Rat dissection labs start next week and continue for three weeks total (Labs 10-12) Dissection kits are provided (check your drawers now), but you are welcome to bring your own kit

Lab 9: Animals III: Deuterostomes

TODAY YOU HAVE A HAND IN FOR YOUR EXIT ACTIVITY

Task C-2 today does NOT deal with echinoderms and chordates… Let’s do it first!

work as a pair get one of the invertebrate keying boxes use the dichotomous key (Table 9-1) CORRECTIONS to Table 9-1 in your lab manual: 9. Two pairs of antennae; cephalothorax present subphylum Crustacea/class Crustacea 9. One pair of antennae, cephalothorax absent (mark out old subphylum here) Wings usually present; three pairs of walking legs....subphylum Hexapoda/class Insecta 10. Wings absent; more than three pairs of walking legs subphylum Myriapoda...11 Task C-2: Invertebrate keying

fill in Table 9-3 for each organism in the box (TAs will be checking for this as part of your exit activity) if you don’t know common names, ask a TA not all have subphyla you should expect to be able to make such phylum, subphylum, and class identifications on the lab final (without help or a key) for these and any other specimens that have been in lab Task C-2: Invertebrate keying

coelomate; unsegmented pentamerous radial symmetry water vascular system dermal endoskeleton with spines Phylum Echinodermata

4 selected classes to examine in lab: Asteroidea (sea stars or starfish) Ophiuroidea (brittle stars) Echinoidea (sea urchins and sand dollars) Holothuroidea (sea cucumbers) watch the video for body plan and feeding…. Phylum Echinodermata

examine the preserved specimens, note the following: for each: compare to Fig. 9-1, note body plan 5- part radial symmetry, endoskeleton, lack of segmentation Task A-1:Phylum Echinodermata Asteroidea (sea stars) – five arms, madreporite, central disc, mouth, tube feet, coelom Ophiuroidea (brittle stars) – five arms, central disc

examine the preserved specimens, note the following: Echinoidea (sea urchins and sand dollars) – look for pentamerous characteristics; jaws Task A-1:Phylum Echinodermata

examine the preserved specimens, note the following: Holothuroidea (sea cucumbers) – not typically sedentary, just slow (lab manual is wrong) Task A-1:Phylum Echinodermata Radial muscle Cloaca & vent

group unified by four traits present at some point in the life cycle for all members Phylum Chordata

three subphyla Urochordata – tunicate or sea squirt Cephalochordata – lancelet or amphioxus Vertebrata – have a backbone; fish, amphibians, reptiles, birds, and mammals (classes listed later) watch the video for some information on the body plan and development…. Phylum Chordata

examine the preserved specimens and models, note the following: Urochordata – tunicate or sea squirt sessile adult; cellulose tunic, holdfast, siphons, pharynx image on following slide…. Task B-1:Invertebrate Chordates

examine the preserved specimens and models, note the following: Cephalochordata – lancelet or Amphioxus specimen, model, and slide; match to Figs. 9-2 and 9-3 note oral hood, fins, myotomes, dorsal nerve cord, notochord, pharynx, pharyngeal gill slits, postanal tail; other items from figures Task B-1:Invertebrate Chordates

Vertebrata – 7 selected classes Agnatha – jawless fish Chondrichthyes – cartilaginous fish (sharks, skates, and rays) Osteichthyes – bony fish with paired fins Amphibia – two pairs of legs; smooth skin (frogs, salamanders, etc.) Reptilia – two pairs of legs; scaly skin (lizards, snakes, alligators, etc.) Aves – feathers; paired wings and legs (birds) Mammalia – hair, mammary glands, two paired appendages Subphylum Vertebrata

obtain a “vertebrate box” and examine the preserved specimens, note the following: Agnatha – brook lamprey jawless; single median dorsal and caudal fins (no paired lateral fins); 7 pairs of external gill slits Chondrichthyes – shark scales (makes sandpapery skin); various fins (note especially those in pairs); claspers on pelvic fins of mature males; cloacal opening Task B-2: Subphylum Vertebrata

Osteichthyes – yellow perch scales, operculum over gills, various fins (note pairs); lateral lines (from operculum to caudal fin) Amphibia – leopard frog and salamander smooth skin (no scales); 4 legs – count digits; tympanum on frog; eyelids (do other box items have eyelids?) Task B-2: Subphylum Vertebrata

Reptilia – green anole lizard, turtle, and garter snake scaly skin, 4 legs (reduced to vestigial in snake); lizard – claws, eyelids; turtle – carapace and plastron Aves and Mammalia – no specimens demonstration table – identify specimens by class (you do NOT include them on Table 9-2, but they ARE eligible to be on the lab final) Task B-2: Subphylum Vertebrata