Thursday, April 5, 2007

Classification of Snakes

Snakes of the world – Part 6.

E.G. Boulenger Image courtsey:

Classification of Snakes

We all know that the snakes are reptiles, but scientists are not satisfied with knowing just that much, as in every plant or animals they have a tendency to go deep in its peculiarities and group them with similar beings and differentiate them based on features that differ from others. The herpetologists as the scientists dealing with snakes are called had toiled a lot (many of them sacrificed their life in this attempt) to bring out the secret life of the snakes in the remote corners of the world.

Green snake image courtsey:

E.G. Boulenger, Malcolm. A. Smith, F. Wall, A. F. Abercromby, Romulus Whittaker, R. H. Beddome, D’ Abreu etc are the names some of great men who dedicated their entire life for the research on snakes. Malcolm Smith’s “The Fauna of British India” and E. G. Boulenger’s “Natural History of World Animals” along with some Malayalam books are the main sources referred for this article.

Nomenclature, the art of naming.

Whether it is snake or any other living things they are known in a name familiar to the local folks, these names vary from area to area thereby a single animal may be having thousands of names! This makes communication between people of different areas impossible; hence scientific names are introduced to enable synergy in research. When the name of a snake is said (Ptyas mucosus the common rat-snake for example) the first word “Ptyas” denotes its Genera and the second “mucosus” means its species name (such naming is called the binomial nomenclature meaning name with two parts), the first comes the genera (first letter capital) second the species.

Living things are divided in to two “kingdoms”.

1. Plantae(Plants)

2. Animalia(Animals)

Animals are grouped of two types (Phyla) based on the presence of back-bone (Notochord)

  1. Chordata.(Gk Chorda = string; ata = bearing) (With a central nerve cord enclosed within cartilaginous structure).
  2. Non-chordata. (without notochord)

Chordata is of four types (Sub-phyla)

  1. Vertebrata (those with well developed vertebral column).
  2. Hemi chordata.
  3. Cephalo chordata
  4. Uro chordata.

These Vertebrates are further divided in to six types (Classes) of which snakes belong to the group (Class) Reptilia.

Class Reptilia is further divided in to 5 types (Orders) of which snakes belong to the order Ophidia (Squamata) all animals by name “snakes” come in this order like Typhlops, Kraits, Python, Viper, Rat-snake, Piscator, Sea-snakes etc.

With Ophidia (Squamata) classification not ends it goes further down-wards. Snakes come in the Sub-order serpents, this sub-order in its turn contain many families (There are about 15 families of snakes in the world of which 11 with several sub families of snakes have been found in the Indian Sub-Continent.

There are about 2500 species of snakes grouped under 389 genera in the Indian Sub- continent; they all are grouped under 11 families. The family Colubridae (known as the typical snakes) has 5 Sub-families with 235 species (most of them harmless like the grass-snake, garter snakes).

A “species” is a biological entity, meaning a male of one species can mate with a female of the same species and give birth to a new life. This is impossible between members of different species. A Genus (plural is genera) is a collection of similar species. Thus several genera a family and many Families a Sub-order and Sub-Orders an Order.

Some important families of snakes.

Typhlopidae. Typhlops consists of two Genera and 21 species (Indian sub-continent). They are tiny worm-like burrowing snakes which are non-poisonous more than 19 species available.

Uropeltidae. Burrowing snakes found in Indian sub-continent, very short in length (less than one foot) all species are viviparous producing 5 to 10 young ones. Feed upon worms and insect larvae. Seven genera with 41 species.

Colubridae (Latin word coluber meaning snake)

Sub-Family Colubrinae is the largest with majority of the family’s members. (Please note that the family name ends with “dae” and a sub-family name ends with “nae”). This system enables the readers to recognize whether the name belongs to family or sub-family.

Classification colubridae based mainly on dentition and other features.

There are 3 sections

They are 1 Aglypha with solid ungrooved teeth, 2 Opisthoglypha with teeth are grooved and connected to poison-glands, 3 Proteroglypha with canaliculated anterior maxillary teeth (front-teethed) they are very poisonous.

Viperidae. Vipers (Latin vivus = alive + parere = bring forth meaning viviparous nature)consists of two Sub-families (Viperinae and Crotalinae) and 7 Genera and 31 species in the area comprising Indian sub-continent China and Malay Peninsula. They are one of the most widely distributed snakes in the world.

Hydrophiidae are aquatic with all adaptations for that life, hydrophiidae has two sub-families (Laticaudinae and hydrophinae) and 12 genera with about 30 species.

Yellow Snake Image courtsey:

Family Elapidae which includes the cobras (Naja) has only one sub-family and three genera.

Boa, Eryx and Pythons Anacondas. (Family Boidae; TwoSub-families Pythonae and Boinae) They are giant constricting snakes.

To be continued...

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