Background:
Dinoflagellates are one of the four main types of phytoplankton, which are photosynthetic, single celled and free living organisms in the ocean. Dinoflagellates cause the Harmful Algal Blooms (HAB) also known as the red tide effect (Hackett et al 2004). Toxicity persisting at upper levels of the food chain is detected in them from the ones which are toxic, but not all such blooms are toxic. Enhanced detection capabilities may in part contribute to observed high frequency and severity of toxic blooms. As they are also important in the health of coral reefs their study has gained significant interest. Species are often selected for genome sequencing based on their importance as a model organism or relevance to human health, such as the HAB case.
Fig 1 Gambierdiscus Toxicus and its golden brown chloroplasts (Image courtesy: Institute Malarde)
Recreating the evolutionary history of dinoflagellates has been challenging as they possess a known ability to transform from noncyst – to cyst – forming strategies (unreferenced/Wikipedia). The dinoflagellate nucleus lacks histones, nucleosomes and maintains continually condensed chromosomes during mitosis (Dodge 1966), making their classification difficult (Hackett et al 2004). Though being classified as eukaryotes, the dinoflagellate nuclei are not characteristically eukaryotic (Dodge 1966). However, typical eukaryotic organelles, such as Golgi bodies, mitochondria and chloroplasts are present in dinoflagellates (Morrill et al 1983). Since dinoflagellate nuclei possess intermediate characteristics between the coiled DNA areas of prokaryotic bacteria and the well-defined eukaryotic nucleus it was termed ‘mesokaryotic’ by Dodge (1966).
This research focuses on Gambierdiscus toxicus which is an armored, marine, benthic species in the phylum Dinoflagellata. It has an epitheca and a hypotheca, that is very similar in size, compressed anterio-posteriorly. The theca is covered with numerous deep and dense pores which are very thick. This species is autotrophic creating energy via several golden-brown chloroplasts (Hackett et al 2004), but is also heterotrophic and hence is referred to as mixotrophic. It has a ventrally – oriented crescent shaped nucleus. (Adachi & Fukuyo 1979). It usually inhabits warmer waters such as bay, mediterranian, tropical/sub – tropical in North/Central America (Shiumuzu et al 1982; Loeblich & Indelicato 1986), Asia/Pacific (Holmes & Tao 2002; Lu & Hodgkiss 2004) and has recently been identified in the Mediterranean (Aligizaki & Nikolaidis 2008). These authors identified the organisms to genus level, at best of their effort, so may have been one of the less common members of its genus although it is unlikely.
During interphase, the cells in both animals and bacteria carry out their division general functions according to the type of their cells. Unlike in plants, a preprophase group of cytoskeletal proteins emerge at a future location of the cell plate. At prophase stage, duplicated chromosomes compress in a way that can be seen with the help of a microscope. On the other hand, the mitotic spindle is formed at one side of nucleus, whereas in plants, spindle is formed around the nucleus. During prometaphase in animals and bacteria, the nuclear membrane disappears, the chromosomes attach themselves to mictotubules and start to move. In plants, however, the preprophase group dissolves while at metaphase stage, the chromosomes get aligned at the core of the cell. At anaphase, there are fewer differences between animals and plants. The chromosomes shift apart towards the both par...
“Cnidarians” is Greek for “stinging nettle” (“Introduction to Cnidaria"). Phylum Cnidaria include freshwater hydra, jellyfish, and corals. Each of these invertebrates go through transitions in body forms. Jellyfish are the most unusual and complex out of the phylum. Jellyfish are in the class Scyphozoa, which means true jellyfish.
Sabellaria cementarium belongs to the phylum Annelids and is an invertebrate polychaete species. They are found in small clumps at the rocky bottoms of the sea floor where they use the rich source of natural phytoplankton as their primary diet (Qian and Chia, 1990). The tube-like worms can behave social and form extensive reefs or independently build hollow tubes in to the sandstone (pawlik and Chia, 1991). Embryos form a polar lobe that is absorbed in to the blastomeres at the end of division. Larval development and movement follows shortly after the 14-15 hour fertilization period where spiral cleaving of the fertilized oocytes appears (Render, 1983). Much is still not known about the invertebrate worm in their natural niche.
The Chesapeake Bay is the nation’s largest estuary with six major tributaries, the James, the Potomac, the Susquehanna, the Patuxent, the York, and the Rappahannock Rivers, feeding into the bay from various locations in Maryland, Virginia, Pennsylvania, and the District of Columbia (Chemical Contaminants in the Chesapeake Bay – Workshop Discussion 1). These areas depend on the Bay as both an environmental and an economic resource. Throughout the last 15 years the Chesapeake Bay has suffered from elevated levels of pollution. Nitrogen and phosphorous from wastewater treatment plants, farmland, air pollution, and development all lead to reduced water clarity and lowered oxygen levels, which harm fish, crabs, oysters and underwater grasses (Key Commission Issues 1). There are other types of pollution in the bay such as toxic chemicals, but because nutrient pollution is the most significant and most widespread in the Bay its effects are the most harmful to fisheries. Nitrogen and phosphorous fuel algal blooms which cloud the water and block sunlight from reaching underwater grass beds that provide food and habitat for waterfowl, juvenile fish, blue crabs, and other species (Blankenship 11-12). Algae plays a vital role in the food chain by providing food for small fish and oysters. However, when there is an overabundance of algae it dies, sinks to the bottom of the Bay, and decomposes in such a manner that depletes the oxygen levels of the Bay (11). The reduced oxygen levels in the Bay reduce the carrying capacity of the environment and these “dead areas” sometimes kill off species that can not migrate to other areas of the Bay, such as oysters (11). Increased abundance of algal blooms also led to the overabundance of harmful and toxic algae species and microbes such as the microbe Pfiesteria, which was responsible in 1997 for eating fish alive and making dozens of people sick (12). The heightened awareness of diseases that can be contracted through consumption of contaminated fish also has an economic impact. Therefore, the excess levels of nitrogen and phosphorous have fueled an overabundance of algal blooms, which has reduced water clarity and lowered oxygen levels, affecting many species within the bay and ultimately the industries that rely on these species.
N fowleri has three stages of their cycle. In the amoeboid trophozoite stage, they are infectious and measure 10-35 µm long. The trophozoite transforms to a non-feeding flagellate when food sources are limited. Flagellates are motile and measure 10-20 µm in length. The amoeba or flagellate will form a cyst, the dormant stage, if the environment is too cold and not conducive to continued feeding and growth. When the organism is in the cyst stage, it has a single layered wall and only one nucleus. The cyst measures 7-1...
A. ocellaris grows up to 11 cm in length. Its bright orange colouration with three vertical white bars that are separated from the orange colour by thin black outlines is a key feature in the identification of the species. The species exhibits sexual dimorphism, whereas females are larger than males. Found in the eastern part of Indian Ocean and West Pacific, the species inhabits sea anemones on the outer slopes of coral reefs. A. ocellaris is known to live in three species of sea anemone: Hetera...
Istiblennius lineatus (Rockskipper Blenny) will be collected from three different tide pools across the island of Mo’orea, French Polynesia in May 2017. Fish will be caught with nets and stored in tanks at UNC Berkley’s Gump Field Station before transport back to Atlanta for use in the lab manipulative portion. Two algal species that The Rockskipper Blenny uses as food sources will also be collected. The algae species collected will be the same for each of the three tide pools and are preferably from two different families of algae. Initial samples from each fish and alga, as well as water samples will be taken in field for 16s gene sequencing to determine the microbial composition. Samples will be stored in RNA and frozen prior to DNA extraction and sequencing. Water samples will be stored in ethanol. The initial fish gut and algae sample will be used to compare the effect of isolation on fish gut microbiome. The water sample will be used to determine differences in water microbial composition between tide pool
The Great Barrier Reef is home to a remarkable number of organisms. The coral itself is made up of the skeletons of tiny, flowerlike water animals called polyps, held together by a limestone substance produced by a type of algae. Hundreds...
The Odiorne Point rocky intertidal zone is a niche that holds numerous stressors that require specific adaptations from the organisms that come to inhabit this diverse environment. What is particularly unique to communities such as the rocky intertidal is the existence of sub-habitats, or zones, within the entirety of a rocky intertidal space. These “zones” are identified by the abundance of the species that occupy it, both autotrophic and heterotrophic. The Odiorne zones of focus include the “Black/Spray Zone”, the “Periwinkle Zone”, and the “Barnacle Zone”. Zones can also be identified by examination of its abiotic factors. To serve as an example to abiotic analysis, the presence of ge latinous cyanobacteria growing on boulders serve as a marker of the “Black
Soft corals are grouped in the phylum Cnidaria, class Anthozoa, and order Alcyonacea. Their distinguishing characteristic is that their polyps always bear eight tentacles which are on both edges fringed by rows of pinnules (Fabricius and De’ath, 2002). The common name “soft coral” comes from the fact that they have no massive external skeleton as compared to the more commonly studied hard corals.
Dinoflagellates have a pair of flagellum, transverse flagellum, that are wound up around the body and then when whipped in a wavelike fashion causes the cell to go in a spinning motion, giving it a forward propulsion. This helps the dinoflagellates keep their planktonic existence because it can help them stay at the top of the water column, making it easier for them to perform
The Great Barrier Reef is an exemplary model of the famous exotic coral reef seen in a copy of the National Geographic or the popular animated film Finding Nemo. Located on the coast of Australia, it is known as the “largest biological organism in the world” (“Human Impact on the Great Barrier Reef” par. 1). The idea bears that coral reefs are again not an assortment of organisms functioning separately but rather working together to thrive. The groups of coral that are seen in t...
Protists and prokaryotes serve as the primal foundation for the evolution of life present on Earth today. This is exemplified through the endosymbiotic theory, which gave rise to eukaryotic cells, as well as development of photosynthetic processes in plants. Despite the two being quite similar, they also possess key distinguishing features. For instance, the primary difference is that prokaryotes are strictly unicellular organisms, meanwhile protists are able to assume a variety of both multicellular and unicellular forms. Another characteristic of prokaryotes that contrasts with protists is that prokaryotes lack a nucleus and instead merely contain a nucleoid region for unenclosed circular genetic material (Campbell Biology 2017). Each
...Dennison, W. C., Duarte, C. M., Fourqurean, J. W., Heck, K. L., & Williams, S. L. (2006). A global crisis for seagrass ecosystems.Bioscience, 56(12), 987-996.