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Research Paper On Choanoflagellatea

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The class Choanoflagellatea was first described by Henry-James Clark in 1867, and are now considered the sister group to Metazoans, also known as animals (Leadbeater, 2015). Choanoflagellates can be colonial or solitary organisms (Hickman, 2015) and can be found practically anywhere from oceans to even in permafrost (Leadbeater, 2015). They tend to be three to ten μm in size and lack chloroplasts (King, 2005). These organisms have no color to them, consist of one flagellum that they use for swimming and to make water flow toward them for capturing food (Leadbeater, 2015), and appear ovoid in shape. Around the flagellum is a collar of microvilli that are actin-based. This collar is the location where food is ingested into the cell body…show more content…
Those with a theca form a collar skirt, which is not the collar of microvilli but something separate where colony forming choanoflagellates lack a skirt. In choanoflagellate that form a skirt, prey gets stuck in between the collar and the skirt with the microvilli engulfs the prey. In colonial ones, the cell instead produces a cup-like structure that grows around their prey to engulf and ingest the quarry (Dayel and King, 2014).
The class Choanoflagellatea is a monophyletic group with over 244 species found and described. The class is considered part of the clade Opisthokonta which are categorized by flat cristae in their mitochondria and one or more flagellum (Carr et al, 2008). Choanoflagellates are further divided into two Orders. The first being the order Craspedida, and the second being the order Acanthoecida (Nitsche et al., 2011). These two orders are divided into families based on morphological traits.
The three families included in class Choanoflagellatea are Codonosigidae, Sapingoecidae, and Acanthoecidae. The first family is Codonosigidae whose members have a glycocalyx coat. This coat may extend from the body and meet with a microfibril stalk. The second grouping is the family Sapingoecidae. This family has a theca that is shaped as either a flask, cup, or tube. The third family Acanthoecidae is surrounded by a lorica and is even further divided into nudiform and tectiform species (Carr et
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