1 / 16

Phylum: Porifera The Sponges

Phylum: Porifera The Sponges. Phylum Porifera. Belongs to Parazoa (beside the animals) Evolved from colonial protozoans Evolutionary “dead end” Most primitive animals. S ponges come in many colors…. Phylum Porifera. General characteristics: pore-bearing animals sessile

hewitt
Télécharger la présentation

Phylum: Porifera The Sponges

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Phylum: Porifera The Sponges

  2. Phylum Porifera • Belongs to Parazoa (beside the animals) • Evolved from colonial protozoans • Evolutionary “dead end” • Most primitive animals

  3. Sponges come in many colors…

  4. Phylum Porifera General characteristics: • pore-bearing animals • sessile • most are marine • asymmetrical •  5,000 species

  5. Porifera General Construction • “one hole sac” • central cavity = spongiocoel • water enters through ostium • water exits through osculum • filter feeders: algae, bacteria, organic debris

  6. Porifera Anatomy • choanocytes or collar cells- create water currents for circulation & feeding • spicule-skeletal element for support • amoebocyte-transport of nutrients from choanocytes to non-feeding cells • mesenchyme-gelatinous protein colloid; not a cellular layer

  7. Anatomy of a Sponge

  8. Porifera Reproduction • Asexual – budding, regeneration, gemmules • Sexual- sperm and ova arise from ameobocytes or choanocytes • Sponges are monoecious (one house) which is a reference to both sperm and ova production by a single organism

  9. Classification of sponges Based on spicule type: • Calcium spicules – CaCO3 (calcium carbonate); chalk sponges • Silicon spicules – Si3O2; glass sponges • Spongin spicules – organic or horny; natural commercial sponges

  10. Classification of sponges Based on canal system: • Ascon – simplest 2 layer sac; Leucosolenia • Sycon – surface is folded to increase surface area; Grantia • Leucon – most advanced & successful; permits maximum surface & size; surface deeply folded to form systems of canals; commercial sponges

  11. D. Class Calcarea (Calcispongiae) • 1. These are calcareous sponges with spicules of calcium carbonate. • 2. The spicules are straight or have three or four rays. • 3. Most are small sponges with tubular or vase shapes. • 4. Asconoid, syconoid and leuconoid forms all occur.

  12. E. Class Hexactinellida (Hyalospongiae) • 1. These are glass sponges with six-rayed spicules of silica. • 2. Nearly all are deep-sea forms; most are radially symmetrical.

  13. F. Class Demospongiae • 1. This class contains 95% of living sponge species. • 2. Spicules are siliceous but not six rayed; they may be absent or bound together by spongin. • 3. All are leuconoid and all are marine except for Spongillidae, the freshwater sponges.

More Related