### animal | worm:

Leech
* All leeches are 'hermaphrodites' like earthworms
  - ectoparasitic and feed on the blood of either invertebrates or vertebrates
  - hermaphrodites, meaning each one has both male and female reproductive organs
  - hermaphroditic and fertilization is internal
  - can crawl, and some are good swimmers
  - live in water except a few which are found in moist soil in warm climates
* Many leeches suck blood
  - swim through the water with snakelike motions
* Most leeches are carnivores, dining upon carrion, snails, insect larvae and nymphs
  - freshwater animals, but many terrestrial and marine species occur
  - sanguivorous, that is they feed as blood sucking parasites on preferred hosts
  - detect movement
  - eat dead animals
  - feed on blood
  - find hosts
* Most leeches have antibacterial properties
  - brains
  - distinctive features
* Most leeches have female organs
  - sex organs
  - genital organs
  - jaws
  - lifespans
  - meals
  - surfaces
  - hide while resting, staying in thick plant growth or hiding in mud
* Most leeches live in fresh water
  - rely on blood
* Some leeches are ovo viviparous
  - predators or scavengers, feeding on worms, snails, and insect larvae
  - burrow into sediments
  - carry their eggs in a clear sack under their body
  - cause infection
  - complete their life cycle in a few months, but many can live for several years
* Some leeches contain beneficial enzymes
* Some leeches eat organisms
  - other organisms
* Some leeches feed on earthworms
  - frogs
  - other vertebrates
* Some leeches have adverse effects
  - anterior suckers
  - curves
  - eyes
  - ovaries
  - patterns of bright colors like red and yellow
  - proboscises
  - prolong effects
  - live for months
* Some leeches live in damp vegetation
  - sea
  - tropical vegetation
  - possess coeloms
* Some leeches reach maturity
  - sexual maturity
* Some leeches take blood meals
  - then drop the eggs into the water
* Some leeches utilize bass
  - smallmouth bass
* also appear to be a major source of adult mortality
  - sensitive to sounds
  - are a choice food, and it occasionally catches and eats duckling and small muskrats
  - bury themselves into the substrate to escape the ravages of winter
  - have the ability to dramatically vary their shape
* are a kind of insects that feed on other insects i.e. they are all carnivores
  - worm, and there are hundreds of different species living all over the world
  - able to swim freely through the water, the body performing vertical undulations
  - also popular in neuroscience and medicine
  - amphibious and like to crawl about
  - annelid worms that inhabit fresh water
  - annelids
  - applied to remove the excess blood
  - attracted to the exposed skin of warm-blooded animals
  - bilaterally symmetrical, with thick muscular bodies
  - blood-sucking animals that leave a circular wound after they have dropped off the fish
* are common in New Zealand, especially in weedy streams
  - freshwater habitats, but only a few species are marine or terrestrial
  - planted ponds and are less likely in non planted ponds
  - warm protected waters of lakes, ponds, streams, and marshes
  - easy to keep alive
  - either scavengers, predators, or parasites
  - external parasites
  - famous as blood-suckers
  - flat worms with segments
  - followers
* are found all over the world, and there are hundreds of species
  - in a wide variety of habitats
  - good in severe cases placed near the outer corner of the eye
* are hermaphrodites and therefore have both a male genital organ and a female genital organ
  - which mean they have both male and female reproductive organs
* are hermaphroditic, but cross-fertilization is the practice
  - which means that a single individual produces both sperm and eggs
  - highly specialized annelids distinguished by a sucker at each end and no parapodia
  - important in the food web of a lake
  - incredible animals
  - of oligochaete ancestry
  - parasites, predators, and scavengers
  - parasitic segmented worms
  - rare
  - segmented worms that reside mostly in freshwater environments and are widespread
  - sensitive to substances such as chlorine, copper, and other chemicals
  - so different from humans biologically
  - treated in the same way as blood products and are reused only on the same patient
  - types of worms
* are used for bloodletting in medicine
  - in medicine today, but in limited, specific ways, including surgical procedures
* are usually aquatic, hermaph- rodite, and have a direct development
  - rare in calcium-poor waters
  - worms which live by sucking the blood of larger animals
* attach their cocoons to substrates such as rocks or plants.
* become dormant and bury themselves in mud or plant debris.
* belong to a group called Hirudinea.
* breathe directly through the epidermis.
* can cause direct wounds to fish and leave sites for secondary infections
  - display bright red, yellow, or orange spots or lines on their bodies
  - grow to be eight inches long
  - live for months on a blood meal so feeding is unnecessary
  - swim with dorsoventral undulations
* clean away the dead or infected tissue.
* cover themselves completely in a cocoon they create just prior to laying eggs.
* die after one or two bouts of reproduction
  - reproducing once or, in some cases, twice
  - when covered in salt, or wrapped into a tightly coiled ball of tissues
* eat only once every month or so.
* feed by piercing the skin of fish and sucking blood through their specialised mouthparts.
* feed on blood and can also be bearers of blood parasites
  - the blood of vertebrates and invertebrates
  - solely on the blood of hosts and suck blood to many fold increase their size
* generally use suckers at their front and rear ends to move like inchworms.
* go after fish, turtles, frogs, frog eggs, snails, worms, and other leeches.
* grow for a season, and are ready to breed by the following spring to begin the cycle again.
* have a fixed number of segments in their bodies
  - natural presentation in action, scent, and taste
  - simple nervous system with large, hardy neurons that are easy to study
  - huge appetite
  - muscular, stretchy bodies with a sucker at each end
  - simple eyes which detect light and dark, rough shapes and motion
  - suckers on both ends of their body
* helps balance independence with social situations to prevent isolation and mental apathy.
* includes brains
  - cell membranes
  - cells
  - corpi
  - cytoplasm
  - heads
  - nuclei
  - plasma membranes
  - sections
  - skulls
  - vacuoles
* inhabit lakes, ponds, marshes and slow moving streams, throughout most of North America.
* lack setae.
* lay eggs in cocoons, and the babies that hatch out look and behave like little adults.
* leave their mark.
* live in fresh water, and in tropical countries infest damp forests
  - moist undergrowth and grasses as well as freshwater areas
* mainly feed on the blood of mammals and can survive for long periods without eating.
* make cocoons in which to deposit their eggs.
* need water.
* occur primarily in fresh water and on land.
* often have an eversible proboscis, or a muscular pharynx with two or three teeth.
* prefer shallow water and waders are more likely to become infested than swimmers
  - water that is eutrophic, meaning it is high in nutrients
* puncture skin.
* seem to do best when they are covered with just enough fresh water to cover their backs.
* stretch out their bodies, extending their anterior ends forward.
* swim gracefully by undulating the body
  - through water
* typically suck until they fall off by themselves.
* use the larger disk on the tail only for clinging to objects.
* usually avoid light by hiding under rocks or among aquatic vegetation or detritus.
* usually have a flattened body with a reduced coelom and segmentation
  - three jaws and make a Y-shaped incision
  - inhabit marshes, rivers and ponds
* vary also in their prey and what they do when they find it.