1. Observations of a live bloodworm.
a) Place a live bloodworm in a container of seawater.
b) Observe and describe its size, color, symmetry and protective adaptations.
c) How does it move? Use a hand lens to study the sides of its body for specialized structures. These paddle-like appendages on each side of every segment categorizes it as a polychaete (poly means many and chaete means bristles).
d) Notice that the body is divided into segments similar to its land cousin the earthworm.
2. Digging worms
a) A trip to the mud flats is an experience that will not be forgotten. Be sure to wear tight boots or a pair of old sneakers for your feet. A complete change of clothes is highly suggested, as well as a garbage bag to take home your muddy clothes.
b) Locate small holes on the surface of the mud which may be the entrances to the worm's burrow. The presence of piles of mud balls called castings near the opening is a sure sign.
c) Identify the worm's mucus-lined burrow as you dig. Why is the wall of the burrow a different color from that of the mud? (The burrow receives oxygen from the surface due to the worms activities)
d) Screen the mud with a sieve or a window screen to observe the contents of the mud. Identify and describe each type of worm that is found in the mud flat.
e) Make the following observations about each worm: (Be aware that some worms bite.)
-swimming technique in a bucket of water -crawling technique on the surface of the mud, any tracks? -body plain or segmented, round or flat, color(s) on top and bottom
-presence or absence of side feet or paddles -tentacles and eyes on the head
-proboscis with teeth
f) When you have completed your observations place the worms back on the surface of the mud and record their burrowing time. Or, you may now take your bait and go fishing. 3. Experiment on the effects of temperature on the metabolic activity of worms.
a) Obtain a bloodworm or sandworm from a mud flat or a local bait dealer.
b) Place the worm in an observation dish or test tube with seawater. Observe the expansion and contraction of the dorsal blood vessel using a dissecting microscope. The tail end of the worm provides a more obvious beat for determining the pulse rate.
c) Prepare water baths of varying temperatures. Place the observation chamber with the worm into these baths and record the pulse rate. Allow the water in the observation chamber to assume that of the bath.
a) The bloodworm industry in the State of Maine. b) The use of worms in recreational fishing.
c) How bloodworms concentrate PCB's (polychlorinated biphenals) and how it effects the food chain. d) The effects of the nuclear power plant "Maine Yankee" on the worm population.
Classification: Phylum: Annelida; Class: Polychaeta
Description: Bloodworms are creamy pink segmented worms with small fleshy projections called
para- podia. Their pale skin allows their red body fluid to show through, hence, the name
"bloodworm." Their anterior end has a small tapered postomium with four small antennae.
Habitat: These worms burrow into sandy-mud or silty-clay of the intertidal and subtidal regions.They can tolerate low levels of oxygen in the substrate as well as minimum salinity.
Movement: Bloodworms are excellent burrowers utilizing their prostomium, short stiff parapodia and peristaltic muscle contractions. During the winter months, they redistribute by swimming to another area thus repopulating a flat.
Respiration: Each parapodia has two finger-like gills where gases are exchanged with their body fluid.
Ingestion: These worms have a large eversible proboscis armed with four hollow jaws which are connected to poison glands. These "fangs" impale and kill their prey and can inflict a painful bite to unwary humans.
Growth: Bloodworms can grow up to fifteen inches in length. Their rate of growth is affected by the availability of food, temperature and salinity.
Excretion: Liquid wastes are eliminated from each segment via tube-like structures called
"nephridia." the nondigestible solids are packaged within fecal pellets and regurgitated.
Nervous System: The anterior brain is connected to a large ventral nerve cord. This cord runs from the anterior to the posterior end of the worm.
Circulation: These worms do not have a highly developed circulatory system. Coelomic fluid containing hemoglobin is circulated by perismlic body movements.
Reproduction: During the middle of June, the water temperature and tidal stage initiate the spawning process of the sexually mature worms. They swim to the surface of the water where the males emit sperm and the females burst releasing their eggs. Both sexes of worms die after spawning.
Common Names: "beak thrower"
Predators: They are preyed upon by other carnivorous worms, crustaceans, fish and seagulls.
Commercial Value: Dollar per pound, bloodworms are Maine's most valuable marine resource. The 1999 landing was 514,717 pounds valued at $2,887,769.
Other Gulf of Maine Species: Sand worm (Nereis virens), Lugwonii (Arenicola marina), Terebellid worm (Amphitrite johnstoni), Scale worms (Harmothoe species) and Trumpet worm (Pectinaria gouldii)
External Anatomy of a Blood Worm
Glycera di Branchiata
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