Dead Man's Fingers

Remains of sponges can be found along the shoreline. Haliclona oculata Class: Demospongiae Order: Haplosclerida Family: Chalinidae Genus: Haliclona Distribution It occurs along the coast of Demospongiae, these sponges are global in distribution. There are North America, from the well over 7,500 known species with probably just as many yet to Gulf of St. Lawrence to be discovered. They are thought to have evolved 500 million North Carolina. Also along years ago. There are several different orders, Haplosclerida being coastal areas of Portugal, one of them. Within this order is the family of Chalinidae which France, the Netherlands, contains the genus Haliclona. There are a great number of species British Isles, Shetlands, in this group including Haliclona oculata. This is a northern Faroes, Denmark, Sweden, species and is well distributed on both sides of the northern Norway, Spitsbergen, Bear Atlantic. It is common in Nova Scotian waters. At Burntcoat Island, White Sea, Kara Sea. Head they occupy the surrounding coastal area. Habitat They live at the bottom of seas, lakes or rivers and can be found Sponges are benthic and for on open coasts and the outer reaches of estuaries, usually in the the most part occur on sublittoral zone. This is the zone between the low tide mark and bedrock, attaching the 100 m depth. Depths vary with geographic location. The themselves to firm, solid hard substrate is typically located at the base of rock cliffs and substrates. They mostly consists of outcrops, boulders, and rock debris of decreasing grow in shallow, subtidal size. They can tolerate low salinity and turbid water with and occasionally intertidal suspended silt. Some (other) species range from intertidal to habitats, often associated hadal depths, occupying deep trenches on the sea floor. with rather silted water. Ambient water is drawn into the body of the sponge from the Food water that constantly passes over their pore covered (ostia) Haliclona are suspension bodies. Excess water and wastes pass out through the excurrent feeders. Minute particles of pores (oscula). Microscopic food particles are removed by a food are filtered from water specialized collar of microvilla cells. These cells capture the for consumption. particles for digestion. Digestion is intracellular (by the cells). Reproduction Hermaphrodite sponges are able to perform both male and Sponges can reproduce female functions, playing one role at a time. When reproducing either sexually or asexually. sexually sperm is released into the water and taken in by other Most are hermaphroditic, sponges. Larvae then develop within the parents and are capable of producing both released along with the excurrent water. Sponges can also eggs and sperm. reproduce by budding off portions of the body. Development Released larvae have an The outer hair like cells are capable of whip like, outer layer of flagellated lashing movement allowing the larvae to move cells used to propel them about. These free-swimming larvae, after leaving through water. The inner the parent sponge, continue to develop until ready mass contains many other to settle down and become new sponges. diversified cells. They are, They also develop from buds. These buds can be in a sense, prefabricated either internal or external. Both types grow into new juveniles. sponges. Characteristics Sponges are animals, not Sponges have no mouth, internal organs or plants. This species of nerves. Instead, their body is full of tiny holes, sponge has a branching which help them to eat and breathe. Skeletal structure. Finger-like structures contain spicules and spongin fibres. projections grow from a Spicules provide support, and spongin fibres short stalk or base. Usual form a mesh work to provide firmness to the size is between 10 and 30 sponge body. Towards the base the sponge is cm. These fingers are firmer. They are often mistaken for plants. compressible and flexible. Pieces of (dead) sponge are commonly found The colour is yellow or light on beaches as their skeletons are strong brown, sometimes with a enough to survive the waves that wash them greenish or reddish tinge. ashore. They have lost their bright colours but generally retain the shape they had when alive. Adaptations They have two amazing abilities to regenerate. They are capable of adapting to local When pieces (buds) have situations. The branches may remain broken off from a living isolated along their entire length. Under sponge a new sponge can sheltered conditions, branches are grow from one of these occasionally flattened, antler-shaped buds. The internal bud and less numerous. The shape and (gemmule) is like a survival degree of branching is greatly affected pod, holding the cells that by the strength of the water counter will start another sponge. If flow, with the many branched form the parent sponge dies the being found in strong currents. gemmule survives and They are able to survive in cool and grows into another sponge. warm ocean temperatures. Status/Threats Currently these are not Predators include spiny sunstars and sea slugs and some species under any environmental of fish. threat. Note. The common name of Dead man’s fingers is quite Sightings in Nova Scotia popular. It not only refers to this sponge but also to a species of These grow in Nova seaweed Codium fragile; a plant and its fruit Decaisnea; a coral Scotian waters just below Alcyonium digitatum; a fungus Xylaria polymorpha, and the gills of the low tide line. some crabs. .

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