1.+Rotifer

Rotifer __** Classification/Diagnostic characteristics: **__
 * Classification: Rotifera, Platyzoa (1)
 * Kingdom: Animalia (1)
 * Class: Eurotataria, pararotatoria (1)
 * Rotifera - wheel of whirling animals (1)

__** Relationship to humans: **__ __** Habitat and niche **__ __** Predator avoidance **__ __** Nutrient acquisition **__ __** Reproduction and life cycle **__ __** Growth and development **__ __** Integument **__ (21) Depicted above is the general body layout of the rotifer. Containing a linear tract, individuals pass nutrients along their entire length before expulsion as waste, increasing cell exposure to uptaken resources. Body surface appearance varies; some species have spines or tubercles and/or a protective casing (lorica). The skeletal lamina, a layer within the animal’s epidermis, produces the lorica (if present), as well as any other surface structures. Many rotifers also have a gelatinous layer outside the epidermis. Some have dorsal or lateral sensory antennae. Many have bodies that are annulated to increase flexibility.hhhjwjwod __** Movement **__ This image displays a rotifer moving using its cilia __** Sensing the environment **__ __** Gas exchange **__ __** Waste removal **__ __** Environmental physiology (temperature, water, and salt regulation) **__ during which the bdelloid enters a state of complete inactivity in response to dry conditions. While in the cryptobiosis state, the bdelloid ceases its metabolic processes, including growth and reproduction. Depending upon the humidity and temperature that the bdelloid encounters, it can stay in cryptobiosis for an extended period of time. In addition, the eggs of some rotifers can also keep from drying out allowing better survival rates during harsh conditions. (14) __** Internal circulation **__ __** Chemical control (i.e. endocrine system) **__ __** Review Questions **__
 * about 2-3 mm in length (7)
 * body is divided into the foot, trunk, and head (7)
 * The digestive tract has mouth and anus (11)
 * They are multicellular (11)
 * Cilia is present around the mouth of the cells. (16)
 * They are mostly omnivores. (16)
 * They are pseudocoelomate invertebrates (15)
 * they have a fluid-filled "false body cavity" that is only partly lined by mesoderm rather than a cavity within the mesoderm. (12)
 * Rotifers are studied by scientists and are an important food source for some creatures that are ecologically important to humans, including nematodes and insects. (8)
 * prey on protists and small animals that can fit through their small size (468- textbook)
 * live in fresh water. Some rest on surfaces of mosses or lichens (468-textbook)
 * Rotifer's predators include fish, jellyfish, and starfish. (18)
 * Rotifers use their cilia to swim through fluid to avoid predators. (13)
 * the coordinated beating of the cilia sweeps particles of organic matter from water into the mouth and down the master, where food is broken down into small pieces. (468- Textbook)
 * Food is broken down by the trophi (jaws), located above the pharynx (19)
 * The head has cilia that allows the rotifer to sift through food by having a vortex of water in their mouth (6)
 * A digestive tract is present in rotifers (1)
 * most don't live longer than a few weeks. In fact, they usually live only a few days.(468-Textbook)
 * They reproduce through a process called parthenogenesis. In parthenogenesis, an individual develops asexually from an unfertilized egg. (3)
 * Males are smaller and less common (1)
 * Rotifers produce eggs which are fertilized by sperm through fluid. (19)
 * The eggs can withstand drying. (12)
 * The eggs develop and grow in the water they were hatched in. most rotifers are 50-500 micrometers long (467-Textbook)
 * =====contains an apical intracytoplasmic lamina (ICL) that functions for both skeletal support and muscle insertion. (4)=====
 * =====Rotifers have bilateral symmetry in their bodies. Their cuticle, which is their outer protective layer, which can be hard and thick, or thin and more flexible, depending on the specific species of Rotifer. The hard shells of Rotifers can be made up of many different hard plates, ridges, or other protruding shapes that form an outer protection. (10)=====
 * when rain falls they absorb the water and become more mobile(468-Textbook)
 * In addition to swimming rotifers, some loop along the bottom of ponds, alternately attaching the head and tail ends; others remain anchored by means of tubes or cases of jelly attached to the bottom (1)
 * the crown of cilia, as seen in the image above, move around the mouth to propel the rotifer through water. (14)
 * The rotifer relies on sensory bristles for touch that surround the corona as well as two pairs of antennae. The rotifer also has cilia lined pits in around the "head". All of these are used to for touch and feeling of its environment. They can also have up to five very simple "eyes" which can detect light in the environment. (20)
 * The rotifer is able to feel best with their feet, and not as well with the rest of their body. (18)
 * no specialized organs for gas exchange (17)
 * small body size is an advantageous adaptation that allows for for the facilitation of gas transport and exchange of gasses (2)
 * Have an anus (5)
 * Excretory system includes a syncytial protonephridial tubules (5)
 * live in freshwater or on mosses (468)
 * some exist in marine environments (9)
 * One of the classes of rotifers known as bdelloids have a unique ability to live even if they dry out through cryptobiosis, a process
 * pseudocoelom acts as the circulatory system (7)
 * Limited is known about their endocrine system. What is known is that they are similar to most aquatic invertebrates. This means that they have limited development of the aquatic system. (20)
 * 1) Under what kind of conditions are Rotifers more mobile, and what do they use to move?
 * 2) Rotifers are most mobile in wet and rainy conditions. In order to move they use cilia and suction cups on their cilia.
 * 3) In what kind of environment can Rotifers live in? Do they have a wide spectrum of the types of environments that they can live in?
 * 4) Rotifers tend to survive in freshwater and on mosses, but some species can survive in a marine environment as well
 * 5) Do rotifers have a specific method to do gas exchange? Is there an advantage to that answer?
 * 6) Rotifers do not have a specific organ designated to gas exchange. This is advantageous because they have very small bodies that do not require an specify organ for gas exchange.
 * 7) How do rotifers reproduce?
 * 8) They lay eggs which are fertilized by the sperm in the liquid go the egg
 * 9) What is the life span of a rotifer?
 * 10) Some rotifers can live to up to a couple of weeks; however, some of them only survive for a couple of days.

__** Sources: **__


 * 1) http://animaldiversity.org/accounts/Rotifera/
 * 2) Newfoundland, Memorial University of. “Ocean Sciences.” //Memorial University of Newfoundland //, 16 Nov. 2015, www.mun.ca/osc/oscedu/rotifera.php.
 * 3) http://www.ucmp.berkeley.edu/phyla/rotifera/rotifera.html
 * 4) http://www.sciencedirect.com/science/article/pii/S0166445X98000745
 * 5) http://www.ucmp.berkeley.edu/phyla/rotifera/rotifera.html
 * 6) http://www.biologydiscussion.com/animals-2/fresh-water-animals/rotifers-shape-structure-and-development/34353
 * 7) https://www.britannica.com/animal/rotifer (1)
 * 8) http://ic.galegroup.com/ic/scic/ReferenceDetailsPage/ReferenceDetailsWindow?disableHighlighting=false&displayGroupName=Reference&currPage=&scanId=&query=&docIndex=&source=&prodId=SCIC&search_within_results=&p=SCIC&mode=view&catId=&u=mlin_s_sharonhs&limiter=&display-query=&displayGroups=&contentModules=&action=e&sortBy=&documentId=GALE%7CCV2642050219&windowstate=normal&activityType=BasicSearch&failOverType=&commentary=
 * 9) http://animaldiversity.org/accounts/Rotifera/classification/
 * 10) http://onlinelibrary.wiley.com/doi/10.1111/ivb.12085/abstract
 * 11) http://animaldiversity.org/accounts/Rotifera/
 * 12) http://eol.org/pages/6851/details
 * 13) http://www.ucmp.berkeley.edu/phyla/rotifera/rotifera.html
 * 14) http://www.ucmp.berkeley.edu/phyla/rotifera/rotifera.html
 * 15) http://www.newworldencyclopedia.org/entry/Rotifer
 * 16) http://www.biologydiscussion.com/animals-2/fresh-water-animals/rotifers-shape-structure-and-development/34353
 * 17) http://cdn.theatlantic.com/static/infocus/obdi072012/s_b13_0rotifer.jpg
 * 18) []
 * 19) __[] __
 * 20) https://www.researchgate.net/publication/229470624_Use_of_freshwater_rotifer_Brachionus_calyciflorus_in_screening_assay_for_potential_endocrine_disruptors
 * 21) http://siera104.com/school/biology/flatroundrotifers/rotifer.gif

Karina Mirochnik