Of the republic of kazakhstan state university
|
|  Yüklə 4.43 Mb.
|
| Parthenogenesis Unisexual reproduction with unfertilized eggs and no contribution by males.
Parturial molt The molt that results in the appearance of complete, functional oöstegites. Patch reef A small circular or irregular reef that rises from the floor of a lagoon behind a barrier reef or within an atoll. Paurometabolous Insect development in which nymphs closely resemble adults but lack wings and are sexually immature. There is no radical metamorphosis. Paxilla (pl. Paxillae) An echinoderm ossicle crowned with small, movable spines. Pectinate Having teeth or side branches arranged like a comb. Pectine A comb-like sensory appendages unique to scorpions. Pedal disc In some sea anemones, a flattened disc at the aboral end of the column for attachment. Pedal laceration Method of asexual reproduction in some anemones in which parts of the pedal disc are left behind as the animal moves. Pedicellaria (pl. Pedicellariae) A small, specialized jawlike appendage of asteroids and echinoids which is used for protection and feeding. Pedicle Muscular, flexible stalk that attaches articulate brachiopods to the substratum. Pedipalp The second chelicerate appendage, it is modified for a variety of functions. Peduncle Muscular, flexible attachment stalk of goose barnacles. Pelagic The water of the open ocean, including the neritic and oceanic zones. Also, organisms living in the water independent of the bottom. Pelagosphera Secondary planktotrophic larva of sipunculans. Pellicle Protozoan “body wall” composed of cell membrane, cytoskeleton, and other organelles. Pellucid Clear, transparent. Penetration anchor An anchor that holds one part of a burrowing animal’s body in place as another part penetrates and advances into the sediment. Peniculus (pl. Peniculi) A modified membranelle that is greatly lengthened and thus tends to be similar to an undulating membrane in function. Pentactula Metamorphosing stage of holothuroid development that bears five primary tentacles. Pentamerous Divided into five parts, characteristic of the body of echinoderms. Periostracum The outer proteinaceous layer of a molluscan shell, composed conchiolin. Periproct The membranous area, often bearing ossicles, around the anus of echinoids. Perisarc A supporting, nonliving chitinous cuticle secreted by the epidermis surrounding most hydroids. Peristalsis A wave of muscular contraction moving along a body or internal tube or vessel. Peristome Buccal cavity of ciliates. The membranous area around the mouth of some echinoderms, i.e., sea urchins. Peristomium The first true segment, immediately posterior to the prostomium, of an annelid. Usually lacks locomotory appendages. Peritoneum The innermost, noncontractile layer of a stratified coelomic epithelium; separates the coelomic fluid from the musculature. Petaloid One of five petal shaped areas on the aboral surface of irregular urchins that bear specialized respiratory podia. Phagocytosis The engulfment of large particles, such as bacteria and protozoans, by evagination of the cell surface. Pharynx (pl. Pharynges) An anterior gut region, often heavily muscularized. Phorozooid A locomotory zooid of doliolids that has a short posterior spur upon which buds differentiate into gonozooids. Photocyte Specialized cell within which light is produced. Photophore A light producing organ. Photosynthate The organic carbon fixed by the photosynthetic pathway. Phyllobranch Having flat, leaflike gills. Phyllode Each of five oral ambulacral areas of irregular echinoids that contains specialized podia for obtaining food particles. Phyllopod Flattened, leaflike appendage. Phytoflagellate A photosynthetic flagellate. Phytophagous Plant eating. Phytoplankton Microscopic algae suspended in the water column of lakes and seas. Pilidium A free swimming and planktotrophic larva of many heteronemerteans which is characterized by an apical tuft of cilia and is somewhat helmet shaped. Pinacocyte One of the epithelial like flattened cells which together make up the sponge pinacoderm. Pinnate Having side branches, like a feather. Pinnule Side branch of an appendage, i.e., on octocoral tentacles, crinoid arms. Pinocytosis A nonspecific form of endocytosis in which the rate of uptake is in simple proportion to the external concentration of the material being absorbed. Planispiral All whorls of a coiled molluscan shell lying in a single plane. Plankton Organisms suspended in the water column and unable to move independently of water current because of small size or insufficient motility. Planktotrophic larva A planktonic larva that feeds on other planktonic organisms. Planula (pl. Planulae) A cnidarian larva that is elongated and radially symmetrical but with anterior and posterior ends. Plasmodium (pl. Plasmodia) Amoeboid syncytial mass. Pleopod The anterior abdominal appendages of malacostracans. Plerocercoid The final stage in the life cycle of certain tapeworms. Plesiomorphic Refers to an evolutionarily primitive state of a homolog. Pleurite (pl. Pleura) Either of the two primary, lateral, exoskeletal plates of each segment of an arthropod; also pleuron. Plicate Folded or ridged. Podocyst A foot extension of some pulmonate embryos for excretion and absorption. Podocyte Cell with branching interdigitating toelike processes, usually over the surface of a blood vessel. An adaptation for ultrafiltration. Polyembryony Development of multiple embryos from a single cell mass. Polymorphism Two or more individuals or zooids of a species modified for different functions. Polyp Form of cnidarian that has a thin layer of mesoglea and is generally sessile. Polyphyletic A taxon that includes the descendants of more than one ancestor. Polypide The innermost parts of a bryozoan zooid, including the introvert, lophophore, and viscera but not the body wall or zooecium. Polypide regression Degeneration and replacement of bryozoan polypide from the cystid. Porocyte A sponge cell that surrounds an opening which extends from the external surface to the spongocoel. Preoral pit The developmental precursor of the wheel organ and Hatschek’s groove that opens on the left side of the head of larval cephalochordates. Pressure drag The difference in pressure at the front end (higher pressure) of a forward moving organism as compared to the rear end (lower pressure). Pretrochal region Apical plate, prototroch, and mouth region of a trochophore larva. Primary host See definitive host. Proboscis (pl. Proboscides) Any tubular process of the head or anterior part of the gut, usually used in feeding and often extensible. Proboscis apparatus The complex, eversible, prey capturing organ of nemerteans. Proboscis pore The opening of the proboscis apparatus at or near the anterior tip of a nemertean. Procercoid Developmental stage of certain tapeworms between oncosphere and plerocercoid. Proctodeum Invaginated embryonic ectoderm joining the anus with the endodermal midgut. Procuticle Thick, inner layer of the arthropod exoskeleton. Proglottid One of the linearly arranged segment like sections that make up the strobila of a tapeworm. Prognathus Anteriorly directed position of insect head. Prograde Propagating in the direction in which the animal is moving, ie posterior to anterior (= direct propagation). Pronate Rotation of the leading edge down. Propodium (pl. Propodia) The front of a gastropod foot which acts like a plough and anchor. Prosopyle Internal opening of a sponge through which water flows from the incurrent canal into a radial canal or flagellated chambers. Protandry Type of hermaphroditism in which the individual is first a male and then a female. Protoconch The shell of the veliger which may remain at the apex of the adult shell. Protogyny Type of consecutive hermaphroditism in which the individual is first female then male. Protonephridium (pl. Protonephridia) A ciliated excretory tubule capped internally by one or more terminal cells specialized for ultrafiltration. Protopod The basal part of a crustacean appendage, consisting of the combined coxa and basis. Protostome Member of a major branch of the Animal Kingdom, in which the blastopore contributes to the formation of the mouth. Prototroch Preoral ring of cilia of a trochophore larva. Protozoea Third larval stage of a decapod (shrimp); after the metanauplius and before the zoea. Proximal Close to the origin, center, or midline. Pseudocoel Fluid filled body cavity that occupies the connective tissue compartment. Differs from the hemocoel only in the absence of a heart. Pseudofeces In filter feeders such as bivalves, material removed from the water flow, aggregated, and rejected before entering the gut. Pseudolamellibranch gill Bivalve gill with filaments bound together with small tissue junctions. Pseudopodium (pl. Pseudopodia) A flowing extension of a cell. Ptychocyst A cnida that discharges a thread used to weave a tube. Pygidium (pl. Pygidia) The terminal, nonsegmental part of the body of a segmented animal. Typically bears the anus. Telson. Pyriform Pear-shaped. Pupa (pl. Pupae) In holometabolous insects, the stage between the last larval instar and the adult. Pyramid Large calcareous plate that composes Aristotle’s lantern; shaped somewhat like an arrowhead with the point projected toward the mouth. Racemose Formed of a number of coalescing ducts draining to a central cavity or duct. Radial canal One of five fluid filled channels of the echinoderm water vascular system that join the ring canal to the lateral canals. Radial cleavage Type of cleavage pattern in which the cleavage spindles or cleavage planes are at right angles or parallel to the polar axis of the egg. Radial symmetry The arrangement of similar parts around a central axis. Radiole Each of the several pinnate tentacles on the head of a sabellid, serpulid, or spirorbid polychaete. Radula (pl. Radulae) A belt of transverse rows of teeth supported by the odontophore. Radula sac Pocket of the buccal cavity from which the molluscan radula arises. Ramus A branch. Raptorial Animals that capture prey. Recent The current epoch of the Quaternary Period. Redia (pl. Rediae Stage in the digenean life cycle between the sporocyst and cercaria. Regulated compartment A space, such as an organelle, gut region, or body cavity, in which the chemical environment can be controlled. Regulative development Embryonic fate determination in which cell fates are determined by a network of cellular communication in the embryo. Relictual A remnant of a once more widespread distribution. Repugnatorial gland Arthropod gland producing repellent and toxic compounds for defense. Reserve stylet One of several accessory reserve stylets present on each side of the nemertean central proboscis stylet. Resilium The inner portion of the hinge ligament. Respiratory tree One of two respiratory organs of most holothuroid echinoderms. Consists of a network of thin walled tubules in the perivisceral coelom that originates from the cloacal wall. Reticulopodium (pl. Reticulopodia)··A pseudopodium that forms a threadlike branched mesh and contains axial microtubules. Retractor muscle Muscle that withdraws an eversible or protrusible body part. Retrograde Passing in a direction opposite the direction of motion of the animal, ie anterior to posterior. Retroperitoneal Outside, or behind, the peritoneum, i.e. outside the coelom but typically bulging into the coelom and covered by peritoneum. Rhabdite Platyhelminth epidermal secretion droplets which are characterized microscopically by a specific, layered ultrastructure. Rhagon Developmental stage immediately following the metamorphosis of a demosponge larva. Typically, it is asconoid or syconoid in structure. Rhinophore One of the second pair of sensory tentacles. Rhombogen A dicyemid rhombozoan similar to a nematogen but whose axial cell is in the process of forming an infusoriform larva. A sexually reproductive nematogen. Rhopalium (pl. Rhopalia) A club shaped, marginal sensory organ of scyphozoans. Rhopalial lappet One of two small, specialized flaps on a rhopalium. Rhynchocoel A fluid filled coelomic cavity that houses the retracted nemertean proboscis. Rhynchodeum In nemerteans, the short anterior canal that joins the proboscis pore to the proboscis. Ring canal Part of the echinoderm water vascular system that joins the stone canal to the radial canals. The marginal canal of the gastrovascular system of some medusae. Rostroconchida An extinct class of molluscs that may have been ancestral to modern bivalves. Rostrum Middorsal projection in some rotifers that bears cilia and sensory bristles at its tip and is also adhesive. Median, anteriorly directed spine from the carapace and head of some crustaceans. Saccate nephridium Excretory organ derived from a coelomic end sac and metanephridial tubule. Sanguivorous Feeding on blood (= hematophagous). Saltatory Jumping, leaping locomotion. Scaphognathite Paddle like projection of the second maxilla that produces a ventilating current; gill bailer. Schizocoel Coelomic cavity derived from the separation, or splitting apart, of a solid mass of mesodermal cells. Schizogamy Apicomplexa. Multiple fission that produces merozoites. Sclerite Thickened, tanned area of cuticle in the exoskeleton of arthropods. Scleroseptum (pl. Sclerosepta)··One of the many radiating calcareous partitions in the skeletal cup of stony corals. Sclerotized Highly tanned (hardened), darkened, and thickened arthropod exoskeleton. Scolex (pl. Scoleces Anterior head region of tapeworms that is adapted for adhering to the host. Scutum (pl. Scuta) One of the calcareous plates forming the barnacle operculum. Scyphistoma (pl. Scyphistomae) A scyphozoan polyp. Segmentation Body composed of a linear series of repeating units, or segments; metamerism. Sediment Particles (clay, sand, detritus) deposited on the ocean or lake bottom. Selective deposit feeding Feeding in which animals selectively remove organic detritus particles from the surrounding sand particles. Seminal receptacle Chamber in the female gonoduct for the reception and storage of allosperm. Seminal vesicle Part of the male gonoduct that functions in the storage of autosperm. Sensillum (pl. Sensilla) Arthropod sense organ involving a specialized part of the exoskeleton. Sensu lato (s.l.) In the broad sense. Sensu stricto (s.s.) In the strict sense. Septum (pl. Septa) A double walled tissue partition in the cross sectional plane of a bilaterian or a radial plane of a cnidarian. Septal filament The free edge of an anthozoan septum that is trilobed. Sessile In anatomy: attached directly to the body surface and not stalked, also flush with the body surface . In ecology: attached firmly to a substratum and not free to move. Seta (pl. Setae) An exoskeletal bristle composed of a -chitin Setiger A segment with setae. Setose Searing setae. Sexual dimorphism Male and female of a species with different shapes or appearances. Shell A rigid skeleton on the outside of an organism. The calcified covering of molluscs and brachiopods. Shield A small calcareous plate in certain echinoderms, especially ophiuroids. Sieve tracheae Arthropod tracheal system in which the spiracle opens into an atrial or tubelike chamber from which a great bundle of tracheae arises. Sigmoid S-shaped Siliceous Composed of silica. Simple epithelium Composed of a single layer of cells, ie monolayered. Sinus Saclike space. Siphon An accessory gut channel of echiurans and some echinoids. A tubular fold of the molluscan mantle used to direct water to or from the mantle cavity. Inhalant and exhalant apertures of urochordates. Siphonoglyph Ciliated groove in the pharyngeal wall of some anthozoans that moves water into the coelenteron. Siphonozooid A highly modified pennatulacean polyp that pumps water into, or allows it to escape from, the interconnected gastrovascular cavities of the colony. Siphuncle A strand of tissue in a delicate calcareous tube functions in filling chambers with gas. Slug Opisthobranch or pulmonate in which the shell is absent or reduced and buried in the mantle. Solenocyte A protonephridial terminal cell with one flagellum and a long microvillar collar. Somatic Pertaining to the body. Somite A body segment or metamere. Spasmin Ciliate contractile protein which requires ATP for extension. Speciose Having many species. Spermatheca (pl. Spermathecae) Another term for a seminal receptacle. Spheridium (pl. Spheridia) An echinoid statocyst. Spicule A small needle like or rodlike skeletal piece. Spinneret Spinning organ of spiders. Spiracle Slitlike external opening of the arthropod tracheal system. Spiral cleavage Type of cleavage pattern in which the cleavage spindles or cleavage planes are oblique to the polar axis of the egg. Spire All the whorls of a gastropod shell above the body whorl. Spirocyst Cnida with a long adhesive thread that functions in capture of prey and in attachment to a substratum. Spongin A large, collagenous, connective tissue fiber of sponges. Spongiome System of small vesicles or tubules that surrounds the contractile vacuole in the contractile vacuole complex of ciliates. Spongocoel Interior cavity of asconoid sponges. Atrium. Sporocyst Nonciliated second stage in the life cycle of digeneans. Arises from a miracidium and gives rise to rediae. Sporosac Incomplete gonophore (made up of only the gonadal tissue) that remains attached to the polypoid colony. Sporozoite Apicomplexa. Infective sporelike stage that results from meiosis of the zygote. Spring tides Tides occurring on new and full moons characterized by large tidal amplitude. Spur A long, slender dorsal appendage of doliolids that trails behind the oozooid and bears buds. Cadophore. Squamous epithelium Epithelium of flattened tile-like cells. Statocyst A sense organ that can provide orientation to the pull of gravity. Typically composed of a chamber containing concretions (statoliths) in contact with receptor cells. Stenohaline Restricted to a narrow range of environmental salinities. Stenopod A narrow, cylindrical, leglike appendage. Stereoblastula A solid blastula, lacking an internal cavity or blastocoel. Stereogastrula A solid gastrula, lacking an archenteron cavity. Sternite The ventral plate of the cuticle of each segment of an arthropod. Sternum (pl. Sterna) The combined sternites. Stolon Rootlike extension of the body that interconnects colonial zooids. Stomodeum Invaginated embryonic ectoderm joining the mouth with the endodermal midgut. Stone canal Part of the echinoderm water vascular system that joins the madreporite with the ring canal. Usually, but not always calcified. Storage excretion Internal, indefinite retention of some excretory products, such as uric acid. Stratified epithelium Composed of two or more layers of cells, only one of which rests on the basal lamina. Streptoneury Gastropod nervous system twisted by torsion into an asymmetrical figure-8. Stridulate To generate sound by rubbing body parts together. Stridulate To produce sound by rubbing one body part against another. Strobila (pl. Strobilae) A scyphozoan polyp that buds medusae; or the posterior part of a tapeworm that consists of proglottids. Strobilation Process by which scyphomedusae arise as buds that are released by transverse fission of the oral end of the scyphistoma. Stylet A dagger like structure associated with various systems of different animal groups. Stygobiotic Living in caves. Subchelate A pincer in which the movable finger closes against a flat palm. Sublittoral The sea floor between the low tide line and the seaward edge of the continental shelf. Subradula organ Cushion shaped chemosensory structure of chitons. Subumbrella Lower oral surface of a medusa. Subterminal Located some distance from the end. Subtidal The sea below the low tide line. Supratidal Above the high tide line. Sulcus A longitudinal groove of dinoflagellates that bears the posteriorly directed flagellum. Suppinate Rotate the leading edge of a limb up. Suspension feeding Feeding on organic particles (plankton and detritus) suspended in water. Suture The junction between the septum and the wall of a cephalopod shell. |