protonephridia, metanephridia... Gills?
lungs kidney skin
invertebrate
Arteries, veins and capillaries are the three major types of blood vessels. They are all found in organs.
The excretory system contains a pair of nephridia in every segment, except for the first three and last one.There are three types of nephridia : integumentary, septal and pharyngeal nephridia. The integumentary nephridia lie attached to the inner side of the body wall in all segments except the first two. The septal nephridia are attached to both sides of the septa behind the 15th segment. The pharyngeal nephridia are attached to 4th, 5th and 6th segment. The nitrogenous wastes are removed by the rhythmic beating of the cilia of the nephridiostomes. The excretory wastes are then finally discharged into the gut.
Three body organs are: the brain, the heart, the liver.
Solid, fluid and gaseous.
Three substances are water, nitrogen, and access salts.
any invertebrate animal with a three-layered body and a pseudocoel
any invertebrate animal with a three-layered body and a pseudocoel
1. Lungs. 2. Skin. 3. Kidneys.
Excretory and reproductive, as both metabolic wastes and sperm/eggs exit there
a unibrow on a unicorn with three kajillion coconuts