Organism Profile SCIN 130
Species Profile of the Maryland Blue Crab (Callinectes sapidus)
Roberto Garcia
American Public University System
Abstract
The Callinectes sapidus also known commonly as the Maryland Blue Crab, is a crustacean found in the Chesapeake Bay. The blue crab is found in aquatic environments, most often in estuaries. It characterized by it’s blue claws. The blue crabs undergo a life cycle of: zoeae, megalop, juvenile, and adulthood. The blue crab’s hard shells serve as a protective barrier for external dangers. The Callinectes sapidus comes from the order of Decapods, whereby it’s carapace has now evolved to be better suited for swimming. Of interest is the blue crab’s mating
…show more content…
It shares ancestral background with shrimp and lobsters. They are omnivores with their prey being mussels, fish, plants, and smaller blue crabs (Society). Although the Blue Crab is well established within its ecosystem it is highly sensitive to environmental and habitat changes ("Blue Crab, Maryland State Crustacean", 2016). The detrimental conditions of the Chesapeake Bay have affected the populations of Blue Crabs along with over harvesting.
Life Cycle The life cycle of a Blue Crab involves Zoeae, Megalops, Juveniles, and Adulthood (Zinski, 2006) (“Blue Crab Life Cycle, 2016). Mating occurs only once for female crabs. Female crabs undergo a pubertal mold which is indicative of a sexually mature state in their life cycle. During the pubertal molt females release pheromones which attract males. The actual ritual of mating does not occur until females molt their shells (Zinski, 2006). At which point females will then retreat to high salinity water to begin spawning. Spawning will occur for the first time 2-9 months after mating. Interestingly, males will protect females during the period which females have molted and it is at this point in which mating occurs (Hill, 2004). As previously mentioned Blue Crabs are highly susceptible to changes in environmental conditions. As an example, larvae require high salinity waters. Larvae require salinity of at least 20 ppt and below that threshold, there is poor likelihood of survival ability.
To approach this problem, eggs of the brine shrimp were placed in 5 different solutions with different salinity. By observing how many eggs hatch per given number of eggs in the solution, the hatching viability was calculated for each solution.
The thick shelled snails that have survived against the predation of the crabs were able to reproduce and have offspring with thick
Crayfish (Procambarus clarkii) are crustaceans that are similarly related to crabs, lobsters and shrimps. They live in partly salty water (brackish water), rivers, ponds and are considered omnivores because they feed on small fishes, plants, detritus, mollusk, and other small invertebrates. Crayfish have a hard-calcified exoskeleton which is typically made of structural polysaccharide called chitin. This calcified exoskeleton must shed for the crayfish to grow (Fitzgerald, 2006).
This species of communal crab only grows to a width of 1 inch, and has a square purplish body. The main source of food for these creatures are the leaves of marsh cordgrass, and the occasional smaller species of crabs like fiddler crabs. They are also nocturnal creatures, which makes them hard to study. Predators of this species include the Blue Crab, Striped Bass, and certain species of marsh birds.
Mira Kamdar, a French writer, writes her article "America's Gun Madness, as Seen from Europe" to inform her audience about the foolish lack of rules America seems to have on guns compared to other European countries. Kamdar's mother lives in a small city in Oregon, which was recently in the news for the mass shooting at a community college. This story not only made national news for America, but according to Mira, made international news to countries like France. After receiving this news, Mira writes this article to compare and contrast the gun laws in France and what seems the lack of gun laws and regulations in the United States. A mass shooting like the one at Umpqua Community College and even Sandy Hook Elementary School stun citizens
This perspective often distorts the view of large crabbing businesses on their harvesting methods which, although are seemingly humane, are actually very detrimental to the crab population. For instance, when Hal Herzog, a Professor of Psychology at Western California University, ventured to Florida’s Gulf coast, the crabbers there explained to him the two varieties of crabs which they harvested; the “lucky” stone crabs and the “unlucky” blue crabs (Herzog). The blue crabs were considered unlucky because they were killed on the spot; however, the stone crabs were considered lucky because of their ability to regenerate their claws, and so crabbers would simply rip their claws off and then throw them back into the sea (Herzog). However,
Crayfish, Orconectes propinquus, are ectotherms that do not generate internal heat and rely on external temperatures to determine their body temperature. The crayfish we tested were found in Medway Creek and therefore undergo considerable temperature changes throughout the year. Since these crayfish are able to adapt to various temperatures allowing them to live in numerous places, their survival rate would be higher than many other organisms.
This essay will explain why the movie Their Eyes Were Watching God differed from the book itself from which it was made. In the book version of Their Eyes Were Watching God the idea of fellowship is portrayed profusely, but the movie has a different viewpoint. The movie over sexualized the book to make it seem more appealing to the people, but it makes the movie seem poor of quality. One of the most important things the movie forgets to present is the coming of age of Janie. By not representing the characters and the scenes precisely the movie lacks being worthy of such a good book.
According to evidence card D, in the area where the crabs live only green and yellow light make it all the way to the ocean floor. That is, if the rays aren't stopped or absorbed. Also according to evidence card A these crabs can see all colors of visible light. If the crab lives on the ocean floor this shows that light does reach the surface and the crabs on the ocean floor can see it. This light may not light up the the entire world around the crab because it depends on what materials absorb the light but as a matter of fact, according to evidence card C, plankton reflect all light so the crabs should be able to see
Taking about a week to fully mature into an adult and living for several months, the shrimp do have a surprisingly long life cycle being also able to reproduce up to 300 cysts every 4 days in the right conditions. Other variables such as salinity, temperature, light, pH levels, water levels and predatory presence play a large role in the hatching rate of the crustacean. The brine shrimp are an extremely versatile micro-crustacean as they can survive up to 10x salt concentration of ordinary sea water (Eol.org, 2016) and are able to protect themselves during drought or when conditions are not ideal for survival. This is called highly resistant encysted gastrula embryo (cyst) that is easily able to hatch under conditions that can be replicated at home.
Ray McClain). The ‘farmed’ and the wild crawfish are both composed of the same species, the red swamp crawfish (Procambarus clarkii) and the white river crawfish (P. zonangulus). The more popular of the two crustaceans the red swamp crawfish, as it is caught more often is purchased more at the market. There are other crustaceans that are important to the basin besides crawfish, however. Blue crabs (Callinectes sapidus) are a vital resource in Louisiana’s seafood industry. The crabs are harvested by way of traps. In the case that the traps are lost or abandoned, they will continue to catch crabs. This is leading to a downturn in the blue crab population. Fish are also affected by the traps, as they are also caught. Despite the risked to the crab population, , the Marine Stewardship Council recognized the Louisiana blue crab fishery as the only sustainable blue crab fishery in the world in March of
The last things that have some effect on the shrimp habitat is the weather. For the last two to three years we have been in a drought. This can also cause the stream or creek to been dry up or low on water. When the stream dry up can cause the whole habitat to an end. Also when we in a drought with little to no rain the shrimp can’t survive due to the water is not moving from other end of the stream. The water is not moving then the shrimp doesn’t have a lot of food source to eat.
Think of the saying, “you are the apple of my eye”. Most of today’s society understands that somebody is referring to someone that they cherish above all else. This phrase is a common metaphor that is used all around the world. Many times authors use a metaphor to convey a message without telling it right out to the reader. This technique is used by Harper Lee in her novel To Kill a Mockingbird. The title of the novel refers to persecution of the innocent which is highlighted by showcasing Arthur Radley as the mockingbird of the story, and the oppression of refugees relates this metaphor to today’s society.
Although the Easter Shore of Maryland is most well known for their shellfish, the abundance of shellfish barely scratches the surface of the marine life found in the Chesapeake Bay. From the shallows of the Bay to the bottom in one hundred feet of water, the life found in the Bay varies drastically. The different conditions foster an assortment of fish such as permanent residents, migrants, and occasional visitors. It is home to mature fish and is also an important nursery ground for millions of ocean fish (Blair and Ansel 111). About two hundred and two species have been recorded as permanent residents of the Chesapeake and there are four classes of migratory fish (“Chesapeake Wildlife”). Species such as shad, alewife, and striped bass leave the marine environment to spawn in fresh water. In the summer, hardhead, spot, and menhaden reside in the Bay. Bluefish are a common migrant found in the
Two crab species, Plagusia and Cyclograpsus, were collected from a local estuary in the littoral and deep water zone for osmoregulation studies. To examine differences in osmoregulatory mechanisms among the species, haemolymph of the specimens was extracted once they were acclimated to varying concentrations of seawater. Using the comparative melting-point, capillary tubes were filled with small samples of seawater and blood then frozen and melted in a -15˚C ethanol bath. The melting time of each was observed thereafter. Subject’s time range fell over 17 minutes of which the majority of the most salinated samples melted