Phylum Porifera 113 120EDITION 14 TH 109 119

Phylum Porifera 113 -120(EDITION 14 TH) 109 -119 (EDITION 15 TH)

Goals for today • Learn to recognized the Phylum Porifera from other animals • Learn the main ‘diagnostic’ characteristics, structures, and their function • Learn about some sponges biology

Phylum Porifera • Most are marine • Freshwater species are found in ponds and streams • Solitary or colonial • Adults are sessile and benthic

Porifera = "pore bearer" These are the simplest metazoans (multi cellular organisms) Protostomia Bilateria Radiata Parazoa Eumetazoa Ancestral colonial choanoflagellate Deuterostomia Ecdysozoa Lophotrochozoa Cnidaria and Ctenophora Porifera Parazoa • No organs, no mouth, no nervous, digestive or circulatory system, only rudimentary nervous integrations. • Little or no tissue organization • No germ layers (so neither diploor triploblastic) • Two thin layers of cells (Epidermis and Endodermis) • Some have radial symmetry some do not

Phylum Porifera Main characteristics of sponges are: • Internal skeletons of spicules or organic fibers (spongin). • Pores and canal systems (asconoid, siconoid, and leuconoid) • Internal cavity= spongocoel that opens to an osculum

Phylum Porifera • Flagellated sponge feeding cells= choanocytes. • By cooperatively moving their flagella, choanocytes generate a flow of water through the sponges pores, into the spongocoel, and out through the osculum.

Phylum Porifera Feeding Behavior http: //www. youtube. com/watch? feature=player_embedded&v=Rm. PTM 965 -1 c

Porifera: Classification Classes: Calcarea: • Spicules of calcium carbonate • Needle-shaped or 3 -4 rayed spicules • Canal systems asconoid, siconoid, or leuconoid • All marine Hexactinellida (Glass sponges): • 3 D, six-rayed spicules • Siliceous spicules (Si. O 2)forming a network • Body often cylindrical or funnel-shaped. • Canal systems siconoid or leuconoid • All marine, and most deep water spp. Demospongiae: • Siliceous spicules (not six-rayed), spongin or both • Canal system leuconoid • One family freshwater, most marine • Most sponges belong to this class

Porifera: Your Tasks Exercise 7: – Phylum: Porifera (sponges) – Class Calcarea • Genus: Sycon (=Scypha, Grantia)

Porifera: Sycon 2. Take a slide from your box with (Sycon, Grantia, or Scypha) this is a cross section cut: identify the incurrent canal, spongocoel, and the radial canal Water enters the incurrent canals and passes through minute openings called? ______ Check your book for answers!

Porifera: Sycon What is the apopyle? Check your book!

Porifera: Sycon 3. Take a slide from your box with (Sycon, Grantia, or Scypha) in a longitudinal cross section you would see the following specialized cells: what are their function?

Porifera: Your Tasks Phylum: Porifera (sponges) – Class Calcarea • Genus: Leucosolenia has an asconoide canal system

Porifera: Leucosolenia 1. Try to find the osculum. This is a colonial species of tubular individuals in various stages of development osculum

Porifera: Leucosolenia 2. Look into the microscope a slide of Leucosolenia body and its spicules

Porifera: Your Tasks – Phylum: Porifera – Class Hexactinellida (Glass sponges) • Genus: Euplectella

Porifera: Your Tasks 1. Look at preserved specimens of Euplectella Some species of Euplectella have a commensal relationship with a shrimp species. A young male and female shrimp enter the central cavity and live there. As they grow they become too large to escape through the sieve-like covering of the osulum, and so spend their entire life inside the sponge.

Porifera: Your Tasks – Phylum: Porifera (sponges) – Class Demospongiae • Gemmulas (asexual reproductive structures) -Gemmules are asexual reproductive structures of freshwater sponges and some marine sponges of the class Demospongiae. -Made up of amoebocytes surrounded by a layer of spicules and can survive conditions that would kill adult sponges. What is their function in reproduction?

Important Links Porifera http: //faculty. uml. edu/rhochberg/hochberglab/Courses/Invert. Zool/Quiz es/Porifera%20 Quiz%201. html http: //www. bumblebee. org/invertebrates/Porifera. htm http: //bioweb. uwlax. edu/zoolab/Table-Of-Contents. htm