Does a slug have a heart?

Answer 1

Yes, it is more likely a one or two chamber heart though.

add. Animals more primitive than and up to the Platyhelminthes, (flatworms) do not have blood supply and consequently have no need for a heart (pump). They just envelop their prey, often using a thick mucous to capture, digest and absorb their prey. Their digestive processes may be distributed over much of the body, and many lack a 'one way' digestive process.

They do have nephridia (primitive kidneys) of some sort, and of course reproductive processes. They have light and chemo receptors to detect their environment, but whether they have a true brain is open to argument. They certainly have connected nerves and may have a central nerve junction.

The next most developed worms are the Nemertine which have a blood supply, but not yet a heart, and have a one way digestive system. Their blood just sloshes round the blood vessels with movement of the animal. They have a brain, supplied with oxygen for its internal activity, and have well developed organ systems for specialized processing.

[It may well be that a true brain requires a blood supply for its internal activities.]