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what critters are part of Phylum Porifera
Sponges
What are their habitat, Movement, and special structure
Mostly Marine, some Freshwater species. Adults are sessile, Larvae are flagellated and free swimming for dispersal, Spicules
Respiration/Circulation/Excretory
Water current brings in a constant supply of oxygen and takes carbon dioxide and other wastes away. Oxygen and carbon dioxide diffuse into and out of individual cells, direct cell contact with water.
(Class) Both stages equally dominant eg. Hydra, Portuguese Man-of-War
Class Hydrozoa
About their movement
Use Hydrostatic Skeleton. Two epidermal muscle layers that push against the water in the Gastrovascular Cavity (GVC) to produce motion. Medusa stage is motile, Polyp stage is mainly sessile “Movement” of Medusa stage is more to sweep tiny organisms through the Cnidocyte laden tentacles. They are moved mainly by water currents
(class) Have Spicules made of Calcium
Class Calcarea
What are Spicules?
Make up the “skeleton” of the Sponge, bound together by Spongin that are produced by cells called Sclerocytes
Reproduction: Asexual (2 Answers)
Gemmule – Small piece of sponge breaks off and forms a new one
Fragmentation/Regeneration When shattered, pieces will grow into new sponges
(class) Medusa stage is dominant eg. Jellyfish
Class Scyphozoa
Special Structures
Cnidocytes– Epidermal Cells that contain Nematocysts, erupt when stimulated. Nematocysts– Poison tipped “harpoon” with thread
Class Demospongiae
Have Spicules made of Silica or Spongin (Protein)
Nutrition/Feeding (sponges)
Body acts as a porous filter, trapping organic material - Collar Cells (Choanocytes) line internal cavity, haveflagella that create the flow of water through the organism. Food particles, that are sucked through, get stuck to the sticky collars of the Choanocytes.
Reproduction:sexual
Hermaphroditic - produce both sperm and egg. Sperm are released into the water, other sponges filter them out, with their food, and use them to fertilize their eggs. Motile larvae then swim away. Amoebocytes produce sperm and egg
(class) Polyp stage is dominant eg. Coral, Sea Anenomes
Class Anthozoa
Nutrition/Feeding
Gastrovascular Cavity(GVC) – single opening digestive system - Captures food with tentacles and Cnidocytes and pulls into GVC - Digested food absorbed by Endoderm cells and diffused throughout the organism - Corals use their Dinoflagellate symbionts to get food energy from the sun (photosynthesis)(mutualism)
(class) Have complex 6 point Spicules. Deep water Glass Sponges
Class Hexactinellida
what are Amoebocytes
they are amoeboid cells that engulf and digest the food particles stuck to the collars. They also distribute nutrients to other cells of the sponge. Amoebocytes also produce gametes.
Ecological Importance/Role
Help form Coral Reefs providing habitat for other creatures. Not a major food source of many animals. Indicator species, sensitive to pollution, become “clogged” Filter Feeders
About their, symmetry, evolution, nervous system, and habitat.
First organisms to have a distinctive gut for digestion and nerves. Radial Symmetry. Has a simple Nerve Net with sensory cells in the ectoderm, no brain. Marine and some Freshwater ecosystems
Respiration/Circulation/Excretion + Reproduction Asexual and sexual
Wastes and Nutrients move mainly by diffusion, flagellated cells in the GVC aid the process.
Asexual-Polyps reproduce asexually by budding, producing more polyps or medusa
Sexual- External Fertilization, sperm and egg released into water - Sexes are often separate, some hermaphroditic
What are their Symmetry, evolution, Cephalization/Nervous System, and Germ Layers?
Asemmetrical (No Symmetry) Very ancient organisms, 600 million years ago. no nervous system. Two cell layers (Ecto and Endoderm) surround the Mesohyl and the Layers are poorly defined
what are Porocytes
they are cells that produce pores within the walls of the sponge.
What sort of critters are part of Phylum Cnidaria
Jellyfish, Coral, Sea Anenomes
About their germ layers
Two cell layers (Ecto and Endoderm)
Ectoderm – Composed of Epidermal cells, Cnidocytes, and Sensory Cells (light) Endoderm – Contains glandular cells that produce digestive enzymes. Mesoglea- Jelly-like layer between the 2 cell layers, it is NonCellular. Nerve fibers pass through it
Ecological Importance / Role
Food for larger organisms - Provide shelter and homes for many species –Coral Reefs - Potential Medical Use – Toxins of Jellyfish