Carcinus: The Evolution Of Exoskeletons

Limpets (Patella vulgate) live in algae rich environments on rocky shores. . It has been proposed that in more sheltered areas, limpet shells will grow to be flatter with a larger diameter, while in more exposed areas of coastline, they will grow a taller and narrower shell shape. To find out whether or not the shores of Aberdeen reflected this, samples were taken from two sites (Site A and Site B) along the Aberdeen coastline that varied in their exposure to wave action. The sites were chosen to provide two sample sites with a notable difference in their environment. In the more sheltered site A, limpets were not exposed to harsh waves, while at site B, there was significantly more wave action. Quadrats were used at both sites to provide an area of sampling for the limpets and they were placed around 5 meters from the waterline. The overall results from the study showed that there is a very strong relationship between diameter and height in Limpet shells and that there was an incredibly slight difference in the relationship between the two sites.

The thick shelled snails that have survived against the predation of the crabs were able to reproduce and have offspring with thick

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).

Cepaea nemoralis, more common known as grove snail is one of the most abundant specie of land snail. It is native from west and north to central Europe but has later been introduced to North America and New Zealand (Cain & Sheppard 1953). Grove snails are highly adaptable to a various type of habitats, they can be found in open wood, shrubs, highlands, various types of forest and even urban conditions like roadsides. They were also located at 1800 meters altitude on the Pyrenees (Schultes n.d.).

• Conch: name give to a number of sea snails, also known by their shell

Green crabs are found in shallow ocean waters and they have a preference for sheltered areas. They are an aggressive and territorial crab species (CBC, 2012). Although this species is known as the “green crab”, they are not always green. In fact, this species of crab can range from a variety of colors such as red, orange, brown, blue and yellow; the colors often depend on when the crab last exuviated. Due to the fact that green crabs cannot be distinguished solely by color, they are often confused with other crab species such as the rock crab. A few ways to distinguish the European green crab from other crabs is by 5 pointy spines which are located on the front end of the carapace on either side of the eye as cited by GOV, (2013) and 3 rounded lobes located between the eyes. European green crabs are also distinguished by their claws of different sizes and the way the tips of its back legs are pointed, flattened and hairy. A European green crab generally doesn’t surpass 4 inches (appx. 100 mm) and an average green crab is approximately 2.5 inches (appx. 63 mm) (Peters et al. 2004). Male green crabs typically range from 40-70mm whereas female green crabs ranged from 40-65mm. If these crabs, male or female, surpassed their average size they were classified as old adults (Yamada and Gillespie, 2008). The adult green crab can survive out of the water for

Freshwater invertebrates make up a vast amount of Alabama’s Biodiversity. Biodiversity is the variability among living organisms from all sources, including terrestrial, marine, and other aquatic ecosystems. Mollusca which are also known as snails are one the most commonly encountered in Alabama. They spend the majority of their life in an aquatic ecosystem. As a matter of fact, Their are 180 different species of Mollusca in Alabama.There are unique species associated with every type of aquatic habitat from the Canadian Arctic to the Everglades of Florida. Mollusca are highly valued because they are either a food source or biological indicators for a healthy habitat.They prove immensely beneficial both economically and medicinally. Alabama

Unlike the yeti, though just as elusive, the yeti crab is no creature of fable. The yeti crab, also known as Kiwa hirsuta, has introduced not only a new species of crustaceans, but an entirely new and unique genus as well. The genus Kiwa was chosen after the Polynesian goddess of shellfish, and the species name hirsuta represents the crab’s hairy, yeti-like arms. Determined to be a decapod, it is related to crabs, lobster, and shrimp. The creature is differentiated from these by its lack of eyes and its obvious yeti-like appearance. Found on the Pacific-Antarctic ridge near Easter Island, this benthic creature is a very strange spectacle. The deep-sea creature survives in a very specific environment, and uses the hair on its legs for most of

In Nigeria, Ghana and Cote d’ivoire, where snail meat is particularly popular, snails are gathered from the forest during the wet season. In recent years, however, wild snail populations have declined considerably, primarily because of the impact of

The characteristics that contribute to the diversity and abundance of arthropods is the ability to adapt because of their rough, exterior skeleton and joint appendages.

The majority of land snails are pulmonates, i.e. they have a lung and breathe air. A minority however belong to much more ancient lineages where their anatomy includes a gill and an operculum. Many of these operculate land snails live in habitats or microhabitats that are sometimes (or often) damp or

The chambered nautilus is a snail-like mollusk found in the Indian and Pacific Oceans that has a protective shell that coils in an upward manner, similar to a spiral staircase. Although the subject of debate, overall the shell’s rate of growth follows the elements of the Golden Ratio or Fibonacci Sequence. Nautilus shells grow logarithmically larger on each spiral by almost the same rate but shell variations and imperfections contribute to deviation from the ideal proportion.

Achatina fulica, commonly known as the giant African snail, is an invasive species native to Africa, of very large, air-breathing land snails that can reach up to 20 cm in length and 10 cm in diameter. The United States Department of Agriculture considers the Giant African Snail to be one of the most damaging species for the agriculture and crops in the country. It consumes a wide variety of fruits and vegetables and is known to eat at least 500 different types of plants. The giant African snail is becoming a significant agricultural pest in the U.S., and can pose a serious health risk to humans. Possession of this snail is illegal in many countries, including the continental United States. This snail is listed as one of the top 100 invasive species in the world and large colonies of this species can be accumulated from just one individual. (Vázquez, Sánchez, Martínez, and Alba 2016)

These techniques led to the discovery of the boundary between the two eras. A single thin layer of clay found within predominantly limestone rocks established this. By comparing the marine life found in, above, and below the clay, the marine life, like the dinosaurs, had been terribly affected by the extinction event. The percentage of life in the upper layers was dramatically lower than that in the lower. This was far more compelling than what was suggested by dinosaur’s fossils.

The shells are the part of the body of a marine animal, in most cases the exoskeleton. The word shell is often used to refer only to the shells of marine mollusk, mollusk shells but it can also be used to mean the shells of a wide variety of marine animals from different phyla. The composition of seashells have three distinct substances involved: the outer layer of the horny substance conchiolin, the intermediate layer of calcite, and the smooth inner layer composed mainly of calcium calbornate. The blood of a mollusk is rich in a liquid form of calcium. A soft outer organ called the mantle concentrates the calcium in areas where it can separate out from the blood, forming calcium carbonate crystals. The mantle deposits sheets of the crystal in varying thickness. The individual crystals in each layer vary in shape and orientation.