INTRODUCTION-
Since its itroduction to the New Jersey shore in 1988, the western Pacific shore crab Hemigrapsus sanguineus has spread to inhabit rocky intertidal locations along the
Atlantic coast from Massachusetts to North Carolina (McDermott 1998). Many reasons have been proposed to explain the rapid spread of this non-indiginous species. For example, it has been shown that H. sanguineus has longer spawning periods along the mid-Atlantic coast than it does in its natural habitat in the western Pacific Ocean, due to a more favorable climate (Epifanio et al 1998). For this reason, these crabs are able to spawn more times per season than indigenous crabs, providing one possible hypothesis for their population explotion.
For this species to expand its range along the Atlantic coast, it will need to have wide tolerances to temperature and salinity. In 1998 Epifanio found that
The purpose of this study is to show the tolerance and behavioral responses of H. sanguineus to varying water and air temperatures, and water salinity concentrations. It is believed that these crabs will be very tolerant to the various extreme conditions that they will be put through. It is the ability of these crabs to survive in these unfavorable situations that is key to their success. This experiment was also designed to prove the hypothesis that the tolerance of H. sanguineus to various environmental factors increases with size.
METHODS AND MATERIALS-
In February 2000, a field trip was taken to Crane Neck Point to collect live specimens for the experiment. The field trip was conducted at low tide. The water temperature was approximately 3 degrees Celcius, with the air temperature slightly above freezing (0-1 degree Celcius). Live crabs were obtained by overturning rocks in the intertidal zone. Hemigrapsus sanguineus was found at all levels of the intertidal zone, although their numbers increased as one moved toward the waterline. The crabs were collected with no distinction toward size. The sizes of the specimens collected were found to range from 0.5 to 4.2 cm. The crabs were collected in a plastic five gallon bucket. Water was added to the bucket to keep the crabs from dehydrating. The crabs were taken back to the lab, where they were kept in the plastic five gallon buckets for a few weeks until the experiment began. Air hoses were added to the buckets in order to oxygenate the water. The water was changed, as necessary.
The first experiment conducted was the experiment regarding water temperature and salinity tolerances. The objective was to conduct an experiment that would provide measurable data on the tolerance of H.
...hypothesis that states they show preference to only brighter environments. Both preliminary hypothesis for pH and temperature were confirmed as A. franciscana prefer basic habitats and cannot survive in acidic ones; also they prefer high temperature ranges between 20-35 ̊ C which expands on what was originally predicted (room temperature).
An abiotic factor affecting growth of T. californicus is the concentration of salinity of the seawater. It can range from 35ppt too much higher salinity concentrations. The concentration of UV radiation also affects t. californicus. They tend to stay in places of low concentration of UV rays when the sun is the strongest.
The picture above shows the vast difference that there can be in animals, to the right is Emerita Analoga (sand crab), and to the left is Zalophus Californianus (California Sea Lion). The sand crab is an invertebrate while the seal is a vertebrate and mammal. Invertebrates make up 90% of all an...
The barnacles not only live and reproduce inside the host crab, but they control it. The tendrils attached to the nerves produce substances that change the crab’s endocrine system. This leads to the crab’s body absorbing its own Y-organ. The Y-organ instructs the crab to molt or grow. The crab’s androgenic gland is also degenerated. The androgenic gland controls sex differentiation. At this point, the crab is unable to grow, molt, regenerate lost limbs and it is infertile. When the barnacle inhabits a male crab, the changes feminize him. The male crab will resemble and act like a female. He may even perform a female mating dance. After all this has taken place, the host crab will take care of the parasitic eggs. The crab acts as if the eggs are its own. At the right time, the crab will climb up onto a high rock, and tend to the egg pouch, as it would do in its own reproductive cycle. When the generous number of eggs are ready to hatch, the crab will bob up and down in the water to release them. The crab will then mix the floating eggs with it’s claw to set them on their way. These larvae will usually find new hosts, which continues this
The Long Island Sound is an estuary, and is in fact one of the largest in the world. An estuary is a place where salt water from the ocean mixes with fresh water from the rivers that drain from the land. Moreover, like other estuaries, the Long Island Sound has an abundance of fish and other waterfowl that add to the natural balance of the island, as well as one of the most important economic factors (Tedesco). Like other estuaries around the world, the Sound provides breeding, feeding, nesting, and nursery areas for many species that will spend most of their adult lives in the oceans (Long Island Sound Study). Despite these similarities to other estuaries, the Long Island Sound is unique from anywhere else in the world. Unlike other estuaries, the Long Island Sound does not just have one connection to the sea but it has two. It has two major sources of fresh water flowing into the bay that empty into the ocean. It combines this two-...
The Chesapeake Bay is a large estuary located on the east coast of the United States. The bay is over 200 miles long and goes through Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia. The bay has much to offer the locals. Many locals have made a career out of harvesting the bay's sea food. The bay's harvest and many of its other attractions bring tourists and in turn revenue for the area. Oysters and blue crab are a big part of the culture in the bay area. However, these organisms are in danger and need help.
of Cape Cod, but has been recorded in Maine and Nova Scotia. The blue crab
Change in water temperature changes the places where grasses are able to grow, when fish and crab feed, reproduce, and migrate ("Chesapeake Bay Program"). The temperature in the bay goes from high in the summer to very low in the winter. During summer, the surface water is warmer than the deeper water which creates two different temperature layers that actually separate surface waters from deeper waters (“Chesapeake Bay Program”). The temperature layers change th...
to the lobster and crab. Their closest living relative today is the horseshoe crab.The name
analysis on how the Atlantic became known as the Atlantic because of the presence of
1. Life is more abundant in the North Atlantic than in the Pacific because the ocean area of the North Atlantic is directly in the path of iron-rich dust from the Sahara Desert, which leads to the development of bigger communities of phytoplankton, and in turn plankton, and so on. This fact is related to global warming because someone thought of an idea to fight global warming by putting huge amounts of iron solution into the ocean so that extreme plant growth would occur and these plants would remove enough carbon dioxide out of the atmosphere to counter the negative effects of humans.
4. A delivery tube with a bung was then placed into the test tube of
To begin with, the horseshoe crab, one the world’s oldest living creatures, are quite active. This fascinating crab has ten small walking legs under a strong, sturdy exoskeleton, a long spine in the abdomen, and a long pointy tail in the back used to push itself back up after being flipped on its back (Swinton, 99). Furthermore, horseshoe crabs got their name in an interesting way. The crab’s arc shaped exoskeleton, or shell, was compared to a horse’s shoe (Horseshoe Crab: Saint Louis Zoo). As mentioned before horseshoe crabs aren’t actually crabs. Though it may look like one, they are actually part of a family called Limuli. Some reasons it could have been misconceived as a crab are because its shell is comparable to a crab’s, the legs look a bit similar, and they are found on the Atlantic coast like other crabs. Also we can find horseshoe crab right here in North America along the hot, sandy Atlantic
Primary coasts are divided into two categories: submergent and emergent coasts. Submergent coastlines result from a general sea-level rise and crustal subsidence. Most of the eastern United States has submergent coastlines. One example is the Chesapeake Bay. Emergent coastlines result from the land being lifted, either by tectonic activity or rebound from the weight of heavy glaciers, which exposes the former sea bottom bit by bit forming continuously new shoreline.
... incredibly relevant to today world. Brine shrimps are also used as test subjects due to their incredible resilience, and are also sold as a novelty item “sea monkeys.” Unfortunately, these unique critters have become threatened in some cases as water is diverted away (for human use) from high saline environments inhabited by brine shrimp. As a result, the water becomes more saline and usually results in a rising pH which can endanger the shrimps. The information provided in these two studies shows the need, function, means, and genetic explanation for osmoregulation. As humans continue to impact the environment, changing salinity will result in changing need for osmoregulation, and as a result, future scientists will need to explore how organisms can react to the need to osmoregulate more or less and how that will impact organism populations’ survival as a whole.