Word | Definition |
Copepodsny | one of many groups of animals belonging to the phylum Arthropoda |
Arthropods | the phylum of animals whose members possess metamerism with tagmatization, a jointed exoskeleton, and a ventral nervous system, includes insects, crustasceans, spiders, and related animals. |
exoskeleton | an external, jointed skeleton |
tagmatization | the specialization of body regions of a metameric animal for specific functions, the head of an arthropod is specialized for feeding and sensory functions |
epidermal layer | sometimes called the Hypodermis because it is covered on the outside by an exoskeleton, and not directly exposed to air or water |
epicuticle | outermost layer of the exoskeleton, made of waxy lipoprotein |
Chitin | a tough leathery polysaccharide, and several kinds of proteins |
ecdysis | Molting process, 4 stages 1)enzymes, secreated from hypodermal glands 2)new procuticle and epicuticle are secreted 3) the old exoskeleton splits open 4)finally, calcium carbonate deposits and hardens the new exoskeleton |
hemocoel | large tissue space within an arthropod that contains blood, derived rom the blastocoel of the embryo |
metamorphosis | a radical change in body form and physiology as an immature stage, usually called a larva, becomes an adult |
biramous appendages | triolobite appendages consisted of two lobes or rami; inner lobe is a walking leg outer lobe bore spikes or teeth, that were used in digging or swimming |
prosma | or cephalothorax, is a sensory, feeding and locomotor tagma, usually bears eyes, and has no antennae |
chelicerae | first pair, often pincerlike or chelate, and are most often used in feeding |
pedipalps | second pair, usually sensory but may also be used in feeding, locomotion or reproduction; paired walking legs follow the pedipalps |
opisthosoma | posterior to the prosoma, contains digestive, reproductive, excretory, and respiratory organs |
limulus polyphenmus | widely distributed in the Atlantic ocean and the Gulf of Mexico |
genital opercula | first pair of opisthosomal appendages cover genital pores on the horseshoe crab |
book gills | five remaining pairs of appendages; derived from the resemblance of these platelke gills to the pages of a closed book |
preadaptation | oocurs when a structure present in members of a species proves useful in promoting reproductive success when an individual encounters new environmental situations. |
coxal glands | paired, thin-walled, spherical bathed in blood of body sinuses, empties through a pore near the proximal joint of the leg |
malpighian tubules | the blind-ending excretory and osmoregulatory tubles that join the midgut of insects and some othe arthropods. Secrete waste products and form urine |
book lungs | modification of the arthropod exoskeleton into a series of internal plates that provide surfaces for gas exchange between the blood and air, found in spiders |
tracheae | the small tubes that carry air from spiracles throught the body cavity of an arthropod, arthropod tracheae are modifications of the exoskeleton |
spiracles | an opeining for ventilation, the opening of the tracheal system of an arthoropod or an opening posterior to the eye of a shark, skate, or ray |
sensilla | modifications of the arthropod exoskeleton that, along with nerve cells, form sensory receptors |
oviparous | organisms that lay eggs that develop outside the body of the female |
ovoviviparous | organisms with eggs that develop within the female reproductive tract and that are nourished by food stored in the egg |
viviparous | organisms with eggs that develop within the female reproductive tract and are nourished by the female |
protopodite | the basal segment of biramous appendage of a crustacean |
endopodite | the medial ramus of the biramous appendages of crustaceans and trilobites |
mandibles | the lower jaw of vertebrates; the paired, grinding oand tearing arthropod mouthparts, derived from anterior head appendages |
maxillae | one member of a pair of mouthparts just posterior to the mandibles of many arthropods |
serially homologous | metameric structures that have evolved from a common form, the biramous appendages of crustaceans are serially homologous |