Tareas

Invertebrates:
* They belong to kingdom animalia.
* Heterotrophic nutrition.
* Eukaryotic and multicellular organisms.
* Most of them can move (except sponges)
* No cell walls,instead a plasma membrane.
* Include sponges, sea anemones, snails, insects and sea stars.

Phylum Porifera (SPONGES)
* Divided in class SCELROSPONGIAE, class DESMOSPONGIAE, class CALCAREA& class HEXACTINELLIDA.
* In this phylum there are NO tissues or organs.
* NO symmetry.
* NO nerves, muscles, mouth, digestive system or sessile.
* Can reproduce sexually orasexually.
* Their Skeletons are composed of CaCO3 or SiO2 spicules or spongin.
* They are filter feeders.
* They can have no skeletal structure at all or a combination (or individual) of sponginfibers, calcareous spicules, silica spicules.
* They ARE EATEN by some fish, seaslugs, turtles or humans but they can release toxins to ward off their predators.
* They provide habitad foras many as 16 000 species.
* Class DESMOSPONGIAE: (1) are 80% of marine sponges. (2) All are freshwater sponges (3) Have a property called leuconoid. (4) Are made of sponging and SiO2 spicules.* Class CALCAREA: contain all asconoid forms (principally syconoids) (2) Usually small (3) Have CaCO3 spicules.
* Class HEXACTINELLIDA: (1) Live in the deep ocean where there is lots of sand.(2) Glass like-lattice work. (3) Made of SiO2 spicules.
* Class SCLEROSPONGIAE: (1) Have both CACO3 and SiO2 spicules. (2) Are found in the pacific and West Indies.
* Their asexual reproductionconsists of three methods: (1) Budding: the production of external buds that detach to form colonies. (2) Gemmule producing: happens where there are unfavorable periods. (3) Fragmentation:regeneration.
* Their sexual reproduction consists of one simple method: Since they are hermaphroditic… eggs are retained in the mesohyl and fertilized by the sponges own sperm. Then they break loose &...