millipede
Millipedes (originating from the Latin , "thousand", and , "foot") are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derive ...
Colobognatha
Colobognatha is a clade (formally considered a subterclass) of helminthomorph millipedes containing four orders: Platydesmida, Polyzoniida, Siphonocryptida, and Siphonophorida.
Description
The Colobognatha are united by several shared trai ...
. This order contains three families and more than 70 described species. The species in this order are also known as camphor millipedes, because
ozopore
An ozopore is the opening of a defensive gland present in some arthropods, notably in millipedes of the order Polydesmida Poison frogs in South America and Madagascar evidently obtain some of their poison from these millipedes.
Description
Millipedes in this order range from 4 mm to 50 mm in length but are usually 10 mm to 15 mm long. Polyzoniidans have a somewhat domed dorsal surface with a flat ventral side. Their heads are small and cone-like, with few
ocelli
A simple eye or ocellus (sometimes called a pigment pit) is a form of eye or an optical arrangement which has a single lens without the sort of elaborate retina that occurs in most vertebrates. These eyes are called "simple" to distinguish the ...
. They lack a dorsal groove and paranota (lateral extensions of each segment). The antennae are relatively thick. These millipedes can have from 20 to 88 segments, with huge variation in segment number within the same species. The body is frequently yellowish or even pink, sometimes featuring characteristic black bands. Legs have six segments. In males, leg pairs 9 and 10 become leglike
gonopod
Gonopods are specialized appendages of various arthropods used in reproduction or egg-laying. In males, they facilitate the transfer of sperm from male to female during mating, and thus are a type of intromittent organ. In crustaceans and millipe ...
s in adults. The posterior gonopods typically have from five to seven segments, but the number of segments in the anterior gonopods is more variable. Juveniles hatch with four leg pairs. Females in this order protect their eggs.
Families
The order Polyzoniida contains three families:
: Hirudisomatidae Silvestri, 1896 (6 genera, 20 species)
: Polyzoniidae Newport, 1844 (6 genera, 22 species)
: Siphonotidae Cook, 1895 (12 genera, 32 species)
Distribution
This order is distributed worldwide, but in Africa is found only in South Africa and Madagascar. The family Hirudisomatidae occurs from Spain to the
Himalayas
The Himalayas, or Himalaya ( ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than list of h ...
in Eurasia, Japan, and in North America from southwest Canada to central Mexico. The family Polyzoniidae has a
holarctic
The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical reg ...
(northern hemisphere) distribution, occurring in the
northwest
The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A '' compass rose'' is primarily composed of four cardinal directions—north, east, south, and west— ...
and
northeast
The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A '' compass rose'' is primarily composed of four cardinal directions—north, east, south, and west—eac ...
United States, eastern Canada, and in Europe from the United Kingdom and France to
Siberia
Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...
. Siphonotidae has a southern distribution, occurring in Brazil and Chile, South Africa, Southeast Asia, Indonesia, Tasmania, and New Zealand.