Abdomen |
the posterior section of the body, behind the thorax or the cephalothorax |
Acoelomate |
any organism that lacks a cavity between the body wall and the digestive tract |
Adductor muscle |
a muscle whose function is to close a bivalved shell or carapace e.g. as in ostracods, bivalved molluscs |
Antenna |
one of a pair of jointed feelers on head of various arthropods |
Antennule |
small antenna or feeler, especially the first pair of antennae in Crustacea |
Anterior |
towards the front, usually the head end (opposite to posterior) |
Appendage |
a limb or other process extending from the body, usually articulated |
Asymmetrical |
not symmetrical |
Basal |
relating to, located at, or forming a base |
Benthic |
living on the seabed |
Bifid |
divided into two parts |
Bilateral symmetry |
a basic body plan in which the left and right sides of the organism can be divided into approximate mirror images of each other along the midline |
Bioluminescence |
production of light by living organisms, this ability occurs in many different organisms, both plants and animals |
Biramous |
in the Crustacea, it describes the condition in which appendages are divided into two segmented branches: exopodite and endopodite, these branches arise from a basal segment called the basipodite |
Birefringent |
the resolution or splitting of a light wave into two unequally reflected or transmitted waves by an optically anisotropic medium such as calcite or quartz |
Bisexual reproduction |
an animal that has the reproductive organs of both sexes |
Bract |
siphosomal element, usually containing much mesoglea, with a protective or buoyancy function |
Brood chamber |
a chamber used to incubate eggs, or young |
Buoyant |
capable of keeping a body afloat |
Calcareous |
of, containing, or like calcium carbonate |
Calyptope |
planktonic larval stage following the nauplius in euphausiid crustaceans |
Carapace |
in the Crustacea it describes a fold of the exoskeleton of the head that extends back over the thorax and may be fused with a few or all of the thoracic segments. It may also extend laterally to protect the sides of the body |
Carnivore |
an animal that eats other animals |
Carotenoid |
any of a group of red and yellow pigments |
Globule |
a small spherical body |
Caudal |
referring to the tail |
Caudal rami |
literally, tail branches |
Cephalosome |
first segment of the prosome (head and thorax of copepods); bears mouthparts (crustaceans) |
Cephalothorax |
fused head and thoracic body segments often covered by a carapace dorsally and laterally (crustacean) |
Chaeta |
bristles protruding from pockets in the body wall |
Chelae |
the pincerlike organ or claw terminating certain limbs of crustaceans |
Chelate |
claw-like or pincer-like; bearing chela or claws |
Cheliped |
either of the pair of appendages bearing a chela |
Chitin |
a tough, protective, semitransparent substance, forming the principal component of the exoskeleton |
Chitinous |
composed of chitin |
Cilia |
minute hairlike organelles, identical in structure to flagella, which line the surfaces of certain cells and beat in rhythmic waves, providing locomotion to ciliate protozoans and moving liquids along internal epithelial tissue in animals |
Ciliary |
relating to cilia projecting from the surface of a cell |
Cirri |
a filament or slender appendage serving as a foot, tentacle, barbel, etc. |
Coelenterate |
the animal phyla Cnidaria and Ctenophora collectively |
Coelenteron |
the single body cavity of a coelenterate |
Coelom |
the body cavity of higher metazoans, between the body wall and intestine, lined with a mesodermal epithelium |
Compress |
to condense, shorten, or abbreviate |
Compound eye |
the eye of most insects and some crustaceans, which is composed of many light-sensitive elements, each having its own refractive system and each forming a portion of an image |
Coxa |
proximal segment of pereiopods of crustacea; may be expanded and plate-like in some forms |
Coxal plate |
coxae of pereiopods laterally expanded into flattened lamellar structures extending freely (as plates) to overhang the coxa-basis hinge of the leg |
Cytoplasm |
the cell substance between the cell membrane and the nucleus, containing the cytosol, organelles, cytoskeleton, and various particles |
Dactyl |
last (distal) segment of the endopodite of crustacean appendages |
Dactylozooid |
a kind of zooid of Siphonophora which has an elongated or even vermiform body, with one tentacle, but no mouth |
Denticle |
small tooth-like process |
Detritivore |
an organism that feeds on and breaks down dead plant or animal matter, returning essential nutrients to the ecosystem |
Detritus |
dead material derived from biota |
Diapause |
resting phase in the life history in which metabolic activity is low, and periods of adverse environmental conditions can be tolerated |
Diel vertical migration |
refers to a pattern of movement that some organisms living in the ocean's photic zone undertake each day, travelling to the surface during the night to feed, then descending to darker, safer depths during the day |
Dinoflagellate |
any of numerous chiefly marine plankton of the phylum Dinoflagellata, usually having two flagella, one in a groove around the body and the other extending from its centre |
Diploblastic |
having two germ layers, the ectoderm and endoderm, as in the embryos of sponges and coelenterates |
Distal
|
situated away from the point of attachment or origin or a central point especially of the body |
Dorsal |
upper surface |
Dorsoventral plane |
pertaining to the dorsal and ventral aspects of the body; extending from the dorsal to the ventral side |
Ectoderm |
the outer germ layer in the embryo of a metazoan |
Endite |
extensions of some basal segments of the endopodite of crustacean appendages that project medially (towards the midline of the animal) |
Endoderm |
the innermost body tissue that derives from this layer, as the gut lining |
Endopodite |
inner branch of a biramous crustacean appendage |
Endopod |
the inner or medial branch of a two-branched crustacean leg or appendage |
Epibenthos |
organisms living on the surface of the seabed or in the water column just above the bottom |
Epidermis |
the outermost living layer of an animal, usually composed of one or more layers of cells |
Epipelagic |
of or pertaining to the stratum of the oceanic zone where enough light is present for photosynthesis to occur, generally at depths of 0 - 200 m (656 ft) |
Epipodite |
extensions of some basal segments of crustacean appendages that project towards the outside |
Euphotic zone |
the uppermost layer of a body of water that receives sufficient light for photosynthesis and the growth of phytoplankton |
Exopodite |
outer branch of a biramous crustacean appendage |
Exoskeleton |
a hard outer structure, such as the shell of an insect or crustacean, that provides protection or support for an organism |
Exumbrella |
convex surface of the bell of a medusa (jellyfish) |
Filter feeders |
animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized structure |
Flagellum |
a long, lashlike appendage serving as an organ of locomotion |
Foliose |
with many leaves; having leaf-like lobes |
Furcilia |
post-calyptope stage in the life cycle of euphausiid crustaceans |
Fuse |
to combine or unite |
Gastrozooid |
feeding polyp, situated on the siphosome, bearing a tentacle usually with several tentilla |
Geniculate |
having kneelike joints or bends |
Genital |
of, pertaining to, or noting reproduction |
Gill |
the respiratory organ of most aquatic animals that breathe water to obtain oxygen, consisting of a filamentous structure of vascular membranes across which dissolved gases are exchanged |
Gonad |
a sex gland in which gametes are produced; an ovary or testis |
Gonophore |
a structure bearing or consisting of a reproductive organ or part, such as a reproductive polyp or bud in a hydroid colony |
Gonozooid |
sexual stage of salps (planktonic tunicates) |
Graze |
to feed |
Gymnoplean tagmosis |
prosome-urosome boundary located posterior to fifth pedigerous somite |
Herbivore |
an animal that mainly feeds on plants |
Hermaphrodite |
an organism having both male and female reproductive organs in a single individual |
Heterotrophic |
capable of utilizing only organic materials as a source of food |
Holoplankton |
organisms that spend their entire life in the water column, often called permanent plankton |
Host |
a living animal or plant from which a parasite obtains nutrition |
Ischium |
first (proximal) segment of the endopod of crustacean thoracic appendages |
Lappets |
lobes of the bell margin of jellyfish (Scyphozoa) medusae formed by scalloping |
Larvae |
the young of any invertebrate animal |
Lateral |
pertaining to, or on, the side |
Locomotion |
the act or power of moving from place to place |
Macrozooplankton |
zooplankters between 2 and 20 mm in length |
Mandible |
a crushing or biting mouth appendage of a crustacean |
Marsupium |
brood pouch found on the ventral surface of the thorax of female peracarid crustaceans, formed from plate-like extensions of the coxa of thoracic limbs (oostegites) |
Manubrium |
tube bearing the mouth hanging down from the under surface of a medusa |
Maxilla |
paired mouthparts of crustaceans located anteriorly to the mandibles |
Maxilliped |
1, 2 or 3 pairs of thoracic appendages of crustaceans adapted for assisting in feeding |
Medusa |
a saucer-shaped or dome-shaped, free-swimming jellyfish |
Megazooplankton |
zooplankters greater than 20 mm in length |
Membranous |
thin and flattened like a membrane |
Meroplankton |
organisms that only spend part of their life cycle in the water column e.g. eggs and larvae, often called temporary plankton |
Merus |
second segment of the endopod of crustacean thoracic appendages |
Mesoglea |
the noncellular, gelatinous material between the inner and outer body walls of a coelenterate |
Mesopelagic |
of, pertaining to, or living in the ocean at a depth of between 180 m (600 ft) and 900 m (3000 ft) |
Mesozooplankton |
zooplankton between 200 µm and 2 mm in length |
Metamorphic |
pertaining to or characterized by change of form, or metamorphosis |
Metamorphosis |
a profound change in form from one stage to the next in the life history of an organism |
Metanauplius |
a larval crustacean in a stage following the nauplius, and having about seven pairs of appendages |
Metasome |
thoracic segments in copepod crustaceans |
Metatroph |
requiring dead organic matter for food |
Microzooplankton |
zooplankton less than 200 µm in length |
Moults |
periodic shedding of the cuticle |
Natatory |
formed or adapted for swimming |
Nauplii |
a larval form with three pairs of appendages and a single median eye, occurring usually as the first stage of development after leaving the egg |
Nauplius |
early planktonic larval stage of crustaceans |
Nectophore |
swimming bell |
Nematocyst |
an organ in Cnidarians consisting of a minute capsule containing an ejectable thread that causes a sting |
Neritic |
living in coastal waters i.e. the shallow water over the continental shelf |
Neuston |
organisms that live at the very surface of the sea |
Omnivore |
an omnivorous animal |
Omnivorous |
eating both animal and plant foods |
Ovigerous |
bearing eggs |
Ovisac |
an egg-containing capsule |
Paedomorphosis |
development of sexual maturity in an otherwise juvenile body |
Palp |
an elongated, often segmented appendage usually found near the mouth in invertebrate organisms such as mollusks, crustaceans, and insects, the functions of which include sensation, locomotion, and feeding |
Papillae |
one of certain small protuberances concerned with the senses of touch, taste, and smell |
Parapodia |
one of the unjointed rudimentary limbs or processes of locomotion of many worms, as annelids |
Parasite |
an organism that lives on or in an organism of another species, known as the host, from the body of which it obtains nutriment |
Parasitic |
of, pertaining to, or characteristic of parasites |
Parthenogenesis |
a form of reproduction in which the egg develops into a new individual without fertilisation |
Pedigerous |
bearing or having feet or legs |
Pelagic |
living in the water column |
Pereiopod |
walking leg (swimming leg of copepods); located under the cephalothorax or metasome of crustaceans |
Periphery |
the external boundary of any surface or area |
Photophore |
light-producing organ |
Photosynthetsis |
the process by which phytoplankton make carbohydrates from carbon dioxide and water, using energy captured from sunlight by chlorophyll, and releasing oxygen as a byproduct |
Phytoplankton |
plankton consisting of free-floating algae, protists, and cyanobacteria, phytoplankton form the beginning of the food chain for aquatic animals and fix large amounts of carbon, which would otherwise be released as carbon dioxide |
Pigmentation |
coloration with or deposition of pigment (a coloring matter or substance) |
Pleopod |
swimming leg located under the abdomen or urosome of crustaceans, often called swimmerets |
Pleosome |
anterior 3 segments of pleon bearing biramous pleopods |
Pleura |
abdominal segments of crustaceans |
Pleurobranchiae |
gills that arise from the lateral walls of the thorax in decapod crustaceans |
Pluteus |
larval stage of echinoid or ophiuroid echinoderms |
Pneumatophores |
a gas-filled sac serving as a float in some colonial marine hydrozoans, such as the Portuguese man-of-war |
Podobranchiae |
gills that arise from the coxae of thoracic appendages in euphausiid and decapod crustacean |
Podoplean tagmosis |
prosome-urosome boundary located posterior to fourth pedigerous somite |
Polyp |
a sedentary type of animal form characterized by a more or less fixed base, columnar body, and free end with mouth and tentacles, esp. as applied to coelenterates |
Posterior |
towards the tail, behind; opposite to anterior |
Propodus |
fourth (penultimate) segment of the endopodite of the crustacean limb |
Prosome |
anterior part of the body in some invertebrates |
Prostomium |
anterior, pre-segmental region of the body, anterior to mouth, may bear eyes, antennae and palps, and encloses part of the brain |
Prototroch |
a preoral circlet of cilia of a trochophore larva |
Protozoan |
any of a diverse group of eukaryotes, of the kingdom Protista, that are primarily unicellular, existing singly or aggregating into colonies, are usually nonphotosynthetic, and are often classified further into phyla according to their capacity for and means of motility, as by pseudopods, flagella, or cilia |
Radially symmetrical |
animals which are symmetrical in 2 or more planes e.g. a sea urchin |
Rostrum |
prolongation of the anterior portion of the carapace that projects beyond the head, usually between the eyes; found in Crustacea |
Scavengers |
an animal or other organism that feeds on dead organic matter |
Scyphistoma |
a stage in the life cycle of a jellyfish or other scyphozoan when it is fixed in place and reproduces asexually to produce free-swimming medusae |
Segmentation |
the subdivision of an organism or of an organ into more or less equivalent parts |
Segments |
a clearly differentiated subdivision of an organism or part, such as a metamere |
Sessile eye |
an eye attached by the base |
Setae |
solid bristle-like structure found in Chaetognatha, that are used for locomotion, in Arthropoda, hollow bristles containing living tissue, which extend from appendages |
Setose |
bearing bristles (setae) |
Solitary |
living habitually alone or in pairs |
Somite |
one member of a series of paired segments into which the thickened dorsal zone of mesoderm is divided |
Spawning |
to deposit eggs, produce spawn |
Spine |
a stiff, pointed process or appendage on an animal |
Stalked eye |
an eye attached to a stem or projection |
Statocyst |
an organ found in many invertebrate animals that is used to orientate the body in space i.e. for balance |
Subchelate prehensile gnathopods |
the claw-bearing and grasping limbs of amphipods for processing food |
Subumbrella |
concave or undersurface of the bell of a medusa (jellyfish) |
Suspension feeders |
animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized structure |
Symbiotic |
the living together of two dissimilar organisms, as in mutualism, commensalism, amensalism, or parasitism |
Symbiotically |
the living together of two dissimilar organisms, as in mutualism, commensalism, amensalism, or parasitism |
Telson |
posterior projection of the terminal abdominal segment of crustaceans, particularly malacostracans. Along with the uropods it forms a tail fan |
Tentacle |
any of various slender, flexible processes or appendages in animals, esp. invertebrates, that serve as organs of touch, prehension, etc.; feeler |
Thermocline |
region of relatively sharp temperature change in the water column, the depth of the thermocline varies seasonally in temperate seas |
Thoracic |
of, relating to, or situated in or near the thorax |
Thorax |
the portion of the body between the head and the abdomen |
Tintinnid |
ciliates of the choreotrich taxon Tintinnida, distinguished by vase-shaped shells called loricae, which are mostly protein but may incorporate minute pieces of minerals |
Uniramous |
in arthropods, an unbranched appendage. In crustaceans the exopodite is often lacking in walking legs |
Uropod |
last of a pair of abdominal appendages in malacostracan crustaceans, they are usually broad and flat and form a tail fan with the telson |
Urosome |
abdomen of copepods, though may be used for abdominal segments bearing uropods in other crustaceans |
Urosomal |
pertaining to the abdomen of copepods, though may be used for abdominal segments bearing uropods in other crustaceans |
Velum |
inward projection of the margin of the bell of hydrozoan medusae |
Ventral |
lower surface (opposite to dorsal) |
Vertical migration |
refers to a pattern of movement that some organisms living in the ocean's photic zone undertake each day, travelling to the surface during the night to feed, then descending to darker, safer depths during the day |
Zooid |
an organic cell or organized body that has independent movement within a living organism, especially a motile gamete such as a spermatozoon |