Spongiaria: The sponges are lower multicellular animals that often have the appearance of plants . Some species form thin plates, others are cup-shaped or branched, globular, or of different shapes.
Summary
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- 1 Features
- 2 Study of Leucosolenia
- 3 Habitat
- 4 Structure
- 5 Life processes
- 6 Sponges that inhabit the seas of Cuba
- 7 General Characters
- 8 Source
characteristics
Some species form thin plates, others are cup-shaped or branched, globular, or of different shapes. Many are gray or brownish, others are bright red , orange , yellow , blue , purple, or black . Most sponges are marine, living from the low tide line to depths of 6,000m; there is a family distributed in fresh waters. They all live fixed on rocks , shells or other objects submerged in water.. This phylum is also known by the name of Porifera (from the Latin, porus: pores; ferre: to carry), for the structure of the body, with numerous openings in the surface. Commercial sponges, used for bathing, are the flexible skeleton of a marine sponge, whose living cells have been completely removed.
Leucosolenia Study
The simplest sponges are represented by Leucosolenia, cylindrical or ovoid in shape, about 10mm high and about 3mm in diameter; whitish or yellowish in color.
Habitat
It lives fixed on the coastal rocks immediately below the low tide line.
Structure
These sponges are formed by a small tube in the form of an elongated cup and joined at the base by irregular tubes. The upward-facing portions consist of a thin sac, which encloses a central cavity called a spongiocele, with a wide opening, the osculum, at the top. The body wall is made up of an external epidermis (dermal epithelium) of cellsthin and flat, a continuous inner lining of flagellated collared cells called coanocytes in weak contact with each other. Between these two layers there is a gelatinous mesenchyme containing free cells or amoebocytes of various kinds and numerous crystalline-looking spicules made of calcium carbonate, which supports the soft wall. This is crossed by numerous inlet openings called ostioli, which extend from the external surface to the central cavity, each pore forming a conduit that crosses a tubular cell of the epidermis: the porocyte.
Life processes
The sponges lack of movement, when more can contract; the pore cells open or close, and some sponges can slowly close the bone. During life the amebosites move freely within the mesenchyme, which is soft, colloidal, or even watery in consistency. Simple sponges perform all the vital activities that allow them to stay alive; Much of these life processes are carried out by independent cells. Some of the sponge cells are organized into budding tissue . The food enters the ostioli and is collected in vacuoles by the coanocytes, where they are digestedintracellular; These substances can pass to the amebosites to complete digestion and then circulate through the spongiocele. Breathing is done by simple diffusion, as is excretion.
Sponges that inhabit the seas of Cuba
On our coasts there are commercial sponge hatcheries located on the coast; from Cárdenas to Nuevitas , on the north coast ; On this coast is the port of Caibarien , which constitutes a fishing center. On the southern coast of Cuba , from Cabo Francés to Cienfuegos , good-sized sponges are extracted, especially in La Coloma and Batabanó . The usable part of this sponge is its skeleton, made up of sponge fibers, a very complex organic substance. The Cuban sponges (both those from the northern and southern zones), which have the most demand in the market are:
- sowed females,
- cave male,
- fine male,
- Calvary male.
- the so-called fluffed female, one of the softest knitting sponges, is very rare nowadays and sporadically a small example is caught.
General Characters
- They live fixed to the bottom of the aquatic environment, almost always marine, but in the larval stage they present cilia and swim freely.
- They have radial symmetry.
- They have a sac or globose shape.
- They have only one opening to the outside: the kissing bone.
- They lack true organs and moving parts.
- The digestion is intracellular.
- Breathing and excretion are carried out through the body wall.
- They lack receptive and nervous cellular elements.
- Agamic reproduction by buds and also gametic.