underwater photography of great white sharks, dolphins, divers and other marine life by Stephen Brunson
underwater photography of great white sharks, dolphins, divers and other marine life by Stephen Brunson underwater photography of great white sharks, dolphins, seals, divers and other marine creatures underwater photography of great white sharks and dolphins by Stephen Brunson Award winning underwater photography of great white sharks and dolphins by Stephen Brunson All about underwater photographer Stephen Brunson underwater photography of great white sharks, dolphins, divers and other marine life by Stephen Brunson free screensavers, free wallpaper, free animations, free images underwater links and reciprocal link exchange
Crustacean: Spider Crab
Crustacean is the common name for mainly aquatic arthropod animals with jaws and two pairs of antennae, such as the crab, lobster, and shrimp, that constitue the class Crustacea. They are among the most successful animals, dominating the sea much as insects dominate the land. The majority of individual animals in the world are marine crustaceans of the order Copepoda. Crustaceans are also successful in fresh water; a few, such as wood lice, are also abundant in moist land environments. Although most crustaceans are small, they have a wide range of body form and habits, and the class includes larger invertebrates such as lobsters up to 2 feet long and a spider crab with a leg span of 12 ft. The class contains about 26,000 known species. Like all arthropods, crustaceans have an external skeleton (exoskeleton) and a body made up of a series of segments; each of these generallly bears a pair of two-branched limbs. In the course of evolution the segments and other parts of the body have become specialized. The limbs, used in respiration, swimming, crawling, and feeding, may be highly modified as jaws, reproductive organs, and other structures, or may be simplified or lost.
Crustaceans are modified for a wide variety of habitats and ways of life; their success may be partly accounted for by their being advanced organisms.  They are important in the the food chain, partly because so many of them eat small plants and animals.  Many of them strain small particles of food from the water, but the larger crustaceans such as lobster, shrimp, and crabs are often omnivores, scavengers, or predators. Several species are also parasites. Crustaceans, in turn, are eaten by many animals, including humans, and are rich in protein, such as lobster tails.
Print Number - CN015
Limited Edition signed color photography for sale by Stephen Brunson

In scientific classification, the terms shrimp, lobster, and crayfish do not refer to definite decapod groups. In popular terminology, shrimp is a term applied indiscriminately to small crustaceans, wheareas lobsters are thought of as large ones, and cray fishes are freshwater animals. Because the zoological classification has little to do with the size or habitat, common names are hard to reconcile with scientific ones. The spiny lobsters, which do not have large crushing claws, are placed in the section Palinura. The lobsters in the narrow sense (Homarus and Nephrops) are placed in the section Astacura, together with the crayfishes and mud shrimp.

Crustaceans are modified for a wide variety of habitats and ways of life; their success may be partly accounted for by their being "advanced" organisms. They are important in the the food chain, partly because so many of them eat small plants and animals. Many of them strain small particles of food from the water, but the larger crustaceans such as lobster, shrimp, and crabs are often omnivores, scavengers, or predators. Several species are also parasites. Crustaceans, in turn, are eaten by many animals, including humans, and are rich in protein, such as lobster tails.

Reproduction is primarily sexual in crustaceans; the only kind of asexual reproduction is parthenogenesis, (development from unfertilized eggs), but this is rare. Usually the sexes are separate; some parasites and most barnacles, however, which have difficulty obtaining mates, are simultaneous hermaphrodites (that is, male and female at the same time). This increases the number of possible partners and may allow self-fertilization as a last resort. A number of crustaceans also switch sex as they get older. Many crustaceans exhibit elaborate courtship behaviours, and the males may fight for the chance to mate.

BrunsonImages@att.net