The military ground snake (''Erythrolamprus miliaris'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

snake Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Colubridae Colubridae (, commonly known as colubrids , from la, coluber, 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest species of the family date back to the Oligocene epoch. Colubrid snakes are found on ever ...

. The species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

Common names

South American common names for ''E. miliaris'' include ''cobra-d'água'' (water snake) and ''cobra-lisa'' (smooth snake) in

Portuguese Portuguese may refer to: * anything of, from, or related to the country and nation of Portugal ** Portuguese cuisine, traditional foods ** Portuguese language, a Romance language *** Portuguese dialects, variants of the Portuguese language ** Portu ...

, and simply ''culebra'' (snake) in

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Cana ...

Taxonomy

''E. miliaris'' was originally described as ''Coluber miliaris'' by

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

in 1758.

Subspecies

Five

subspecies In biological classification, 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. Not all species ...

are recognized, including the

nominotypical subspecies In biological classification, 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. Not all species ...

. *''Erythrolamprus miliaris amazonicus'' ( Dunn, 1922) *''Erythrolamprus miliaris chrysostomus'' (

Cope The cope (known in Latin as ''pluviale'' 'rain coat' or ''cappa'' 'cape') is a liturgical vestment, more precisely a long mantle or cloak, open in front and fastened at the breast with a band or clasp. It may be of any liturgical colours, litu ...

, 1868) *''Erythrolamprus miliaris merremi'' ( Wied, 1821) *''Erythrolamprus miliaris miliaris'' (

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

1758 Events January–March * January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of Systema Naturae, 10th edition of ''Systema Naturae'', the sta ...

) *''Erythrolamprus miliaris orinus'' (

Griffin The griffin, griffon, or gryphon (Ancient Greek: , ''gryps''; Classical Latin: ''grȳps'' or ''grȳpus''; Late Latin, Late and Medieval Latin: ''gryphes'', ''grypho'' etc.; Old French: ''griffon'') is a legendary creature with the body, tail ...

, 1916) The

subspecific name In zoological nomenclature, a subspecific name is the third part of a trinomen. In zoology there is only one rank below that of species, namely "subspecies". In botanical nomenclature, there are several levels of subspecific names, such as ''vari ...

, ''merremi'' is in honor of

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...

herpetologist Herpetology (from Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is the branch of zoology concerned with the study of amphibians (including frogs, toads, salamanders, newts, and caecilians (gymnophiona)) and rept ...

Blasius Merrem Blasius Merrem (4 February 1761 – 23 February 1824) was a German naturalist, zoologist, ornithologist, mathematician, and herpetologist. In 1804, he became the professor of political economy and botany at the University of Marburg. Early li ...

.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 312 pp. . (''Liophis miliaris merremi'', p. 176).

''Liophis milaris intermedius'', a taxonomic error

In 1991, ''Erythrolamprus miliaris intermedius'' was described by Henle and Ehrl. However, they made a mistake. It was later discovered by Dixon and Tipton, through various comparisons of morphometrics, that ''Erythrolamprus miliaris intermedius'' was actually ''

Erythrolamprus reginae The royal ground snake (''Erythrolamprus reginae'') is a species of snake in the family Colubridae. The species is endemic to northern South America. Geographic range It is found in Venezuela, Peru, and Trinidad and Tobago. Diet It feeds on fr ...

''.

Geographic range

''E. miliaris'' is found in South America east of the Andes, from the

Guyanas The Guianas, sometimes called by the Spanish loan-word ''Guayanas'' (''Las Guayanas''), is a region in north-eastern South America which includes the following three territories: * French Guiana, an overseas department and region of France * G ...

south to Paraguay. The former subspecies extending further south (southeastern Brazil, Paraguay, Uruguay and northeastern Argentina) is now recognized as a full species, ''

Erythrolamprus semiaureus ''Erythrolamprus semiaureus'' is a species of snake in the family Colubridae. The species is found in Paraguay, Argentina, Brazil, and Uruguay Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), ...

''.

Physical characteristics

''E. 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%. Adults may attain a total length (including tail) of about 50 cm (about 20 in). 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. (''Rhadinæa merremii'', pp. 168-169).

Dorsally Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

, it is pale olive-brown or yellowish, with each smooth

dorsal scale In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

edged with black. Ventrally, it is uniformly yellow.

Feeding

''E. miliaris'' feeds on a wide range of

prey Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

items. They include primarily

amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...

s (including eggs and

tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found i ...

s), but also

fish Fish are aquatic, craniate, gill-bearing 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. Approximately 95% of li ...

and even

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

s and small

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

s. Invertebrates have also been reported but may have been secondarily ingested. However, there is little information on its feeding habits. A study indicated that females with oviductal eggs did not feed, whereas those females with secondary vitellogenic follicles fed more often than did the non-reproductive ones.

Sexual dimorphism

There is

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

with respect to size of adult ''Erythrolamprus miliaris''. Adult females are larger in the subspecies ''merremi'' and ''orinus''. 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 size, the comparison of head size in ''E. 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 and southern coast Atlantic forest, and the northern and southern inland forest, the reproductive output recorded for ''Erythrolamprus miliaris orinus'' and ''Erythrolamprus miliaris merremi'' were determined via number of eggs, size of eggs, and number of 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 lower in the northern coast Atlantic forest than the other regions.

Parasitism

Parasitism Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...

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 ''orinus'' and ''merremi''. The first were adults of the nematod ''Ophidiascaris'' sp. in the stomach. Also cystacaths of the

acanthocephala Acanthocephala (Greek , ', thorn + , ', head) is a phylum of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to p ...

n ''Oligatanthorynchus spira'' were in the peritoneum. The prevalence found in the four different regions, northern and southern coastal Atlantic forest and northern and southern inland Atlantic forest, were observed in Pizatto's and Marques' study. The lowest prevalence was seen in the northern coastal Atlantic forest. The level of parasite

infestation Infestation is the state of being invaded or overrun by pests or parasites. It can also refer to the actual organisms living on or within a host. Terminology In general, the term "infestation" refers to parasitic diseases caused by animals su ...

did not differ between the males and females. Female reproductive status was unaffected by the level of infection, nor was the number of eggs she carried. The male reproductive system was unaffected by the level of infestation as well.

Habitat

''Erythrolamprus miliaris'' inhabits aquatic and riparian habitats. It occurs in both lowland tropical rainforest and

Atlantic forest The Atlantic Forest ( pt, Mata Atlântica) is a South American forest that extends along the Atlantic coast of Brazil from Rio Grande do Norte state in the northeast to Rio Grande do Sul state in the south and inland as far as Paraguay and th ...

at elevations below .