Invertebrates

Question 1

Characteristics of Cnidaria

Answer 1

Radial symmetry
Body forms = polyp or medusa
Gastrovascular cavity, only one opening
Respiratory through diffusion
Nematocysts

Question 2

Families in Cnidaria: Anthozoa

+ Characteristics

Answer 2

Anemones, corals

Can move as colony
Liver near islands
Make CaCo3
Have a stomach cavity

Question 3

Characteristics of phylum Ctenophora (comb jellies)

Answer 3

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

Question 4

Characteristics of Porifera (sponges)

Answer 4

-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

Question 5

Characteristics of Phylum Platyhelminthes (flatworms)

Answer 5

20,000 + species 
Central nervous system, brain, nerve chords, muscularity system, organs
Bilateral
Many parasites 
No skeleton
Sexual, most have larval stage

Question 6

Characteristics of phylum Nematoda (roundworms)

Answer 6

Bilateral symmetry
Digestive tract, true organs
Hydrostatic skeleton
Many decomposes and parasites
Sexual with larvae
Often seen in fish flesh

Question 7

Characteristics of lophophorates

Answer 7

Bilateral
Unsegmented, colonial
Exoskeleton
U shaped gut
Sexual and asexual
Benthic filter feeders

Question 8

Characteristics of Phylum Annelida

Answer 8

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

Question 9

Characteristics of polychaete worms

Answer 9

Most Annelida: 6,000 sp.
Build tubes
Uses cilia and mucus for feeding
Can live singly or in aggregations

Question 10

Characteristics of Phylum sipuncula (peanut worms)

Answer 10

All marine: 350 species.
Benthic; most intertidal, a few deep sea
Unsegmented
Mouth and anus same end
Burrows
Sexual; external fertilization

Question 11

Characteristics of Phylum Echiura (fat innkeeper)

Answer 11

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

Question 12

Characteristics of cheatognatha (arrow worms)

Answer 12

Bilateral
Unsegmented, flattened, small
Cilia senses movement in water
Hydrostatic 
Planktonic
Predators
Hermaphrodites

Question 13

Characteristics of Molluscs

Answer 13

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

Question 14

Characteristics of Gastropoda (snails, midi branches, limpets)

Answer 14

90,000 species
Feed with radula & rasping tongue
Most have coiled shell
Most grazers
Some sessile but most mobile

Question 15

Characteristics of Bivalvia (clams, mussels, oysters)

Answer 15

2 crystalline shells made from enzyme secretion
Siphon, foot, gills
Make pearls
Laterally compressed
Some burrow, bore, or starch to hard surfaces

Question 16

Class Cephalopoda

Answer 16

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

Question 17

Class polylacophora

Answer 17

Chitons. 8 plates, radula, foot

Question 18

Phylum anthropoda

Answer 18

1 mil species: most abundant
Exoskeleton of chitin
Most periodically

Question 19

Characteristics of Crustacea

Answer 19

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

Question 20

Characteristics of Copepoda

Answer 20

Planktonic, major consumers of phytoplankton

Question 21

Characteristics of Decapoda

Answer 21

Crabs, shrimps, lobsters

Tail used to tell sex

Question 22

Characteristics of Isopoda

Answer 22

Kelp Isopoda

Some parasitic

Question 23

Characteristics of amphipoda

Answer 23

Sand fleas, caprellids
Occur in great numbers
Many benthic in soft sediment

Question 24

Characteristics of Cirripedia

Answer 24

Barnacles
Sessile, filter feed with feet
Hermaphroditic

Question 25

Characteristics of Echinodermata

Answer 25

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

Question 26

Characteristics of Asteroidea

Answer 26

Sea stars

Can have up to 50 arms
External digestion

Question 27

Characteristics of Echinoidea

Answer 27

Urchins and sand dollars

No arms
Sand dollars filter feed with tube feet and move with spines
Urchins graze algae

Question 28

Characteristics of Ophiuroidea

Answer 28

Brittle and basket stars

Arms wave like snake; used for movement and filter feeding

Question 29

Characteristics of Holothuroidea

Answer 29

Sea cucumbers

Lack spines (soft spiny projection)
Filter and deposit feeders
They clean the sand