Eyelash Pit Viper

''Bothriechis schlegelii'', known commonly as the highland eyelash-pitviper, Schlegel's eyelash-pitviper, or eyelash viper, is a species of pit viper in the family Viperidae, native to Colombia.

Somewhat small, arboreal snakes, ''B. schlegelii'' is perhaps best known for the namesake superciliary ("eyelash") scales above its eyes, and for having distinctly keeled or "raised" scales covering the bulk of its body. The species is also known for producing a veritable rainbow of color forms ( morphs). It is the most common of the green palm-pitvipers (genus ''Bothriechis''), and is often present in zoological exhibits, owing to its general hardiness. The specific name ''schlegelii'' honors Hermann Schlegel, who was a German ornithologist and herpetologist.

For other common names, see below. No subspecies are currently recognized as being valid.

Description

The eyelash viper is a relatively small species of pitviper, with adults ranging from long, and females being longer and more variable in size than males, which can grow to long. It has a wide, triangular-shaped head, and eyes with vertical pupils. Like all pit vipers, it is solenoglyphous, having large, hypodermic needle-like fangs in the front of the upper jaw that fold back when not in use, and has heat sensitive organs, or pits, located on either side of the head between the eye and nostril.

Its most distinguishing feature, and origin of its common name, is the set of modified scales above the eyes that look much like eyelashes. The eyelashes are thought to aid in camouflage, breaking up the snake's outline among the foliage where it hides. The eyelash viper occurs in a wide range of colors. No external features distinguish the two sexes.

Common names

Common names of ''B. schlegelii'' include the eyelash viper, eyelash pit viper, eyelash palm viper, eyelash palm-pitviper, Schlegel's viper, Schlegel's pit viper, Parker HW, Grandison AGC (1977). ''Snakes -- A Natural History''. Second Edition. British Museum (Natural History) and Cornell University Press. 108 pp. 16 plates. LCCCN 76-54625. (cloth), (paper), Schlegel's palm viper,Brown, John Haynes (1973). ''Toxicology and Pharmacology of Venoms from Poisonous Snakes''. Springfield, Illinois: Charles C. Thomas. 184 pp. LCCCN 73-229. . eyelash snake, eyelash lancehead, eyelash mountain viper, and horned palm viper. In Spanish, the primary language of countries comprising its distribution, common names include ''bocaracá'', ''oropel'' (golden morph), ''víbora bocaracá'', ''toboba pestañas'', ''víbora de pestañas'' (eyelash viper), and ''serpiente loro'' (parrot snake).

Geographic range

Previously thought to range from southern Mexico to northwestern South America, a systematic revision of the species in 2024 caused many of the populations in its purported range to become their own separate species. Although these species are very closely related, this restricts the range of ''B. schlegelii'' ''sensu stricto'' to Colombia, in primarily highland regions.

Behavior

Like other ''Bothriechis'' species, ''B. schlegelii'' is adapted to a nearly completely arboreal lifestyle, possessing a strong, prehensile tail with which it secures itself around tree limbs, often coiled into a tight bundle during the day, as the species is primarily nocturnal. After dark, the eyelash viper awakens and awaits the presence of small, tree-dwelling animals that may cross its path, including mammals (rodents, bats), amphibians (tree frogs), birds or lizards ( anoles, geckos, juvenile iguanas).

In typical ambush-predator fashion, ''B. schlegelii'' waits patiently for potential, unsuspecting prey to wander by. In some cases, individuals have been known to select specific ambush sites, returning each year in-time for the spring bird migration. Studies have indicated that individuals of ''B. schlegeli'' perfect their own strike accuracy with practice, over time.
/sup> Sometimes, ''B. schlegelii'' (especially juveniles) will employ what is known as " Caudal (anatomical term), caudal luring", wriggling their tail in a "worm"-like fashion to entice potential prey, such as hungry frogs or lizards, to move within striking-range.

The eyelash viper is not known to be an aggressive snake towards humans, and is likely to be avoidant of creatures larger than itself, but will not hesitate to strike if repeatedly harassed. Certain local mythologies and folktales (notably in remote areas of northern South America) describe how after one is bitten by an eyelash viper, the snake will "wink" its "eyelashes" at the victim. In reality, no snake is physiologically capable of such behaviors as they possess no true eyelids and cannot close their eyes; however, most reptiles possess a thin, membranous "eyelid" as a retractable "shield" for their eyes, mainly when resting.

Venom

Composition

The most important components of ''B. schlegeli'' venom are phospholipase A2 related to the production of edema, tissue damage and myotoxicity, metalloproteases with dermonecrosis, L-amino acid oxidases with tissue damage, serine proteases with tissue damage and hemorrhagic diathesis, lectin type C with tissue damage and hemorrhagic diathesis, disintegrins with detachment of cells from their extracellular matrix leading to blisters and platelet function impairment, bradykinin-potentiating peptides with hypotension, enzymes that degrade fibrinogen, plasminogen activators, prothrombin activators, factor V activators, factor X activators, and anticoagulant activities (including inhibitors of prothrombinase complex formation, inhibitors of thrombin, phospholipases, and protein C activators).

Clinical Management

Snakebites inflicted by ''B. schlegelii'' in humans are characterized by pain, edema, and ecchymosis at the site of the bite, rarely with blisters, local necrosis, or defibrination. Some investigations using venom samples of ''B. schlegelii'' from the northern region of Colombia have reported a typical bothropic envenomation characterized by pain, rapid local tissue damage, edema and inflammatory reactions at the site of the bite, followed by systemic alterations such as coagulopathy and acute renal failure.

Reproduction

The eyelash viper reaches sexual maturity at around two years of age, and the ovoviviparous species reproduces throughout the year in warm environments. Females carry eggs for around six months before they hatch internally, where the young complete their development. Pregnant females have enlarged lower abdomens, and may stop eating in later stages of pregnancy. In a typical brood they give birth to 2–20 live young, which are in length and appear physically similar to adults.

Males engage in a sometimes hours-long courtship ritual called a "dance of the adders", in which two males posture and intimidate one another in an upright, "cobra-like" stance until one is pushed away or falls to the ground. They are polygynous, and usually mate at night.

Captivity

Despite its venom, ''B. schlegelii'' is frequently available in the exotic animal trade, and is well represented in zoos worldwide. It is frequently captive bred for color and pattern. Exporting from the wild is not as common as it once was, but is not unknown. In general they make hardy captives, readily feeding on provided mice.

Taxonomy

Some authorities also recognize a montane form that is treated either as a subspecies (''B. s. supraciliaris'') or as a species ('' B. supraciliaris''). Found in the province of San José in Costa Rica, it was sometimes referred to as the ''eyelash mountain viper'', while more recent publications recognizing the species designation refer to it as the blotched palm-pitviper.Although considered to likely contain multiple species for some time, the great variety of colour patterns in the species has previously made this difficult to verify.

In 2024, a systematic revision of ''B. schlegelii'' through DNA-sequencing finally split it into an additional number of species: '' B. klebbai'', '' B. rasikusumorum'', '' B. khwargi'', '' B. rahimi'', and '' B. hussaini''. At the same time names that were previously synonyms were revalidated: '' B. nigroadspersus'' (Steindachner, 1870), '' B. nitidus'' (Günther, 1859), and '' B. torvus'' (Posada Arango, 1889a). Due to the close relation between these species alongside '' B. supraciliaris'', they are considered to be part of a ''B. schlegelii'' species complex, otherwise referred to as the "eyelash clade" within ''Bothriechis''. These "eyelash vipers" form a monophyletic clade that is sister to the rest of the genus.

Conservation

Eyelash vipers have not been evaluated by the IUCN Red List, and were removed from CITES Appendix III in 2002. While not listed as threatened, they could be at risk of habitat loss from increased deforestation for timber, agriculture, and urbanization.

Gallery

File:Los ofidios venenosos del Cauca (6260742560).jpg, Illustration
File:Eyelash Viper (Bothriechis schlegelii) female threat display (captive specimen) (14813138374).jpg, Eyelash Viper (''Bothriechis schlegelii'') female threat display (captive specimen)
File:Bothriechis schlegelii 28759363.jpg
File:Bothriechis schlegelii 80081508.jpg
File:Bothriechis schlegelii 98839418.jpg

References

Further reading

* Berthold AA (1846). "''Über verschiedene neue oder seltene Reptilien aus Neu-Grenada und Crustaceen aus China'' ". ''Abhandlungen der Königlichen Gesellschaft der Wissenschaften zu Göttingen'' 3: 3-32 + Plates I-III. (''Trigonocephalus schlegelii'', new species, p. 13 + Plate I, figures 5-6). (in German and Latin).
* Boulenger GA (1896). ''Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the ... Viperidæ.'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiv + 727 pp. + Plates I-XXV. (''Lachesis schlegelii'', pp. 567–568).

External links

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Eyelash viper
a
WhoZoo

Eyelash pit viper

{{Taxonbar, from=Q905234

schlegelii
Reptiles described in 1846
Reptiles of Mexico
Reptiles of Costa Rica
Reptiles of Honduras
Reptiles of Guatemala
Reptiles of Peru
Reptiles of Colombia
Taxa named by Arnold Adolph Berthold