Invertebrates Flashcards
Characteristics of Cnidaria
Radial symmetry Body forms = polyp or medusa Gastrovascular cavity, only one opening Respiratory through diffusion Nematocysts
Families in Cnidaria: Anthozoa
+ Characteristics
Anemones, corals
Can move as colony
Liver near islands
Make CaCo3
Have a stomach cavity
Characteristics of phylum Ctenophora (comb jellies)
8 rows of ctenes (ciliary combs) Bi-radial symmetry Cilia beats continuously-refracts light Realities at body surface Some have sticky cells (colloblasts) Rudimentary organs & simple guy
Characteristics of Porifera (sponges)
-most simple
-no symmetry
-collar cells intake food + O2
-pore cells intake H2O
-made of CaCo3, SiO2, or spongin
-sessile, benthic filter feeders
Most hermaphrodites w/ internal fertilization + broadcasting
-some reproduce asexually
Characteristics of Phylum Platyhelminthes (flatworms)
20,000 + species Central nervous system, brain, nerve chords, muscularity system, organs Bilateral Many parasites No skeleton Sexual, most have larval stage
Characteristics of phylum Nematoda (roundworms)
Bilateral symmetry Digestive tract, true organs Hydrostatic skeleton Many decomposes and parasites Sexual with larvae Often seen in fish flesh
Characteristics of lophophorates
Bilateral Unsegmented, colonial Exoskeleton U shaped gut Sexual and asexual Benthic filter feeders
Characteristics of Phylum Annelida
Bilateral, segmented Gut cavity. Complex movements and systems 2 central nerve chords Peristaltic movement Kidney for nitrogenous waste and parapodia on each segment Closed circulatory system Gills Hydrostatic skeleton Sexual; trochophore larvae
Characteristics of polychaete worms
Most Annelida: 6,000 sp.
Build tubes
Uses cilia and mucus for feeding
Can live singly or in aggregations
Characteristics of Phylum sipuncula (peanut worms)
All marine: 350 species. Benthic; most intertidal, a few deep sea Unsegmented Mouth and anus same end Burrows Sexual; external fertilization
Characteristics of Phylum Echiura (fat innkeeper)
Create U shaped burrows: habitat for other species
Sweeps detritus with proboscis and urechis using a mucus net
Pumps water through burrow and net
Can curl up like peanut worm
Many live in wetlands
Characteristics of cheatognatha (arrow worms)
Bilateral Unsegmented, flattened, small Cilia senses movement in water Hydrostatic Planktonic Predators Hermaphrodites
Characteristics of Molluscs
2nd abundant phylum in ocean; 110,000+ species Soft body with CaCo3 shell Bilateral, Unsegmented Ventral, muscular foot Radula made of chitin Desperate moth and anus Most have open circulatory system Most have trochophore larval stage
Characteristics of Gastropoda (snails, midi branches, limpets)
90,000 species Feed with radula & rasping tongue Most have coiled shell Most grazers Some sessile but most mobile
Characteristics of Bivalvia (clams, mussels, oysters)
2 crystalline shells made from enzyme secretion
Siphon, foot, gills
Make pearls
Laterally compressed
Some burrow, bore, or starch to hard surfaces
Class Cephalopoda
Siphon for jet propulsion
Funnel, ink, pen, beak
Octopuses: 8 arms. No shell
Squid: 10 arms, 2 tentacles, pen, largest invertebrate
Cuttlefish: 8 arms, 2 tentacles, cuttle bone
Class polylacophora
Chitons. 8 plates, radula, foot
Phylum anthropoda
1 mil species: most abundant
Exoskeleton of chitin
Most periodically
Characteristics of Crustacea
Copepods, crabs, lobsters, shrimp, krill, barnacles
Bilateral, segmented, jointed legs Dorsal heart and central nerve chord Simple brain Open circulatory system Separate sexes, planktonic nauplius larvae
Characteristics of Copepoda
Planktonic, major consumers of phytoplankton
Characteristics of Decapoda
Crabs, shrimps, lobsters
Tail used to tell sex
Characteristics of Isopoda
Kelp Isopoda
Some parasitic
Characteristics of amphipoda
Sand fleas, caprellids
Occur in great numbers
Many benthic in soft sediment
Characteristics of Cirripedia
Barnacles
Sessile, filter feed with feet
Hermaphroditic
Characteristics of Echinodermata
6,000 species Radial pentamerous symmetry as adults; bilateral larva 3 body cavities Endoskeleton of CaCo3 Water vascular system Poor circulatory system Non segmented Most benthic Most separate sexes
Characteristics of Asteroidea
Sea stars
Can have up to 50 arms
External digestion
Characteristics of Echinoidea
Urchins and sand dollars
No arms
Sand dollars filter feed with tube feet and move with spines
Urchins graze algae
Characteristics of Ophiuroidea
Brittle and basket stars
Arms wave like snake; used for movement and filter feeding
Characteristics of Holothuroidea
Sea cucumbers
Lack spines (soft spiny projection)
Filter and deposit feeders
They clean the sand
