The special cells of the sponge include those that filter sea water cells that are phagocytic (that engulf and digest food particles) those that form the external 'skin', breathing pores and tubes through which water enters and leaves the body and those that secrete the mineral and organic skeletons, called spicules and fibres, respectively. In addition, sem observations showed that the body frame is basically formed from a bundling spicule with an extremely intricate construction [4,6] however, few studies have examined the silica nanostructure (atomic-scale structure) of the body frame and spicule. Sponge spicules and diatom frustules are frequently observed in ponded or poorly drained soil environments sponge spicule fragments are mainly characterized by an acicular shape and the presence of an axial canal ( drees et al, 1989 . 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. A sponge has differentiated cells and functionally distinct layers the ameobocytes secrete spicules which stack up together to make the sponge the choanocytes are composed of a flagellum and a collar (collar cells.
Observations transmission e/ectron microscopy of sectioned spicu/es and replicas most of the spicules in sections of non-decalcified sponge tissue are seen to be. Calcareous sponges (clade or class calcarea) have spicules composed of calcium carbonate they are small, usually vase shaped and asconoid, syconoid, or leuconoid in structure glass sponges (clade or class hexactinellida) are mostly deep sea forms. Observations of the spicules of a sponge supplies microscope prepared slide: sponge lab notebook colored pencils natural sponges hypothesis we will learn more in depth about sponges and the complexity of this animal procedure set up microscop as instructed in previous expiraments place the prepared slide under the microscope.
The sponge skeleton may be composed of mineral spicules, spongin fibers or a combination of these two, depending on the kind of sponge spicules may be calcareous (composed of ca co 3 ) or siliceous (composed of h 2 si 2 o 7 . Of sponge spicules (sponge microscleres can be only a couple of pm thick), careful observations on a large population of spicule-like objects suggest that they at least. The siliceous spicules of these sponges indicate close ties to the genera spirastrella and diplastrella but morphological peculiarities of spicules and the presence of an elaborately structured. Phylum porifera a taxonomy class calcarea - sponges having calcareous spicules with 1 to 4 rays (asconoid, syconoid, leuconoid) class hexactinellida - sponges having siliceous spicules with 6 rays. Spicules are composed of either calcium carbonate or silicon dioxide, and the skeleton may consist entirely of collagenous fibers (spongin) or a combination of spicules and spongin see the poriferan taxonomy for the characteristics of the four classes of porifera.
Gray (1867) was first to subdivide all sponges into 'porifera silicea' and 'porifera calcarea' based on the chemical composition of sponge spicules (silica vs calcium carbonate), a view still advocated by some scholars (eg, böger 1988. Tubular cells that allow water to flow from the outside of the sponge to its central cavity pinacocytes outer sponge cells thin, leathery and tightly packed together and collectively form the pinacoderm. Calcareous spicules: the organic material in this type of spicules is calcium carbonate or calcite this is the characteristic of the sponges of class calcarea this is the characteristic of the sponges of class calcarea. Such as freshwater sponge or other mineral grains the skeleton of the freshwater sponge consists of spicules that are cemented through organic junctions (keding et al, 2010.
Currently, the accepted classification is that proposed by bidder following observations by minchin , and which is based on the position of the nucleus within the choanocytes, the shape of the spicules, the type of larva and the first type of spicule to appear during ontogeny. The amebocytes secrete spicules of calcium carbonate in the gelatinous protein matrix of the sponge between the epidermis and the choanocytes as diploblasts, sponges including grantia exhibit only two germ layers, the endoderm and ectoderm. This contrast with the spicule assemblage from new zealand, which characterized deeper waters based on the presence of numerous strictly deepwater sponge taxa, and the absence of spicules of shallow-water demosponges represented in the australian material. Observations of the spicules of a sponge essay sample hypothesis we will learn more in depth about sponges and the complexity of this animal procedure.
Hypothesiswe will larn more in deepness about sponges and the complexness of this animate being procedureset up microscop as instructed in old expiramentstopographic point the prepared slide under the microscopeobeserve under low power and pull what you see in your notebook. Sponge - form and function: sponges are unusual animals in that they lack definite organs to carry out their various functions the most important structure is the system of canals and chambers, called a water-current system, through which water circulates to bring food and oxygen to the sponge.
However, some of the spines belonging to the glass sponges of hexactinellids, which is the group to which euplectella belongs, are of stunning complexity consider the following example or this spicules, the so-called dumbbell spicule, which is from a bizarre sponge called hyalonema. In fact, sponge spicules are so conspicuous that their absence from the ediacaran fossil record seemed peculiar fortunately, clear examples have of hexactinellid, demosponge and, perhaps, calcarean sponges have now been recovered from the ediacaran of mongolia, china and india. Sponge-spicules 3 of exquisitely symmetrical forms, the meaning of which it is impossible to interpret in terms of the physiological require-ments of the sponge. Demosponge included are the yellow tube sponge, aplysina fistularis, the purple vase sponge, niphates digitalis, the red encrusting sponge, spiratrella coccinea, and the gray rope sponge, callyspongia sp.