Researchers at the Alfred- Wegener- Institute for Polar and Marine Research in Bremerhaven, Germany have recently published a peer-reviewed article about the effects of temperature and ocean acidification on the calcium content of young spider crab larvae, Hyas araneus. Kathleen Walther, Franz J. Sartoris, and Hans O. Pörtner decided to research these effects to determine if the continued temperature and acidification of the oceans will have a negative effect on the spider crabs development. Furthermore, the researchers measured the calcium content in each larvae of crab at different temperatures and CO2 content. For the spider crabs, the calcium levels they have are crucial for development of their exoskeleton. Lower levels of calcium in the crab could be detrimental to the development of it because of …show more content…
the inability to construct an exoskeleton. The scientist collected spider crabs from the northern and southern most areas where the species is located along the latitudes of 79°N and 54°N, respectively. In the northern most location near Svalbard, Norway, 60 pregnant females were collected to harvest their eggs. In the southern most location near Helgoland, Germany, divers caught only 15 pregnant females. After the collection of the females, the scientists could only harvest 9,450 larvae from three females from Helgoland and 8,100 larvae from four females from Svalbard. The scientists then split up these larvae into groups of 1,050 from Helgoland and 900 from Svalbard to use in the experiments. The researchers used nine different flasks for the experiment at temperatures of 3°C, 9°C, and 15°C to test effects of the different temperatures and CO2 content.
In each temperature increment there were three different flasks filled with different levels of CO2 in the water to show the effects of ocean acidification on the larvae. The first flask was filled with present day CO2 levels of 380 parts per million (ppm), the second was filled with 710 ppm CO2, and the third was filled with 3,000 ppm CO2. The last two flasks are estimated of what the ocean CO2 levels will be in year 2100 and 2300, respectively. The results of each flask were assessed on days 3, 7, and 14 and were tested to find out the levels of calcium the larvae contained. However, not all larvae were tested because the researchers used random sampling to test the larvae to because this created separation from the few mothers of each larvae. To test the calcium content of the larvae the researchers used ion chromatography. Ion chromatography separates different ions to show the content of each ion in the larvae, so this shows the calcium levels because calcium ion can be separated to show the
level. At 380 ppm CO2 the larvae’s calcium content rose as they aged and the temperature increased. However, at 3°C and 9°C the Helgoland larvae had the highest levels of Calcium, but at 15°C both the populations roughly had the same levels of Calcium. At 710 ppm CO2, both populations had lower calcium levels at temperatures 3°C and 9°C than at 380ppm CO2, but the Helgoland still had more calcium. However at 15°C the Svalbard population had more calcium content than the Helgoland larvae. At 3,000ppm CO2 all of the levels of calcium were severely diminished in both populations. The Helgoland population had higher levels of calcium than Svalbard in temperatures of 3°C and 9°C, but had lower levels at 15°C. On average, both larvae populations had an increase of calcium content as they got older regardless of the CO2 levels. However as CO2 levels increased the larvae’s calcium content decreased except the Svalbard larvae at the temperature of 15°C in 710 ppm CO2. The larvae actually stayed mostly the same except on day 7 there was an increase in calcium content in the 710 ppm CO2. In conclusion of this study it is observed that in both populations of spider crabs as the temperature increases and CO2 in the water increases the larvae produce less calcium. This results in a weakened exoskeleton of the crab which could result in extinction of the species. These results prove that acidification of the water poses a real threat to this species of crabs.
T. californicus is found from Alaska to Baja in small, shallow tidepools and tidal flats in the upper spray zone where they cannot avoid the full effect of visible and ultraviolet (UV) radiation. Individuals assemble in areas of lower radiation at midday, yet have no preference to the intensity of light at dawn and dusk (Hartline and Macmillan 1995). These tiny arthropods inhabit all types of marine sediments from sand to fine mud and ooze. Along with plankton, T. californicus eats microscopic algae, protists, bacteria, diatoms, algae and microbes (McGroarty 1958). When the concentrations of the species in their habitats are high, T. californicus will turn to cannibalism for a food source. The nautilus eye present in the species is rich with fatty acids and provides a good food source for the animal.
The crustacean moult cycle is initiated when the Y-organ in the head secretes the hormone Ecdysone (E) into the circulatory system[3,4,5]; the Y-organ is the primary source of E[5]. Upon contact with the haemolymph (a combination of blood and tissue fluid) within the circulatory system E is converted to its active form, 20-hydroxyecdysone (20E), by a P450 enzyme[4]. This causes the epidermal cells to secrete moulting fluid, which contains a mixture of enzymes such as proteases and chitinases. The moulting fluid degrades the exo- and endocuticle, and the digested cuticle is reabsorbed to create new cuticle; moult fluid also has a role in initiating the moult. The degraded cuticle is replaced by water or air so that the animal can swell in order to lose the shell. During the passive phase of the moult cycle, the shell splits along the break point caused by the decalcification of the shell, in the crab this is along the epimeral lines. Once the shell has split, the animal wiggles side-to-side to free itself from i...
The purpose of this lab was to study the response of the genus Daphnia to chemical stimuli and to examine human responses to different stimuli. A stimulus is an incentive; it is the cause of a physical response. Stimuli can have a physical or chemical change; an example of a physical change is a change in temperature and sound. An example of chemical change would be changes in hormone levels and pH levels. Muscular activity or glandular secretions are responses that occurs when stimulus information effects the nervous and/or hormone system. Daphnia is a genus; it is a small crustacean that lives in fresh water. The body of the daphnia is visible and its internal organs are clearly seen thus it was chosen for this exercise. The
The experiment was conducted to test three different variables. These variables are an assessment of female aggressiveness, food deprivation, and staged male to female interactions. When testing the female aggressiveness, virgin females were run through a latency of attack assay to determine their aggressiveness. The spiders were given 30 seconds and a cricket was dropped in and a measurement was taken of how long interaction occurred between the cricket and the spider. When testing food deprivation, the number of days that female spiders went without food varied and was paired in groups of 1, 3, and 5 days for routine feeding. It was predicted that the longer female spiders went without food, the hungrier they would be. When testing staged male and female interactions, the males were placed in female containers with open lids as an escape route. Each pair interacted for six hours and all pairs resulted in successful copulation, sexual cannibalism, or the male abandons the female’s web. All instances of cannibalism were precopula and occurred shortly after males initiated their courtship sequence. After interaction, the remaining males were taken out the female web and females that cannibalized a male were given 24 hours to feed on the male before being given another male. A female never cannibalized two males consecutively. It was concluded that females that attacked prey more rapidly were more likely to cannibalize their first male mate. There is no detection of an association between cannibalism or food deprivation and female’s body mass. There is a positive association between the mass of egg cases and the number of offspring in females. The study proved that two factor are important in sexual cannibalism, female hunger state and female aggressiveness. There is also a source of fitness benefit for the female.
The North American brine shrimp goes through several stages in development before reaching adulthood. The brine shrimp is first encased in a protective capsule within a female brine shrimp’s brood sac (Drewes, C, 2006). Here, egg development rapidly...
The reduction in photosynthesising biomass led to an increased reliance on the Worlds other carbon sink, Oceans. Between 26-44% of CO2 in the atmosphere is absorbed by oceans by photosynthesising organisms, mainly phytoplankton (Archer, D. and Pierrehumbert, R., 2011), seawater chemically reacts with aqueous Carbon Dioxide, one of the end products is Hydrogen ions (H+) (NOAA, 2013). The increased concentration of H+ results in the ocean becoming more acidic, since pH is determined by concentration of Hydrogen ions.
The scientific name given to the blue crab was derived from Latin and Greek: Calli, beautiful; nectes, swimmer; and sapidus, savory. Thus, a literal transition might be the beautiful, savory swimmer. The blue crab is an important and interesting species. The blue crab is a species whose life history involves a complex cycle of planktonic, nektonic, and benthic stages which occur throughout the marine environment in a variety of habitats. The blue crab is one of the more abundant estuarine invertebrates and supports important commercial and recreational fisheries along the Atlantic and Gulf coasts.
The experiment measured the survival rate, the growth rate, and the size of the brine shrimp at the time harvested in various environments. To obtain these measurements, three environments were created: sea water, brackish water, and freshwater. For this experiment the scientists used 5 liter plastic buckets. Every two days, half of the water from each bucket was discarded and new water, of each respective salinity, was added into each bucket...
With carbon dioxide levels continuing to rise over the past few decades (fig. 1) and now into the future, concern has been brought to what is happening to the carbonate chemistry of the oceans. Because of these changes in chemistry, the ocean is becoming more acidic. Along with climate change, ocean acidification may be one of the greatest threats to our planet. The higher the ocean’s acidity level goes, the lower the calcium carbonate levels will drop. Even though this is a big scale issue, my goal is to focus on and underline what these changes will mean for the marine life that depend on the calcium carbonate in seawater. I will go in depth with specific regards to a study regarding pteropods or sea butterflies.
In absence of calcium carbonate, coral and shellfish can’t survive. The ecosystem of ocean depends on these organisms because they offer a large source of food at the bottom of the food chain. They need to be abundant in order t...
The study used a variety of species of fish, crab, shrimp, lobster, and other crustaceans known to live on the bottom waters of the Long Island Sound were exposed to low levels of oxygen in the laboratory. The effect of different concentration of oxygen on growth and survival was measured.
Over the last century, [it is evident that] the current levels are beginning to impact organisms that make their shells out of the minerals aragonite and calcite…” (Bralower) “Coral reef[s] are highly vulnerable to ocean acidific...
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
The location is one of the most critical factors to analyze thoroughly because it helps predict whether the sales of the choosing location will be good or not? Although the Boiling Crab is in the growth stage, it still has to focus on new locations that the owner plan to extend to these areas. As I mentioned in the introduction, the owner plans to open the Boiling Crab in four new locations soon.
Arthropods are in the kingdom Animalia which is in the subphylum Arthropoda. A species can be classified as an Arthropod if they have an exoskeleton, a coelom, and if they are mostly dioecious. An “ exoskeleton is an external skeleton made of chitin. [A] coelom is fluid filled cavity between organs and body wall” (Babin,2017). Examples of Arthropods are: spiders, ticks, millipedes, and centipedes. The objective of this experiment was to find Arthropods and test. Different habitats were established to see which will produce a greater amount of Arthropod. It was believed that the Arthropod diversity of a shaded area will be more that that of an area near a canal. The shaded area would have more arthropod diversity because more plants would be around it. Since there will be leaves and trees, plant diversity will be greater. Also, having “ plant diversity can positively affect arthropod{s}” ( Bennett and Gratton, 2013) because there will be more arthropods to utilize.