Shark Taxonomy
Basking Shark © Charles Hood.

Taxonomy is the scientific field concerned with the classification and naming of species and forms the bedrock for everything we know - and want to find out - about sharks, skates, rays and chimaera. Taxonomy is also the very first step towards understanding how human activities are affecting these species and the marine ecosystem in which they play such central roles.

Up until the 1600’s each animal and plant were referred to by their common names but these varied within the same language - in English the Basking Shark (Cetorhinus maximus) can also be known as Bone Shark and Elephant Shark. These names vary again according to the language spoken, so in France it is known as pélérin or éléphant de mer, in Spanish peregrino, in Portugese albafar and in Italian lo squala elefante. This system of naming species therefore caused some confusion and made it difficult for scientists to compare species across different countries.

In the 1600’s, a Swedish scientist called Carl Linneaus invented a system that created order from chaos. Although this system has altered over time, the concept has remained the same and is used by scientists today.

Below is a simple introduction to taxonomy, which is based on a hierarchy made up of seven main levels. However, this system is much more complex and includes intermediate classification ranks such as Super-class, Super-order, Sub-order and Super-families, housed in between these levels.

Kingdom - Organisms are grouped together under very wide categories, such as Animalia (Animal) or Plantae (Plant). Sharks belong to the Kingdom Animalia.

Phylum - This level divides the Kingdoms into smaller groups that share similar characteristics. Sharks belong to the Phylum Chordata and the Sub-phylum Vertebrata, as they possess a spinal chord, notochord and a backbone (vertebrae).

Class - These groups include the more familiar Aves (Birds), Mammalia, Reptila and Amphibia that all belong to the Animal Kingdom and Chordata Phylum. Sharks belong to the Class Chondrichthyes, which include fish that have a cartilaginous skeleton. They are further divided into two Sub-classes; Elasmobranchii (sharks, skates and rays) and Holocephali (chimaera).

Order - Further identification of some animals and plants at this level requires specialist help. For example members of the Order Pristiophoiformes (Sawsharks), all have long saw-like snouts and may appear very similar in appearance, making it difficult to identify down to species. Click here to find out more about the nine orders of shark that exist today.

Family - These groups include species that are closely related. For example apes, monkeys and humans belong to the Family Primates. Some Families are extremely large while others contain just a few members.

Genus - The Genus shows just how closely related species are to each other, as the first word of the species scientific name is it’s Genus, for example, the Shortfin Mako Shark (Isurus oxyrinchus) and the Longfin Mako Shark (Isurus paucus) – Isurus shows us they are closely related.

Species - A species is a group of organisms (animal or plant) that are capable of interbreeding and producing fertile offspring. The first part of a species name refers to the Genus and the second part completes the species name, eg, Carcharodon carcharias – the White Shark. The Genus is written with a capital letter and the species name in lower case. The name is then italicised or underlined.

Angelshark © Simon Rogerson.An example of a taxonomic hierarchy is:

Kingdom: Animalia
Phylum: Chordata
Class: Chrondrichthyes
Order: Squatiniformes
Family: Squatinidae
Genus: Squatina
Species: Squatina squatina (Angelshark)

All organisms have a scientific name, written using Latin grammatical rules, and a common name. Common names vary within the same language and when spoken in other languages but the scientific name will always remain the same.

Family Tree for British Sharks:

British Sharks Family Tree (pdf)

➤ Download our British Sharks Family Tree (pdf)

➤ Download our British Skates and Rays Family Tree (pdf)

Related Links:

Shark Orders