Starting with Man.
(All the answers begin with 'man')

Vegetarian marine mammals known popularly as sea cows.

Perching duck that shares its name with Oriental royalty.

Shoreline swamp habitat named after a salt-tolerant tree.

Colourful baboon from the forests of western Africa.

'Portuguese' floating deathtrap with long, trailing tentacles.

Predatory insect that holds its front legs as if in prayer.

Long-legged dog from the grasslands of South America

Giant plankton-eating ray found in tropical waters.

(courtesy of Reader's Digest, "The Animal World")