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
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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.
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.
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
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
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.
Crabs spawn near the mouth of the Bay in Virginia water, therefore few sponge crabs (female crabs carrying eggs) are seen in Maryland (“Chesapeake Wildlife”). Juvenile crabs migrate northward to feed and grow in the brackish creeks of the Tidewater.
Horseshoe crabs live in the Delaware Bay and give birth to their offspring there. At this time the red knots, a type of bird, migrate to the area to collect food. The food they collect is the newly conceived horseshoe crab eggs that are buried along the shore sand.
Crayfish can tolerate different conditions related to temperature, salinity and stress. To survive during loss of water, they migrate to another area where water is available, or they burrow. During this process, their heart rate and metabolism is constantly
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.
Horseshoe crabs are considered “living fossils” or evolutionary survivors because the external appearance barely changed in over 150 million years. The horseshoe crab is part of the arthropods, which include organisms such as spiders and scorpions. The horseshoe crab is made up of the prosoma, which is the head, opisthosoma, which represents the central part of the body and the telson, which is the tail. The tail is harmless and is only used to help the crab flip itself over if it’s turned over on the wrong side. Horseshoe crabs have been researched numerous times. Findings include their, ancestry, survival, morphological changes (if any) and phylogenetic research among the different variations of horseshoe crabs.
Green Crab: This crab has been carried all over by ships. It eats many forms of shore life, including worms and mollusks. In certain areas, due to the appetite of the crab, it has affected the commercial shellfish industry.
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.
The Caribbean Spiny Lobster, a uniquely adorned decapod, is found in subtropical to tropical waters, inhabiting rocky crags to sponges to sea grass. A carnivorous species, they will feed on gastropods, sea urchins, worms, and crustaceans. In addition to this, they are also important aquatic scavengers, aiding in the process of decomposition of dead organisms that fall to the ocean floor (Kanciruk 1980). Commonly fed on by moray eels and nurse sharks, they play a significant role in the food chain for not only marine species, but for humans as well. According to the FAO Fisheries and Aquaculture Department, this is one of the most important Palinurid species that is harvested in American waters due to high demand (Holthuis 1991). The economic
Approximately, two or more weeks after the eggs have been laid, larval horseshoe crabs will emerge from the eggs. These larva then migrate to near shore waters and settle on the sandy bottom of tidal flats where they will further develop for another year or so (National Wildlife Federation 2015). As the horseshoe crab larva develops over these next few years, it will gradually move to deeper water and begin eating food more typical of an adult. Limulus polyphemus will reach reproductive age after about ten years. During these years and those after, horseshoe crabs will molt shedding their exoskeleton allowing them to grow a larger shell for their growing size (National Wildlife Federation 2015). Horseshoe crabs will typically molt 16 or 17 times during their
Inside the shells of a bivalve is a soft body which is protected by the shells. The majority of bivalves are filter feeders which have no radula or head. Most bivalves bury themselves in the sediment of the ocean floor and others attach themselves to rocks or even docks and posts in the water. The shells of bivalves are made up of calcium carbonate. Bivalves can be found in both salt water and fresh water habitats. The anatomy of a bivalve includes a mantle, gills, adductor muscle(s), foot, digestive system and circulatory system, nervous system and a urogenital system (FAO). The mantle of a bivalve covers the soft parts of its body. The gills are used for filter feeding and respiratory purposes. Adductor muscles are used to close the valves, and the foot of the bivalve is used to burrow into the sediment and is used as an anchor to hold the bivalve into a certain position (FAO). One of the most common bivalves found in the Puget Sound is the Blue Mussel. Blue mussels can be found in abundant quantities all over the Puget Sound and are a popular food choice for seafood lovers. Other than humans, blue mussels have numerous predators which include birds, sea stars, sea snails, crabs and even fish. Blue mussels attach themselves to hard surfaces such as rocks and docks by using byssal threads which are threads produced by the byssal gland located in the foot of the mussel. Blue
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