Symphyla
Encyclopedia
Symphylans, also known as garden centipedes or glasshouse symphylans, are soil
-dwelling arthropods of the class
Symphyla in the subphylum Myriapoda
. Symphylans resemble centipede
s, but are smaller and translucent. They can move rapidly through the pores between soil particles, and are typically found from the surface down to a depth of about 50 cm. They consume decaying vegetation, but can do considerable harm in an agricultural
setting by consuming seeds, roots, and root hairs in cultivated soil.
Juveniles have six pairs of legs, but, over a lifetime of several years, add an additional pair at each moult
so that the adult instar
has twelve pairs of legs . Lacking eyes, their long antennae
serve as sense organs. They have several features linking them to early insects, such as a labium (fused second maxillae), an identical number of head segments and certain features of their legs .
About 200 species are known worldwide .
myriapods without eyes and without pigment
. The body is soft and 2 to 10 mm (0.078740157480315 to 0.393700787401575 in) long, divided into two body regions: head and trunk.
The head has long, segmented antennae, a postantennal organ, three pairs of mouthparts
: mandibles
, the long first maxillae, and the second pair of maxillae which are fused to form the lower lip or labium of the mouth. Disc-like organs of Tömösvary, which probably sense vibrations, are attached to the base of the antennae
, as they are in centipedes.
The trunk comprises 15–24 segments, which are protected by overlapping dorsal plates. Ten or twelve segments bear legs
. The first segment is large and usually provided with a pair of legs, the last segment is slender, lacks legs, and possesses a pair of cerci
. Immature individuals have six pairs of legs on hatching. Each pair of legs is associated with an eversible structure, called a "coxal sac", that helps the animal absorb moisture, and a small stylus that may be sensory in function. Similar structures are found in the most primitive insects.
Symphyla are rapid runners. They are primarily herbivore
s and detritus
feeders living deep in the soil, under stones, in decaying wood, and in other moist places where they feed on the root hairs and rootlets and can sometimes cause crop failure. The garden centipede, Scutigerella immaculata can be a serious pest of vegetable crops and tree seedlings and occurs in greenhouses as well as agricultural situations. A species of Hanseniella has been recorded as a pest of sugar cane and pineapple
s in Queensland
. A few species are found up trees and in caves . A species of Symphylella has been shown to be predominantly predatory , and some species are saprophagous.
Symphylans breathe through a pair of spiracle
s on the sides of the head. These are connected to a system of tracheae
that branch through the head and the first three segments of the body only.
The genital openings are located on the fourth body segment, but the animals do not copulate. Instead, the male deposits 150 to 450 packages of sperm, or spermatophore
s, on small stalks. The female then picks these up in her mouth, which contains special pouches for storing the sperm. She then lays her eggs, and attaches them to the sides of crevices or to moss or lichen with her mouth, smearing the sperm over them as she does so. The eggs are laid in groups of 8 to 12.
Symphylans have been reported as living up to four years, and moult
throughout their life.
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
-dwelling arthropods of the class
Class (biology)
In biological classification, class is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order...
Symphyla in the subphylum Myriapoda
Myriapoda
Myriapoda is a subphylum of arthropods containing millipedes, centipedes, and others. The group contains 13,000 species, all of which are terrestrial...
. Symphylans resemble centipede
Centipede
Centipedes are arthropods belonging to the class Chilopoda of the subphylum Myriapoda. They are elongated metameric animals with one pair of legs per body segment. Despite the name, centipedes can have a varying number of legs from under 20 to over 300. Centipedes have an odd number of pairs of...
s, but are smaller and translucent. They can move rapidly through the pores between soil particles, and are typically found from the surface down to a depth of about 50 cm. They consume decaying vegetation, but can do considerable harm in an agricultural
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
setting by consuming seeds, roots, and root hairs in cultivated soil.
Juveniles have six pairs of legs, but, over a lifetime of several years, add an additional pair at each moult
Ecdysis
Ecdysis is the moulting of the cuticula in many invertebrates. This process of moulting is the defining feature of the clade Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, rotifers, tardigrades and Cephalorhyncha...
so that the adult instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
has twelve pairs of legs . Lacking eyes, their long antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
serve as sense organs. They have several features linking them to early insects, such as a labium (fused second maxillae), an identical number of head segments and certain features of their legs .
About 200 species are known worldwide .
Description
Symphyla are small, crypticCrypsis
In ecology, crypsis is the ability of an organism to avoid observation or detection by other organisms. It may be either a predation strategy or an antipredator adaptation, and methods include camouflage, nocturnality, subterranean lifestyle, transparency, and mimicry...
myriapods without eyes and without pigment
Pigment
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...
. The body is soft and 2 to 10 mm (0.078740157480315 to 0.393700787401575 in) long, divided into two body regions: head and trunk.
The head has long, segmented antennae, a postantennal organ, three pairs of mouthparts
Mouthparts
The mouthparts of arthropods have evolved into a number of forms, each adapted to a different style or mode of feeding. Most mouthparts represent modified, paired appendages, which in ancestral forms would have appeared more like legs than mouthparts. In general, arthropods have mouthparts for...
: mandibles
Mandible (arthropod)
thumb|250px|The mandibles of a [[Bull ant]]The mandible of an arthropod is either of a pair of mouthparts used for biting, cutting and holding food. Mandibles are often simply referred to as jaws. Mandibles are present in the extant subphyla Myriapoda , Crustacea and Hexapoda...
, the long first maxillae, and the second pair of maxillae which are fused to form the lower lip or labium of the mouth. Disc-like organs of Tömösvary, which probably sense vibrations, are attached to the base of the antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
, as they are in centipedes.
The trunk comprises 15–24 segments, which are protected by overlapping dorsal plates. Ten or twelve segments bear legs
Arthropod leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa , trochanter , femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus ,...
. The first segment is large and usually provided with a pair of legs, the last segment is slender, lacks legs, and possesses a pair of 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...
. Immature individuals have six pairs of legs on hatching. Each pair of legs is associated with an eversible structure, called a "coxal sac", that helps the animal absorb moisture, and a small stylus that may be sensory in function. Similar structures are found in the most primitive insects.
Symphyla are rapid runners. They are primarily 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 detritus
Detritus
Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
feeders living deep in the soil, under stones, in decaying wood, and in other moist places where they feed on the root hairs and rootlets and can sometimes cause crop failure. The garden centipede, Scutigerella immaculata can be a serious pest of vegetable crops and tree seedlings and occurs in greenhouses as well as agricultural situations. A species of Hanseniella has been recorded as a pest of sugar cane and pineapple
Pineapple
Pineapple is the common name for a tropical plant and its edible fruit, which is actually a multiple fruit consisting of coalesced berries. It was given the name pineapple due to its resemblance to a pine cone. The pineapple is by far the most economically important plant in the Bromeliaceae...
s in Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
. A few species are found up trees and in caves . A species of Symphylella has been shown to be predominantly predatory , and some species are saprophagous.
Symphylans breathe through a pair of spiracle
Spiracle
Spiracles are openings on the surface of some animals that usually lead to respiratory systems.-Vertebrates:The spiracle is a small hole behind each eye that opens to the mouth in some fishes. In the primitive jawless fish the first gill opening immediately behind the mouth is essentially similar...
s on the sides of the head. These are connected to a system of tracheae
Invertebrate trachea
The invertebrate trachea refers to the open respiratory system composed of spiracles, tracheae, and tracheoles that terrestrial arthropods have to transport metabolic gases to and from tissues....
that branch through the head and the first three segments of the body only.
The genital openings are located on the fourth body segment, but the animals do not copulate. Instead, the male deposits 150 to 450 packages of sperm, or spermatophore
Spermatophore
A spermatophore or sperm ampulla is a capsule or mass created by males of various animal species, containing spermatozoa and transferred in entirety to the female's ovipore during copulation...
s, on small stalks. The female then picks these up in her mouth, which contains special pouches for storing the sperm. She then lays her eggs, and attaches them to the sides of crevices or to moss or lichen with her mouth, smearing the sperm over them as she does so. The eggs are laid in groups of 8 to 12.
Symphylans have been reported as living up to four years, and moult
Ecdysis
Ecdysis is the moulting of the cuticula in many invertebrates. This process of moulting is the defining feature of the clade Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, rotifers, tardigrades and Cephalorhyncha...
throughout their life.