A layer of tissue in mollusks that secretes the shell and may form a cavity for respiration and excretion.

manteau

A larval stage in many crabs that follows the zoea stage and already resembles a small crab before becoming a young bottom-dwelling crab.

mégalope

The middle layer of cells in an embryo, which gives rise to muscles, bones and the circulatory system.

mésoderme

The jelly-like, non-cellular middle layer of a sponge, located between the outer and inner cell layers.

mésogelée

A simple, primarily plant-like organism, often referring to algae or other non-vascular plants.

métaphyte

A multicellular animal with differentiated tissues and organs.

métazoaire

A region of Oceania made up of small islands in the western Pacific Ocean, including the Federated States of Micronesia, Palau and the Marshall Islands.

Micronésie (région)

A country in the western Pacific ocean, officially called the Federated States of Micronesia, composed of over 600 small islands.

Micronésie (pays) ou Etats Fédérés de Micronésie

A relationship between two different species in which both benefit from the association.

mutualisme

Baleen whales: large whales that filter-feed using baleen plates instead of teeth.

mysticètes