Invertebrate Classification Flashcards

Invertebrate Classification

• Porifera: Phylum of sponges, characterized by a porous body and lack of true tissues and organs.

• Cnidaria: Phylum including coelenterates with stinging cells and a hollow digestive cavity; classes include Hydrozoa (hydra, Portuguese man-o-war), Scyphozoa (jellyfish), and Anthozoa (coral, sea anemone).

• Platyhelminthes: Phylum of flatworms, features three main classes: Turbellaria (planaria), Trematoda (flukes), and Cestoda (tapeworms).

• Nematoda: Phylum of roundworms, distinguished by their cylindrical body shape.

• Rotifera: Phylum that includes rotifers, microscopic and generally aquatic organisms.

• Mollusca: Phylum characterized by soft-bodied organisms often protected by shells; includes classes Polyplacophora (chitons), Gastropoda (snails, slugs), Pelecypoda (clams, oysters), and Cephalopoda (octopuses, squids).

• Annelida: Phylum of segmented worms; major classes are Oligochaeta (earthworms), Polychaeta (marine worms), and Hirudinea (leeches).

• Arthropoda: Phylum with jointed-foot organisms, divided into subphyla Crustacea (crabs, lobsters), Chelicerata (spiders, scorpions), and Uniramia (insects, millipedes, centipedes).

• Echinodermata: Phylum of marine animals with spiny skin; includes classes Echinoidea (sea urchins, sand dollars), Asteroidea (starfish), Crinoidea (sea lilies), Holothuroidea (sea cucumbers), and Ophiuroidea (brittle stars).

Subphylum Details

• Crustacea: Subphylum of Arthropoda; features cephalothorax, antennae, mandibles, and typically five pairs of legs and swimmerets.

• Chelicerata: Subphylum of Arthropoda; characterized by the absence of antennae, presence of chelicera (pinching mouthparts), and four pairs of legs; includes classes Merostomata (horseshoe crabs) and Arachnida (spiders, ticks).

• Uniramia: Subphylum of Arthropoda; features chewing mouthparts and one pair of antennae; includes classes Diplopoda (millipedes), Chilopoda (centipedes), and Insecta (ants, bees, beetles).

Class Specifics

• Hydrozoa: Class within Cnidaria, includes freshwater and marine species such as hydra and Portuguese man-o-war.

• Scyphozoa: Class within Cnidaria, includes true jellyfish like Aurelia.

• Anthozoa: Class within Cnidaria, encompasses coral and sea anemones.

• Turbellaria: Class of Platyhelminthes known for planarians.

• Trematoda: Class of Platyhelminthes, includes parasites like flukes.

• Cestoda: Class of Platyhelminthes, known for parasitic tapeworms.

• Polyplacophora: Class of Mollusca, known for having many plates; includes chitons.

• Gastropoda: Class of Mollusca, features univalves or "stomach-footed" species like snails and slugs.

• Pelecypoda: Class of Mollusca, includes bivalves such as clams, oysters, and scallops.

• Cephalopoda: Class of Mollusca, characterized by a head-foot structure; includes octopuses, squids, nautilus, and cuttlefish.

• Oligochaeta: Class within Annelida, represented by earthworms.

• Polychaeta: Class of marine annelids known for their bristle-like appendages, such as feather duster worms.

• Hirudinea: Class of Annelida, includes leeches.

• Arachnida: Class of Arthropoda within Chelicerata; includes spiders, ticks, scorpions, and mites.

• Merostomata: Class of Chelicerata; includes horseshoe crabs.

• Diplopoda: Class of Uniramia; known for millipedes.

• Chilopoda: Class of Uniramia; includes centipedes.

• Insecta: Class of Uniramia; encompasses many diverse species including ants, bees, and beetles.

• Echinoidea: Class within Echinodermata; includes sea urchins and sand dollars.

• Asteroidea: Class within Echinodermata; known for starfish.

• Crinoidea: Class within Echinodermata; includes sea lilies and feather stars.

• Holothuroidea: Class within Echinodermata; known for sea cucumbers.

• Ophiuroidea: Class within Echinodermata; includes brittle stars.