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Molluscs , Arthropods, Lophophorates , Echinoderms, and Invertebrate Chordates. Molluscs. Name means “soft-bodied” Usually covered by shell made of calcium carbonate Ex: chitons , snails (gastropods), clams (bivalves), octopods, squid, Range in size from microscopic to giant.
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Molluscs, Arthropods, Lophophorates, Echinoderms, and Invertebrate Chordates
Molluscs • Name means “soft-bodied” • Usually covered by shell made of calcium carbonate • Ex: chitons, snails (gastropods), clams (bivalves), octopods, squid, • Range in size from microscopic to giant
Body Structure: • Head-foot region • Covered by mantle • Used for locomotion • Can help form shell • Visceral mass • Radula contains teeth • Adapted for scraping, piercing, tearing, or cutting pieces of food
Reproduction and development: • Mainly sexual • Can have separate sexes or be hermaphrodites • Type of feeding: • Herbivores, Carnivores, Filter feeders, Suspension feeders, Scavengers, Deposit feeders
Ecological roles: • Source of food and calcium • Hosts to parasites • Can cause commercial damage
Arthropods • Name means “jointed-leg” • Body Structure: • Paired jointed appendages for locomotion, mouthparts, sensory structures • Hard exterior (exoskeleton) • Made of protein and chitin • Sophisticated sense organs highly developed nervous system • Segmented body
Reproduction: • Herbivores, Carnivores, Filter feeders, Suspension feeders, Scavengers, Deposit feeders • Chelicerates • Horseshoe crabs • Sea siders
Mandibulates • Decapods: crabs, lobsters, true shrimp • Mantis shrimp • Krill • Amphipods • Copepods • Barnacles • Ecological roles: • Food source • Common symbionts • Nutrient recycling • Can cause commercial damage
Lophophorates (Phoronida) • Sessile • Body Structure: • Lack distinct head • Feeding: • Possess lophophore • Feeding device • Also used for gas exchange • Ciliated tentacles around mouth
Reproduction: • Asexual by budding or fission • Some are hermaphrodites • Some have separate sexes • Phoronids wormlike • Secrete a leathery tube around the body • Bryozoans • Brachiopods lamp shells • Ecological roles • Filter feeders • Supply food • Fouling ship’s bottoms
Echinoderms • Name means “spiny skin” • Mostly benthic • Ex: sea stars, sea urchins, sea cucumbers • Body Structure: • Radial symmetry • Endoskeleton of calcium carbonate (ossicles) • Water vascular system • Used for locomotion, feeding, and circulating internal fluids
Reproduction • Asexual and sexual • Feeding • Herbivores, carnivores, filter feeders, deposit feeders, scavengers • Ophiuroids • Brittle stars, basket stars, serpent stars • Crinoids • Sea lilies, feather stars • Ecological roles • Source of food for molluscs, sea otters, spider crabs, and humans • Predators • Destroy kelp forests
Tunicates (Urochordates) • Sessile • Body structure: • Covered by a tunic composed of polysaccharides • Reproduction: • Asexual: in colonies • Sexual: hermaphrodites
Feeding: • Filter feeders on plankton • Ecological roles: • Channels nutrients for other organisms • Can have symbiotic relationship with photosynthetic bacteria • Widely distributed in all seas • Ex: sea squirts, salps, larvaceans
Cephalochordates • Fish-like chordates (lancelets) • Lack bones • Body resembles an eel • Reproduction: • Separate sexes • External fertilization • Feeding: • Feed on organic material from particles filtered from the water • Ecological role: • Channels nutrients for other organisms
Arrowworms (Chaetognatha) • In marine plankton (tropical water) • Body Structure: • Body is torpedo-shaped • Grasping spines around the mouth • Reproduction: • Hermaphrodites • Feeding: • Predators that feed on zooplankton • Carnivores • Ecological role: • Channels nutrients for other organisms