Zoology 05 Porifera to Cnidaria PDF

General Zoology ANIMAL DIVERSITY 1 Porifera, Placozoa, Cnidarians, Ctenophora Diego Tirira PhD Esta presentación está protegida por una...

General Zoology ANIMAL DIVERSITY 1 Porifera, Placozoa, Cnidarians, Ctenophora Diego Tirira PhD Esta presentación está protegida por una licencia: Licencia Este presentación está protegida por una licencia Creative Commons CC BY-NC-SA 4.0 https://creativecommons.org/licenses/by-nc-sa/4.0/deed.es Usted es libre de: Compartir (copiar y redistribuir el material en cualquier medio o formato) y adaptar (remezclar, transformar y construir a partir del material), bajo los siguientes términos: Atribución: Usted debe dar crédito de manera adecuada. Puede hacerlo en cualquier forma razonable, pero no de forma tal que sugiera que usted o su uso tienen el apoyo del licenciante. No Comercial: Usted no puede hacer uso del material con propósitos comerciales. Compartir Igual: Si remezcla, transforma o crea a partir del material, debe distribuir su contribución bajo la misma licencia del original. No hay restricciones adicionales. El licenciante no puede revocar estas libertades en tanto usted siga los términos de la licencia.  Para = near Metazoa Eu = true Parazoa Metazoa = Animalia Parazoa (Porifera) Eumetazoa = Animals that have tissues. Include all metazoans, with the exception of porifera (sponges) and placozoans. Wikipedia  Porifera Diego Tirira Porifera https://www.youtube.com/watch?v=33rMjlciRGU Porifera Porifera ('pore bearer’). Sponges (esponjas). Basal animal clade as a sister of the Eumetazoa. Multicellular organisms that have bodies full of pores and channels allowing water to circulate through them. Diego Tirira Appear approximately 750 Mya. Porifera Sponges have unspecialized cells that can transform into other types. They do not have organs or nervous, digestive or circulatory systems (this is the only animal that lack a nervous system). Similar to other animals, they are multicellular, heterotrophic, lack cell walls and produce sperm cells. Diego Tirira Unlike other animals, they lack true tissues and organs. Porifera Some of them are radially symmetrical, but most are asymmetrical. Asymmetrical Symmetrical https://2.bp.blogspot.com https://20palabras.com  Osculum Porifera Debris (escombros): Diagnostic: loose natural material The shapes of their bodies consisting are adapted for maximal especially of efficiency of water flow broken pieces. through the central cavity. Detritus: A large cavity and opening at material the top (like a chimney) is the resulting from osculum (diagnostic feature). the decomposition Water and debris (no detritus) Wikipedia of a solid mass exit through the osculum. into particles.  Mesophyll designates Exterior Interior Porifera the tissue found between the epidermis of the upper and lower leaves. Diagnostic: In the mesohyl (inner layer) are numerous elastic collagen fibers and siliceous or calcareous spicules, depending on the class to which the sponge belongs. The spicules are the mineral part of the skeleton and what gives it hardness. Wikipedia  Exterior Interior Choano = funnel Porifera (embudo) Diagnostic: Sponges have flagellate cells (choanocytes) that resembling to the choanoflagellate protist clade. The movement of choanocyte flagella causes water to penetrate the sponges to extract nutrients and remove debris. Wikipedia (both) Movements are not coordinated in time, but in direction. Porifera Sponges lack a mouth and a digestive system. Unlike other metazoans, they depend on intracellular digestion (endocytosis), so phagocytosis and pinocytosis are the Wikipedia mechanisms used for food ingestion. Phagocytosis Wikipedia a & i: pores (inhalant and exhalant). Wikipedia b: organic particles e: choanocyte c: inorganic particle g: digestive vacuole d & f: archaeocytes h: flagellum Porifera Biology: They try to maintaining a constant water flow through their bodies to obtain food and oxygen www.coolgalapagos.com and to remove wastes. Porifera Biology: Longevity In temperate waters, sponges live for at most a few years, but in tropical waters, and perhaps www.coolkidfacts.com/porifera/ some deep-ocean ones, may live for 200 years or more. Some calcified sponges grow by only 0.2 mm/year. If that rate is constant, a specimens 1 m wide must be about 5000 years old. Porifera Reproduction: All sponges reproduce sexually, but various types of asexual reproduction are common. Most are hermaphrodites, but there is great variability: in the same species hermaphrodite www.dreamstime.com individuals coexist with dioecious individuals. Fertilization is almost always cross-fertilized. Porifera Reproduction: Sexual reproduction: Sponges lack gonads. Gametes and embryos https://es.vecteezy.com/arte-vectorial are found in mesohyl. Some sponges start sexual reproduction when only a few weeks old, while others wait until they are several years old. Porifera Reproduction: The sperm is expelled abroad through the aquifer system (the osculum). http://hoopmanscience.pbworks.com Fertilization occurs in the mesophyll or in open water. Planktonic larvae are then formed and released into the water (free-swimming larva part of the plankton).  Coanocytes Porifera Wikipedia (both) Exterior Interior Reproduction: Coanocytes play an important role in reproduction: They are the cells that give rise to spermatozoa. In some species, the coanocytes phagocytize spermatozoa from other individuals, then detach, transform into amoeboid cells (phorocytes) and carry the spermatozoa to an egg. After fertilization, larvae are released through the aquifer system.  https://areyouinvertebrate.weebly.com Sponge larvae Porifera Reproduction: The larvae has free life for no more than two days. The greatest numbers of sponges are usually found on firm https://true-wildlife.blogspot.com surfaces such as rocks Some sponges can attach themselves to soft sediment by means of a root-like base. Porifera Reproduction: Asexual reproduction: Given the full potential of their cells, all sponges can reproduce asexually from fragments. Many fresh water sponges produce gemmules (gémulas), www.dreamstime.com a kind of cell like buds (yemas) of plants.  A fact that is used Porifera to defend the colonial theory on Phylogenetic relationships the origin of Traditionally, is supported animals. that sponges were first to branch off the evolutionary tree (last common ancestor of all animals). Making them the sister group of all other animals. Based in coanocytes similarity with Wikipedia coanoflagellates. Porifera Phylogenetic relationships: However, new evidence suggests that Ctenophora would be the sister group. Wikipedia Porifera Chordata Hemochordata Phylogenetic Mollusca relationships Annelida Cnidaria 2017 Placozoa Porifera Ctenophora Hehenberger et al. (2017) Porifera Diversity and classification Species described > 10,800 (estimated 15,000 species). They are divided into 5 classes mainly according to the composition of their skeletons. Main classes are: Porifera Calcarea (400 species) Hexactinellida (690 species) Demospongiae Wikipedia (8,800 species) Porifera: Calcarea Calcarean sponges (esponjas calcáreas). Skeletons made of calcite, a form of calcium carbonate, which may form separate spicules or large masses. Traditionally considered to be the most primitive group of sponges. Wikipedia Porifera: Hexactinellida Glass sponges (esponjas vítreas). Sponges whose mineral skeleton is composed of siliceous spicules of six sides crossing at right angles, known as hexactines. It is believed that glass sponges are the longest-lived animals on Earth; tentatively estimate a maximum age of up to Wikipedia 15,000 years. Porifera: Demospongiae Silicane sponges (esponjas silíceas). They have silicate spicules or spongin fibers or both within their soft tissues. Here are included the bath sponges. This is the most diverse class of Wikipedia sponges (90% of the species).  Hexactinellida Porifera Calcarea Calcarea Calcarea Demospongiae Body complexity: Wikipedia Asconoid Syconoid Leuconoid Diameters: 0,1 mm Few centimeters >1m  Higher species diversity in Porifera tropical and subtropical areas. Mainly in marine waters, but Distribution few species in fresh water. Sponges are worldwide in their distribution. Living in a wide range, from polar Wikipedia regions to the tropics. Placozoa Wikipedia Trichoplax Placozoa https://www.youtube.com/watch?v=0KdUcRXq-OQ&t=28s Placozoa Wikipedia Placozoa (placozoos = “flat animals”). They are considered the basal form of marine free-living multicellular organism. They are the simplest in structure of all animals. 1883, first discovered. 1970s, more systematically analyzed. Trichoplax Placozoa Diagnostic: It looks like a multicellular amoeba (appear like a complex protozoa). It does not have any specialized organ, and Wikipedia lacks tissues. At first it was thought that Placozoa body structure in cross section: 1. Lipid it was the larva of some drop, 2. Cilium, 3. Dorsal layer of cells, 4 & 7. Vacuole, animal. 5. Fibrous syncytium, 6. Glandular cell, 8. Ventral layer of cells, 9. Zones of intercellular contacts.  Wikipedia Placozoa Diagnostic: Amoeboid body. Size: long 0.5–1.00 mm long; thick 25 µm. Placozoa Wikipedia (both) Biology: It tends to adhere to substrates and is usually Trichoplax found in the interstitial medium (space between cells). It climbs rocks and eats any algae that lives on them. It feeds by absorption and structures have been observed to trap food. Placozoa Reproduction: Sexual reproduction has been reported to occur where intergenic recombination was observed. It produces eggs and sperm in the lower surface, but has no sexual Gregory J. Retallack (2022) organs. Asexual reproduction has also been observed, budding off smaller individuals. Placozoa Phylogenetic relationships Given their simplicity, they were thought to be the most primitive animals. However, various anatomical and genetical evidences suggest that they would have appeared later. Placozoans, more than simple animals, would be simplified animals, Wikipedia derived from other more complex ones.  Wikipedia Placozoa Diversity and classification: Poorly known. Three genera and species: Trichoplax adhaerens (described in 1883). Hoilungia hongkongensis (described in 2018). Polyplacotoma mediterranea (most basal) (described in 2019). It has been suggested that there may be up to 100 species, still unknown. Placozoa Distribution They inhabit marine waters. Wikipedia  Cnidaria Diego Tirira Cnidaria https://www.youtube.com/watch?v=yQduHyiWe9o Cnidarian Cnidarians (include Wikipedia anemones, jellyfish, coral). Anemone Hydra Diego Tirira (all except one) Coral Jellyfish Cnidaria Their distinguishing feature is cnidocytes, specialized cells (stinging cells). Cnidocytes secrete a stinging substance whose mission is both defense against predators Wikipedia (both) and attack to capture prey. Cnidaria Their bodies consist of mesoglea, a jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick. sessile polyps swimming medusae Cnidarians mostly have two basic body forms: swimming medusae and sessile polyps. Both body forms are radially Diego Tirira (both) symmetrical with mouth surrounded by tentacles that bear cnidocytes. Cnidaria Basic body forms: Medusae (free swimming). Polyp (sessile polyp). Both forms have a single Wikipedia orifice and body cavity that are used for digestion sessile polyps swimming medusae and respiration. Diego Tirira (both) They have sensory organs, with a simple nervous system. Cnidaria Biology: There are aquatic animals found mainly in marine waters, but some species inhabits freshwater. The adults have gonads that release ova and sperm into the Diego Tirira water in the breeding season.  Wikipedia Cnidaria Reproduction: Sexual reproduction: Often involves a complex life cycle with both polyp and medusa stages. For example, in Scyphozoa (jellyfish) and Cubozoa (box jellies) a larva swims (1–3) until it finds a good site, and then becomes a polyp (4–8). Life cycle of a jellyfish: 1–3 Larva searches for site, 4–8 Polyp grows, 9–11 Polyp strobilates, 12–14 Medusa grows.  Wikipedia Cnidaria Reproduction: This polyp grows normally but then splits horizontally into a series of disks that become juvenile medusae, a process called strobilation (9–11). Life cycle of a jellyfish: 1–3 Larva searches for site, 4–8 Polyp grows, 9–11 Polyp strobilates, 12–14 Medusa grows.  Wikipedia Cnidaria Reproduction: The juveniles swim off and slowly grow to maturity (12–14), while the polyp re-grows and may continue strobilating periodically (11). Life cycle of a jellyfish: 1–3 Larva searches for site, 4–8 Polyp grows, 9–11 Polyp strobilates, 12–14 Medusa grows.  Wikipedia Cnidaria Reproduction: Asexual reproduction: All known Cnidaria can reproduce asexually by various means. Asexual reproduction makes the daughter cnidarian a clone of the adult. Cnidaria Asexual reproduction: Hydrozoan polyps only bud (brote), while the medusae of some hydrozoans can divide down the middle. Scyphozoan polyps can both bud and Wikipedia split down the middle. Cnidaria Phylogenetic relationships Wikipedia Cnidaria Diversity and classification Species number: approx. 16,000 Cnidarians are classified into seven classes: Anthozoa (sessile anemones, corals, sea pens) Cubozoa (box jellies) Hydrozoa (hydras) Scyphozoa (swimming jellyfish) Staurozoa Myxozoa Wikipedia Polypodiozoa  Diego Tirira Cnidaria: Anthozoa Diversity and classification (sessile sea anemones, corals, sea pens): Species number: 6100 Marine species Only polyp form (sessile). Medusa phase: no. Wikipedia Number of medusae produced per polyp: no. Gorgonian with polyps expanded Cnidaria: Cubozoa Diversity and classification (box jellies, sea wasps): Species number: 42 Marine species They have a potent venom in each of their tentacles (up to 500,000 cnidoblasts). Medusa and polyp phase: yes. Wikipedia Number of medusae produced per polyp: 1. box jellies Cnidaria: Hydrozoa Diversity and classification https://animalia-life.club/qa/pictures/phylum-cnidaria-hydra Hydrozoa (Hydra): Species number: 3600 Marine and freshwater species They alternate generations, with asexual (benthic polyps) and sexual (planktonic jellyfish) phases. Medusa phase: some species. Number of medusae produced per polyp: many. Cnidaria: Hydrozoa The best known is the Portuguese Orden Siphonophorae man-of-war (Physalia physalis) Form floating colonies. (carabela portuguesa). They can float thanks to gas-filled structures. Some 175 species have been described. Specimens can reach 50 m in length. Wikipedia  Monotypic = all individuals come Portuguese man-of-war from a single egg It is a monotypic colonial species of the class Hydrozoa. Each individual in the colony are clones, called zooids. It is commonly found in open sea, in all warm waters of the planet. Their sting is dangerous and very painful. Each colony goes alone, not in groups. Wikipedia Tentacles from 10–50 m.  Structure of a Portuguese man-of-war Wikipedia Portuguese man-of-war (Physalia physalis) https://www.youtube.com/watch?v=aIovmgzyuL0 Cnidaria: Scyphozoa Diversity and classification (swimming or true jellyfish): Species number: 228 Marine species. Medusa phase: yes. Polyp phase: yes. Number of medusae produced per polyp: many. Diego Tirira Large: up to body 2 m, but tentacles reach 70 m. Cnidaria: Myxozoa Diversity and classification Species number: 1300. http://science.peru.edu/acanths/html/myxozoa.html Marine species of parasitic life. Microscopic parasitic animals classified formerly as protozoa. They came from highly simplified multicellular animals. Myxozoa are unicellular amoeboid animals with multicellular spores. Cnidaria: Myxozoa Diversity and classification Species number: 1300. Marine species of parasitic life. Microscopic parasitic animals classified formerly as protozoa. They came from highly simplified multicellular animals. Myxozoa are unicellular Wikipedia amoeboid animals with multicellular spores. Cnidaria: Polypodiozoa Diversity and classification Species number: 1 (monotypic). Marine species of parasitic life. They live inside the cells of other animals. Wikipedia  Worldwide; mainly living in a wide Cnidaria range of ocean habitats. Few species inhabits freshwater Distribution: systems. www.pikpng.com/downpngs