do rotifers have a circulatory system?
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Simple Circulatory Systems The simplest animals, such as the sponges (Porifera) and rotifers (Rotifera), do not need a circulatory system because diffusion allows adequate exchange of water, nutrients, and waste, as well as dissolved gases (figure a).
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A unicellular organism has no need for a transport system. The resources it needs to survive can just be transported through the cell membrane, and the waste materials likewise. Think of a cell deep inside one of your tissues though.
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['Exoskeleton. Arthropods are invertebrates, which means their bodies do not have internal bones for support. ... ', 'Segmented Bodies. Arthropods have bodies that are internally and externally segmented. ... ', 'Jointed Appendages. ... ', 'Bilateral Symmetry. ... ', 'Open Circulatory System.']
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Marine animals are usually osmoconformers, while freshwater species are generally osmoregulators. The sharks' bodies are particularly high in urea and trimethylamine N-oxide.
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In the case of freshwater fish, their blood and bodily fluids are much saltier than the water they swim in, so water will flow in through their gills. ... As well as getting water through osmosis, saltwater fish need to purposefully drink water in order to get enough into their systems.
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First, they all possess five-part radial symmetry around a central disk. Second, they all possess a very unique water vascular system (vascular system based on water). These unique characteristics distinguish echinoderms from other animals in the animal kingdom.
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Most mollusks have tentacles for feeding and sensing, and many have a muscular foot. ... Different classes of mollusks have different ways of obtaining food. Annelids are segmented worms such as earthworms and leeches. Annelids have a coelom, closed circulatory system, excretory system, and complete digestive system.
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The Circulatory System The circulatory (or cardiovascular) system is a closed network of organs and vessels that moves blood around the body (Figure 1). The primary purposes of the circulatory system are to deliver nutrients, immune factors, and oxygen to tissues and to carry away waste products for elimination.
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The water vascular system is a hydraulic system used by echinoderms, such as sea stars and sea urchins, for locomotion, food and waste transportation, and respiration.
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In most animals, the circulatory system is used to transport blood through the body. Some primitive animals use diffusion for the exchange of water, nutrients, and gases. However, complex organisms use the circulatory system to carry gases, nutrients, and waste through the body.
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Nematodes do not have blood vessels, lungs, or other circulatory appendages. Instead circulation in nematodes occurs via gas diffusion through the skin.
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These fish have muscular bodies, ossified bones, scales, well developed gills and central nervous systems, and large hearts and kidneys. Mesopelagic plankton feeders have small mouths with fine gill rakers, while the piscivores have larger mouths and coarser gill rakers.
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Their body swells by movement of water and they have continual loss of body salts to the surrounding environment..Marine animals - Depending on their ability to tolerate different salinities aquatic animals they maintain an osmotic difference between their body fluid and the surrounding environment are osmoregulators.
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The circulatory system, also called the cardiovascular system or the vascular system, is an organ system that permits blood to circulate and transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body to provide nourishment and help in ...
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The abalone has a pair of eyes, a mouth and an enlarged pair of tentacles. ... Since it has no obvious brain structure, the abalone is considered to be a primitive animal. However, it does have a heart on its left side and blood flows through the arteries, sinuses and veins, assisted by the surrounding tissues and muscles.
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Canal system: The body of sponges is organised in such a manner as to form a complex pore and canals. This system is called as canal system. ... This system is called as water vascular system because this system acts like the circulatory system of body maintaining the continuous flow of water in and out of the body.
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Adult zebra mussels feed by filtering large amounts of plankton and detritus from the water. Each mussel can filter one liter of water per day! Zebra mussels thrive in nutrient-rich water which supports healthy populations of plankton.