How many animal has 32 brains?

What Animal Has 32 Brains

Leeches have 32 brains. The internal body of the leech is divided into 32 segments. Each of these segments has its neural ganglia that connect to the next. Anatomically, it is the same brain that exists in 32 parts across the body. Physiologically, because each ganglion manages its corresponding portion and acts independently, it is considered to have 32 brains.

Leeches are parasitic or predatory worms with segmented bodies that belong to the phylum Annelida's subclass, Hirudinea. They are linked to oligochaetes, which include earthworms, and have soft, muscular segmented bodies that may extend and contract like them. Both groups are hermaphrodites with clitellum, but leeches differ from oligochaetes in that they have suckers at both ends and ring marks that do not correlate to their internal segmentation. The body is muscular and solid, and the coelom, a vast body cavity seen in other annelids, has been reduced to microscopic channels.

The Nervous System Of Leech (Hirudinaria granulosa)

The neural system of a leech is composed of a few massive nerve cells; because of their huge size, leeches are useful as model animals for the study of invertebrate nervous systems. The cerebral ganglion above the stomach and another ganglion underneath it comprise the central nerve center, with connecting nerves creating a ring around the pharynx a little below the mouth. In the ventral coelomic channel, a nerve cord containing 21 pairs of ganglia in segments 6 to 26 extends ahead from this. Other paired ganglia combine to produce the caudal ganglion. Several sensory nerves link directly to the cerebral ganglion; sensory and motor nerve cells are attached to each segment's ventral nerve cord ganglia.

Leeches have two to ten pigment spot ocelli positioned in pairs at the front of the body. In one annulation of each segment, sensory papillae are also organized in a lateral row. Many sensory cells are found in each papilla. Leeches can detect touch, vibration, movement of adjacent objects, and chemicals emitted by their hosts, and freshwater leeches may crawl or swim towards a possible host standing in their pond in a matter of seconds. Species that feed on warm-blooded hosts migrate to warmer environments. Many leeches avoid light, but when they are ready to feed, certain blood feeders gravitate towards light to increase their chances of locating a host.