Arthropods

Arthrpoda has an extinct class Marrellomorpha and an the extinct Trilobite subphylum. The order Eurypterida (eurypterids) or sea scorpions, related to arachnids are also extinct. They may have been the largest arthropods to have ever lived.

A typical arthropod, such as an ant, has three body sections - head, thorax and abdomen.

However, the phylum "arthropoda" which literally translates to "jointed foot" (or, by extension, "jointed leg") includes more than a million species, some of which (the lobster, for instance) have as many as eight body sections, and others such as the arachnids (spiders), only two.

For a basic science test, 3 is probably the answer.

The vertebral column or spine comprises individual bones (vertebrae) as part of an internal skeleton or endoskeleton. Arthropods differ in that they have no bony internal skeleton, instead they rely on an external or exoskeleton, whose rigidity creates the defining characteristics of the arhtropod phylum; the joint appendages and segmented body.

No, at least not in the backbone sense. Arthropods have their skeleton on the outside (exoskeleton); spines or vertebral columns are characteristic of vertebrates under a different phylum - Chordata, including fish, birds, mammals, etc.

Mosquitoes are insects. They are in winged insects (pterygota), then holometabola, meaning they posses true metamorphosis with larval, pupal and adult stages. Within holometabola they belong to the diptera or flies, which can be distinguished from other insects in that their hind wings are reduced to a balance organ called a haltere. Within diptera they are the family culicidae which can be distinguished from other flies by a piercing proboscis and scales on the veins of the wings.

You have to be more specific to which arthropod you are researching. There are many classifications: insects, arachnids, crustaceans, etc. Some spiders weave webs while others go out in search of food. Crabs, lobsters, and shrimps scavenge. Bees go around and outward from their hive in a circular motion in search of flowers.

Arthropod skeletons differ from ours in that they are external, or exoskeletons. By contrast ours are internal, or endoskeletons.

Grasshoppers and crickets

Arthropods are characterized by segmented bodies, an exoskeleton made from chitin, and joint appendages. They have an internal body cavity (hemocoel) and an open circulatory system which employs hemolymph, a fluid that does not distinguish between interstitial fluid like lymph and oxygen carrying fluid like blood as in most vertebrates. They use a copper-based oxygen carrier molecule instead of the iron-based hemoglobin, which floats freely around in the hemolymph and is not bound to blood cell proteins. They do not have a dedicated and separate branch of their circulatory system just to oxygenate; internal organs (and cells) are simply bathed in this fluid; many arthropods (e.g., insects) oxygenate directly from the air through tubules connected to holes (spiracles) in their body segments. Their nervous system is 'ladder-like' on their ventral surface, and their brains formed around the esophagus from fused segment nerve ganglia.

An arthropod is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda (from Greek ἄρθρον árthron, "joint", and ποδός podós "foot", which together mean "jointed feet"), and include the insects, arachnids, crustaceans, and others. Arthropods are characterized by their jointed limbs and cuticles, which are mainly made of α-chitin; the cuticles of crustaceans are also biomineralized with calcium carbonate

One species of particularly long millipede has instances of over 300 body sections.

Lobsters in the wild are generally mottled yellow, green, brown, and almost never red. The reason they turn red during cooking is that other pigmentations are broken down by heat, but the red pigments are not.

Lobster survival strategy involves a good deal of hiding from predators. They accomplish this by locating and occupying crags, hiding below rocks, and burrowing into the sea floor. They also have a highly acute chemical sense and have been shown to react to minute trace of chemicals indicating the presence of predators.

One might also argue they stay alive by blind luck. The vast majority of lobsters die before reaching adulthood; their reproductive strategy involves releasing tens of thousands of eggs. This is necessary since only one in ten thousand is estimated to survive long enough to end up on your dinner plate.

Under arthropoda are subphyla Chelicerata, Myriapoda, Crustacea, and Hexapoda. There is also an extinct class Marrellomorpha and an the extinct Trilobite subphylum. The chelicerata, like spiders, scorpions, mites, etc., get their name from having appendages appear before the mouth; myriapods like centipedes and millipedes characterized by a high count of body segments and legs; crustaceans like crabs, shrimp, woodlice characterized by their biramous (two-part) limbs and a nauplius larval form; hexapoda named for their consolidated thorax with three pairs of legs.

Some text may show subphyla as "classes" but usually the term 'class' has a specific denotation within taxonomy; there are more than just three classes under these subphyla. Some examples would be class Arachnida, Chilopoda, Branchiopoda, Insecta, and Malacostraca - but there are many more.

jointed appendages.

Arthropods have the common characteristics of exoskeletons made of chitin, necessitating the further characteristics of segmented bodies and joint appendages. The phylum's name arthropoda comes from the greek meaning jointed legs or feet.

* centipedes * horseshoe crabs * insects * millipedes

1. A hard outer body covering called an exoskeleton.
2. Specialized mouth parts
3. Jointed legs
4. Compound Eyes
5. Segmented body

Yes, they do reflect a high degree of internal organization with organ systems for circulatory, reproductive, digestive and neurological functions to support a sensory array including (in most) vision and (in many) a highly attenuated chemical sense.

Arthropod is the largest in the animal kingdom. They include lobsters, crabs, spiders, mites, insects, centipedes, and millipedges. Arthropods can be found in every habitat on Earth. They show a great variety of adaptations which included living in aquatic environments, and some groups even have adapted for flight.

The lobster you might be used to seeing with the big claws is the american lobster (Homarus americanus), and lives off the east coast of North America, from below Maine up to Newfoundland. They are actually not red in the wild; the red color is a consequence of non-red pigments breaking down during cooking.

The exoskeleton of arthropoda is made of a tough protein called chitin, a long chain polymer comparable to cellulose. It fills the same role as the protein keratin in other animals where it would be found in hair, nails, hooves, claws, beaks, etc.

Some arthropods, like crustaceans, further harden their chitin exoskeleton by biomineralization with calcium carbonate. Because it is inflexible, the organism has to periodically shed it (moult) in order to grow.

Arthropods, which fall under the phylum of Arthropoda, encompass many animals such as spiders, insects, crustaceans, centipedes, and scorpions. One characteristic of arthropods is their exoskeleton, which they have because they are invertebrates and do not have any internal bones to support them. Other characteristics of arthropods include their segmented bodies, bilateral symmetry, open circulatory system, and jointed appendages.

The largest non-extinct arthropod in size was a Japanese spider crab caught in 1921 measuring about 12 feet across the claws. The heaviest on record was a lobster weighing about 45 pounds. On land, the largest is the coconut crab at about 3 feet across. Some anecdotal evidence exists for even larger crustaceans, based on recovered exoskeletons/exuviae.