Glossary | M

Macrophyte
any large living marine plant such as algae, sea grasses, mangroves
Madroporite
sieve-like button-shaped process on top surface of Echinoderms that serves as the external opening of the water vascular system
Mammal
any member of the Class Mammalia; warm-blooded, have hair, have live births, nurse their young, breath air, have a 3 part inner ear structure; e.g., whales, bears, humans
Mangrove
variety of salt tolerant trees and shrubs that inhabit the intertidal zone of tropical and semi-tropical regions
Mantle
portion of the body wall in mollusks that lines and secretes the shell or forms the body wall
Marine
pertaining to or inhabiting the sea, ocean, or other salt water
Marsh
area of wetland periodically flooded by water and colonized by marsh grasses and other marsh plants
Marsh plain
coastal area that is raised above the highest tide level and has become dry
Marsupial
mammal in which the embryonic young are born, travel to a pouch on the mother's abdomen, and attach to a nipple to complete development
Mean sea level
average level of all the tides
Medusa
adult bell or umbrella shaped form of cnidarians; includes fresh and salt jellies; the sexual free-swimming form; Spanish word for jelly is medusa
Melanistic
color phase in which the skin, plumage, or pelage is black or near black due to the presence of the pigment melanin
Melon
fatty cushion structure in the forehead region of toothed whales and dolphins that is used during echolocation
Mermaid’s purse
leathery egg case laid by some cartilaginous fishes; largely composed of keratin
Mesoglea
middle jelly, the substance between the inner and outer dermal layers of a jelly's bell; consistency is species dependent; gives jelly its common name
Metabolism
physical and chemical changes within a living organism involved in the maintenance of life
Microorganism
any microscopic organism
Midden
refuse heap; commonly used to describe the garbage heaps of ancient Native American villages
Migration
periodic and often habitual movement of animals from one area to another for purposes of breeding and eating
Milt
secretions from male reproduction organs of fishes
Mimicry
superficial resemblance of one organism to another or to objects in its environment for concealment or protection
Mollusk
any member of the Phylum Mollusca; invertebrates with a soft unsegmented body, often somewhat enclosed by a shell; e.g., abalone, snails, clams, slugs, and cephalopods
Molt
periodic shedding of exoskeleton, hair, feathers, and/or skin that allow new growth to take place underne
Monoecious
male and female parts on the same plant
Monogamy
mating with only one partner
Morphology
body structure and form of an organism
Mudflat
expanses of mud that are periodically exposed to low tide and are usually adjacent to salt marshes
Mustelid
any member of the family Mustelidae; carnivorous mammals that secrete a musky odor and often show delayed inmplantation
Mutualism
symbiotic close association between two organisms in which each derives some benefit
Myoglobin
red iron containing and oxygen carrying protein pigment found in the muscles of vertebrates