Definition: In unequal cleavage, the first two cell divisions are unequal producing four cells in which one cell is bigger than the other three. This larger cell is specified as the D macromere.
Definition: The capability of producing eggs (OVA) from which young are hatched outside the body. While mostly referring to nonmammalian species, this does include MAMMALS of the order MONOTREMATA.
Definition: The capability of producing eggs (OVA) from which young are hatched outside the body. While mostly referring to nonmammalian species, this does include MAMMALS of the order MONOTREMATA.
Definition: Direct developers are characterized by young that resemble the adult form even in early stages of development. The larval stages of marine direct developers generally have very low dispersal potential.
Definition: Direct developers are characterized by young that resemble the adult form even in early stages of development. The larval stages of marine direct developers generally have very low dispersal potential.
Definition: An organism that moves through the water column via movements of its fins, legs or appendages, via undulatory movements of the body or via jet propulsion; includes pelagic phases during reproduction (swarming at the surface)
Definition: An organism that moves through the water column via movements of its fins, legs or appendages, via undulatory movements of the body or via jet propulsion; includes pelagic phases during reproduction (swarming at the surface)
Definition: An organism that moves through the water column via movements of its fins, legs or appendages, via undulatory movements of the body or via jet propulsion; includes pelagic phases during reproduction (swarming at the surface)
Definition: Planktotrophic species generally have fairly long pelagic larval durations and feed while in the water column. Consequentially, they have the potential to disperse long distances.
Definition: Planktotrophic species generally have fairly long pelagic larval durations and feed while in the water column. Consequentially, they have the potential to disperse long distances.
Definition: Planktotrophic species generally have fairly long pelagic larval durations and feed while in the water column. Consequentially, they have the potential to disperse long distances.
Definition: The enlarged, fluid filled nucleus of a primary oocyte, the development of which is suspended in prophase I of the first meiotic division between embryohood and sexual maturity.
Definition: Mucus is a bodily fluid consisting of a slippery secretion of the lining of the mucous membranes in the body. It is a viscous colloid containing antiseptic enzymes (such as lysozyme) and immunoglobulins. Mucus is produced by goblet cells in the mucous membranes that cover the surfaces of the membranes. It is made up of mucins and inorganic salts suspended in water.
Definition: Mucus is a bodily fluid consisting of a slippery secretion of the lining of the mucous membranes in the body. It is a viscous colloid containing antiseptic enzymes (such as lysozyme) and immunoglobulins. Mucus is produced by goblet cells in the mucous membranes that cover the surfaces of the membranes. It is made up of mucins and inorganic salts suspended in water.
Definition: Mucus is a bodily fluid consisting of a slippery secretion of the lining of the mucous membranes in the body. It is a viscous colloid containing antiseptic enzymes (such as lysozyme) and immunoglobulins. Mucus is produced by goblet cells in the mucous membranes that cover the surfaces of the membranes. It is made up of mucins and inorganic salts suspended in water.
Definition: Mucus is a bodily fluid consisting of a slippery secretion of the lining of the mucous membranes in the body. It is a viscous colloid containing antiseptic enzymes (such as lysozyme) and immunoglobulins. Mucus is produced by goblet cells in the mucous membranes that cover the surfaces of the membranes. It is made up of mucins and inorganic salts suspended in water.
Definition: Eye-spots which may be set into a pit to reduce the angles of light that enters, to allow the organism to deduce the angle of incoming light. Lens-like structures may be present, but stemmata, unlike lens eyes, cannot form an image, either for lack of refractive power or retinal resolution.
