Limulus Polyphemus: The American Horseshoe Crabs

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 profile of Pallarenda beach as shown in figure 1 is very typical of a North Queensland, medium energy beach. The lack of organisms present higher up the beach was due to the harsh conditions at low tide. Ghost Crabs, Ocypode quadrata, can survive these areas as a result of their adaptations (The Otter Island Project). The ghost crab burrows during the day and feeds at night to avoid the heat of the day (The Otter Island Project). These crabs can actively take up moisture from damp sand to wet their gills (The Otter Island Project).

The food chain of the Chesapeake Bay is very simple. It has fish, big fish depend on small fish. The small fish feed off of oysters or sometimes zooplankton. Oysters then feed off of many small zooplankton. Once, it gets down to what the zooplankton feed off of it is mostly algae or grass. Now, since there is a major decrease in the algae population, this

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,

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.

Imagine that a huge wave crashes down on you. Then it drags you back into the ocean. On your way you pass by an animal that is clinging on for dear life. In order to survive in these harsh conditions, animals need adaptations. An ecosystem is a biological community of interacting organisms and their physical environment. The California Spiny Lobster lives in the neritic e zone which is in between 200 meters and 0 meters. It is located on the continental shelf. They like living in coral reefs and the ocean ground. In order to survive in the neritic zone with predators, sea floor hiders, and other environmental threats, animals need adaptations.

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.

Three years ago, the author took a trip to Delaware. As his family was walking on the beach they came across some horseshoe crabs mating. He wondered how they have changed. The type of horseshoe crab he saw along the beach was called “limulus polyphemus”. Limulus Polyphemus is not found in the fossil records. The fossil record for horseshoe crabs is deeper than 20 million years, and the

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.

This lab is based off of European Green Crabs preying on Periwinkle Snails. From the name, one can tell the European Crab originated in Europe and is not native to North America. The crab ranged its expansion north of Cape Cod, where Periwinkle snails were introduced to a new predator. (McRae, 2015-pg. 1)

The Mantis shrimps has an important role in marine ecosystems, like keeping some types of fish from over populating and having a much richer overall species. Mantis shrimps are also very sensitive to anything that is polluting the area or habitat that they live in and for that very reason is why they are good bioindicators for pollution on the coral reefs. Mantis shrimp also inhabit coral reefs in marine and aquatic ecosystems. They like to live in burrows in sand, rock, or coral. They live in tropical and subtropical shallow waters near the coast about 3 to 40 meters deep so about 10 to 130 feet deep into the ocean. The water that they make their habitat in is warm, with temperatures of about 68 degrees. The deep and tropical oceans are full

They will eventually shift north as the area warms and becomes suitable for the tree’s growth, but in the meantime, there is a vast swath of the Aratus range in salt marshes instead of mangroves. Here the crabs’ main substrate is spartina. Aratus also revealed a shift in diet from mangrove leaves to more insect based consumption. This presents a curious case, as Aratus is highly dependent on the mangrove system for all aspects of life.

The habitat of the green crab changed after 1900 and this is important because all of the shells found prior to 1900 are thin and taller than the ones found after the green crab migrated to Cape Cod, Massachusetts. This information can be found in introduction of Seeley’s paper.

Shrimps and mud lobsters use the muddy bottom as their home.[10] Mangrove crabs mulch the mangrove leaves, adding nutritients to the mangal muds for other bottom feeders.[11] In at least some cases, export of carbon fixed in mangroves is important in coastal food webs.

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