### animal | arthropod | crustacean:

Daphnia
* Most Daphnia are cyclical parthenogens.
* are extremely sensitive to pesticides, metals, detergents, and bleaches
  - widespread and common throughout the world
  - microscopic crustaceans that populate lakes and ponds throughout the world
  - phenotypically very plastic
  - represented worldwide as a number of different species
  - small fresh water crustacean
  - translucent and are usually amber or devoid of color
  - very advanced microscopic creatures
* display non-linear biophoton emission with increasing population density.
* eat by using feather like feet to kick food in their mouth
  - small aquatic plants
  - the infusoria and other microorganisms which grow in such water
* feed by filtering plankton and microscopic debris from the water.
* feeds on bacteria, fine detritus and very small algae.
* give birth to live young, but the eggs are incubated in a brood pouch.
* have open circulatory systems.
* live an average of one month.
* reproduce rapidly.
* shows the influence of potassium chloride, lidocaine and cupric sulfate on the heart rate.
* use their large second antennae to swim, resulting in jerky movements through the water.
+ Daphnia, Anatomy, Circulatory: Branchiopods
  * Daphnia have open circulatory systems. Instead of having blood vessels, the daphnia have a fluid called haemolymph.

Decapod crustacean
* have five pairs of limbs.
* occur worldwide.

Fairy shrimp
* are backstrokers, their ventral side is oriented to the light
  - small crustaceans related to sea shrimp
* have few natural predators.

Gooseneck barnacle
* favor floating objects in the sea, such as logs, debris and sea turtles.
* feed on amphipods and other creatures up to the size of a house fly.

### animal | arthropod | crustacean:

Isopod
* Many isopods take advantage of their flexibility to curl up into a ball when disturbed.
* Most isopods live in the water but pillbugs are one of the few isopods to live on land.
* Some isopods scavenge dead fish and other animals on the ocean bottom.
* also react to light.
* are a cosmopolitan group with representatives in most habitats
  - actually crustaceans, as are shrimp, crabs, and crayfish
  - also a food source for other animals
  - cold blooded, which means their bodies take on the temperature of their surroundings
  - crustaceans, like lobsters and crabs
  - distant relatives of lobsters and even have gills
  - dorsoventrally depressed whereas amphipods are laterally compressed
  - egg laying, but have no larval stages
* are found in dark, damp areas, especially under rocks and in leaf litter
  - many of the same environments as amphipods
  - gray in color with a shell-like body and have seven pairs of legs
  - important macro decomposers
  - marine woodlice
  - omnivores or scavengers feeding on dead or decaying plants or animals
  - tiny and mostly marine, but pillbugs and sowbugs are terrestrial
* can grow up to half an inch.
* eat plant and animal tissues.
* find food with acute sense of smell.
* have many legs that look alike.
* live in the sea, in fresh water, or on land
  - where it is moist and usually in a shaded area
* means similar footed.
* occupy many habitats, from the deep sea to true terrestrial niches.
* reproduce sexually, as there are both male and female animals.
* shed half of their exoskeleton at a time when they molt.
+ Isopod, Description
  * Isopods can grow up to half an inch. They are usually gray or brown or black, with an oval-shaped body. They also have seven pairs of short legs.

### animal | arthropod | crustacean | isopod:

Giant isopod
* are brown or pale lilac in color
  - carnivores
* live on the shelves or slopes of the world's sea floors.
* reproduce by laying eggs.