''Nosferatu'' is a proposed

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

cichlid Cichlids () are a large, diverse, and widespread family of percomorph fish in the family Cichlidae, order Cichliformes. At least 1,760 species have been scientifically described, making it one of the largest vertebrate families, with on ...

fishes endemic to the

Río Pánuco Rio or Río is the Portuguese and Spanish word for "river". The word also exists in Italian, but is largely obsolete and used in a poetical or literary context to mean "stream". Rio, RIO or Río may also refer to: Places United States * Rio, Fl ...

Basin and the tributaries of the adjacent Tamiahua Lagoon (to the South) and San Andrés Lagoon (to the North) in the states of

Veracruz Veracruz, formally Veracruz de Ignacio de la Llave, officially the Free and Sovereign State of Veracruz de Ignacio de la Llave, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entit ...

Hidalgo Hidalgo may refer to: People * Hidalgo (nobility), members of the Spanish nobility * Hidalgo (surname) Places Mexico :''Most, if not all, named for Miguel Hidalgo y Costilla (1753–1811)'' * Hidalgo (state), in central Mexico * Hidalgo, Coah ...

San Luis Potosí San Luis Potosí, officially the Free and Sovereign State of San Luis Potosí, is one of the 32 states which compose the Federal Entities of Mexico. It is divided in 59 municipalities and is named after its capital city, San Luis Potosí. It ...

Tamaulipas Tamaulipas, officially the Free and Sovereign State of Tamaulipas, is a state in Mexico; one of the 31 states which, along with Mexico City, comprise the 32 federal entities of Mexico. It is divided into 43 municipalities. It is located in nor ...

and

Querétaro Querétaro, officially the Free and Sovereign State of Querétaro, is one of the Political divisions of Mexico, 32 federal entities of Mexico. It is divided into Municipalities of Querétaro, 18 municipalities. Its capital city is Querétaro Cit ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. The genus is characterized by a prolongation in the size of the symphysial pair of teeth relative to that of the other teeth in the outer row of the upper jaw (nosferatuform teeth); breeding pigmentation that consists of darkening of ventral area extending over nostrils, opercular series, and pectoral fins; depressed

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

rarely expands beyond anterior third of

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

; and an elongated, elastic, smooth

caecum The cecum ( caecum, ; plural ceca or caeca, ) is a pouch within the peritoneum that is considered to be the beginning of the large intestine. It is typically located on the right side of the body (the same side of the body as the appendix, ...

adhered to a saccular stomach. All species in ''Nosferatu'' had previously belonged to genus ''

Herichthys ''Herichthys'' is a genus of cichlid fishes native to North America, North and Central America. Most are Endemism, endemic to Mexico, but ''Texas cichlid, H. cyanoguttatus'' is also found in southern Texas (United States), and has been Introduced ...

''.

Species

There were 7 species proposed for this genus: * '' Nosferatu bartoni'' ( T. H. Bean, 1892) (Barton's cichlid) * '' Nosferatu labridens'' ( Pellegrin, 1903) (Curve-bar cichlid) * '' Nosferatu molango'' ( De la Maza-Benignos & Lozano-Vilano, 2013) (Aztec cichlid) * '' Nosferatu pame'' ( De la Maza-Benignos & Lozano-Vilano, 2013) * '' Nosferatu pantostictus'' ( J. N. Taylor & R. R. Miller, 1983) (Chairel cichlid) * '' Nosferatu pratinus'' ( De la Maza-Benignos & Lozano-Vilano, 2013) * '' Nosferatu steindachneri'' (

D. S. Jordan David Starr Jordan (January 19, 1851 – September 19, 1931) was the founding president of Stanford University, serving from 1891 to 1913. He was an ichthyologist during his research career. Prior to serving as president of Stanford Universi ...

& Snyder, 1899) (Steindachner's cichlid) These species are currently placed in genus ''

''.

Phylogenetics

Separate analysis of the mitochondrial gene ''

Cox1 Cytochrome c oxidase I (COX1) also known as mitochondrially encoded cytochrome c oxidase I (MT-CO1) is a protein that is encoded by the ''MT-CO1'' gene in eukaryotes. The gene is also called ''COX1'', ''CO1'', or ''COI''. Cytochrome c oxidase ...

'' by León-Romero ''et al.'' and by De la Maza-Benignos, ''et al.'' confirmed the monophyly of the genus group, and revealed the existence of three clades within: The

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

''bartoni''

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

, conformed by

sympatric In biology, two closely related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter each other. An initially interbreeding population that splits into two or more distinct spe ...

''N. labridens'' and ''N. bartoni''; the

(in their study León-Romero ''et al.'' did not consider ''N. pame'' nor included ''N. pratinus'' and consequently report

monophyly In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent comm ...

) ''steindachneri''

, conformed of the allopatric ''N. pratinus'', and sympatric ''N. pame'' and ''N. steindachneri''; and the

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

''pantostictus''

(in the study by León-Romero ''et al.'' some of the lineages of ''N. pantostictus'' are misidentified as ''N. labridens''; consequently they report

polyphyly A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as homoplasies, which ar ...

) composed of the nominal species ''N. pantostictus''. In comparison to ''Herichthys'', high levels of intrageneric

divergence In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the rate that the vector field alters the volume in an infinitesimal neighborhood of each point. (In 2D this "volume" refers to ...

and

structure A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...

within ''Nosferatu'' were revealed.

Evolution

Divergence time for the split between ''Herichthys'' and ''Nosferatu'' has been estimated in ~5 Mya. During these times (i.e.

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 ...

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58endorheic An endorheic basin ( ; also endoreic basin and endorreic basin) is a drainage basin that normally retains water and allows no outflow to other external bodies of water (e.g. rivers and oceans); instead, the water drainage flows into permanent ...

shallow lakes, where ''Nosferatu'' evolved into the ''bartoni'' (~3 Mya), ''steindacheri'' (~2 Mya) and ''pantostictus'' (~2 Mya) clades. Later on (~1.8 Mya), as regional faulting rejoined the Rio Verde with the Pánuco Basin during the course of the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

, the genus re-invaded the Pánuco, this time with the evolved mechanisms of reproductive isolation that allows its

sympatry In biology, two closely related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter each other. An initially interbreeding population that splits into two or more distinct spe ...

with ''

''.

Name

The name of this genus, ''Nosferatu'', was given because of the pair of well-developed recurved fangs in the upper jaw present possessed by all species of the genus; these were said to be reminiscent of those of

Count Orlok Count Orlok (; ; ) is a fictional character who first appeared in the silent film ''Nosferatu'' (1922) directed by F. W. Murnau. Based on Bram Stoker's Count Dracula, he is played by German actor Max Schreck, and is depicted as a repulsive va ...

F. W. Murnau Friedrich Wilhelm Murnau (born Friedrich Wilhelm Plumpe; December 28, 1888March 11, 1931) was a German film director, producer, and screenwriter. He is regarded as one of cinema's most influential filmmakers for his work in the silent era. An e ...

's ''

Nosferatu ''Nosferatu: A Symphony of Horror'' () is a 1922 silent film, silent German Expressionism (cinema), German Expressionist vampire film directed by F. W. Murnau from a screenplay by Henrik Galeen. It stars Max Schreck as Count Orlok, a vampire who ...

''.

References

{{Taxonbar, from=Q16797260 Heroini Cichlid genera Controversial fish taxa Obsolete vertebrate taxa Taxa named by Ignacio Doadrio Villarejo Taxa named by Mauricio De la Maza-Benignos Taxa named by María de Lourdes Lozano-Vilano

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...