Arthropods in the context of "Ganglia"

Play Trivia Questions online!

or

Skip to study material about Arthropods in the context of "Ganglia"

Ad spacer

⭐ Core Definition: Arthropods

Arthropods (/ˈɑːrθrəˌpɒd/ AR-thrə-pod) are invertebrates in the phylum Arthropoda. They possess an exoskeleton with a cuticle made of chitin, often mineralised with calcium carbonate, a body with differentiated (metameric) segments, and paired jointed appendages. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. They form an extremely diverse group of up to ten million species.

Haemolymph is the analogue of blood for most arthropods. An arthropod has an open circulatory system, with a body cavity called a haemocoel through which haemolymph circulates to the interior organs. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. They have ladder-like nervous systems, with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, and their brains are formed by fusion of the ganglia of these segments and encircle the esophagus. The respiratory and excretory systems of arthropods vary, depending as much on their environment as on the subphylum to which they belong.

↓ Menu

>>>PUT SHARE BUTTONS HERE<<<
In this Dossier

Arthropods in the context of Central nervous system

The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts. It is a structure composed of nervous tissue positioned along the rostral (nose end) to caudal (tail end) axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain, though precursor structures exist in onychophorans, gastropods and lancelets.

The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals.

↑ Return to Menu

Arthropods in the context of Dichlorodiphenyltrichloroethane

Dichlorodiphenyltrichloroethane (DDT) is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride. Originally developed as an insecticide, it became infamous for its environmental impacts. DDT was first synthesized in 1874 by the Austrian chemist Othmar Zeidler. DDT's insecticidal action was discovered by the Swiss chemist Paul Hermann Müller in 1939. DDT was used in the second half of World War II to limit the spread of the insect-borne diseases malaria and typhus among civilians and troops. Müller was awarded the Nobel Prize in Physiology or Medicine in 1948 "for his discovery of the high efficiency of DDT as a contact poison against several arthropods". The WHO's anti-malaria campaign of the 1950s and 1960s relied heavily on DDT and the results were promising, though there was a resurgence in developing countries afterwards.

↑ Return to Menu

Arthropods in the context of Animal product

An animal product is any material derived from the body of a non-human animal or their excretions. Examples are meat, fat, blood, milk, eggs, honey, and lesser known products, such as isinglass, rennet, and cochineal.

The word animals includes all species in the biological kingdom Animalia, except humans. This includes, for example, tetrapods, arthropods, and mollusks. Generally, products made from decomposed animals, such as petroleum, or crops grown in soil fertilized with animal remains or manure are not characterized as animal products. Products sourced from humans (e.g. breast milk) are not typically classified as animal products.

↑ Return to Menu

Arthropods in the context of Birds-of-paradise

The birds-of-paradise are members of the family Paradisaeidae of the order Passeriformes. They are found mainly in New Guinea, as well as eastern Australia and the Moluccas. The family has 45 species in 17 genera. The members of this family are perhaps best known for the plumage of the males of the species, the majority of which are sexually dimorphic. The males of these species tend to have very long, elaborate feathers extending from the beak, wings, tail, or head. For the most part, they are confined to dense rainforest habitats. The diet of all species is dominated by fruit and to a lesser extent arthropods. The birds-of-paradise have a variety of breeding systems, ranging from monogamy to lek-type polygamy.

A number of species are threatened by hunting and habitat loss.

↑ Return to Menu

Arthropods in the context of Breeding in the wild

Breeding in the wild is the natural process of animal reproduction occurring in the natural habitat of a given species. This terminology is distinct from animal husbandry or breeding of species in captivity. Breeding locations are often chosen for very specific requirements of shelter and proximity to food; moreover, the breeding season is a particular time window that has evolved for each species to suit species anatomical, mating-ritual, or climatic and other ecological factors. Many species migrate considerable distances to reach the requisite breeding locations. Certain common characteristics apply to various taxa within the animal kingdom, which traits are often sorted among amphibians, reptiles, mammals, avafauna, arthropods and lower life forms.

↑ Return to Menu

Arthropods in the context of Ommatidia

The compound eyes of arthropods like insects, crustaceans and millipedes are composed of units called ommatidia (sg.: ommatidium). An ommatidium contains a cluster of photoreceptor cells surrounded by support cells and pigment cells. The outer part of the ommatidium is overlaid with a transparent cornea. Each ommatidium is innervated by one axon bundle (usually consisting of 6–9 axons, depending on the number of rhabdomeres) and provides the brain with one picture element. The brain forms an image from these independent picture elements. The number of ommatidia in the eye depends upon the type of arthropod and range from as low as five as in the Antarctic isopod Glyptonotus antarcticus, or a handful in the primitive Zygentoma, to around 30,000 in larger Anisoptera dragonflies and some Sphingidae moths.

↑ Return to Menu

Arthropods in the context of Protichnites

Protichnites is an ichnogenus of trace fossil consisting of the imprints made by the walking activity of certain arthropods. It consists of two rows of tracks and a medial furrow between the two rows. This furrow, which may be broken, set at an angle, and of varying width and depth, is thought to be the result of the tail region contacting the substrate.

↑ Return to Menu

Arthropods in the context of Proarticulata

Proarticulata (also known as Dickinsoniomorpha) is a phylum of extinct, near-bilaterally symmetrical animals known from fossils found in the Ediacaran (Vendian) marine deposits, and dates to approximately 567 to 550 million years ago. The name comes from the Greek προ (pro-) = "before" and Articulata, i.e. prior to animals with true segmentation such as annelids and arthropods. This phylum was established by Mikhail A. Fedonkin in 1985 for such animals as Dickinsonia, Vendia, Cephalonega, Praecambridium and currently many other Proarticulata are described (see list).

Due to their simplistic morphology, their affinities and mode of life are subject to debate. They are almost universally considered to be metazoans, and due to possessing a clear central axis have been suggested to be stem-bilaterians. In the traditional interpretation, the Proarticulatan body is divided into transverse articulation (division) into isomers as distinct from the transverse articulation segments in annelids and arthropods, as their individual isomers occupy only half the width of their bodies, and are organized in an alternating pattern along the longitudinal axis of their bodies. In other words, one side is not the direct mirror image of its opposite (chirality). Opposite isomers of left and right side are located with displacement of half of their width. This phenomenon is described as the symmetry of gliding reflection. Some recent research suggests that some proarticulatans like Dickinsonia have genuine segments, and the isomerism is superficial and due to taphonomic distortion. However, other researchers dispute this. Displacement of left-right axis is known in bilaterians, notably lancelets.

↑ Return to Menu