Inverts Exam 3 Vocab

Ecdysozoa

Clade of protostomes with a cuticle that molt by ecdysis to grow

Ecdysis

Molting or shedding of the cuticle or exoskeleton for growth

Cuticle

Nonliving outer layer secreted by the epidermis

Ecdysone

Hormone that regulates molting in ecdysozoans

Lophotrochozoa

Protostome clade that does not molt and often has trochophore larvae or lophophores

Nematoda

Phylum of roundworms with unsegmented cylindrical bodies and pseudocoelom

Pseudocoelom

Body cavity not completely lined by mesoderm

Hydrostatic skeleton

Support system using fluid pressure inside the body cavity

Longitudinal muscles

Muscles running lengthwise that produce thrashing movement in nematodes

Dioecious

Species with separate male and female individuals

Ascaris lumbricoides

Large human intestinal roundworm parasite

Necator americanus

Hookworm that feeds on blood and can cause anemia

Trichinella spiralis

Roundworm causing trichinosis from undercooked meat

Enterobius vermicularis

Pinworm that lays eggs near the anus causing itching

Wuchereria bancrofti

Filarial worm that can cause elephantiasis

Nematomorpha

Horsehair worms with parasitic juveniles and free-living adults

Loricifera

Microscopic marine ecdysozoans with a protective lorica

Kinorhyncha

Tiny segmented marine animals that burrow using head scalids

Priapulida

Marine burrowing worms with retractable introvert and spines

Onychophora

Velvet worms with slime glands and unjointed legs

Tardigrada

Water bears known for cryptobiosis and extreme survival ability

Cryptobiosis

Suspended metabolic state during harsh conditions

Arthropoda

Largest animal phylum with segmented body, jointed appendages, and exoskeleton

Tagmata

Fused body regions specialized for function such as head thorax and abdomen

Metamerism

Body segmentation into repeating units

Exoskeleton

External supportive covering made largely of chitin

Chitin

Strong structural polysaccharide in arthropod exoskeletons

Sclerotization

Hardening of the cuticle after molting

Jointed appendages

Segmented limbs that allow flexible movement

Hemimetabolous metamorphosis

Incomplete metamorphosis with egg nymph and adult stages

Holometabolous metamorphosis

Complete metamorphosis with egg larva pupa and adult stages

Kin selection

Behavior that helps relatives survive and reproduce

Chelicerata

Arthropod subphylum with chelicerae and no antennae

Chelicerae

First pair of appendages used as mouthparts in chelicerates

Pedipalps

Second pair of appendages in chelicerates used for sensing feeding or reproduction

Merostomata

Chelicerate group including horseshoe crabs and extinct sea scorpions

Pycnogonida

Sea spiders with long legs and reduced body

Arachnida

Chelicerate class including spiders scorpions ticks and mites

Book lungs

Layered respiratory organs in many arachnids

Malpighian tubules

Excretory organs that remove wastes in many arthropods

Acari

Ticks and mites, many are parasites or disease vectors

Crustacea

Mostly aquatic arthropods with two pairs of antennae and biramous appendages

Biramous appendages

Branched limbs with two main parts

Maxillae

Mouthparts used for handling food in crustaceans

Nauplius larva

Common early larval stage of crustaceans

Ostracoda

Small crustaceans enclosed in a bivalved shell-like carapace

Copepoda

Important planktonic crustaceans in aquatic food webs

Thecostraca

Crustacean group containing barnacles

Malacostraca

Large crustacean group including shrimp crabs lobsters and isopods

Decapoda

Crustaceans with ten walking legs such as crabs and lobsters

Cheliped

Claw-bearing appendage of many crustaceans

Swimmerets

Abdominal appendages used for swimming or reproduction

Myriapoda

Arthropods with many body segments and numerous legs

Chilopoda

Centipedes with one pair of legs per segment and venom claws

Diplopoda

Millipedes with two pairs of legs per segment and detritivore diet

Hexapoda

Arthropods with six legs including insects

Insecta

Class of hexapods with three body regions and usually wings

Thorax

Middle body region bearing legs and wings in insects

Abdomen

Posterior body region containing many organs

Echinodermata

Marine deuterostomes with endoskeleton and water vascular system

Ossicles

Calcareous plates forming echinoderm endoskeleton

Water vascular system

Hydraulic canal system powering tube feet in echinoderms

Tube feet

Extendable podia used for movement feeding and gas exchange

Madreporite

Sieve plate where water enters the water vascular system

Pentaradial symmetry

Adult body plan arranged in five parts around a center

Pedicellariae

Tiny pincer-like structures used for defense and cleaning

Dermal branchiae

Skin gills used in gas exchange in some echinoderms

Asteroidea

Sea stars with broad arms and tube feet with suckers

Ophiuroidea

Brittle stars with slender flexible arms and no suckers

Echinoidea

Sea urchins and sand dollars with test and Aristotle's lantern

Aristotle's lantern

Complex jaw apparatus of sea urchins

Holothuroidea

Sea cucumbers with elongated body and defensive tubules

Cuvierian tubules

Sticky expelled structures used for defense in sea cucumbers

Crinoidea

Sea lilies and feather stars that suspension feed with feathery arms

Regeneration

Ability to regrow lost body parts

Hemichordata

Deuterostome phylum including acorn worms and pterobranchs

Enteropneusta

Acorn worms that burrow and deposit feed

Pterobranchia

Small colonial hemichordates with tentacles

Chordata

Phylum defined by five key traits at some life stage

Notochord

Flexible supportive rod found in all chordates at some stage

Dorsal hollow nerve cord

Nervous system tube located above the notochord

Pharyngeal gill slits

Openings in pharynx used for feeding or respiration

Post-anal tail

Tail extending beyond the anus

Endostyle

Mucus-secreting feeding structure homologous to the thyroid gland

Cephalochordata

Lancelets that retain all chordate traits as adults

Urochordata

Tunicates with chordate traits mainly in larval stage

Tunicate

Marine filter feeder with tough outer tunic

Lancelet

Small fishlike cephalochordate living in sand

Salp

Free-swimming barrel-shaped tunicate

Larvacean

Planktonic tunicate retaining larval form as adult