Biodiversity and Conservation Chapter 13: Phylum Arthropoda, Exam 2 Content

Arthropoda

Most abundant group of animals on earth

Cambrian

Time period in which Arthropods first appeared

Stair shape

Survivorship curves of arthropods may be this shape instead of curved because of molting events that cause them to be more vulnerable

Tagmata

Refers to the body regions of arthropods, such as the abdomen, head, thorax, etc)

Cephalothorax

One segment of fused head and thorax

Adaptations of Arthropods

Exoskeletons, Segmentation and appendages, air distribution directly to cells, highly developed sensory organs, and complex behavior patterns

Cuticle

Part of the exoskeleton that is secreted by the underlying epidermis; consists of the epicuticle and the procuticle

Epicuticle

Relatively thin outer layer of the exoskeleton; made of protein and often lipids

Procuticle

Inner, thicker layer of the exoskeleton, divided into the exocuticle and the endocuticle; made of chitin bound to proteins

Exocuticle

Part of the procuticle that is secreted before molting

Endocuticle

Part of the procuticle that is secreted after molting

Molting

The process necessary for the growth in size of arthropods

Ecdysis

The last step of molting, the shedding of skin

Terrestrial arthropods

Geographic group of arthropods that breathe via a tracheal system

Marine arthropods

Geographic group of arthropods that breathe via gills

Tracheal system

A system of air tubes which deliver oxygen directly to tissues and cells

Trachae

Part of the tracheal system that opens to the outside through spiracles

Class Merostomata

Class of Arthropods that contain species such as the extinct giant water scorpion or horseshoe crabs

Horseshoe crabs

Group of Arthropods that have a carapace, abdomen, telson, an open circulatory system, and copper in their blood that makes their blood blue

Class Arachnida

Class of Arthropods that contains over 100,000 species, including spiders, scorpions, whip scorpions, pseudoscorpions, ticks, mites, harvestmen, and more; composed of a cephalothorax and an abdomen

Class Chilopoda

Class of Arthropods that contains centipedes, with one pair of legs on each segment, and modified maxillipeds on the first segment that become venom claws

Group of ocelli

Structure that makes up the eyes of centipedes

Class Diplopoda

Class of Arthropods that contains millipedes, which have between 25 to 100 segments and are typically herbivorous

Four thoracic segments

Number and type of segment on millipedes that only have one pair of legs

Abdominal segments

Type of segment on millipedes that have two pairs of legs