Coelomates Flashcards
(41 cards)
Coelomates
animals that have a true body cavity within their mesoderm, contains most body systems, acts as a support structure
Protostomes: Mollusca, Nemertea, Annelida, Arthropoda
Deuterostomes: Echinodermata, Chordata
Phylum Mollusca
snails, slugs, bivalves (clams, mussels), chitons,
cephalopods (octopus, squid, cuttlefish, nautilus)
use sexual reproduction
found in terrestrial and aquatic (freshwater & marine) systems
Coelomate, Bilateral, Protostome, non-segmented
How does Phylum Mollusca feed?
Most have a true or modified RADULA for feeding (not including cone snails, others)
Squids and Octopi: beaks (modified radula) used for feeding
Cone snails: also have modified radula –as toxin-filled harpoon
Bivalvia(clams/mussels): use filter feeding(they pump water into their shell using specialized muscles; then filter organic matter particles as they draw water into their shells)
Bivalvia
under Phylum Mollusca, include –clams, mussels,
scallops, oysters
Reproduction is complex, mussels use Glochidia(that attach to fish &
amphibian gills as parasites on blood; Once developed, they drop off the host fish and develop into an adult)
Some mussels use lures to get fish in close to blast glochidia at their gills
Chitons
Mollusca living in marine environments; have dorsal plates, ventral foot, radula, and mouth
Gastropoda
group under phylum Mollusca
snails, slugs, sea slugs; freshwater, marine,
terrestrial; predators, herbivores, Omnivores, detritivores (which each dead organic matter)
Extensive sensory systems for chemosensory and vibration detection
Hermaphrodites – same individual produces egg/sperm; alternately inseminate each other
Nudibranchs(sea slugs)
under Phylum Mollusca
sea slugs – marine environs.
herbivores, carnivores
accumulate toxins, nematocysts, &chloroplasts from their food – and
integrate these into their skin & defense systems
includes examples of Blue Dragon Nudibranch
Cephalopoda
Under Phylum Mollusca
marine habitat; primarily predators; change color (chromatophores)
and shape, excellent senses, very intelligent
Phylum Nemertea
RIBBON WORMS; marine predators
Bilateral, Coelomate, Protostomes, non-segmented
primarily marine in distribution (coral reefs, deep ocean, intertidal), a few freshwater and terrestrial species
predators: Feed using projectile proboscis (nose) that either injects prey with toxin (or sticks to them) and then moves prey into their mouth
Phylum Annelida
bristleworms, tubeworms, earthworms, leeches
predators, herbivores, detritivores, parasites
freshwater, marine, terrestrial
coelomate, protostome, bilateria, segmented
ALL HAVE: 1) bodies with repeated segments, each with excretory system, ability to move; 2) circulatory and nervous systems span ALL segments (nutrients & neuron-dependent signals passed to whole organism)
Two Major Groups of Phylum Annelida
Class Clitellata and Class Polychaeta
Class Clitellata
include earthworms, leeches; have FEW hairs or setae on body; have clitellum (unique reproductive organ)
primarily terrestrial, few freshwater; detritivores (very important in
producing soil);
ALL hermaphrodites –exchange sperm during mating with another individual, leading to fertilization of each of their sets of eggs; some used(leeches) for medicinal purposes
Class Polychaeta
include bristleworms, tubeworms; have MANY hairs or setae
on body; no clitellum
some mobile, others sessile; found in all marine habitats, few freshwater spp.; coral reefs, sand, deep ocean, hydrothermal vents
important in food web as predators, detritivores, breaking down organic matter; also important as prey
Tubeworms as Symbiont
Mutualism (+,+) between tubeworms and bacteria makes it possible for them to live there; tubeworm fans collect O2, CO2, and hydrogen
sulfide, which their symbiotic bacteria use for energy/carbon; worm gets ALL of their energy and nutrients from bacteria
Christmas Tree Worms
in Class Polychaeta from Phylum Annelida; marine –coral reefs
tube-building worms, do not move once they have drilled hole into coral
detritivores that filter particles out of water using the fans (“trees”); fans also used for respiration
Bone-eating snot flowers
in class Polychaeta under Phylum Annelida
polychaete worms that get their carbon, nutrients, and energy from fats/lipids in bones of deep-sea carcasses (like whales); discovered in 2002
Phylum Arthropoda
coelomate, protostome, Bilateral, segmented
largest animal phylum
mostly insects, also arachnids, crustaceans, millipedes, centipedes
predators, parasites, herbivores, detritivores
terrestrial, marine, freshwater
What combined characteristics make an arthropod?
exoskeleton, jointed appendages, and segmentation
Most arthropods have three body Segments (head, thorax, abdomen); Arachnids and Crustaceans have Two segments…with the head & thorax fused into cephalothorax, and Their abdomen; A few have many segments…e.g., centipedes and millipedes
ALL grow within life stages and metamorphose between life stages (e.g., larvae to adult; major change in morphology/body function); all increase in size occurs through MOLTING –shedding old exoskeleton
Two major groups of Arthropoda based upon mouthparts
Chelicerate (e.g., spiders)
– jaw has pincer-like fangs
Mandibulate (e.g., insects, others)
– jaw is composed of mandibles
Chelicerata
group under phylum Arthropoda, jaw has pincer-like fangs
spiders(Sexual size Dimorphism common in arachnids), scorpions, daddy long-legs, ticks, mites, horseshoe crabs; 8-leg, no antennae; predators, parasites, detritivores
Class Hexapoda
under Phylum Arthropoda
PRIMARILY INSECTS; freshwater, terrestrial; detritivores, predators, herbivores; omnivores, parasites; 6-legged; all have antennae
flies, beetles, butterflies, moths, wasps, bees, and ants
Metamorphosis
transformation of body to new life stage; common to all insects(larval stage, resting stage, adult stage)
Class Chilopoda
under Phylum Arthropoda
centipedes – one pair legs/segment; terrestrial predators, venomous
Class Diplopoda
under Phylum Arthropoda
millipedes– two pairs legs/segment; terrestrial detritivores, produce chemicals to avoid being eaten
