Liophis miliaris is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of snake

Snake

Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

 originally described by Carl Linnaeus in 1758, one of more than fifty species of the genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Liophis. The genus name was indicated to mean "common snake". In 1964 Gans gave it the name "common water snake". Liophis miliaris is endemic to Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, Paraguay

Paraguay

Paraguay , officially the Republic of Paraguay , is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Paraguay lies on both banks of the Paraguay River, which runs through the center of the...

, Uruguay

Uruguay

Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...

, and northeastern Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. Liophis miliaris is a very polymorphic colubrid

Colubrid

A colubrid is a member of the snake family Colubridae. This broad classification of snakes includes about two-thirds of all snake species on earth. The earliest species of the snake family date back to the Oligocene epoch. With 304 genera and 1,938 species, Colubridae is the largest snake family...

 snake with a wide range of distribution in South America. There are approximately six different subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 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.

Feeding

Liophis miliaris feeds on a wide range of prey items. They include amphibian

Amphibian

Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...

s (also, eggs and tadpoles), invertebrates, lizard

Lizard

Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...

s, fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s, and small rodent

Rodent

Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

s. However, there is little information on its feeding habits.
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.

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.

Sexual dimorphism

Sexual dimorphism

Sexual dimorphism

Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...

 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.

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.

Parasitism

Parasitism

Parasitism

Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...

 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.

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.

Location

Liophis miliaris is seen in the Atlantic forest of Southern America, visible in rainforest in eastern Brazil and semi-deciduous forests in southeastern Brazil.