Welcome to the Amazing World of Annelids. The Annelida are a medium sized phylum of more than 9, species of worms. Most species prefer aquatic environments, but there are also a number of well know terrestrial species. Only a few species of annelids are commonly known to human beings, these include the delightful Rain, Dew or Earthworms that work so hard to make our soils healthy, the Ragworms and Lugworms used by marine fishermen and the much smaller Tubifex or Red worms used by aquarists to feed their fish.
General characters and Classification Posted on: They are triploblastic, bilaterally symmetrical schizocoelomate protostomes. They exhibit metameric segmentation and true coelom. Their fluid filled coelom acts as hydrostatic skeleton and helps for burrowing and locomotion.
General Characters of Phylum Annelida Cephalization is more pronounced with distinct head, bearing tentacles, eyes etc. Annelida exhibits homonomous metamerism. Body is divided into linear series of similar segments, which are separate from one another externally by inter segmental grooves and internally by inter segmental septa.
In Annelida, body is divided into three regions: Trunk consists of a longitudinal series of similar segments. Growth results from the addition of new segments from teloblastic growth zone located just in front of pygidium.
Body wall consists of fibrous collagenous cuticle, epidermis, dermis, musculature and parietal peritoneum. Chitinous bristles that project out from the epidermis are called setae. They provide grip on the substratum.
Body cavity is schizocoelom, formed by the splitting of mesodermal cells. Each segment has a pair of coelomic cavities separated from each other by dorsal and ventral mesenteries. Coelomic fluid acts as hydrostatic skeleton. Alimentary canal is straight muscular type in Annelida. Digestive glands occur in the walls of the alimentary canal.
Exchange of respiratory gases occurs by diffusion through the body wall and gills. In many polychaetes parts of parapodia are modified into gills. Blood vascular system is of closed type. In all non-chordates respiratory pigments if present, are dissolved in the blood plasma unlike chordates where they are retained in the blood corpuscles.
Excretory organs are segmentally arranged metanephridia.
They open into coelom by nephrostome and to exterior by a nephridiopore. Nervous system consists of circum-pharyngeal nerve ring and a ganglionated double ventral nerve cord.
Sensory structures include eyes and simple receptors like photoreceptors, chemoreceptors and mechanoreceptors. Unisexual forms spawn gametes through metanephridia. Bisexual forms have gonoducts.
Cleavage is spiral and holoblastic in Annelida. Development is direct or indirect. During metamorphosis the larval episphere becomes the prostomium whereas the part posterior to the telotorch becomes the pygidium.
Trunk segments arise from a growth zone anterior to the telotorch. Classification of Phylum Annelida There are 8, species described in this phylum. This phylum Annelida is divided into four main classes on the basis of presence and absence of parapodia, setae, metameres and also other morphological characters.
The following is the classification of phylum Annelida: They are the most diverse group of Annelida. These animals are chiefly marine and some fresh water forms are also present The segmentation in these animals is both internal and external.
These animals have a distinct head with eyes, palps and tentacles. They also have numerous setae on lateral parapodia. The setae exist as bundles. Clitellum is absent in these animals The sexes are separate.
Most of the segments bear gonads in many species of this class.Phylum Annelida.
Your project is on the Class Hirudinea which is in the Phylum Annelida. You may use up to five, x 11 in sheets of paper to create an informational brochure to include the following. Phylum Chordata. Biology Animal Phylums "Write a three sentence description for each phylum and list two examples for each.
Also, draw a picture of a common example from each. (or cut out of a magazine).
Describe five kingdom classification Margulus and schwartz. OR Describe the structure and characteristics of Virus. Phylum Protozoa Phylum Porifera Phylum Coelenterata Phylum Annelida Phylum Mollusca Phylum Echinodermata Phylum Arthropoda OR Write four common characteristics of the following? We will write a custom essay sample on Chem. Major subdivisions of phylum chordata: Brief classification of chordate with characters: The chordates form a large heterogeneous grouping of members differing widely from one another in many respects. This creates problems in their systematic classification. Different schemes have been proposed by a number of taxonomists from time to time. Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college benjaminpohle.com doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts.
You will be graded on how accurate your information is as well as neatness.". Platyhelminthes is a very interesting phylum that contains nearly 20, species. These organisms are generally hermaphrodites, meaning they can have both male and female sexual organs and can.
Classification of Phylum Annelida Phylum Annelida is divided into four main classes, primarly on the basis of setae, parapodia, metameres and other morphological features.
Class 1 Polychaeta. Describe five kingdom classification Margulus and schwartz. OR Describe the structure and characteristics of Virus.
Phylum Protozoa Phylum Porifera Phylum Coelenterata Phylum Annelida Phylum Mollusca Phylum Echinodermata Phylum Arthropoda OR Write four common characteristics of the following?
We will write a custom essay sample on Chem. Exam revision notes for grade 11 biology. Units covered: microscopy, classification, plant & animal kingdoms, ecosystems, cycles, /5(9).