Ch.1 (bio lab)

• Phylum Porifera (Sponges) are characterized by the presence of pores in the chamber walls, hence the name porifera.
• Genus Grantia is one of the simplest sponges, with a plant-like tubular structure and filter-feeding behavior.
• Genus Spongia are more complex sponges, with a large lobed structure and their skeleton composed of a network of primary and secondary fibers of the protein spongin, a modified form of collagen, promoting flexibility.
• The polyp stage dominates the hydrozoan life cycle but both polyps and medusae may be present in their life cycle.
• Examples of hydrozoans include Hydra, Obelia, Physalia, and Gonionemus.
• Nematocysts are predominantly used for prey capture and defense, but also for locomotion.
• The generalized life cycle of cnidarians is diploblastic, having two germ layers, with a mesoglea, a gelatinous layer, between the ectoderm and the endoderm.
• Obelia, also known as the Portuguese man-of-war, is a floating colony of polymorphic polyps, with some of the polyps forming a gas-filled sac that floats and suspends the long tentacles of nutritive polyps.
• The larva of cnidarians will be released into water and will pass later from the juvenile state (mobile) to an adult state (sessile).
• Most cnidarians are carnivores that catch the prey by their tentacles and push it through the mouth into the gastrovascular cavity where two types of digestion can occur: extracellular digestion, where enzymes are secreted into the gastrovascular cavity to digest food into smaller particles, and intracellular digestion, where small food particles are absorbed by the cells lining the cavity to complete the process of digestion.
• Phylum Cnidaria is characterized by radial symmetry.
• Hydra are small, less than 1 cm tall, live in shallow, freshwater ponds, and have no medusa stage.
• Obelia have colonial polyps and free-swimming medusae, with polyps being polymorphic and gastrozooids and gonozoids being digestive and reproductive polyps respectively.
• Heartworms are parasites of dogs and cats, transmitted by mosquitoes, and mature stages reside in the heart and lungs where they disrupt blood flow, making them parasites.
• Filaria causes elephantiasis, a condition caused by the clogging of the lymphatic system that drains the host’s appendage, leading to fluid accumulation and swelling of the appendage.
• Al wall with hooks or suckers is a type of intermediate host.
• Proglottids are long (10 - 15 m) and contain male and female reproductive organs, making them an intermediate host.
• Trichinella adult females live in the intestine of their host (usually pork), release larvae, and the larvae migrate through the body to striated muscles, forming calcified cysts.
• Encysted larvae of Trichinella are eaten by another host (humans), and humans are infected by eating poorly cooked pork containing encysted larvae.
• Neck is a part of the body that can serve as an intermediate host.
• Trichinella, Hookworms, pinworms, and heartworms cause diseases such as trichinosis, anemia in livestock, and heartworms in dogs and cats, respectively, making them parasites.
• Hookworms cause anemia in livestock, making them parasites.
• Ascaris is a large nematode that infects the intestinal tract of humans and other vertebrates, making it an intermediate host.
• Loa loa is an eye worm that lives under the skin of humans and occasionally crawls across the surface of an eye, making it an intermediate host.
• Pinworms infect the intestine of children and inflame the anus, making them parasites.
• Sponges lack specialized tissues, but show several types of cells: Pinacocytes, epithelial cells that form the outermost layer of the body; Choanocytes, flagellated cells that generate the water current and line the body cavity (spongocoel); Porocytes, showing intracellular pores (ostium, several ostia); and Amoebocytes, mobile cells with many functions including digestion and the ability to differentiate into other cell types as needed, such as eggs.
• Touching the nematocysts on the dangling tentacles is lethal for small fish and very painful for swimmers.
• Class Hydrozoa: Physalia and Gonionemus are examples of atypically large medusa with a rough surface.
• Trematoda have a ventral surface with two adhesive organs or suckers that surround the mouth.
• Trematoda, commonly called flukes, are parasitic and infect vertebrates as endoparasites, ectoparasites, or both.
• Subphylum Neodermata includes parasitic flatworms, with two subgroups: Trematoda or flukes, and Tapeworms and their relatives.
• Subphylum Turbellaria are free-living in freshwater, saltwater, and moist terrestrial environments, are hermaphroditic, and have a incomplete digestive system.
• Schistosoma, a blood fluke, is dioecious and undergoes mating of blood flukes.
• Cercomeromorpha are tapeworms, which are endoparasites of the gut of vertebrates, have no mouth, no digestive tract, and absorb nutrients efficiently through the cuticle.
• Class Anthozoa includes anemones and corals, which are the largest class of cnidarians, with anthozoan polyps being solitary or colonial, and no medusa.
• The body parts of tapeworms from anterior to posterior are: Scolex for adhesion to intestine.
• Class Scyphozoa includes jellyfish such as Aurelia and Cassiopeia, where the gelatinous medusa dominates their life cycle.
• Class Cubozoa includes box-shaped medusae, with the polyp stage being inconspicuous or unknown, and tentacles at each corner of the box, making them strong swimmers.
• Like cnidarians, flatworms have a layer of ectoderm and endoderm, but also a third germ layer called mesoderm.
• Mesohyl is a gelatinous mesenchymal matrix that fills the space between the external pinacoderm and the internal choanoderm, and Amoebocytes are suspended within the mesohyl.