ClassificationKingdom: Animalia
Phylum: Arthropoda Class: Crustacea Order: Thoracica Family: Archaeobalanidae Genus: Semibalanus |
MorphologySymmetry: Bilateral
Structure: The opening at the top of the 'cone' is diamond-shaped, and can be covered by movable plates when the tide goes out. This protects the animal inside from desiccation Appearance: Adult acorn barnacles are sessile; they have a cone shaped shell-wall comprising a number of calcareous pates. Distribution Map![]() This species lives in the intertidal zones of the boreo-arctic regions of the Atlantic and Pacific oceans.
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BiologyThe barnacle functions as both a male or female. There is a single breeding season during autumn. Functional males extend the penis, which is much longer than the body, out of the shell wall and seeks a nearby functional female. After fertilisation, the embryos are stored within the barnacle's body, until they develop into 'naupilus' larvae. These are released into the water from February to May, and live in the water column feeding on plankton for several weeks. They undergo six moults, before developing into a second larval form known as a 'cyprid' larvae. This stage is specialised for seeking a suitable site for settling. They search the substrate with their antennae; once a suitable site has been found they release a substance that fastens them to the rock. This typically occurs in spring and early summer. They then undergo metamorphosis into the adult form. Sexual maturity may be reached in the first year after settlement, but it usually takes 2 years. An adaptation they have is being able to close their shell when high tide.
ImportanceRecently, there has been great interest in barnacle cement for its possible use in both dentistry and bone surgery due to its incredible properties. For example, a layer of cement three thousandths of an inch thick over one square inch will support a weight of 7,000 pounds. At high temperatures the glue will not crack and it does not dissolve in most strong acids, organic solvents, or water. Through its usage, filings could be placed on teeth and bones could be mended.
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Facts
* Barnacles are hermaphroditic (they have both female and male sex organs), so they cross-fertilize with their next-door neighbors.
* Barnacles are successful creatures with abundant and diverse populations. Scientists have identified about 1,445 living species, of which 900 are acorn barnacles. * Barnacles encrusted on ships can cause enough drag to increase fuel consumption by 40 percent. * Barnacles brood fertilized eggs within their shells. * Cement glands within the antennae produce the brown glue that fastens a barnacle to a hard surface. Acids and alkalis do not dissolve this incredibly strong glue that can hold the base of the shell to a surface long after the barnacle is dead. Dentists, interested in the adhesive power of this glue, have been trying to determine its properties. |
Vocabulary
Calcareous
Containing free calcium carbonate, chalky.
Hermaphrodite
Possessing both male and female sex organs.
Larvae
Stage in an animal's lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
Metamorphosis
An abrupt physical change from the larval to the adult form.
Containing free calcium carbonate, chalky.
Hermaphrodite
Possessing both male and female sex organs.
Larvae
Stage in an animal's lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
Metamorphosis
An abrupt physical change from the larval to the adult form.
Resources
http://www.arkive.org/acorn-barnacle/semibalanus-balanoides/
http://www.montereybayaquarium.org/animal-guide/invertebrates/acorn-barnacle
http://www.montereybayaquarium.org/animal-guide/invertebrates/acorn-barnacle
Echinoderm- Chocolate Chip Sea Star
ClassificationKingdom:Animalia
Phylum:Echinodermata Class:Asteroidea Order:Valvatida Family:Oreasteridae Genus:Protoreaster Species: P. nodosus Distribution MapChocolate chip sea stars live in the warm areas of the Pacific Ocean, Indian Ocean and Red Sea. Found all over sea grass beds and sandy areas, these sea stars live in shallow water areas. They can also be found on coral reefs to depths of 100 feet.
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ImportanceEconomical: Common to both the pet fish and souvenir trade alike, the Chocolate Chip Starfish is well known among aquariums as well as to tourists and curio collectors.
Ecological: P. nodosus possess rows of spines or "horns"; black conical points arranged in a single row, radially on the dorsal side, which may erode and become blunt. These dark protrusions are used to scare away possible predators, by looking frightening or dangerous.
Facts*Chocolate chip sea stars reproduce by spawning or releasing eggs and sperm into the ocean at the same time.
*Females can produce up to 65 million eggs per each spawn.
*Sea stars go through five growth stages before coming to be the star-shaped animals with which we are familiar.
*Chocolate chip sea stars that get too large for the home aquarium and may try to eat their tank mates.
*After they get big enough, these sea stars emerge and begin to travel the reef in search food.
Vocabularycentral disc- the central portion of a sea star from which the arms or rays radiate
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MorphologySymmetry: Radial
Structure: Like a chocolate chip cookie, this sea star has dark brown pointytubercles or horns shaped like chocolate chips all over the top of it for protection.
Appearance: The chocolate chip sea star has five arms and can be found in a variety of shades ranging from light brown or cream to a brilliant deep orange. The 'chocolate chips' are variable in size, color and pattern between individuals. There aren't two chocolate chip sea stars exactly alike. Chocolate chip sea stars can be up to 16 inches.
Biology Sea stars can regenerate or regrow arms if they are bitten or ripped off by a predator or grow a new individual from a ripped off arm. Sea stars cannot see. They have an ‘eye spot’ on the end of each arm. The eye spot can detect changes in light and dark, but cannot make out distinct shapes, colors or details.
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Resources
https://en.wikipedia.org/wiki/Protoreaster_nodosus
http://www.svsu.edu/~tkschult/moia/chocolate-chip-sea-star.html
http://www.svsu.edu/~tkschult/moia/chocolate-chip-sea-star.html
https://www.acaquarium.com/animals/chocolate-chip-sea-star/
http://www.wetwebmedia.com/ca/volume_6/volume_6_2/choc.htm