Eunectes is a genus of non-venomous boas found in tropical South America, commonly called anacondas. An aquatic group of snakes inhabiting swamps and rivers, its members include some of the largest snakes in the world. Despite this, little was known about them until recently. The name Eunectes is derived from the Greek word Eυνήκτης, which means "good swimmer." Three species are currently recognized.[2]
Description
There are some debates about the maximum size of these snakes. Mehrtens (1987) states that the average adult length for the green anaconda, E. murinus, is 18 to 20 feet (5.5–6.1 m), with 25 feet (7.6 m) specimens being very rare. He sets a more conservative maximum at 23 feet (7.0 m). Estimates of 35 to 40 feet (11–12 m) (see Giant anaconda) are based on vague data and should be regarded with caution.[3] In a study of 1,000 specimens captured in Venezuela, the largest was 17 feet (5.2 m) long and weighed 100 pounds (45 kg).[4]
The Wildlife Conservation Society has, since the early 20th century, offered a large cash reward (currently worth US$50,000) for live delivery of any snake of 30 feet (9.1 m) or more in length. This prize has never been claimed.[5] In any case, measuring a snake that is stronger than a person is not an easy task. It was found that two scientists independently measuring the same 12-foot (3.7 m) plus snake showed a variation of more than 20% in their results.[6]
Common names
Local names in South America include the Spanish term "matatoro," meaning "bull killer," and the Native American terms sucuri and "yakumama."
A possible origin for the common is perhaps an alteration of the Sinhalese word henakandaya, meaning 'whip snake' or anaconda is the Tamil anaikondran, meaning "elephant killer", or anaikkonda, meaning "having killed an elephant". A name first used in English to name a Ceylonese python, it erroneously was applied to a large South American boa, called in Brazil "sucuri". The word is of uncertain origin, and no snake name like it now is found in Sinhalese or Tamil. Another suggestion is that it represents Tamil. It is unclear how this name originated so far from the snake's native habitat; possibly this is due to its vague similarity to the large Asian pythons.
Feeding Habits
The Yellow Anaconda (Eunectes Notaeus) were studied in regularly flooded areas in the Pantanal region of southwestern Brazil. The data directly observed from predatory instances, analysis and examination of gut and waste contents, and affirmations of local residents and other researchers indicate the snake to be not only carnivorous but also a generalist (one who has well understanding and proficiency that can be applied to a field). The prey list analyzed and other evidences support that the E. notaeus employs both "ambush predation" and "wide-foraging" strategies, meaning that it will eat the dead and alive. Yellow Anacondas claim to forage predominately in open, flooded habitats, in relatively shallow water; most predation instances occur from June to November, when flooded areas noticeably dry out. Wading birds, at the proper times, are the most common prey selection for this hungry reptile. Yellow Anacondas also tend to prey on fish, turtles, small-sized caimans, lizards, bird eggs, small mammals and fish carrion. This extremely large prey to predator weight ratio indicates its prey has a much lower weight than those known for other types of boids (the family of non-venomous, constriction snakes).[7]
Species
| Species[2] |
Taxon author[2] |
Subsp.*[2] |
Common name |
Geographic range[1] |
| E. deschauenseei |
Dunn & Conant, 1936 |
0 |
Dark-spotted anaconda |
South America in northeastern Brazil and coastal French Guiana. |
| E. murinusT |
(Linnaeus, 1758) |
1 |
Green anaconda |
South America in countries east of the Andes, including Colombia, Venezuela, the Guianas, Ecuador, Peru, Bolivia, Brazil and on the island of Trinidad. |
| E. notaeus |
Cope, 1862 |
0 |
Yellow anaconda |
South America in eastern Bolivia, southern Brazil, Paraguay and northeastern Argentina. In Argentina it is found in the provinces of Corrientes, Chaco, Entre Rios, Formosa, Misiones and Santa Fe. |
*) Not including the nominate subspecies.
T) Type species.[1]
Species Mean SVL ± SD (mm) Scalation Microhabitat
Boids
Candoia carinata - 642.6 ± 225.7 (357 – 1324, n = 143) - Ventrals: 160–200 Subcaudals: 38–56 - Terrestrial (0)
Video Links
<http://www.metacafe.com/watch/233285/when_anacondas_attack/>
<http://au.truveo.com/tag/anaconda>
<http://www.leechvideo.com/tag/anaconda/>
References
- ^ a b c McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).
- ^ a b c d Eunectes (TSN 209577). Integrated Taxonomic Information System. Retrieved on 18 July 2008.
- ^ Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X.
- ^ The Search for the $50,000 Snake at MSN Encarta. Accessed 18 July 2008.
- ^ Splendor in the Mud: Unraveling the Lives of Anacondas by Carol Kaesuk Yoon, April 2, 1996, at New York Times. Accessed 18 July 2008.
- ^ Rivas JA, Ascanio RE, Muñoz MDC. 2008. What is the length of a snake? Comtemporary Herpetology, Vol. 2008(2):1-3. PDF at Comtemporary Herpetology. Accessed 18 July 2008.
- ^ Strussmann, C (1997-06). "Feeding habits of the yellow anaconda, Eunectes notaeus Cope, 1862, in the Brazilian Pantanal". Biociencias 5 (1): 35-52.. Retrieved on 2008-10-06.
External links
|
