In zoology, there is a family of animal, which is called SYNGNATHIDAE of fish. It has a unique characteristic that the female fish will lay their eggs on the male fish chest (exciting event). The male fish will incubate the eggs. It is the duty of the male fish to fertilize those eggs and give birth. When the fry are ready to be born, the male undergoes muscular contractions to expel them from his pouch. The male typically gives birth at night (dark light) and is ready for the next batch of eggs by morning when his mate returns. The number of young released by the male varies from species to species (seahorse averages 100-200 for most species, but may be as low as 5 for the smaller species, or as high as 1500, with pregnancy lasting from two to four weeks, depending on the species).

Examples of this animals are: (already mentioned Seahorse - Genus Hippocampus, examples are Big-belly seahorse, Hippocampus abdominalis, Winged seahorse, Hippocampus alatus, West African seahorse, Hippocampus algiricus, Narrow-bellied seahorse, Hippocampus angustus, Pygmy seahorse, Hippocampus bargibanti, and so many)
• Pipefish,
• Weedy sea dragon,
• Leafy dragon fish.
It (Syngnathidae) is the only family to which the term "male pregnancy" has been applied.

• Other are three transgender (pregnant) men:
(1. Matt Rice, 2. Thomas Beatie, 3. Scott Moore).

• In some mythology, Lord Vishnu (male) gives birth to Lord Brahma (male).

http://en.wikipedia.org/wiki/Male_pregnancy
http://en.wikipedia.org/wiki/Seahorse
http://scienceray.com/biology/giving-birth-animals-and-stars-in-action/

The Syngnathidae family of fish are the only species to incur the male-pregnancy.
including,
Seahorses
Pipefish
Weedy Sea Dragons
Leafy Sea Dragons (reference)

And of course Thomas Beatie the "Pregnant Man"