Cephalopod excretion system

The excretion organ of cephalopods is also metanephrosis, but it is cystic. Nautilus has 4 kidney capsules, and 2 other animals. The outer renal foramen opens on the renal papilla in the mantle cavity, and the other end is surrounded by the kidney around the heart cavity. The tube communicates with the pericardial cavity.

After the current posterior large vein branches into the renal capsule, a large number of folds are formed around the wall of the vein, called renal appendage. Its pulsation is consistent with the pulsation of the gill heart, and the metabolites in the blood leak After the renal appendages enter the kidney capsule, after being reabsorbed by the renal capsule, the metabolites are discharged from the outer renal foramen to the outer cavity, and discharged from the body when water is sprayed through the funnel.

Nautilus's kidney circumscribes the cardiovascular opening in the mantle cavity. In addition, under the gill heart of the squid is a pair of branchial heart appendages, which are equivalent to the pericardial glands of other mollusks and can collect metabolites in the pericardial cavity. The excrement is mainly guanine.