Machilidae
Encyclopedia
Machilidae is a family of primitive insect
s belonging to the order Archaeognatha
(the bristletails). There are around 250 described species worldwide. These insects are wingless, elongated and more or less cylindrical with a distinctive humped thorax
and covered with tiny, close-fitting scales
. The colour is usually grey or brown, sometimes intricately patterned. There are three "tails" at the rear of the abdomen
: two cerci
and a long central epiproct. They have large compound eyes, often meeting at a central point. They resemble the silverfish
and the firebrat
.
Machilids undergo virtually no metamorphosis
during their life cycle and both nymphs
and adults are generally inconspicuous herbivore
s and scavenger
s. Many species are restricted to rocky shore
lines, but some are found in well vegetated habitats inland. They can move very fast and often escape by jumping considerable distances when disturbed.
Like all Archaeognatha, machilids transfer sperm indirectly from male to female. Some species can spin silken threads that lead the female to the spermatophore. Other species can produce silken stalks on which they place droplets of sperm.
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s belonging to the order Archaeognatha
Archaeognatha
Archaeognatha is an order of wingless insects, also known as jumping bristletails. They are among the least evolutionarily changed insects, appearing in the Devonian period along with the arachnids. The name Archaeognatha is derived from Greek Archaeos meaning "ancient" and gnatha meaning "jaw"...
(the bristletails). There are around 250 described species worldwide. These insects are wingless, elongated and more or less cylindrical with a distinctive humped thorax
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
and covered with tiny, close-fitting scales
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
. The colour is usually grey or brown, sometimes intricately patterned. There are three "tails" at the rear of the abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
: two cerci
Cercus
Cerci are paired appendages on the rear-most segments of many arthropods, including insects and arachnids but not crustaceans. Cerci often serve as sensory organs, but they may also be used as weapons or copulation aids, or they may simply be vestigial structures.Typical cerci may appear to be...
and a long central epiproct. They have large compound eyes, often meeting at a central point. They resemble the silverfish
Silverfish
Lepisma saccharina, frequently called silverfish, fishmoths, carpet sharks or paramites, are small, wingless insects in the order Thysanura...
and the firebrat
Firebrat
The Firebrat is a small insect similar to the Silverfish, both in the order Thysanura....
.
Machilids undergo virtually no metamorphosis
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation...
during their life cycle and both nymphs
Nymph (biology)
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph moults it never enters a...
and adults are generally inconspicuous herbivore
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
s and scavenger
Scavenger
Scavenging is both a carnivorous and herbivorous feeding behavior in which individual scavengers search out dead animal and dead plant biomass on which to feed. The eating of carrion from the same species is referred to as cannibalism. Scavengers play an important role in the ecosystem by...
s. Many species are restricted to rocky shore
Shore
A shore or shoreline is the fringe of land at the edge of a large body of water, such as an ocean, sea, or lake. In Physical Oceanography a shore is the wider fringe that is geologically modified by the action of the body of water past and present, while the beach is at the edge of the shore,...
lines, but some are found in well vegetated habitats inland. They can move very fast and often escape by jumping considerable distances when disturbed.
Like all Archaeognatha, machilids transfer sperm indirectly from male to female. Some species can spin silken threads that lead the female to the spermatophore. Other species can produce silken stalks on which they place droplets of sperm.