- المجال: Government
- Number of terms: 30456
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NOAA Coral Reef Conservation Program, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
Brittle stars are echinoderms (class Ophiuroidea) which are closely related to sea stars (starfish). They possess radial symmetry with a central body disc from which five highly flexible snake-like arms protrude. There is no replication of internal organs,as in the arms of sea stars, just one set in the central disk. Compared to starfish, brittle stars have a much smaller central disc and no anus. Wastes are eliminated through the mouth, which is situated on the undersideof the disc. The name is derived from their arms breaking off as a means of defense. New arms are easily regenerated. They are also called serpent stars because of the snakelike movements of the five arms.
Industry:Natural environment
Having separate sexes. Individuals within the species contain only one or the other of male and female reproductive systems.
Industry:Natural environment
Paleoclimatic evidence that can be used to indirectly infer or estimate some aspect of the paleoenvironment, such as precipitation or temperature. Temperature proxies such as tree ring widths and ice core layering are used by paleoclimatologists to create a past temperature record. Tree ring widths can also be used to infer precipitation changes. Isotopic variations in ice cores can be used to infer temperature changes and ice sheet volume. Beryllium 10 variations can be used to infer past solar irradiance .
Industry:Natural environment
Speciation occurring during a period of geographical isolation.
Industry:Natural environment
The electromechanical component of a sonar system that is mounted underwater and converts electrical energy to sound energy and vice versa.
Industry:Natural environment
The potential evolutionary success of an allele or genotype, which is defined as the reproductive success or the proportion of genes that an individual leaves in the gene pool of a population (expected contribution to future generations). The individuals with the greatest fitness leave the largest numbers of offspring.The fitness of genes and organisms is always relative to the other genes and organisms that are present in the same population.
Industry:Natural environment
The total amount of chemical energy fixed by the processes of photosynthesis minus the chemical energy lost through respiration; same as 'net photosynthetic rate'.
Industry:Natural environment
the National Oceanic and Atmospheric Administration (NOAA) is a federal agency within the US Department of Commerce that is dedicated to predicting and protecting the environment. NOAA's overall mission is to understand and predict changes in the Earth+s environment, protect life and property, provide decision makers with reliable scientific information, conserve and manage the Nation+s living marine and coastal resources to meet our Nation+s economic, social, and environmental needs, and foster global environmental stewardship. To achieve its mission, NOAA+s focus through 2008 will be on four mission goals:
1. Protect, restore, and manage the use of coastal and ocean resources through ecosystem-based management.
2. Understand climate variability and change to enhance society+s ability to plan and respond.
3. Serve society+s needs for weather and water information.
4. Support the Nation+s commerce with information for safe, efficient, and environmentally sound transportation.
Industry:Natural environment
A chemical agent which retards and prevents the reproduction and growth of algae.
Industry:Natural environment
