Chapter 7 Marine Animals sans Backbone Where are

Chapter 7 Marine Animals sans Backbone

Where are we in geologic time? So are, we’ve moved from bacteria to plankton, and through some alage (seeweed). Now we’ll examine primative animals without vertebrae.

How are we related? ?

Introduction • Most (97%) of the amazing life which is located within the oceans, or anywhere else, doesn’t have a backbone! • In every class of invertebrate we can find a marine example…convenient, eh?

Summary of Invertebrates • • Sponges-sponge Cnidarians- “jellyfish” Comb Jellies- comb jellies Symmetrical Worms-flat, round, segmented worms Molluscs-snails, clams, oysters, scallops, octopuses Arthropods-copepods, shrimp, and lobster Echinoderms- seastars, brittlestars

1. Sponges • Phylum – Poriferia “pore bearers” • Loose aggregation of specialized cells. • Cells do not actually form organs or tissues, but do serve similar functions, keeping the animal(s) alive.

Porifera-Sponges (the pore bearers) Spicules are like calcium carbonate or silica re-bar for sponges, providing support for a larger congregation.

Sponges • Of the 6, 000 known nearly all are marine. • Do they “sits and thinks, or do they just sits? ? ” • Sponges are sessile and remain permanently attached to the substrate they alight upon.

Sponges: Composition • Ostia (tiny pores) – allow water to enter and circulate through series of canals where plankton and organic particles are filtered and eaten • If cells separated, can even regroup and form new sponge • Flexible skeletal frame (spicules) gives spongy texture

Porifera-Sponges (the pore bearers) Spicules are like calcium carbonate or silica re-bar for sponges, providing support for a larger congregation.

Sponges: Composition • Spicules are transparent and made of siliceous or calcareous supporting structures of different shapes and sizes • Skeleton made of protein sponging • Spicules, spongin, or both

Sponges: Composition • Wandering cells, amebocytes, secrete spicules and sponging, transport and store food particles, and transform into other types of cells to quickly repair damage

Porifera-Sponges (the pore bearers) Spicules are like calcium carbonate or silica re-bar for sponges, providing support for a larger congregation.

Still, if you carve ‘em up, they come back for more!! It’s more amazing than that. If you mix groups of sponges together, they will usually reorganize into their original groups.

Sponges: Feeding • Outer surface covered with flat cells called pinacocytes and pore cells (porocytes) which allows water to enter • Water pumped into larger feeding chamber lined with collar cells (choanocytes) • Each choanocytes have flagellum that creates currents and a thin collar that traps food particles, which is ingested by body of cell

Suspension feeding: natural water purification

Sponges: Feeding • Water leaves through osculum, large opening at top of sponge

http: //www. youtube. com/watch? v= Rm. PTM 965 -1 c

Sponges: Reproduction • Asexually • If piece breaks off, it can form new sponge • Sexually • Specialized collar cells or amebocytes can turn into gametes • Large nutrient rich egg and smaller sperm with flagellum

Sponges: Reproduction • Most are hermaphrodites • Some have separate male and female organisms • Typically utilize broadcast spawning • Egg retained inside body until fertilization

Sponges: Reproduction • Early development takes place inside • Flagellated sphere of cells (larva), parenchymula, is planktonic • Settles and metamorphosis into juvenile

Reproduction: Asexual vs. sexual Damage to a sponge can actually promote asexual reproduction, as “parts” can land elsewhere and form new sponges.

General Sponge Types Sponges fall into several basic categories, mostly depending on Shape, ranging from tropics to poles: branching tubular Hawaiian encrusting sponge round encrusting glass boring (destructive) Sclerosponge (Ca. CO 3) Ceratoporella nicholsoni

Sponges: Diversity • • • Branching and Tubular – volcano-like masses Encrusting – thin and brightly colored on rocks Glass – anchored in deep water sediments • Siliceous spicules (lace like) • Boring – bore into calcium carbonate (oysters and corals) • Sclerosponges (coraline) – calcium carbonate skeleton forms beneath body of sponge

Sponges: Diversity • Bath sponges • Harvested in Gulf of Mexico and Mediterranean • Spongin are the fibers that remain after the death of the sponge