Garden Snails (Cornu aspersum)
Snails, along with all gastropods and many mollusks, have an excretory organ called the nephidrium. The organ is necessary to maintain fluid balance within snails. Water, minerals, and other substances go through the nephidrium to filter the It is a long coiled Another vital part of the snail's excretory anatomy is the haemolymph, or heart sac. The organ removes nitrogenous waste from the body of the snail. The snail produces urea containing very little amounts of fluid, this is caused by the snails ability to resorb much of the water in their body. Though, they use the kidney to process this urea. The kidney is used to process the blood and remove all toxins from it. This takes any toxins, minerals and, excesses to remove it from the body.
Clam (mercenaria Mercenaria)
The clam, similarly to Snails, also have a nephidrium. Funnel-like tubes filters the blood of the clam, ridding of all toxins and excess water. The clam, along with this, have two kidneys that move waste from the pericardial to mantle cavity. The waste from the mantle cavity has its wasted washed away by water. The clam, too, produces the chemical ammonia, which is poisonous to humans.
Squid (Loligo Duvaucelii)
The squid has two kidneys, this cleans the blood of any excesses within it. This kidney is located rather closely to the heart. Then these kidneys are extended through to the liver, where it eventually is excreted in the funnel, which is a tube located behind the head of the squid. The squid also has an ink sac; ink is also released through the funnel. The ick sac allows for the squid to discharge and ink like black substance from it. The use of this excretion is to disorient the squids prey. The squid eats mainly other animals and as an evolutionary advantage discharges this black mucous like substance to hide from its food. With the animal disoriented by the "ink," the squid is more easily able to kill and consume all those against it. This also works as a defense mechanism when it tries to escape from any animals trying to harm or consume the squid.