Jim Armbruster
Squaliformes
Name – Squaliformes, comes from the Latin root squama meaning scale.
Taxonomic status – Class - Chondrichthyes
Subclass - Elasmobranchii
Superorder- Selachimorpha
Contains 120 species and seven families
Description – This order generally has two dorsal fins and spines may be present. They lack an
anal fin. There are five gill slits with spiracles, a small hole behind the eye that connects
to the mouth.
Habitat – Found in marine habitats generally in deep water
Distribution – The species is found around the world in a variety of habitats ranging from cold
to warm water.
Ecology and life history – Squaliformes tend to hunt other fish for food. They have large teeth
on the upper and lower jaw that are designed for ripping other fish. The Squalidae family
have stomachs that are lined with squalamine. Squalamine is a chemical found in the
liver and stomach and is used in a wide variety of medical drugs; used for its ability to
decrease the size of blood vessels in humans.
Additional details – The skin of the squalidae is sometimes rough to the touch and some species
like the dogfish possess venom in their spines.
Recent research – Dental structure of the Giant lantern shark, Etmopterus baxteri,
(Chondrichthyes: Squaliformes) and its taxonomic implications. The dental structure of
squaliformes is not well known. The purpose of the paper is to examine the difference
between juvenile and adults, between males and females, and to test to see if dental
structure can be used for taxonomic purposes.
References used
Dianne J. Bray, 2011, Dogfish Sharks , SQUALIFORMES, in Fishes of Australia.
http://www.fishbase.org/summary/OrdersSummary.php?order=Squaliformes
Straube, N., Kriwet, J., & Schliewen, U. (2008). Dental structure of the Giant lantern shark
Etmopterus baxteri (Chondrichthyes: Squaliformes) and its taxonomic implications.
Environmental Biology of Fishes, 82(2), 133-141.