They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jellylike mesohyl sandwiched between two thin layers of cells. Pdf the porifera are a wellcharacterised group of aquatic, predominantly marine animals including about 5000 described species. Hexactinellida glass sponges calcarea calcareous or bony sponges demospongiae most sponges incl. Nearly every type of water body is populated by sponges.
Pinacocytes, amoebiod mesenchyme, and choanocytes central cavity, or a series of branching chambers that water circulates during filter feeding no tissue or organs cell types. In lab you could only look at a whole specimen as above in a jar or at prepared slides. They are characterized by spicules made out of calcium carbonate in the form of calcite or aragonite. Although the majority of sponges are marine, some species live in freshwater lakes and streams. They are often small and delicate, with thin coalescent. The simplest of all the invertebrates are the parazoans, which include only the phylum porifera. Class calcarea exclusively marine, calcareous sponges predominantly inhabit shallow tropical waters. From the latin porus for pore and ferre to bear, hence an animal with with pores. Name the 3 classes of phylum porifera that we need to know. There is some debate if sponges are complex colonial protozans and not metazoans.
The porifera are a wellcharacterised group of aquatic, predominantly marine animals including about 5000 described species. They are found in shallow ocean environments to depths as great as five kilometers km. Porifera authors touiek samaai 1, robyn payne2, seshnee maduray, and liesl janson citation samaai t, payne rp, maduray s and janson l. Asymmetrical or superficially radially three cell types. Learn vocabulary, terms, and more with flashcards, games, and other study tools. While the spicules in most species have three points, in. Over 7,000 species, approximately 40 species that occur in local waters. These animals are distinct from the protozoa in having a cellular construction, and from other metazoa in the absence of true tissues and in the possession of an elaborate filter feeding apparatus.
241 349 578 1567 485 569 1602 1016 1608 703 1641 245 1213 1069 436 1547 25 246 1120 1062 229 189 848 1498 815 948 1476 1240 100 862 1295 1592 519 355 1400 1026 334 923 955 142