Annelida (Obrúčkavce) PDF

**Annelida (Obrúčkavce)** Annelida - **ringed** - z latinského slova **annelus** - - malý krúžok Ciri Ciri Hewan Annelida Terlengkap Beserta Penjelasannya \... **Characteristic features:** 1\. they are segmented 2\. triploblastic 3\. bilaterally symmetrical 4\. they have **coelom** all life...

**Annelida (Obrúčkavce)** Annelida - **ringed** - z latinského slova **annelus** - - malý krúžok Ciri Ciri Hewan Annelida Terlengkap Beserta Penjelasannya \... **Characteristic features:** 1\. they are segmented 2\. triploblastic 3\. bilaterally symmetrical 4\. they have **coelom** all life They are **metamerically segmented** each ring is a segment. They have a **fixed number** of segments and they are all the **same age** in contrast to **proglottids** in tapeworms. The segmentation helps them to burrow. Each segment contains the same organs - nerves, muscles, blood vessels, heart and excretory organs. In ancestral annelids segments were separated by **septa** (prepážka). **Classification of Annelida:** 1\. Class Polychaeta (mnohoštetinavce) 2\. Class Oligochaeta (máloštetinavce) 3\. Class Hirudinea (pijavice) Annelida, general characteristic video: [[https://www.youtube.com/watch?v=\_Ex2T11wMDQ]](https://www.youtube.com/watch?v=_Ex2T11wMDQ) Annelida, classification video: [[https://www.youtube.com/watch?v=NBzdBOzv6wY]](https://www.youtube.com/watch?v=NBzdBOzv6wY) **1. Class Polychaeta (Mnohoštetinavce)** **Characteristic features of Polychaeta:** 1\. they have many **bristles** (štetiny) which are called **chaetae** on lateral projections from the body called **parapodia** (panôžky) -bočné výbežky 2\. most of them are marine 3\. most of them have a distinct head **Representatives:** (Nereis) ragworm, Palolo viridis (Palolo zelený)  Nereis (ragworm) with chaetae **Palolo viridis (Palolo zelený)** One night every October, Samoan families wade into the ocean with nets and flashlights. It's seven days after the full moon and, right on schedule, the milky mix of worms in the shallow water signals it's *palolo* harvesting time. Men, women, and children dip their nets or bare hands into the water and come up with long, spaghetti-like strands. Some might slurp one into their mouths, savoring the flavor that many liken to roe.  The following day, Samoans will throw feasts to celebrate their bounty, frying the palolo with eggs, baking them into bread with coconut milk and onions, or simply sprinkling them on toast. The worm, which can be reddish-brown (male) or bluish-green (female), is a delicacy in the South Pacific: The coral-dwelling critters have the salty, fishy flavor of seaweed or caviar coupled with the stringy texture of noodles. If you ever have the chance to dig into a palolo dish, you might notice that the worm doesn't seem to have a head. That's because its head is still alive, safe and sound, back in its coral home. The palolo has the rare ability to bisect itself, detaching its lower half each mating season so it can float to the surface and release eggs or sperm. It's these "tails," that nocturnal hunters catch and fry up. While its posterior is being devoured, the rest of the palolo lives in blissful ignorance beneath the ocean's surface. In fact, it's already regenerating a new rear that will be ready by the end of the week. CSEAS NEWSLETTER No.74 \| In Memory of Pak Igarashi Tadataka (1945 \... Palolo viridis (red-brown -- a male, blue-green -- a female) **2. Class Oligochaeta (Máloštetinavce)** **Characteristic features of Oligochaeta:** 1\. they don´t have parapodia, have just few chaetae 2\. they do not have a distinct head 3\. they live in fresh water or soil, only a few of them live in marine environment **Representatives:** Lumbricus terrestris (earthworm) (Dážďovka zemná), Tubifex tubifex, Megascolecides australis (Dážďovka austrálska)  Tubifex tubifex \| gadnio \| Flickr Lumbricus terrestris (Dážďovka zemná) Tubifex tubifex  **Megascolides australis -- giant earthworm (Dážďovka austrálska)** **Giant earthworms video: [[https://youtu.be/YtafVwMeCO8]](https://youtu.be/YtafVwMeCO8)** **Oligochaeta body plan video: [https://youtu.be/ph5NRKwTtxc]** **Morphology of Oligochaeta:** GREEN CALGARY - chels dyer (With images) \| Kindergarten math \... **Anatomy of Polychaeta:**  **Anatomy of Oligochaeta:** Earthworms **Digestive system:** mouth, salivary glands, pharynx, esophagus, **crop**, **gizzard** mechanical digestion (stomach), intestine, anus parasitic species (Hirudinea) leeches (pijavice) have suckers **Breathing system:** no special organs, diffusion of gases through the cuticle, **Circulatory system:** **closed**, dorsal and ventral blood vessel, **5 pseudohearts** (pumping vessels ) **Excretory system:** a pair of **metanephridia** with **nephrostome** and **nephropore** in each segment **Nervous system:** **2 cerebral ganglia** (brain), smaller ganglia in each segment connected with nerve cords, **ladder like nervous system** (rebríčková sústava), **ventral** nerve cord **Sense organs:** Polychaetae -**palps,** **tentacles**, **antennae**, **eyes**. All Annelida classes have **chemoreceptors.**  **Reproductory system:** **Mostly hermaphrodites** (Oligochaetae), have both sexual organs and release fertilized eggs in **cocoon**, they **copulate** to exchange sperms (they store sperms from other individual in seminal receptacles) and ferilize its eggs when they are mature. They have a **direct development.** Some Annelida have **separate sexes** (Polychaetae, Hirudinea), Polychaetae have **larval stage** (**trochophore**), indirect development. **Locomotion:** two types of muscles - **circulatory** and **longitudinal** used for locomotion, Polychaetae have also **parapodia with chaetae**, Oligochaetae have only few chaetae on ventral side, Hirudinea are **without parapodia and chaetae** **Habitat:** Polychaetae - marine waters, some freshwater, brakish areas, Oligochaetae - marine, freshwater and terrestrial, Hirudinea- marine, freshwater and terrestrial Anatomy of Oligochaeta video: [[https://youtu.be/ph5NRKwTtxc]](https://youtu.be/ph5NRKwTtxc) **Life cycle of Oligochaetae:** Life cycle of the earthworm Octodrilus complanatus (Oligochaeta \... **Life cycle of Polychaetae:**  **Characteristic features of Hirudinea:** 1\. no chaetae or parapodia 2\. they don´t have a distinct head, there are suckers on anterior and posterior ends 3\. they are usually ectoparasites or predators **Representatives:** Hirudo medicinalis (medicinal leech) - pijavica lekárska Medicinal Leech-hirudo Medicinalis Stock Photo, Picture And \... **Benefits of Annelida:** Earthworms form the bottom of the **food chain** for a number of organisms. They are a source of food for many birds, mammals, and other invertebrates. Their are also important **decomposers** - decompose dead plants and animals in soil and mix them with soil to fertilize soil and **create mold** (humus). They also make the soil porous and which helps with aeration of the soil. Some species can break down petroleum stains and they contribute to cleaning of the soil. Other **annelids**, such as the lugworms and **Palolo viridis** of the class Polychaetae, contribute to **human** food sources as well. We use these species as bait to catch fish. Hirudinea are used for **medicinal purposes**. In the past they were used largely in medicine. They are effective in increasing blood circulation and breaking up blood clots. They contain a peptide called **hirudin** in their salivary glands to prevent blood clotting. Anatomy of Annelida: [[https://youtu.be/YH1VT21-1DQ]](https://youtu.be/YH1VT21-1DQ)