LAB # 5: PHYLUM ANNELIDA
Movie
I. Phylum Annelida - Segmented Worms
A. Class Polychaeta – Mainly Marine Annelids
1. Nereis – A large Marine Polychaete
a. Study external features of preserved Nereis (Pp. 185-187).
Note black jaws with teeth inside the pharyngeal region (Fig. 12.3 and Fig. 12.4). * Recycle your specimen (this means put it back in the container)!
b. Slides of X.S. and parapodia; compare with Fig. 12.5 on p.187.
2. Other Marine Polychaetes (Pp. 188–189) – DEMO preserved specimens:
a. Chaetopterus – a tubeworm similar to Diopatra (Fig.12.15, p.195) with preserved tubes.
b. Arenicola – preserved lugworm, p. 195 Fig. 12.17.
c. Bloodworms – Smaller, smiliar to Nereis with smaller parapodia, commonly used in salt water fishing.
d. Sea Mouse (Aphrodita) – A large bottom dwelling polychaete covered with setae, preserved.
e. Small, Live! Polychaetes on bottom of Reef Tank!
B. Class Oligochaeta – Earthworms and Relatives
1. Lumbricus terrestris – the large “Nightcrawler”
a. Live! Specimens, rinse off dirt and place a worm in the anesthesia for 40-50 seconds. Quickly dissect open the anterior most 1 ½ inches of the Dorsal (dark) side to observe their beating hearts at very low power through a dissecting scope (Fig. 12.9, p. 190). Dispose of worm in White Bucket when done.
b. Dissect the first 2 in. of a preserved specimen; study external & internal anatomy (pp. 189-191).
c. Use Model for difficult structures such as nephridia (Fig. 12.9 p.190) which are color coded green on Model.
d. Study Slides of X-Sections for certain internal structures such as the typhlosole (Fig. 12.12, p. 192). What is the function of this structure?
C. Class Hirudinea – Leeches
1. Live Specimens! – Make some new friends.
2. Slides of X- Sections
3. *DEMO of whole small leech, compare with Fig. 12.14, p.194
4. Preserved Specimens – Note the Large Medicinal Leech.