The trinket snake (''Coelognathus helena''), also known commonly as the common trinket snake, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of nonvenomous constricting

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Colubridae Colubridae (, commonly known as colubrids , from , 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. C ...

. The species is native to southern

Central Asia Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...

Etymology

The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

of this snake, ''helena'', is thought to be a reference to

Helen of Troy Helen (), also known as Helen of Troy, or Helen of Sparta, and in Latin as Helena, was a figure in Greek mythology said to have been the most beautiful woman in the world. She was believed to have been the daughter of Zeus and Leda (mythology), ...

, considered by many to be the epitome of female beauty and the most beautiful woman in the world. Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . (''Elaphe helena'', p. 120).

Geographic range

''C. helena'' is found in

Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, ...

, southern

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

( Shangla),

Nepal Nepal, officially the Federal Democratic Republic of Nepal, is a landlocked country in South Asia. It is mainly situated in the Himalayas, but also includes parts of the Indo-Gangetic Plain. It borders the Tibet Autonomous Region of China Ch ...

, and

Bangladesh Bangladesh, officially the People's Republic of Bangladesh, is a country in South Asia. It is the List of countries and dependencies by population, eighth-most populous country in the world and among the List of countries and dependencies by ...

. Its type locality is "India: Vishakhapatnam" (Daudin, 1803).

Description

:''See

snake scales Snakes, like other reptiles, have skin covered in scales.Boulenger, George A. 1890 The Fauna of British India. p. 1 Snakes are entirely covered with scales or scutes of various shapes and sizes, known as snakeskin as a whole. A scale protects ...

'' for terms used.'' ''C. helena'' has the following scalation. The rostral is a little broader than deep, and visible from above. The suture between the internasals is much shorter than that between the prefrontals. The frontal is as long as its distance from the end of the snout, but shorter than the parietals. The loreal is somewhat longer than deep. One large preocular and two postoculars are present. The temporals are arranged 2+2 or 2+3. There are 9 (exceptionally 10 or 11) upper labials, and the fifth and sixth (or fourth, fifth, and sixth) enter the eye. There are 5 or 6 lower labials in contact with the anterior chin shields. The anterior chin shields are as long as or a little longer than the posterior chin shields. The dorsal scales are in 23 to 27 rows at midbody, smooth, or feebly keeled on the posterior part of the body and on the tail. The ventrals number 220-265; the anal plate is entire; and the subcaudals number 75-94. The young are pale brown above, with black crossbands, each crossband enclosing four to six white ocelli. The adults are darker brown, with a transverse series of squarish black spots, or with more or less distinct traces of the color pattern of the young. There is a vertical black streak below the eye, and an oblique black streak behind the eye. Some specimens have a white, black-edged collar; others have two black longitudinal streaks on the head; and others are intermediate in this respect. The lower parts are yellowish, with or without a few small black spots, sometimes with a more or less distinct festooned marking on each side. Boulenger GA (1890). ''The Fauna of British India, Including Ceylon and Burma. Reptilia and Batrachia''. London: Secretary of State for India in Council. (Taylor and Francis, printers). xviii + 541 pp. (''Coluber helena'', pp. 331-332). Adults may attain a total length of , which includes a tail long.

Subspecies

Three

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of ''C. helena'' are recognized as being valid, including the

nominotypical subspecies In biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. ...

. *''C. h. helena'' *'' C. h. monticollaris'' *''C. h. nigriangularis'' ''

Nota bene ( ; plural: ) is the Latin language, Latin phrase meaning ''note well''. In manuscripts, ''nota bene'' is abbreviated in upper-case as NB and N.B., and in lower-case as n.b. and nb; the editorial usages of ''nota bene'' and ''notate bene'' fi ...

'': A trinomial authority in parentheses indicates that the subspecies was originally described in a

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 ...

other than ''Coelognathus''.

Habitat

The preferred natural

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

of ''C. helena'' is

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

, at altitudes from sea level to , but it also found around houses.

Diet

The trinket snake preys upon

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

s (mice, rats, squirrels), small snakes,

gecko Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates. They range from . Geckos are unique among lizards ...

s, and

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

Behaviour

''C. helena'' is both diurnal and

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

. It is noted for its temper and will strike repeatedly if molested. The males of this species are generally more aggressive than the females. Its bites are often very damaging due to its inward pointing teeth.

Reproduction

''C. helena'' is

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

. Eggs are laid throughout the year, and

clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

size is 6–12 elongated eggs.

Gallery

Image:AB099_Elaphe_helena.JPG, Sideview of trinket snake head Image:AB100_Elaphe_helena.JPG, Pattern on anterior half of body Image:AB101_Elaphe_helena.JPG, Pattern on posterior half of body AB097 Elaphe helena

References

* Boulenger GA (1894). ''Catalogue of the Snakes in the British Museum (Natural History). Volume II., Containing the Conclusion of the Colubridæ Aglyphæ.'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xi + 382 pp. + Plates I-XX. (''Coluber helena'', pp. 36–37). * Das I (2002). ''A Photographic Guide to Snakes and other Reptiles of India''. Sanibel Island, Florida: Ralph Curtis Books. 144 pp. . (''Coelognathus helena'', p. 32). * Daudin FM (1803). ''Histoire Naturelle Générale et Particulière des Reptiles ... Tome sixième'' olume 6 Paris: F. Dufart. 447 pp. + Plates LXXI-LXXX. (''Coluber helena'', new species, pp. 277-280 + Plate LXXVII, figure 1). (in French and Latin). * Helfenberger N (2001). "Phylogenetic relationship of Old World Ratsnakes based on visceral organ topography, osteology, and allozyme variation". ''Russian Journal of Herpetology'' 8: 1–62. * Kornacker P (1986). "''Die indische Schmucknatter'' ". ''Herpetofauna'' 8 (44): 10. (in German). *Kornacker P (1988). "''Bemerkungen zur Biologie, Haltung Zucht von'' Elaphe helena ''(Daudin 1802)''". ''Herpetofauna'' 10 (57): 27-33. (in German). *Mehta RS (2003). "Prey-handling behavior of hatchling ''Elaphe helena'' (Colubridae)". ''Herpetologica'' 59 (4): 469-474. *Niehaus, Guido; Schulz, Klaus-Dieter (1987). "''Die hinterasiatischen Kletternattern der Gattung'' Elaphe. ''Teil XI'' Elaphe helena ''(Daudin, 1803)''". ''Sauria'' 9 (4): 3-7. (in German). *Schulz K-D (1996). ''Eine Monographie der Schlangengattung'' Elaphe ''Fitzinger.'' Berg (CH): Bushmaster. 460 pp. (in German). *Schulz K-D (1996). ''A monograph of the colubrid snakes of the genus'' Elaphe ''Fitzinger''. Koeltz Scientific Books. 439 pp. * Sharma RC (2003). ''Handbook: Indian Snakes''. Kolkata: Zoological Survey of India. 292 pp. . * Smith MA (1943). ''The Fauna of British India, Ceylon and Burma, Including the Whole of the Indo-Chinese Sub-region. Reptilia and Amphibia. Vol. III.—Serpentes''. London: Secretary of State for India. (Taylor and Francis, printers). xii + 583 pp. (''Elaphe helena'', pp. 149–150). * Utiger U, Helfenberger N, Schätti B, Schmidt C, Ruf M, Ziswiler V (2002). "Molecular systematics and phylogeny of Old World and New World ratsnakes, ''Elaphe'' Auct., and related genera (Reptilia, Squamata, Colubridae)". ''Russ. J. Herpetol.'' 9 (2): 105-124. * Wall F (1921). ''Ophidia Taprobanica or the Snakes of Ceylon''. Colombo, Ceylon ri Lanka Colombo Museum. (H.R. Cottle, Government Printer). xxii + 581 pp. (''Coluber helena'', pp. 197–203, Figure 42). * Whitaker R,

Captain A Captain is a title, an appellative for the commanding officer of a military unit; the supreme leader or highest rank officer of a navy ship, merchant ship, aeroplane, spacecraft, or other vessel; or the commander of a port, fire or police depa ...

(2008). ''Snakes of India: The Field Guide''. Chennai: Draco Books. 495 pp. . {{Taxonbar, from=Q280938 Coelognathus Reptiles of South Asia Reptiles of Pakistan Reptiles described in 1803 Taxa named by François Marie Daudin Helen of Troy