Blue Crab Isa Species example essay topic
447 words
The scientific name given to the blue crab was derived from Latin and Greek: Calli, beautiful; nec tes, swimmer; and sapid us, savory. Thus, a literal transition might be the beautiful savory swimmer. The blue crab is an important and interesting species. The blue crab isa species whose life history involves a complex cycle of planktonic, nekto nic, and benthic stages which occur throughout the marine environment in a variety of habitats. The blue crab is one of the more abundant estuarine invertebrates and supports important commercial and recreational fisheries along the Atlantic and Gulf coasts. The blue crab plays an important role in the marine food web, providing prey for many species and a predator on other species. The blue crab is a highly prized commodity to consumers. Eight species of Callinectes have been documented in the Gulf of Mexico: C., C. danae, C., C. exasperates, C., C. similes and C., and Callinectes sapid us. The original range of the blue crab is from Nova Scotia and throughout the Gulf of Mexico to northern Argentina. The blue crab is rarely found north of Cape Cod, but has been recorded in Maine and Nova Scotia. The blue crab has been introduced into Europe, North Africa, and Southwest Asia. Introduction's into the Mediterranean Sea and surrounding waters have produced breeding populations whereas others were probably temporary occurrences.
The blue crab also has been introduced into Japan. Blue crabs are one of the most common marine invertebrates and are generally abundant throughout the oceans. Peak abundance of adult crabs occurs during the warmer months. During winter, crabs are found in areas of tidal exchange in the lower estuary. Juvenile blue crabs are most abundant in waters of low to intermediate salinity during the winter months.
Males become sexually mature at the 18 or 19th molt but may continue to grow and molt an additional 3-4 times thereafter. Female crabs were initially thought to rarely, if ever, molt again following their mature molt. However, mature females undergoing a second molt have been verified. No data on maximum age of blue crabs is available from the Gulf of Mexico, although it has been estimated to reach a maximum age of 4 years in Florida and 7-8 years in Chesapeake Bay. Autotomy (voluntary breaking of appendages) and regeneration are common in blue crabs.
One survey found that 19-25% of blue crabs were either missing or regenerating a limb. A functional appendage is formed by regeneration following the next molt, although three molts may be required for 100% limb regeneration.
