significantly. Populations have been affected more heavily in some countries and species are listed in some national red lists. The Anatolian, Balkan and the Macedonian crested newt, recognised only recently, have not yet been evaluated separately for conservation status. The major threat for crested and marbled newts

10355-453: The southern marbled newt which expanded northwards and replaced the marbled newt. Today's most widespread species, the northern crested newt, was likely confined to a small refugial region in the Carpathians during the last glaciation, and from there expanded its range north-, east- and westwards when the climate rewarmed. The northern crested newt and the marbled newt are the only species in

10464-462: The southern parts of the distribution range. Southern marbled newts mainly breed from January to early March and may already enter ponds in autumn. The time adults spend in water differs among species and correlates with body shape: while it is only about three months in the marbled newts, it is six months in the Danube crested newt, whose slender body is best adapted to swimming. Triturus newts in their aquatic phase are mostly nocturnal and, compared to

10573-445: The species' life history , behavior , physiology , and karyology , may be explored. For example, territorial songs are indicative of species in the treecreepers , a bird genus with few morphological differences. Mating tests are common in some groups such as fungi to confirm the reproductive isolation of two species. Analysis of DNA sequences is becoming increasingly standard for species recognition and may, in many cases, be

10682-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

10791-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

10900-422: The surrounding terrestrial habitat largely determines whether an otherwise suitable water body will be colonised. Juveniles often disperse to new breeding sites, while the adults in general move back to the same breeding sites each year. The newts do not migrate very far: they may cover around 100 metres (110 yd) in one night and rarely disperse much farther than one kilometre (0.62 mi). For orientation,

11009-438: The tail tip (presumably to mimic a prey animal and lure the female). Females usually engage with several males over a breeding season. The eggs are fertilised internally in the oviduct . The female deposits them individually on leaves of aquatic plants, such as water cress or floating sweetgrass , usually close to the surface, and, using her hindlegs, folds the leaf around the eggs as protection from predators and radiation. In

11118-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

11227-549: The term "species group." Often, such complexes do not become evident until a new species is introduced into the system, which breaks down existing species barriers. An example is the introduction of the Spanish slug in Northern Europe , where interbreeding with the local black slug and red slug , which were traditionally considered clearly separate species that did not interbreed, shows that they may be actually just subspecies of

11336-418: The term to a group of species among which hybridisation has occurred or is occurring, which leads to intermediate forms and blurred species boundaries. The informal classification, superspecies, can be exemplified by the grizzled skipper butterfly, which is a superspecies that is further divided into three subspecies. Some authors apply the term to a species with intraspecific variability , which might be

11445-592: The two species. Nevertheless, there is introgression, occurring in both directions at some parts of the contact zone, and only in the direction of the southern marbled newt where that species had historically replaced the marbled newt (see also above, Glacial refugia and recolonisation ). Most of the crested and marbled newts are listed as species of " least concern " by the International Union for Conservation of Nature , but population declines have been registered in all assessed species. The Danube crested newt and

11554-566: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

11663-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

11772-502: The year on land, depending on the species, and thus depend on both suitable aquatic breeding sites and terrestrial habitats. After larval development in the first year, juveniles pass another year or two before reaching maturity; in the north and at higher elevations, this can take longer. The larval and juvenile stages are the riskiest for the newts, while survival is higher in adults. Once the risky stages passed, adult newts usually attain an age of seven to nine years, although individuals of

11881-445: Was originally described as Triton cristatus by Josephus Nicolaus Laurenti in 1768, but Linnaeus had already used the name Triton for a genus of sea snails ten years before, making a new genus name for the newts necessary. Triturus included most European newt species until the end of the 20th century, but was substantially revised after it was shown to be polyphyletic . Three separate genera now accommodate former members of

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