Limulus Polyphemus

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).

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.

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

Horseshoe crabs are an important part of the wetland ecosystem, however they are going extinct. Due to harvesting, pollution, and other animals consuming their offspring their numbers are dwindling. They play an important part in the ecosystem and need to be protected so they do not become extinct. The Delaware bay has decided to protect them for their future uses in medicine and to keep them as an important role in the ecosystem.

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

The Purple Marsh Crab, or simply known as the Marsh Crab, is a small crab that is native to the Eastern United States. They live in the salt marshes and mud flats of brackish estuaries, and create networks of connected tunnels within the flats.

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)

Studies have found information on ancestral species of current horseshoe crabs. Xiphosurids, which are very old fossils that were not easily found; however, they were compared in body structure of current time horseshoe crabs and showed that there was hardly any change in the body structure. The body plan of a xiphosurid is described as having large crescent like shield in the anterior portion of its body resembling an invertibrate with lateral compound eyes. Xiphosurids are also classified as having opisthosomal tergites built into a thoracetron and having a long styliform telson (Rudkin et al. 2008).

The above mentioned habitats are crucial because it support priority species in the Bay. Although more than 3,600 different species of plants and animals live in the tidal waters of the Bay, there are priority species that shall be protected. The most important keystone species are the Blue Crab, the Oysters, the Bald Eagle and the Black Duck. Keystone species are valuable components at the community scale because they maintain biodiversity and influence critical ecological process (Peck, 1998:34). Blue crabs not only

The zebra mussel (Dreissena polymorpha) is a small freshwater mussel. Native to the Black Sea region of Eurasia, the zebra mussel began appearing in European lakes in the late 1700s and early 1800s. It is generally assumed that they were accidentally brought to America in the ballast water from ships carrying their larvae, juveniles or adult mussels. Canals may have also played an enormous role in the unknowing transportation and distribution of zebra mussels between major drainage basins. Within just a few years, zebra mussels have been known to travel to all of the Great Lakes, Lake St. Clair and the Mississippi river watershed.

Lobsters are benthic organisms because they on the ocean bottom (Townsend, 2012). These animals are on the bottom of the seabed and do not swim as much as organisms that never touch the seabed (Townsend, 2012). In this case, epifaunal is a word to characterize that lobsters live on the seabed (Townsend, 2012). Lobsters do not burry themselves into the seabed, but instead hind under rocks for protection from prey (Townsend, 2012). In addition, the mobility of lobsters was designed to catch prey and the mobility of a lobster is used for a survival technique that is heavily influenced based on feeding styles (Townsend, 2012). Furthermore, feeding styles increase growth in a lobster therefore molting and temperature of ocean are also important to study (Townsend, 2012). Studies are trying to find correlations that climate change can be linked to molting patterns, or with more carbon dioxide in the water lobsters carbon shells could be impacted (Townsend, 2012). Surprisingly, after over twenty years of studying many lobsters researcher Dr. Jelle Atema has come up with a detailed explanation for lobster mating behaviour where female lobster does not have a shell (University of Maine, 2016). On the other hand, Dr. Robert Steneck debates technology is best used to understand the lifestyle of a lobster (Gulf of Maine Research

The partial Chesapeake Bay food chain begins with the algae, and continues all the way up to the fish and beyond. All of the organisms living within the Chesapeake Bay need the algae to survive whether they feed directly off of the algae or not. If the algae population decreased, all other aquatic organism populations living within the Chesapeake would decrease as well. With the dying population of algae, the population of zooplankton would slowly begin to decline due to a lack of food. Without as many zooplankton floating throughout the water, oysters would not have as plentiful of a food source thus causing the oyster population to decrease. If the oyster population decreased, fish would not have shelter or clean water to swim in. while oysters are filtering the water for food, they unintentionally clean the water. The fish population would decrease due to poor living conditions and a lack of food. The survival of algae within

The Horseshoe crab, is in the phylum classification of Arthropods. The Limulidae, or the horseshoe crab, is closely related to trilobites which existed about 544 million years ago. There are four different species of horse shoe crabs, the Limulus polyphemus found on the coast of south eastern coast of the US, and three Indo-pacific known as Tachypleus gigas, Tachypleus tridentatus and Carcinoscorpius rotundicauda. Horseshoe crabs have long spines on their tails used just to help them flip themselves upright if they get flipped over.

Predation pressure by the common shore crab (Ozuis truncates) and various fish species may also be responsible for pushing populations of B. melanostoma towards the high-intertidal zone. In high tidal regions, the periwinkles spend less time submerged and thus less time is permissible for marine predators to feed on them, resulting in a greater survivorship. This is supported by another study which found significantly higher predation related mortality in snails not allowed to migrate to areas further out of water (Vaughn and Fisher, 1988). However, it should be noted that this field experiment was conducted in a marsh habitat and used vertical migration as sanctuary from predation. Compiling results from a new study on a rocky coastline with periwinkle snails should be undertaken to more accurately consider the relationship between tidal changes and competition/predation on B. melanostoma populations.