Platyhelminthes (flatworms):

Why is flatworm mesoderm termed parenchyma?

Do flatworms have an open body space?

Which flatworms have rhabdites and what is their function?

What are three categories of symbiosis?

Distinguish commensalism, mutualism, and parasitism.

What are typical adaptations found in parasites?

How and why do free-living and parasitic flatworms differ in their tegument (epithelium or ectoderm)?

Which flatworms have a complex life history?

What are common intermediate/definitive hosts?

Briefly describe the specific life cycle:

a) Trematoda (flukes); b) Tapeworms

Describe and order these terms:

miracidium, sporocyst, rediae, cercariae,


Why are some flatworm teguments termed syncytial?

What similar (analogous function do these structures have?

the opisthaptor (Monogenea)

the scolex (Cestoda)

What is a proglottid?


Basic Molluscan Features:



mantle cavity



coiling vs. torsion

Mollusc subgroups:

"aplacophorans" —some molluscs lack shells

Polyplacophora (chitons) — bilaterally symmetrical, 8 shells, repeated gills, trochophore larva

Conchifera (incl. snails, clams, squids, etc.)

Gastropods (snails, slugs) — torsion, veliger larva

Cephalopods — (squids, Nautilus) — predators, large head, siphuncle

Bivalves — (clams, etc.) — no head, most feed with gills (ctenidia)


positive/negative aspects of molluscs

visceral mass (gut, blood, gonads)

blood pigments — hemocyanin

spiral cleavage (as in annelids, some flatworms)

serial repetition (ancestral or derived?)

What is HAM and why was it criticized in lecture?

How do various snails achieve sanitation designs while circulating water past their gills?

What is the periostracum?

Contrast prismatic and nacreous shell layers.

What is the primary function of each of a clam mantle’s three folds?

How do land snails respire?

Distinguish torsion and coiling in molluscs.

What is a potential advantage of a coiled shell?


polychaete ("setae") annelids ("rings")

clitellate annelids not covered (earthworms, leeches)

but what synapomorphy characterizes them?

crawlers: Nereis (Fig. 17-3, 17-7)

crawlers use setae on ventral parapodia

what are aciculae?

what are dorsal parapodia used for?

how does Nereis eat?

where are its gametes, blood cells?

what is a mesentery?

what is prostomium? peristomium? pygidium?


Amphitrite (Fig. 17-4) and Arenicola (17-5)

earthworm (Fig. 31-5, p. 647)

compare locomotion to crawlers

tube-builders: Sabella (Fig. 17-2, 17-10)

sanitation problem of living in tube

compare feeding with burrowers?

suspension vs. detritus feeders


Arthropods, Diversity

General Terms

• exoskeleton, cuticle layers, molting

• segmentation (contrast annelids), tagmatization

• know underlined groups on hand-out

• know the basic body plan of four groups

chelicerates, myriapods, crustaceans, and insects

• how are chelicerates (and trilobites) different in their mouthparts?

• why are arthropods so diverse and abundant?

• advantages/disadvantages of exoskeleton

• what secretes cuticle? what are the layers?

procuticle (exocuticle/endocuticle) vs. epicuticle

• molting/ ecdysis/ ecdysone / juvenile hormone (pp. 425-426)

• specialized segments (tagma)/appendages

• limbs as levers, rapid striated muscles

• sensory hairs

• feeding/locomotion

• trachea on land

• compound eyes

• antennae (sensory), mandibles (masticatory), maxillae (food handling)

• "caridoid facies" of malacostracan crustaceans

• cuticle, ecdysis, ecdysone, juvenile hormone

• compare lobster vs. moth molting (pp. 397, 425)

• who has: nauplius larva? cyprid larva? zoea larva?

• name a maxillopod relative of a barnacle

• be familiar with underlined crustacean names

• can you draw a cladogram of selected names?

• how are remipedes and cephalocarids noteworthy?

• can you name a branchiopod? a maxillopod?

• name three groups of malacostracans

• does an arthropod have a coelom?

• does an arthropod have blood pigments?

• what are major groups of land arthropods?

• which groups have the most species?

• which insect "orders" are most speciose?

• what factors contribute to being speciose?

springtails/silverfish lack what common insect body parts?

• why are these missing?

• contrast hemi- and holometabolous development

• give some examples with each type

• who has internal wing pads as larvae?

• what are the three body regions of an insect?

• what structures are found on the head?

• give some examples of different insect mouthparts

• how are antennae used?

• what paired structures are found on the thorax?

• give examples of wing modification

• what structures are found at the abdomen?

• how do insects respire?

• how do they control the openings to the outside?

• what are malpighian tubules? sensilla?

• how do insects sing? attract mates? exchange gametes?

• what are instars? nymphs?

• contrast brain, molting, and juvenile hormones