An ontology describing the anatomical structures and characteristics of Porifera (sponges)
external definition
synonyms that refers to the corresponding trait
variant of
Sponge bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells that can transform into other types, often migrating between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes, and the shapes of their bodies are adapted to maximize the efficiency of the water flow. All are sessile aquatic animals and, although there are freshwater species, the great majority are marine (salt water) species, ranging from tidal zones to depths exceeding 8,800 metres (5.5 mi)
An extracellular matrix enclosed by pinacoderm and choanoderm, the mesohyl is composed primarily of galectin, collagen, fibronectin-like molecules, dermatopontin, and other polypeptides. The mesohyl contains cells (microbial and eukaryotic) and skeletal elements (collagen, spongin, chitin, and/or minerals). (Boury-Esnault and Rützler 1997; Müller 2003)
A cell that lines the interior of Asconoid, syconoid and leuconoid body type sponges that contain a central flagellum surrounded by a collar of microvilli which are connected by a thin membrane. The choanocyte is ovoid, with one end adjacent to the mesohyl (in some species). It is the closest family member to the free-living ancestor called choanoflagellate. The flagellae beat regularly, creating a water flow across the microvilli which can then filter nutrients and other food from the water taken from the collar of the sponge. Food particles are then phagocytosed by the cell. Choanocytes are found dotting the surface of the spongocoel in asconoid sponges and the radial canals in syconoid sponges, but they comprise entirely the chambers in leuconoid sponges. By cooperatively moving their flagella, choanocytes generate a flow of water through the sponges pores, into the spongocoel, and out through the osculum. This improves both respiratory and digestive functions for the sponge, pulling in oxygen and nutrients and allowing a rapid expulsion of carbon dioxide and other waste products. Although all cells in a sponge are capable of living on their own, choanocytes carry out most of the sponge's ingestion, passing digested materials to the amoebocytes for delivery to other cells.
They bear more than a passing resemblance to Choanoflagellates, and demonstrate key steps in the evolution of animals. Scientist Nicole King helped to establish the distinction.[1] DNA sequencing indicates that multicellular choanoflagellates and poriferans are sister groups, both descended from the same eukaryotic clade. One can see modern choanoflagellates living in small colonies, illustrating the evolution of sponges by analogy. More complex animals, notably the cnidarians, possess cells whose structures are clearly derived from choanocytes, demonstrating their historical ties to phylum porifera.
Sponge cells adhere to form tissue-like layers, but a true epithelial cell layer, characterized by aligned cell polarity, belt-form junctions and underlying basal lamina, is thought to be a eumetazoan innovation. Amphimedon possesses all the main components of the Par, Crumbs and Discs Large (Dlg) complexes, a set of interacting proteins that are largely metazoan-specific and determine polarity in epithelial cells[http://www.nature.com/nature/journal/v466/n7307/full/nature09201.htm]
amoeba-like cells that move slowly through the mesohyl and secrete collagen fibres.
Large cell with numerous rod-like inclu sions parallel to the long axis of the cell containing acid mucopolysaccharides
secrete polysaccharides that also form part of the mesohyl
Posterior non-ciliated larval cell that will differentiate into a pinacocyte.
anterior ciliated cell of the sponge larva that will differentiate into a choanocyte or spicule-forming cell
spicule secreting cells, found in sponges. They secrete calcareous or siliceous spicules which are found in the mesohyl layer of sponges. The sclerocytes produce spicules via formation of a cellular triad
compare: "Cell involved in spicule secretion. In Demospon- ges, with intracellular secretion, sclerocytes are characterized by numerous mitochondria and the presence of spicule-axial filaments. In Calcarea, where secretion is extracellular, sclerocytes have septate junctions between them (sc in figure)." [http://www.portol.org/thesaurus]
In addition to or instead of sclerocytes, demosponges have spongocytes that secrete a form of collagen that polymerizes into spongin, a thick fibrous material that stiffens the mesohyl.
conduct signals and cause parts of the animal to contract. They are assumed to regulate the flow of water by increasing or decreasing the diameter of these openings to the aquiferous system.
cells that acts as sponges' equivalent of an immune system.
TODO: Merge with glycocyte?
amoeba-like large cells with large nuclei that are totipotent. They also have important roles in feeding and in clearing debris that block the ostia.
siliceous or calcareous entities that form the mineral skeleton of a sponge
A component of the mineral skeleton, typically composed of silica or calcium carbonate[portol]. A structural element that provides structural support and deter predators. Large spicules, visible to the naked eye are referred to as megascleres, while smaller, microscopic ones are termed microscleres. The meshing of many spicules serves as the sponge's skeleton. Spicules are formed by sclerocytes, which are derived from archaeocytes. The sclerocyte begins with an organic filament, and adds silica to it. Spicules are generally elongated at a rate of 1-10 μm per hour. Once the spicule reaches a certain length it protrudes from the sclerocyte cell body, but remains within the cell's membrane. On occasion, sclerocytes may begin a second spicule while the first is still in progress.
located primarily in the mesohyl, but some project through the pinacoderm (Barnes).
an excretory structure in the living sponge, a large opening to the outside through which the current of water exits after passing through the spongocoel. Wastes diffuse into the water and the water exits through the osculum at a velocity of nearly 8.4 cm/second, carrying away with it the sponge's wastes. The size of the osculum is regulated by the myocyte. Its size, in turn, determines the amount of water flowing through the sponge.
large, central cavity of sponges. Water enters the spongocoel through hundreds of tiny pores (Ostia) and exits through the larger opening (osculum). Depending on the body plan of the sponge (which can be asconoid, syconoid, or leuconoid), the spongocoel could be a simple interior space of the sponge or a complexly branched inner structure. Regardless of body plan or class, the spongocoel is lined with choanocytes, which have flagella that push water through the spongocoel, creating a current.
ATRIUM: "Preoscular cavity. This term is used specifically to designate the central exhalant cavity" [http://www.portol.org/thesaurus]
Any opening in the exopinacoderm through which water enters the sponge.
flat cells found on the outermost layer of sponges. They can expand and contract to slightly alter the size of the sponge, and can also produce collagen. Delimits the sponge from the external milieu and always only in a layer one-cell deep
a pore through which water is drawn from the outside into one of the saclike chambers formed by the evagination of the body wall.
Compare: "Opening of an inhalant canal into a choanocyte chamber (pro in figure)." [http://www.portol.org/thesaurus]
Any cavity lined by choanocytes and located between inhalant and exhalant systems[portol]. either the choanocyte-lined radial canal in syconoid, or the choanocyte-lined filter chamber in leuconoid[cjm].
Asconoid is one of three possible body plans for sponges, which form the phylum Porifera in kingdom Animalia and subkingdom Parazoa which means that they do not have a definite body shape. The asconoid body plan is characterized by a stalk-like spongocoel surrounded by a single layer of choanocytes. These choanocytes are cells that have flagella, and the flagella beat to push water through the spongocoel, creating a current. At somewhat regular intervals along the lining of the spongocoel are openings called ostia (singular, ostium). These protrude through the outer layer of the sponge (somewhat like an epidermis, but not entirely like it, since this terminology implies germ layers, which sponges do not have). Finally, at the top of the sponge is the osculum, which is the final exit for water circulating through the sponge. This single layer of choanocytes limits the size of asconoids, with the largest having a diameter of only 1 mm. This is due to the surface area : mass ratio which would not allow an asconoid sponge of larger size sufficient nutrition.
Sponge in which the body wall is pleated. The inner pockets of the pleats are lined with choanocytes, which connect to the outer pockets of the pleats by ostia. This increase in the number of choanocytes and hence in pumping capacity enables syconoid sponges to grow up to a few centimeters in diameter
The "leuconid" pattern boosts pumping capacity further by filling the interior almost completely with mesohyl that contains a network of chambers lined with choanocytes and connected to each other and to the water intakes and outlet by tubes. Leuconid sponges grow to over 1 metre (3.3 ft) in diameter, and the fact that growth in any direction increases the number of choanocyte chambers enables them to take a wider range of forms, for example "encrusting" sponges whose shapes follow those of the surfaces to which they attach. All freshwater and most shallow-water marine sponges have leuconid bodies. The networks of water passages in glass sponges are similar to the leuconid structure.
Skeletal substance in Demospongiae made up of collagen microfibrils of ~10 fim diameter[portol]. a modified type of collagen protein, forms the fibrous skeleton of most organisms among the phylum Porifera, the sponges. Spongin gives a sponge its flexibility. True spongin is found only in members of the class Demospongiae
A spicule composed largely of calcite having a radiate form, the number of rays being either two (diactine), three (triactine), or four (tetractine).
A trab is structural element within a sponge formed by the fusion of dendroclones. In the Anthaspidellidae, when spicules (usually dendroclones) connect at their tips to form a ladder-like structure, trabs may be formed.[1] Oxeas are sometimes employed in the central rod.[1][2] Trabs have a feather-like structure, or may form rods.[1][3] Trabs are usually regularly spaced, usually at sub-millimetric intervals.[1] Further dendroclones may interconnect adjacent trabs, forming ladder-like structures
In syconoid sponge, water passes through dermal pores to the incurrent canal and through the prosopyle to the choanocyte-lined radial canal.
The pinacoderm is the outer most layer of cells (pinacocytes) in the phylum Porifera (sponges), similar to the epidermis in other organisms. The pinacocytes are on the external surface of the sponge body and characterized as an epithelial layer of flattened cells.
compare with: "Surface lined by pinacocytes (ex and en in figure)." [http://www.portol.org/thesaurus]
cell that surrounds a pore (ostium). In an asconoid sponge, water enters the sponge through the porocytes, passes directly to the choanocyte-lined spongocoel, and then out of the sponge through the osculum.
a pore in each of the saclike chambers formed by the evagination of the body wall, through which water passes into the excurrent canals.
A large spicule, visible to the naked eye.
Prefix meaning spined, as in acanthostyle or acanthomicrorhabd
Spicule having two to six stout spined rays, typically surrounding the point of insertion of the root tuft in Hyalonema species.
Architecture of the Skeleton and Spicules of Hexactinellida
A megasclere echinating the primary skeleton. See ECHINATING SPICULE.
Architecture of the Skeleton of Demospongiae
Regularly anisotropic reticulation with ascending (primary and radial) fibers or tracts and interconnecting fibers or tracts about equal in thickness
Pointed like a needle; adjective referring to the extremities of megascleres. See OXEA.
A centered ray containing an axis or axial canal. See also CLAD.
Calcareous Spicules and Calcareous Spicule Skeleton
Elongated contractile cell often grouped in sphincter- like structure around the osculum, below the sieve- plates, and around the large exhalant canals. Characterized by numerous filaments of actin within their cytoplasm. New term for the contractile cell (ac in figure).
Creating substrate or support by cementing together a mixture of foreign material, such as sand, shell, or rock.
Macroscopical Features: Habit, Surface Characteristics, and Consistency
One of the thin, wing-like or spatulate structures in each recurved portion of a chela. The anterior ala is the one facing the shaft; others are lateral alae. See CHELA.
Skeleton arranged around choanosomal cavities
Paleontological term for longitudinal, tunnellike canal opening to the exhalant surface by slit-like apertures.
Diactin with spines recurved toward the center
Without definite shape. To be rejected, vague term. See MASSIVE.
A microsclere with microspined rays radiating from both ends of a shaft; the rays are shorter than the shaft
Hollow, ovoid larva, with anterior flagellated and posterior nonflagellated groups of cells; typical of Calcaronea
Dumbbell-shaped microsclere with ends developed into umbel-like expansions. Three size classes, termed macramphidisc, mesamphidisc, micramphidisc
A double triaene with a short rhabd bearing two opposed cladomes
Tracts, lines, or fibers are interconnected
A triaene in which the clads are sharply curved backward
Anchor-like spicule, protruding free from the basal part of the sponge; derived from diactine, triactine, or tetractine spicules, with terminal rays or spines, curved in the proximal direction along the main ray
An isochela with three or more free alae (at each end) in the form of recurved processes shaped like anchor claws (unguiferous) or anchor blades (spatuliferous); with two incipient lateral alae fused with the shaft over their entire length and a gently curved, not abruptly arched shaft. An anchorate chela with three teeth is called a tridendate chela.
Sharply bent; referring to overall spicule shape, as in oxea or sigmas. See OXEA.
Prefix meaning unequal; generally referring to the ends of a spicule; see ANISOCHELA.
Reticulate skeleton with primary and secondary tracts, lines, or fibers
To be rejected. See ASTROCLONE, SPHAEROCLONE.
Pole directed forward when larva is swimming.
An euaster with tuberculate, denticulate, or spined, sometimes digitate, expansions at the ray tips (Chondrilla grandis)
Spicules of Demospongiae. TODO: request PATO term
A special form of spiraster (genus Anthosig mella; = Cliona); to be rejected.
Type of choanocyte chamber that connects directly with the inhalant canals through prosopyles and with the exhalant canal through an apopyle extended by an aphodus. Only one chamber opens into one aphodus
Small exhalant canal leading from the apopyle to an exhalant canal (ap in figure).
The fourth actine of a tetractine that is joined to the basal triradiate system
Endopinacocyte lining the exhalant canal (ai in figure).
To be rejected; in fossil sponges, an opening forming an exit from an apochete (= osculum).
Cell surrounding the apopyle and located between the choanocytes and the apopinacocytes (ay in figure).
In fossil sponges, canal closed at the outer end (cf. epirhysis).
The entire water-conducting system between the ostia and the oscula, which comprises the inhalant system, choanocyte chambers, and the exhalant system
Erect, branching habit, tree-like in appearance (Axinella polypoides)
An isochela with three free alae and the shaft characteristically curved outward, often bow-shaped.
Surface covered by numerous circular ectosomal areas (Hamigera)
Choanoskeleton composed of several rows of similar spicules
Aquiferous system in which the internal cavity of the sponge is entirely lined by choanocytes
An elongate-compressed microsclere in which the numerous rays are fused and end in minute spinose projections (Erylus spp.)
Hexaster with numerous S-shaped terminal rays whose external curved ends form several successive tiers
Traces of the excurrent canal system on or within a rigid skeleton that appear as radiating or star-shaped grooves.
Adjective referring to the extremities of a megasclere. See OXEA.
Dermalia belonging wholly or at least primarily to the outer bounding skin, without actin protruding inside the sponge body
Gastralia with one actin protruding into the atrium
The organic core around which a siliceous spicule is organized.
A type of skeletal organization in which some components are condensed to form a central region or axis
Structure with a dense core of parallel fibers or strands fanning out toward the periphery of a sponge See also PLUMOSE or PLUMORETICULATE.
Cell containing prokaryotic microsymbionts
The dense area of compacted spongin surrounding the central zone in pithed fibers
The three rays of a tetractine that correspond to those of a triactine
Spicules protruding from lower sponge surface; sometimes called root spicules, anchors, barbed basalia; in some species, forming a root tuft
Pinacocyte affixing the sponge to the substratum by external secretion of a collagenous matrix (bs in figure).
A modified anisochela with fused alae connected by a short curved shaft (genus Iophon)
A type of microsclere with a straight shaft and umbrella-shaped ends
Adjective referring to the extremities of megascleres. See OXEA.
Ectosomal brush of spicules perpendicular to the surface of the sponge, with pointed ends outward.
Spreading out in branches (see also ARBORESCENT and REPENT).
An asexual reproductive body composed of various types of cells (e.g., Tethya spp., Axinella damicornis).
Regular triactine whose center is not in the same plane as the extremities of the recurved rays.
Hexaster with stout main rays and with terminal rays directed outward
A special form of lophocalthrop characterized by branching, multispined rays
Modified, ellipsoid isochela with wing-like extensions on one (the bottom) side (genus Cercidochela)
Modified choanocyte that transports a captured spermatozoid to an oocyte
Nonflagellated cells arranged in tetraradial fashion in the amphiblastula of Calcaronea
Interlocked or adjacent spicules firmly linked by calcareous cement; the cement may be restricted to the junction area or may progressively encase the entire spicule
Point of union of the three rays of a triactine or of a basal triradiate system.
Single cell located at the apopyle of choanocyte chambers
A triaene with three clads and two small rhabds (genus Triptolemus)
Spicules of Demospongiae. Editors note: Definition inconsistent with parent?
Spicule with a median tyle (globular swelling). See OXEA.
A microsclere with a curved shaft and recurved ala at each end.
Tetractine with the unpaired ray of the basal system and the apical ray in the same alignment
Dendroclone with a very short central shaft.
Microsclere composed of two crossed sigmas (genus Chiastosia)
Cell that buds anucleate outgrowth called COLLAR BODY; in Hexactinellida
Hexactinellida equivalent of the choanocyte chambers of Demospongiae and Calcarea.
Skeleton of the part of the sponge that contains choanocytes
Skeleton of the main body, supporting the canal system and responsible for the form of the sponge.
The internal region of a sponge, including the choanocyte chambers.
Predominantly radiate, occasionally confused arrangement of megascleres including triaenes with cladome outward, lacking spongin, and commonly with a cortex.
Hollow larva, entirely flagellated, with a central ring of pigmented cells; typical of Homoscleromorpha
Any ray or axial branch containing an axis or axial canal confluent with that of the protoclad or protorhabd in any type of spicule; term chiefly used in triaene spicules.
The clads of a triaene or triaene-derivative spicule.
Monaxon megasclere, one end with knobs, the other with hooks
Resembling open latticework (Clathrina coriacea)
Polyhedral arrangement of fibroreticulate sheets
Isodictyal or subisodictyal arrangement of fibers cored and/or echinated by styles in the family Microcionidae
A ring-shaped microsclere (genus Merlia).
Sceptrule with one terminal umbel or with terminal anchor teeth
A chela with the ends (anterior alae) very close to each other (e.g., Clathria echinata)
Discohexactin with long, dendate, umbel-like structures
Hollow larva composed of an envelope of morphologically similar equipotent cells, to which a few larger nonflagellated cells may be added at the posterior pole.
Term for cnidarians, used for the solid skeleton in stromatoporoids; to be rejected for sponges in favor of rigid calcareous skeleton.
A dense band of intercellular collagen fibrils, which has a skeletal role in some sponges (e.g., genus Chondrosia)
Editor note: consider using 'anucleate cell' from CL
Cell with branching pseudopods/cytoplasmic strands, involved in the secretion of collagen (co in figure).
collenocyte
Radial skeletal element in stromatoporoids, with a greater degree of continuity and larger than PILLARS.
Shape of solid, erect cylinder (Petrosia capsa)
Parenchymalia located close and parallel to principalia
Several fibers merged or intricately interconnected
Surface with numerous cone-shaped projections raised up by underlying skeleton (Dysidea sp.)
In cnidarians, term for the external skeleton of a polyp; to be rejected for sponges in favor of PSEUDOCALYX.
A fiber that incorporates indigenous spicules or foreign material (spicules and sediment); coring may be light and limited to a central axis or may fill in the whole fiber
Surface with alternating parallel ridges and grooves (Callyspongia plicifera)
A superficial region of a sponge reinforced by a special organic or inorganic skeleton
Ectosomal skeleton reinforced by a layer of special skeleton elements.
Spicule or skeleton of the external layer or cortex of the sponge
Massive shape, with a broad base and large central depression (Xestospongia muta).
The fundamental, inceptional body of a desma before it is modified by deposition of multiple layers of silica. A monocrepid desma develops from a monaxon spicule that is recognized by a straight, undivided axial thread (canal); a tetracrepid desma is based on a tetraxon spicule with a four-rayed axial thread (a small calthrops; see bottom of figure); an acrepid desma is based on a polyaxon fundamental structure lacking axial threads.
Prefix indicating spiral or annulate ornamentation, as in cricalthrop (genus Sphinctrella)
Masses of thesocyte-like cells lodged within the basal crypts (chambers) of the calcareous skeleton (see ct in figure).
Organization of the skeletal crystals observed after special preparation showing the relationship between organic and mineral phases.
Referring to spicule shape (may be symmetrical or asymmetrical). See OXEA.
A spongin layer covering the surface or a part of the surface of a sponge.
A sigma with semilanceolated extremities (genus Pozziella)
Cell with a single large vesicle containing amorphous material identified as polysaccharide and occupying most of the cell volume
To be rejected for habit (term used as a descriptor of skeleton, see "Architecture of the Skeleton of Demospongiae").
A skeleton consisting of single or ramifying fibers or tracts that branch but rarely anastomose (tree-like branching)
Desma with branched ends or tetracladine, amphitrider-like; always positioned perpendicular to skeletal fibers.
Spicules of the external sponge surface. See AUTODERMALIA, HYPODERMALIA
A typical interlocked megasclere with hypertrophic terminal secretion of silica.
An actinal branch or a distal, branched portion of a ray. See DICHOTRIAENE.
Megascleres with two rays and frequently with central swellings indicating the hexactin origin.
Megasclere with two actines (two rays or two points)
Spicules of Demospongiae. Editors note: we use the variant_of relation here to avoid inconsistency
A microsclere with hooked, knife-shaped ends, notched where they join the shaft and in the middle of the shaft (genus Hamacantha)
Sagittal triactine with parallel paired rays
tuning-fork spicule
In fossil sponges, radial canal in the honeycomb- like skeleton of Aphrocallistidae.
An ortho or plagiotriaene in which the clads are bifurcate
Tuberculate monaxial desma, arch shaped, tripodal, tetrapodal, or rarely polygonal; zygomes are terminal, like those of the tetraclone.
Three-dimensional network of fused, regular hexactins
Microxea or microstrongyle ornamented by two discs along the shaft (genus Didiscus)
Deeply divided, finger-like outgrowths from basal mass (Halichondria bowerbanki)
Any diactine spicule with a central double-bent kink
An astrose microsclere in which the rays or spines radiate from two, slightly distant, points
Type of choanocyte chamber that connects with the inhalant canals through a canaliculum called the prosodus and with the excurrent canal through an apopyle extended by an aphodus
A collective term for DISCORHABD and SCEPTRUM; to be rejected.
A modified isochela whose disc-shaped alae are very close to each other and connected on their margins by two extremely reduced shafts (genus Coelodischela)
Octaster with terminal rays ending in umbel-like disks
Hexactin with rays terminating in dentate, umbel-like structures
Hexaster with dentate, umbel-like terminal rays.
A rod-shaped microsclere with several smooth or serrated discs along the shaft (genera Latrunculia, Podospongia, Sceptrinus)
sceptrum
A triaene with a disc-shaped cladome. The single clads may be distinguished by the presence of short axial canals (genus Discodermia)
Hexaster with sickle-like terminations (genus Dictyaulus)
Megasclere that protrudes from the spongin plate, a fiber, or a spicule tract
Skeleton found in the superficial region of a sponge, distinct from that of the choanosome.
The superficial region of a sponge that has no choanocyte chambers.
Thin, sheet-like coating of the substrate (Hymedesmia spp.)
Occupying cavities in hard substrata (see also EXCAVATING).
Pinacocyte lining the inhalant and exhalant canals. In some Demospongiae orders, it has a flagellum (en in figure).
Main part of body buried in sand (Oceanapia peltata)
Calcareous or siliceous spicules that are not part of the primary spicule framework but are progressively enclosed within a solid skeleton during growth
Cell with inclusions that react positively with eosine.
Part of the developed desma formed by the deposition of concentric layers immediately around the crepis.
In fossil sponges, canal closed at inner end (cf. aporhysis).
A thin, wrinkled, calcareous layer, different in structure from the normal skeleton, covering the dead basal part of a rigid calcareous skeleton
Spicules of Demospongiae. Editors note: merge with Oxea?
General term for having a vertical (away from substrate) growth strategy.
A collective term for astrose microscleres in which the rays radiate from a central point
Type of choanocyte chamber that connects directly with the inhalant canals through prosopyles and with the excurrent canal through an apopyle. There is no special canal after the apopyle, and several chambers open into the same exhalant canal
Living in galleries or cavities bored into limestone or other calcareous materials (species of Cliona, Thoosa, Aka)
Any canal forming part of the exhalant system, lined by the apopinacoderm.
Part of the aquiferous system between the apopyle and oscule
Fusiform or T-shaped pinacocyte covering the free surface of a sponge. In exceptional cases, it has a flagellum (Homoscleromorpha) (ex in figure).
Styles or tylostyles with enlarged or omated distal end, projecting from the sponge surface
Structurally distinct skeleton arising from or surrounding an axial region
The plane passing through tips of the three rays of a triactine or of a basal triradiate system of a tetractine.
Crystal fibers fanning outward and radiating upward. In the penicillate type (e.g., Ceratoporella), crystal fibers are feebly divergent; in the water-jet type (e.g., Merlia), crystal fibers progressively fan outward around the growth axis; in the trabecular type (cnidarian, unknown in sponges), the crystal fibers are symmetrically arranged around the growth axis and axial fibers are absent
A column (strand, thread) of spongin forming a reticulate or dendritic skeleton, with or without indige nous spicules or foreign material.
Microsclere consisting of two bent rays derived from greatly reduced oxyhexaster (in Holascus fibulatus)
Secondary calcareous skeleton that partitions or fills abandoned parts of the skeleton.
Narrow structure, similar to an ala, flanking the shaft of an anchorate chela
Solid, requires considerable pressure to deform sponge (species of Chondrosia).
A tube-like protuberance projecting from the sponge surface. See also PAPILLA
Bearing fistules (Coelosphaera hechteli).
To be rejected. See CHOANOCYTE CHAMBER and CHOANOCHAMBER.
Shaped as a single, very long, erect branch (Raspailia viminalis)
Referring to the spicule shape. See OXEA.
sinuous spicule
Discohexaster with S-shaped terminal rays that end in a plate provided with teeth or claws
In the form of a leaf (Carteriospongia foliacens)
Circular pore in laminae connecting adjoining interlamellar spaces (fo in figure, which also shows cc = choanocyte chamber; ct = crypt tissue; sk = rigid aspicular skeleton; spi = spicule; and ta = tabula).
Breakup of a sponge without concomitant formation of special reproductive bodies.
A ray that projects through the external or the atrial surface.
Cell with inclusions that react positively with acid fuchsin.
Shape of a monactin spicule, tapering regularly toward a point. See OXEA.
Obsoleted as fusiform is better represented as a quality
All spicules that line the main exhalant cavity. See AUTOGASTRALIA, HYPOGASTRALIA
A resistant asexual reproductive body, composed of a mass of archaeocytes charged with reserves and enclosed in a noncellular protective envelope or coat
Cell with a single large globule, a reduced cytoplasm, and a small conical nucleus (Clathriidae)
Ball shaped, spherical (Tethya aurantium)
Cell with conspicuous dictyosomes, characterized by the presence of glycogen rosettes and osmiophilic inclusions. Also known as gray cell
Hexaster with long, thin, parallel branches forming terminal brushes
Confused skeleton except at the surface; choanosomal skeleton may be in vague tracts
Firm consistency, unyielding to pressure (most lithis tids, species of Petrosia).
Spicule remaining isodiametric for most of its length, with the point or points tapering abruptly. See OXEA.
Desma with elongate and usually sinuous shaft, without branches, possibly with small digitations at the ends; the zygomes are lateral notches. An axial canal is usually found along most of the length of the spicule
Hexaster in which two opposite rays are longer than the other four; the branched rays are reduced or absent (genus Aphrocallistes)
Siliceous spicule with six unbranched rays perpendicular to one another.
Microhexactin with six actins ending in amphidisclike umbels
A more or less distinct, funnel-shaped depression in the surface of a STERRASTER, situated on one side in ellipsoidal forms; also occurs in ASPIDASTERS in reduced form, resembling an umbilicus.
Surface with long and scattered spicular projections (Stelletta spp.)
Spicules projecting through the pinacoderm.
A fiber without central pith and without conspicuous layers
Surface with polygonal pattern of ridges (Verongula gigantea)
Skeleton of encrusting sponge where monactine megascleres are arranged singly with heads fixed to a basal plate of spongin and points directed outward
Dermalia with one actin protruding inside the body and the other ones tangential to the external surface
Gastralia with one actin protruding inward, the other ones oriented tangentially to the atrium
Choanoskeleton composed only of the unpaired rays of the subatrial spicules and of one of the rays of the cortical or subcortical spicules. Without specific spicules of the choanoskeleton
Any canal forming part of the inhalant system and lined by the prosopinacoderm.
Part of the aquiferous system between ostia and prosopyle.
Parenchymalia situated among the principalia or dictyonalia
Free choanosomal spicule not included in tracts or fibers, common in subectosomal skeleton
Long, slender (0.5-15 urn thick) spongin element, terminally knobbed; intertwined or free in the sponge body
Structure in which tangled crystal fibers have no preferred orientation (e.g., genus Vaceletia). Shape and nature of the crystal fiber may be diverse
Prefix meaning equal (generally referring to the ends of a spicule).
Isotropic reticulation in which the meshes are triangular and have sides one spicule long
Reticulation without differentiation into primary or secondary fibers, tracts, or lines.
Plate-like erect (Phyllospongia lamellosa).
Calcareous plate in stromatoporoids, perpendicular to radial skeletal components
A fiber in which concentric layers are visible
A macroscopic, banded calcareous skeletal plate in stromatoporoids
Aquiferous system in which the choanocytes are restricted to discrete choanocyte chambers, which are dispersed in the mesohyl.
Soft to the point of collapsing out of water.
Spicules that are interlocked by zygosis, without cement
Condition of a surface in which oscula and ostia are inconspicuous (in old descriptions).
Main skeleton consisting of an interlocked assemblage of desmas
Modified calthrop with one (monoloph), three (triloph), or four (tetraloph) rays
Discohexaster with short, stout main rays and numerous slender secondary rays
Hexactin with a center resembling a perforated octohedron; building block of fused (dictyonal) framework called LYCHNISCA (lower two lychnics shown in optical section).
Dictyonal hexactin framework formed by lychnises
Spicular framework formed by the juxtaposition and interlacing of elongate rays of hexactins
Rounded regular or irregular elevation of the skeleton surface; may or may not show correlation with astrorhizae
Prostalia that project in a wreath-like arrangement from the oscular margin
Large, compact structure without definable shape (Spongia officinalis).
Arch-shaped desma with a short crepis. The zygomes vary from oblique lateral facets to tongue- or hand-like terminal expansions
Sheet of collagen separating the choanochambers of hexactinellids.
A triaene in which the rhabd is extended beyond the cladome
A microsclere with a twisted shaft no longer than the spines; intermediate between plesiaster and spi raster
Prefix used for naming microscleres that are similar in shape to megascleres (e.g., microxea, microstyle).
A small tetractine anchor (described only from the atrial skeleton).
Structure of microcionid sponges in which spicules project from an elevation of the basal plate of spongin
A cell with cytoplasm filled with small dense granules
Diverse structure in which small, round elements are scattered
Large category of microscleres lacking spines and appendages (Monorhaphis)
Structure in which the crystal fibers are disposed in criss-cross layers, mostly parallel to the surface of the skeleton (e.g., genus Acanthochaetetes)
Opening in the gemmule coat through which cells leave a hatching gemmule (mp in figure).
A general term for a straight, monaxonic microsclere.
The arrangement of crystals that form the skeletal components, as seen without special preparations.
Prokaryotic or more rarely eukaryotic microorganism living inside a sponge. May be unicellular or multicellular filamentous, with or without pigments, and may occur intra- or intercellularly
Linear, nonradiate spicule, or a spicule type not having more than two rays along one axis.
Adjective referring to the nipple-like point of a megasclere. See OXEA.
Fiber or tract composed of six or more spicules adjacent to one another.
Junction of spicule tips cemented by spongin.
Cells that are incorporated in developing oocytes to provide nutrient material for further growth
Spicule with eight rays, generally six in one plane, the other two perpendicular to them.
Octactin microsclere with branched rays.
Earliest developmental stage with a functional aquiferous system, with a single choanocyte chamber opening directly into the osculum; typical of some calcareous sponges
A long, thin, finely spined, asymmetric microsclere
Hexaster with terminal rays ending in four actins that are perpendicular to the rays
onychohexactin
onychohexaster
The crystallographic trigonal axis of the calcite spicule.
Diactin in which the two rays belong to different axes of a triaxon and form an angle of 90 degrees
Microstructure in which the crystal fibers are in perpendicular and radial orientation relative to a central axis
A triaene in which the clads are directed at right angles to the rhabd
Mode of reproduction in which embryo develops outside the parent sponge.
Monaxon (diactinal) spicule pointed at both ends (a-m in figure). Different types are distinguished by shape and tip morphology. Shape may be fusiform (a), angulate (b), centrotylote (c), curved (d), or flexuous (e). Tips may be acerate (f), asymmetrical (g), blunt (h), conical (i), hastate (j), mucronate (k), stepped (1), or symmetrical (m).
Prefix referring to radiate spicule types with rays gradually tapering to a point.
An euaster with acerate free rays and a small centrum less than one-third the diameter of the whole spicule)
One or both equivalent rays of a sagittal spicule.
Perpendicular arrangement of ectosomal spicules, with points directed outward
An iso- or anisochela in which the lateral alae coalesce with the shaft over their entire length, and the single, median, anterior ala (one at each end) stands free and widens distally
Nipple-like protuberance projecting from the sponge surface and bearing either ostia, oscula, or both.
Surface bearing papillae (Polymastia spp.)
Graphicome-like spicule with diverging terminal rays
Bilaterally symmetrical triactine or tetractine with unequal actines, having equal angles (120 degrees) between the basal rays when projected into a plane perpendicular to the optic axis.
Arrangement of ectosomal spicules intermediate between the palisade and tangential type
Tangential ectosomal skeleton in which the megascleres are arranged in a tight feltwork
Larva composed of an envelope of flagellated cells surrounding an internal mass of cells
Fiber or tract with two to five megascleres adjacent to one another
Supported by a short stalk containing choanosome (Aplysina pedunculata)
Radial skeletal component, relatively short compared with COLUMN
Pentact or hexact spicule with four basal rays and one perpendicular ray ornamented by obliquely set spines directed distally.
Central area of a fiber made up of more or less diffuse wisps of collagen or of a coarsely granular collagen material. See PITHED FIBER.
A fiber in which pith is easily distinguished from the surrounding bark.
A special type of isochela with plate-like alae. The alae and the shaft are internally ornamented by radial ridges (genus Guitarra)
A triaene in which the clads are directed forward and form with the rhabd an angle of about 45 degrees, and may be recurved distally
Thickly lamellate, usually in horizontal orientation.
A streptaster with a very short shaft (always shorter than the spines)
Spicules protruding from lateral surface.
A type of plumose skeletal construction in which cross-connections occur
A type of skeletal construction made of primary fibers or spicule tracts from which skeletal elements radiate obliquely
Special kind of bacteriocyte that surrounds an area of the intercellular matrix, including microsymbionts
Megasclere with several annular swelling along its shaft
A furrow in the ectosome where the ostia are located
A specialized area of the ectosome with a cluster of ostia and an underlying inhalant cavity called the vestibule
crible
Cup-shaped depressions with pore-sieves, typical of some genera of Tetillidae
Pole opposite to anterior pole when larva is swimming, often without flagella.
Cf. apopore (= osculum); in fossil sponges.
An ascending fiber ending at a right angle to the surface
The major structural megasclere in any particular sponge.
Framework of spicules around which a cement is deposited
Spicules making up main skeletal framework
In fossil sponges, inhalant canal leading to prosopore.
A small inhalant canal leading to a prosopyle.
Endopinacocyte lining the inhalant canals.
The proximal, unbranched portion of a branched ray. See DICHOTRIAENE.
The original simple shaft of ornamented monaxons and of triaenes.
A triaene in which the clads are directed or sharply curved forward, away from the rhabd
One of a group of skeletal tubes - closely packed together, mostly hexagonal in shape and containing the live material - that resemble the calices or corallites of cnidarians.
Accumulation of gemmular archaeocytes (crypt cells, tract cells) in basal cavities of a solid calcareous skeleton
A subcortical triactine essentially sagittal, but having unequally long and differently curved rays on each side of the unpaired angle
Surface appearing dotted because of microscopic pores.
A small euaster in which the rays are merely low conules; to be rejected.
A type of skeleton in which the structural components diverge from a central region toward the sponge surface
A very thin, hair-like microsclere, often in bundles called trichodragmas
A multicellular mass resulting from the disorganization of a sponge and presumably capable of reorganizing into a new functional sponge.
Triactine or tetractine spicule with basal rays of equal length, and with equal angles (120 degrees) between them, when projected into a plane perpendicular to the optic axis
Growing along or just above the substrate, simple or branching, attaching to the substrate at intervals (Hali clona simulans)
Resumes original shape after deformation.
Three-dimensional network of fibers, tracts, lines, or single spicules.
A collective term for a monaxonic megasclere, later applied to the one ray of a triaene that is distinct from the other three, mostly in length (= rhabdome).
Diactin in which the two rays are aligned in a single axis.
The rhabd of a triaene and of a triaene-derived spicule.
Earliest functional stage with multiple choanocyte chambers and aquiferous canals, typical for Demospongiae
Nontuberculate irregular monaxial desma, with spiny to root-like zygomes that are usually mainly lateral
Surface with series of ridges (Xestospongia muta) ; ridges not necessarily parallel, as in CORRUGATED.
Skeleton that originates from the direct secretion of aspicular elements made up of calcium carbonate; siliceous or calcareous spicules may be secondarily entrapped in the skeleton during the growth process (sk in figure).
A skeleton in which the main framework is first made up of fused or linked spicules that may later be invested by an aspicular cement
Anchored to or into substrate with root-like processes (Pheronema grayi).
Having a rough and ridged surface (Topsentia spp.)
Triactine or tetractine with two equal angles (paired angles) and one dissimilar angle (unpaired angle) at the center, when projected into a plane perpendicular to the optic axis.
A rhabd-derived, straight microsclere having spines at intervals along the entire length. Spines along the shaft are perpendicular to the axis and may or may not be spirally arranged; those at the ends diverge obliquely (e.g., genera Tribrachium, Disyringa)
Sceptrule with one end swollen and ornamented with distally directed spines
Disc-shaped microsclere forming ectosomal ('dermal') armor (genus Lepidosphera)
Uncinate marginalia, with spiny shaft acerated at one end; terminating in four very short actins at the other (Pheronematidae, genus Semperella)
A small, prostal monactin spicule exhibiting peculiar secondary developments at one end (order Hexactinosa).
In fossil sponges, continuous system of interconected canal spaces (Tretodictyidae).
Aggregate of crystals forming a microstructural unit of the calcareous skeleton
Fork-like sceptrule with one end branched (leptoscopule, pachyscopule).
In a reticulate skeleton, a fiber that links the primary fibers.
Skeletal components formed after the deposition of the primary calcareous skeleton
A special type of spiraster approaching the shape of a sterraster (genus Placospongia)
Perforated plate that extends over the broad terminal opening of some tubular-shaped Hexactinellida (Euplectella). See "Architecture and Spicules of Hexactinellida"
A contorted-sigmoid microspined microsclere (family Tetillidae)
Hexaster with long, S-shaped terminal rays (Dictyaulus)
All structures supporting and protecting the sponge body.
Architecture of the Skeleton of Demospongiae. The skeleton of sponges consists of microscopic calcareous or silicious spicules. The demosponges include 90% of all species of sponges. Their "skeletons" are made of spicules consisting of fibers of the protein spongin, the mineral silica, or both. Where spicules of silica are present, they have a different shape from those in the otherwise similar glass sponges[WP].
Surface without any projections (Chondrosia reniformis).
An anchorate chela (usually isochela) having alae that are completely free from the shaft and that are spatulate or shaped like anchor teeth
Modified, encysted spermatozoid transported by a carrier cell to the oocyte
Modified isochela, consisting of two ellipsoid ridged plates intersecting at right angles (genus Melonanchora)
Anaxial desma in which several ray-like arms extend from one side of a globular centrum that is spiny on the other side
Hexactin with rays ending in spherical knobs
Hexaster with terminal rays ending in spherical knobs
An euaster with short rays and a thick centrum; the diameter of the centrum (more than one-half the total diameter) exceeds the length of the rays
Euaster with a discrete centrum that is more than one-third the total diameter
Globular (centric or excentric) arrangement of crystal fibers radiating from a common center (e.g., genus Astrosclerd)
Cell filled with large round spherules that occupy almost the entire cell body, compressing the cytoplasm into thin sheets (sp in figure).
A spongin component of the skeleton that has the form of a diactinal, triactinal, or polyactinal spicule
spongin spicule
Surface with scattered, stiff, and sharp spicular or fiber projections (Pleraplysilla spinifera)
Spiral, rod-shaped microsclere with spines peripherally arranged.
Discohexaster with a bunch of terminal, spirally twisted rays (genus Rhabdodictyum)
Particular gemmule that lacks a complex spongin coat and is covered externally by megascleres; typical of the freshwater Potamolepidae.
Reduced hexactin with four rays all arranged in one plane
Reduced hexaster with four rays all arranged in one plane
A spherical or ellipsoidal microsclere in which the numerous rays are fused and end in stellate terminations (e.g., genus Geodia).
Ball-shaped euaster with numerous conical or flattened, often denticulate or tuberculate protuberances; to be rejected. See STERRASTER.
Supported by a long stalk (Stylocordyla stipitata)
Condition in which distinct, massive parts of a sponge are interconnected by repent, rope-like structures (Haliclona tubifera).
Developmental stage of amphiblastulas that precedes the reversion stage and is characterized by internal flagella and a large opening through which the eversion occurs
Aster in which the rays proceed from an axis that is usually spiral
Plumicome with numerous slender terminal rays arranged in two concentric circles
Aster with free, isodiametric, blunt rays
An isodiametric, diactinal megasclere with rounded ends
Monaxon spicule with one end pointed, the other (head or base) blunt
Spicules of Demospongiae. NOTE: wp says megasclere
Sagittal spicule with paired rays adjacent to the atrial skeleton.
A pseudosagittal triactine, with unpaired actine and a shorter paired actine adjacent to the cortex, or a tetractine with basal triradiate system adjacent to the cortex.
Term to be rejected. See SUBCORTICAL SPICULE.
Term to be rejected. See SUBATRIAL SPICULE.
Skeleton consisting of a loose assemblage of desmas
Tylostyle with one end pointed, the other with a slight swelling or knob; the swelling, more or less distinct, may be displaced along the shaft
Furrowed with longitudinal, or meandering (gyriform), parallel channels (Myrmekioderma styx)
Aquiferous system with elongated choanocyte chamber containing free distal cones or extending from cortex to atrium.
Aquiferous system with elongate choanocyte chambers arranged radially around invagination of the atrial cavity (Leucilla uter)
Bridges composed of siliceous cement joining spicules
Plate or floor that partitions the basal part of a skeletal cavity (ta in figure).
Osculum in stromatoporoids that has been repeatedly partitioned by secondarily deposited tabulae.
Ectosomal skeleton arranged parallel to the surface (figure shows upper right, view from the top).
Spicule arranged parallel to the surface.
Large, smooth triactin (genus Monorhaphis).
In a reticulate skeleton, a fiber interconnecting the secondary fibers
Tetraxial desma that does not show a triaenose symmetry; the zygomes are typically terminal.
A spicule with four rays (in figure, sagittal tetractine at the top and regular tetractine at the bottom).
Microsclere with four actins ending in amphidisc like umbels
A rare, modified isochela having two small disks both at the extremities and in the middle of a straight shaft; the two in the middle are fused (genus Tetrapocillon)
A rare, minute anisochela with the smaller extremity jar- or slipper-shaped and partly enveloped by four alae issuing from the opposite end and forming an umbrella-like structure (Mycale thaumatochela).
Vitelline-rich archaeocyte in a sponge gemmule (th in figure).
Toxa-like, smooth to spinose microsclere, double- bent in the middle and often with central swelling (genus Rhabderemia)
Gigantic, isolated diactin (Hyalonema toxeres).
A straight, isodiametric, diactinal megasclere with conical or mucronate extremities
Syncytia in hexactinellids occurring around the choanochambers.
General term for a tetractinal megasclere having one unequal ray (termed rhabd) that is commonly much longer than the other three (termed clads, forming the cladome).
Architecture of the Skeleton and Spicules of Hexactinellida. WP: Triaxons have three axes; in triods, each axis bears a similar ray; in pentacts, the triaxon has five rays, four of which lie in a single plane; and pinnules are pentacts with large spines on the non-planar ray - Eugenio Andri; Stefania Gerbaudo; Massimiliano Testa (2001).
Hexactinellid larva, distinguished by median zone with multiflagellated mononucleate cells between anterior and posterior poles; with special larval stauractin skeleton
A triaene in which the clads are trifurcate.
Thin, hair-like straight monaxon spicules present in general around the osculum or protruding from the cortex.
A chela with three free alae. See also ANCHORATE CHELA.
Variant of tetraclone, with triaenose symmetry and three similar arms.
Triact in which the rays are equal, straight, in one plane, and diverging at an angle of 120 degrees.
A modified triod with rays forming a regular pyramid.
Nurse cell involved in the initial stages of gemmule and oocyte formation.
Aster with crowded, blunt rays (genus Rhabdastrella).
Shape of hollow, erect cylinder (Aplysina fistularis)
Resembling an inverted cone (Cribochalina vasculum)
Any rounded swelling or knob in a spicule (c in figure).
A style with a tyle (globular swelling) at the base
Diactinal megasclere with a swelling on each end
Diactin covered with short spines directed distally (barbule); size classes are designated by macrouncinate, microuncinate
Adjective referring to the extremities of megascleres. See also ANISO-.
An anchorate chela in which the recurved processes are in the form of claws or sickles and are normally connected to the shaft by expansions called falces
ancora unguifera
In sagittal spicules, the ray of a triactine or of a triradiate basal system of a tetractine lying in the plane of bilateral symmetry.
To be rejected (old-fashioned, heraldic term used to describe massive forms).
Surface with dense, short spicular projections, feeling soft and smooth to the touch.
Spicule ornamented by whirls (e.g., genus Agelas)
Hollow, bladder-like (Inflatella belli).
Subectosomal cavity. An inhalant aquiferous cavity close to the surface (see also PORE SIEVE).
subdermal cavity
Surface shaggy, with dense, long spicular bundles (Rosella villosa)
Mode of reproduction in which internal fertilization and incubation of the embryo occur inside the parent sponge.
Part of a desma that interlocks with another spicule.
Mode of junction between siliceous and calcareous tetraradiates characterized by the interlocking of their terminal or lateral expansions; cement, if present, is secondary.
body layer
spermatid
spongiocyte
bromotyrosin
granular cell
membrane-bound inclusion
large dense membrane-bound inclusion
large granular membrane-bound inclusion
small granular membrane-bound inclusion
exopinacoderm
reproductive body
rigid skeleton
stellate spicule where where 1-6 primary rays undergo terminal branching to form secondary rays (differs from definition used for desmosponges)
aster
collagen fibril
sponge surface
surface protruberance
mode of reproduction
anatomical axis
ray axis
plate
ectosomal spicule
pole of larva
flagellated cell
chamber
groove, pit or depression
hilum of sterraster
hilum of aspidaster
calcareous skeleton
relationship to substrate
substrate
cell component
nucleus
sponge larva
structural quality
gemmule coat
multicellular anatomical structure
envelope of flagellated cells
crypt cell
tract cell
flagellated endopinacocyte
flagellated exopinacocyte
calcareous plate
choanocyte-lined radial canal
choanocyte-lined filter chamber
organism subdivision
triaene clad
bifurcate clad
trifurcate clad
macramphidisc
mesamphidisc
micramphidisc
monaxial desma
choanosomal spicule
microstrongyle
A pentact with large spines on the non-planar ray[WP]
pinnule
protein
enzyme which catalyzes the formation of silicate polymers
silicatein
enzyme in sponges, proposed to be involved in silica restructuring and maintenance. The proposed mechanism involves bound zinc acting as a Lewis acid catalyst to break the silicate ester bond between silicon and oxygen
silicase
spiculogenesis
cavity of canal
arm of trider
skeletal element of sponge
Shape of a monactin spicule, tapering regularly toward an end.
Subtypes of acanthostyle other than verticillate acanthostyle have yet to be named
acanthostyle
spine
Editor's note: logical definition still to be added
verticillate acanthostyle
anisochela I
anisochela II
growth_form
PATO_0000701 A texture quality inhering in a bearer by virtue of the bearer's posessing a surface free of roughness or irregularities.
smooth
size class
mineral skeleton
Megasclere with a single actine (one ray or one point)
monactine
Anatomical system that has as its parts the organs concerned with reproduction.
a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.