Observations: April 10, 2002 Time: 10:15 am Weather: light rain

Dead Man's Finger Sponge Dead Man's Finger Sponge (Haliclona oculata) is a primitive animal whose ancestors date back 550 million years ago. It lives permanently attached to hard surfaces on the floor of the Bay of Fundy. Visitors often find dead specimens lying along the "strand line", an area on the upper beach where the waves deposit all sorts of the bay's treasures, especially after a storm. The sponge is considered primitive because it does not have organs. Eating, waste removal and breathing are handled by individual cells, which act almost independently. Holes or pores on the surface of the sponge contain tiny cells that produce a current inward to bring in food and oxygen and outward to remove waste. The waste pores or "osculum" are the larger pores along the body. Tiny plankton or fine particles of plant material suspended in the water are the foods that nourish the sponge. One "finger" of this sponge will filter up to 113 liters (30 gal) of water a day.The skeleton of the sponge is constructed of tiny rods of a protein called spongin. It is these skeletons that are used for natural bath sponges.

What Colour is that Crab? During your visit to the park, be on the lookout for green crabs (Carcinus maenas) in the tidal pools and under rocks and rockweed during low tide. Their carapace (back shell) is slightly square in shape, olive-green in colour, and is usually no larger than 6-7 cm (1 1/2 - 2 1/4 inches) across. These green crabs may be distinguished from a Rock Crab by the 5 marginal "teeth" (points) along each side of their carapace. A green crab's diet consists of small marine worms and shellfish, but they also scavenge on dead fish found on the sea floor. Park visitors often find the green crab's empty shells or "molts" along the park's beaches and in the saltmarsh. As the crab grows larger, its outer shell (exoskeleton) does not grow. The green crab breaks out of the old shell through a small opening in the rear. (These are the pieces of crab shell you will find on the beach.) Then the crab eats large amounts of water and minerals (calcium) to "puff up" and begin creating a new, larger shell.

Look for Prickly-backed Tiny Fish in Salt Water Marsh Puddles Sticklebacks (family: Gasterosteidae) are small fish only 2.5 - 7.5 cm (1 - 2 1/4 inches) long. Look for the spines on their backs that give them their name. You will find them in the salt water puddles (salt pannes) within the marsh. These hardy fish are able to survive large water temperature changes from the sun and the cold in the shallow pannes. As the water evaporates in summer heat these tiny fish also survive changes in salt and dissolved oxygen concentrations in their puddle habitat. Generally, sticklebacks feed on fish eggs and small invertebrates. Male sticklebacks construct tunnel-shaped nests from bits of aquatic vegetation held together with mucus the fish secrete from their kidneys. After the female lays her eggs in the nest and the male stickleback fertilizes them, the male then guards the eggs. He remains until the eggs have hatched and are over a week old. This protection from the father stickleback significantly increases the survival rate of the small fry.

The Naturalist's Notebook is a regular publication. If you have any questions or topics that you would like to see addressed, please call John Gilbert, Manager, Fish and Wildlife, J.D. Irving, Limited, (506) 632-7777 or email honeyman.kelly@jdirving.com