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Liophis miliaris is a species of snake originally described by Carl Linnaeus in 1758, one of more than fifty species of the genus Liophis[1]. The genus name was indicated to mean "common snake". In 1964 Gans gave it the name "common water snake".[1] Liophis miliaris are currently distributed in countries of Brazil, Paraguay, Uruguay, and northeastern Argentina.[2] Liophis miliaris is a very polymorphic colubrid snake with a wide range of distribution in South America. There are approximately six different subspecies of Liophis miliaris.
Physical characteristics[]
Liophis miliaris is stout bodied (muscular) and relatively short tailed. Tail length/total length ratios vary from 15.0%-19.8% with an average of 18.6.[3]
Feeding[]
Liophis miliaris feeds on a wide range of prey items. They include amphibians (also, eggs and tadpoles), invertebrates, lizards, fish, birds, and small rodents. However, there is little information on its feeding habits. [4] A study indicated that females with oviductal eggs did not feed, whereas those Liophis miliaris snakes with secondary vitellogenic follicles fed more often than did the non-reproductive females.Template:Citation needed
Sexual maturity[]
Sexual maturity is regarded by experts as difficult to determine, however, can be assed by the snout-vent length (SVL). Size at sexual maturity is positively correlated to the mean body sizes. In order to determine the sexual maturity of a Liophis, scientists have determined the diameter of ovarian follicles if seen to be >10 as indicative of sexual maturity in females. Also, if they had oviductal eggs. Males were considered mature if the testes were large and turgid or if the deferent ducts were opaque and convoluted, indicating the presence of sperm. Females in the subspecies population of Liophis miliaris meremmii and Liophis miliaris orines were seen to be greater in body size than the males.[3]
Sexual dimorphism[]
Sexual dimorphism with respect to size of adult Liophis. Adult females are larger in the subspecies meremii and orines. They were seen to be larger than the adult males. The sexual dimorphism index was seen to be similar in the geographic areas of the Northern coastal Atlantic forest, Southern coastal Atlantic forest, Northern inland Atlantic forest and southern inland Atlantic forest. This was indicative of no geographic variation in sexual size dimorphism. It is believed that body size may differ either because of local genetic modification or direct phenotypic effect of food availability on the growth rates. In addition to body sizes, the comparison of head size in Liophis miliaris is seen to show no dimorphism. Head size is considered to be associated with inter-sexual dietary divergence.[3]
Reproductive output[]
With respect to reproductive output in the Northern, Southern coast Atlantic forest, and the Northern and Southern inland forest, the reproductive output recorded for Liophis miliaris orines and Liophis miliaris meremii were determined via number of eggs, size of eggs and neonates. The mean egg volume in the Southern coast Atlantic forest was seen to be the largest of the four regions. The reproductive frequency was low in Northern coast Atlantic forest than the other regions.[3]
Parasitism[]
Parasitism is not understood very well in the context of snake ecology. The only inferences that have been made are those with the influence on natural populations. It is thought to be related to the snakes feeding behavior and immunological resistance.Two parasites were discovered in the subspecies orines and merimii. The first was adults of Ophidiascaris sp. (Nemaotoda)in the stomach. Also Cystacaths of Oligatanthorynchus spira (Acanthocephala) in the peritoneum. The prevalence sought in the four different regions N. and S. coastal Atlantic forest and N. and S. of the inland Atlantic forest were observed in Pizatto's and Marques study. The lowest prevalence was seen in the N. coastal Atlantic forest. The Level of parasite infestation did not differ within the males and females. Female reproductive status was unaffected by the level of infection, nor did the number of eggs she carried. Male reproductive system was unaffected by the level of infestation as well.[3]
Liophis milaris intermedius and the wrong taxonomy[]
In 1991, Liophis miliaris intermedius was classified by Henle and Ehrl. However, they made a mistake. It was later discovered by Dixon and Tipton through various comparisons of body composition, that Liophis miliaris intermedius was actually Liophis reginae.[3]
Location[]
Liophis miliaris is seen in the Atlantic forest of Southern America, visible in rainforest in eastern Brazil and semi-decidious forests in southeastern Brazil.[1]
References[]
- ↑ 1.0 1.1 1.2 Esquedo, Luis F., Marco Natera -Mumaw, and Enrique La Marca. "First Record of Salamander Predation by a Liophis (Wagler, 1830) Snake in Venezuelan Andes." Journal of Herpetology 37.1 (2003): 191.
- ↑ Marques, Otavio A.V, Andes Eterovic, and Whaldener Endo. "Seasonal Activity of Snakes in the Atlantic Forest in Southeastern Brazil." Amphibia-Reptilia 22.1 (2001): 103-11.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Dixon, James R. "Liophis Miliaris Intermedius (Henle and Ehrl, 1991) Is Actually Liophis Reginae (serpentes: Colubridae)." Journal of Herpetology 37.1 (1993): 191.
- ↑ Pizzatto, Ligia, and Otavio A.V Marques. "Interpopulation Variation in Sexual Dimorphism, Reproductive Output, and Parasitism of Liophis Milaris (colubridae) in the Atlantic Forest of Brazil." Amphibia-Reptilia 27 (2006): 37-46.