Topics 2-4

Microscopic crystalline structures, give sponges rigidity & form, consist of spines / rays that radiate from a point

Tiny holes in outer walls through which water is drawn by sponges

Unique cnidarian cell, contains nematocysts (organelles) which are used to deliver sting when triggered

Organelle that contains coiled thread, used to sting organisms when triggered, found in cnidarians

Cnidarian appendages equipped with stinging cells, used to capture prey and for defense

One of two main cnidarian structural forms, cylindrical and sessile, mouth surrounded by tentacles ("upside down jellyfish")

One of two cnidarian body forms, free-swimming bell-shaped body with tentacles and a mouth hanging down (jellyfish)

Primary organ for digestion and circulation in cnidarians, has a single opening, used in gas exchange, waste disposal, and digestion

Branching cavity that serves as primary organ for digestion and circulation, brings in food and dispels waste

Light-sensitive sensory cells located on head of platyhelminth (flatworm)

Platyhelminthes lack a body cavity (lost in evolution), results in flattened body

Specialized body segment in Platyhelminthes, found at front end of tapeworms, covered with hooks/suckers, used to anchor parasite to host

Platyhelminth segment found in tapeworms, self-sufficient units that contain male and female reproductive organs, produced at the scolex and released in feces of host organism (pumpkin seed-shaped when passed, look like rice grains when dry)

Large fluid-filled cavity surrounded by mesoderm, provides efficient hydrostatic skeleton, supports metabolic processes, maintains osmotic balance with environment

Bodies divided into segments by rings (annuli), organs often repeated, segments able to regrow

Lateral outgrowths from annelid bodies, used for movement

Microscopic larval stage in bivalves, parasitic and released by females which have evolved fish-like lures

Hard, two-part shell that encloses body of bivalve mollusk, each half called a valve and hinged together by elastic ligament

Exoskeleton that protects gastropod's soft body, provides protection, stores calcium, traps and kills parasitic nematodes

Organ that allows gastropod to move, attach to surfaces, mold egg capsules, connect to shell, seal shell

Feeding organ found in gastropods, used to scrape and cut food before entering the esophagus

Boneless limbs that extend from cephalopod head, covered in suckers, used to catch prey and adhere to surfaces (shorter appendages)

Series of chambers separated by walls (septa), shape varies between cephalopods: nautilus - spiral nacreous shell, squid - reduced / remnants of shell (pen), octopus - no shell

Key feature, made of chitin, used to slice up prey, made up of upper and lower mandible

Fluid-filled body cavity in nematodes, not completely lined with mesoderm

Multilayered eggshell, protects larvae and allows hatching under favorable conditions, resistant to stress but able to respond to environment, prevents premature hatching

Silk-producing organ in spiders, located on the abdomen, tubular/conical in shape with many spigots that connect to silk glands

External respiratory appendages found in some chelicerates (eg horseshoe crabs), allow exchange of gasses in water and circulation of blood and water

Internal, plate-like structures located in abdomen of arachnids, deliver and remove waste gasses from body through blood, likely evolved from book gills

Second pair of appendages on a chelicerate, located laterally to the chelicerae, used to sense environment, manipulate food, and copulate in male spiders

Tail-like structure present at the end of the abdomen in horseshoe crabs, allows them to right themselves when overturned

One of two main body segments, contains respiratory and sexual organs

Anterior (front) part of the body, covered by rigid carapace, six pairs of appendages: chelicerae, pedipalps, walking legs

Fold of exoskeleton that covers back of head and part of trunk of many crustaceans, protects cephalothorax, helps with respiration, brood care, and hydrodynamic streamlining

Mouthpart appendages, used to cut and grind food items, acts a central feeding appendage

Pincer-like appendage, used for defense, grasping food, and courtship in crustaceans

Long, feathery appendages on crustaceans used for feeding, found on barnacles

Used for locomotion on the seabed, allows for bending and extension at each joint, enables movement with coordinated steps

Outer layer called a chorion, yolk provides nutrients for the embryo, seen in incomplete and complete metamorphosis

Structure depends on type of hexapod, seen in complete metamorphosis

Immature stage of hexapod with six legs, head, thorax, and abdomen, seen in incomplete metamorphosis

Mouthpart of chelicerates, usually made up of three sections, size varies across species along with function (blood-feeding in ticks, part of venom gland in spiders)

Part of complete metamorphosis process, period of dormancy often involving cocoon

Usually located on ventral (bottom) side of echinoderms, used for feeding and digestion

Located on the oral disk, one at the base of each jaw

Found in some species like sea urchins, have five of these (self-sharpening), able to converge like a vice to grab food

Exit for food in digestive system, often located on dorsal (top) side of body

Used for protection, movement, and digging; long, thin, and sharp on sea urchins

Interlocking plates of calcium carbonate covered by thin layer of skin (endoskeleton)

Series of openings in the pharynx of chordates, used in respiration, filter feeding, and developing inner ear & jaw (only present in embryonic development in terrestrial chordates)

Flexible rod of cells and connective tissue that runs along midline of body, main skeletal element of early embryo (essential for elongation) and produces signals that pattern surrounding tissue, seen in lancelets and in embryonic/larval stages of other chordates

Extension of body that extends past the anus and contains skeletal elements and muscles, used in locomotion (aquatic species), courting, balance, and signaling danger

Mesh-like structure in urochordates (tunicates) that contains many slits, water drawn into structure by cilia where mucus traps food particles and water exits through slits

Opening in body cavity of urochordates, allows water and food to enter the animal

Opening in body cavity of urochordates, allows for expulsion of filtered water and waste

Curve formed by the intestine in urochordates, may have one or two loops

important part of digestive system, further digestion of food occurs here after being in stomach, nutrients absorbed into body

specialized pigment-containing cells, allow for color changing/camouflage

crucial part of reproductive system, saddle-like ring around the body

sac that stores food for short amount of time

produces digestive enzymes that help break down food and absorb nutrients

pumps blood to aortic arches

feathery structures essential for respiration

used in place of teeth to grind up food

five pairs of aortic arches, play central role in circulatory system

muscular pouch used for defense, contains ink mainly composed of melanin

food moves here after being broken up, continues to be broken down by digestive fluids

first pair larger and more rigid, used to transfer sperm to female during mating

found in center of arms, used to grind food with radula

responsible for secreting gelatinous substances that forms egg cases/masses

located in rear end of mantle cavity, produces thousands of eggs

transports mature eggs from ovaries to uterus

serves as site for muscle attachment, provides structural support

located within mantle cavity, used to transfer sperm to female

part of digestion system, creates suction force to ingest soil and food particles

structure that stores sperm from another earthworm during copulation

used to produce mature sperm, where sperm maturation occurs

tiny, hair-like bristles, used for locomotion

used for jet propulsion, also aids in waste removal, respiration, and ink expulsion

small, paired appendages, used for swimming, burrow ventilation, and carrying eggs

produce and store sperm

houses and nurtures fertilized eggs, connects oviducts to vagina

passage through which eggs are expelled

central nervous system, consists of two located above the mouth

main covering, encases internal organs

pumps food through mouth to intestine

absorbs nutrients from food that has been broken down by enzymes

storage sight for spermatogonia which is produces in the testis

used in mating to open vulva of female in order for sperm to be transmitted

plume-like structures, extract dissolved oxygen

muscles used for rapid escape responses, used in tail movement

part of exoskeleton in hexapods, periodically shed and replaced through molting

hollow strucutre in chordates, develops into the brain and spinal cord, make up central nervous system

part of crayfish digestive system, functions similarly to teeth but located within stomach

found in the appendages, used in reproduction to release eggs/sperm into the water

located in the appendages, responsible for enzyme secretion and nutrient abosrbtion/storage

used in trout to filter waste products out of the blood

used in detoxification and digestion, secretes bile that is stored in the gall bladder to help digest fats

fleshy fins supported by single bone that extends from body

located on sea star surface, filters water into vascular system and regulates pressure, allows control over tube feet movement

plate that covers and protects gills in trout

small, claw-shaped appendages on sea star, used in defense and capturing prey

used in digestion and nutrient absorbtion, secretes digestive enzymes in trout

located in central disc of sea star above cardiac stomach, used to process food

component of water vascual system, found in appendages, used for movement, feeding, and respiration

central component of water vascular, encircles the mouth, used in feeding, movement, and respiration

involved in production of blood cells in trout, crucial for producing antibodies

crucial part of trout digestive system, breaks down food and initiates digestion

organ in trout used to control buoyancy, maintaining depth in water with little energy

located on underside of sea star appendages, used for locomotion, feeding, and respiration

transport sperm from seminal vesicle to cloaca in reproductive system

allows extraction of oxygen from water