Snails and Slugs: Phylum Mollusca, Class Gastropoda. The Class Gastropoda (in Phylum Mollusca) includes the groups pertaining to snails and slugs. The majority of gastropods have a single, usually spirally, coiled shell into which the body can be withdrawn. The shell of these creatures is often what is recovered in a fossil dig.
Causes of bleeding in the stomach can include: 1  Ulcers: Ulcers may enlarge and erode through a blood vessel, causing bleeding. 2  Gastritis. 3  Cancer. Gastric varices.  Dieulafoy 1  lesions. Portal gastropathy.
Trauma, rupture of blood vessels or bleeding disorders could result in the accumulation of blood in the abdominal cavity. Heart disease, in which there is failure of the right side of the heart, can also cause fluid buildup in the abdomen as the heart loses its capacity to pump blood. This results in a buildup of pressure in the abdominal cavity and causes fluid accumulation as a result of portal hypertension. Liver disease, inflammation of the kidneys or a decrease in the blood albumin levels are other conditions that result in abdominal fluid buildup.