Group 4 Presenters: Tracy Noel Patience Fadzai Phylum Annelida

QUESTION  Discuss the diversity in feeding habits and locomotion in the phylum Annelida. Phylum Annelida

keywords Diversity Feeding habits Locomotion Phylum Annelida

Diversity of annelids manifest in modes of feeding: suspension feeding, deposit feeding, scavenging, herbivory & carnivory

Phylum Annelida SEGMENTED WORMS

Main Characteristics  Bilateral symmetry  Metameric  Protostomes  Triploblastic  Setae  Closed Circulatory System  Nerve Cords  Metanephridia Phylum Annelida

Classes of Annelids  Polychaeta ~(nereis)  Hirudinea~(leeches)  Oligochaeta ~(earthworms) Phylum Annelida

Class Polychaeta

Polychaeta Feeding  Most carnivorous and some are herbivorous  Feeding habits are closely related to the structure  Some feed on large particles have either a pharynx with jaws called glycera and some feed on fine matter are filter feeders, surface deposit feeders and burrowers Phylum Annelida

Polychaeta feeding habits  Filter feeders either capture floating material with tentacles or pump water through the barrels  Surface deposit feeders take in material through a pharynx with jaws  Burrowers mostly live with their anterior end in the sediments to feed on fine particles since the specks of organic matter are settled on the bottom. Phylum Annelida

Polychaeta locomotion (swimming)  Uses circular and longitudinal muscles.  Parapodia all helps in locomotion. Parapodia and setae acts against the water and produce propulsive force.  longitudinal muscles of 1 side of the body acts antagonistically to the longitudinal muscles of the other side.  Waves moves from the posteria end towards the head. Phylum Annelida

Locomotion cont Burrowing  Burrowing polychaetes push through sand and mud by contractions of the body wall.  They make burrow during eating. Phylum Annelida

Class Hirudinea Phylum Annelida

Hirudinean Feeding  Many are carnivorous for example leeches and they are primarily blood suckers  they have a mouth in the anterior sucker  they feed on body fluids of small vertebrates  Feeding is facilitated by the secretion of hirudin  Hirudin: is the chemical in secretion of leeches that allows them to suck out blood freely from the body and prevent blood from clotting. Phylum Annelida

Hirudean locomotion  The anterior and posterior suckers serves as point of contact  When the posterior suckers attaches to the surface, the circular muscles contract beginning at the posterior end  The leech thus elongate and the anterior end fastens to the surface  When the posterior sucker is released a wave of contraction of the longitudinal muscle moves in a forward direction and completes one cycle. Phylum Annelida

Hirudean locomotion conti.. This completes one cycle. The coelom fluid act as a hydrostatic skeleton. Phylum Annelida

locomotion of the Leech Phylum Annelida

The feeding habits of Hirudinea Leeches are primarily blood suckers E.g. the medicinal leech, Hirudo feeds on mammalian blood, but also sucks blood from snakes, frogs, snails, tortoises and fish. Marine leeches attach to host and feed directly from the gills of fish and other marine creatures Blood feeding leeches have projection of blade- like jaws slitting host’s skin. Others secrete enzymes to digest host cell. Phylum Annelida

feeding habits of Hirudinea conti.. Leech secrete hirudin, an anticoagulant which induces insensitivity to pain to prevent detection of incision It detaches when engorged with blood. Phylum Annelida

Class Oligocheata Phylum Annelida

Oligochaetes locomotion Movement involves extending the body, anchoring it to a surface with setae and contracting body muscles. When the worm begins a forward movement, circular muscles at the anterior end contract, extending the head forward. At the same time the anterior end lift from the surface to facilitate forward movement. Phylum Annelida

locomotion conti.. A wave like contraction originating in the circulatory muscles then passes toward the posterior end. When the wave of contraction nears mid-region of the body, longitudinal muscles contract thereby, shortening the region. A wave of contraction follows and the cycle is repeated.  Setae of a segment extended by certain body muscles to prevent backward movement of the segment during the contraction of the longitudinal muscles.  But however, the worm is capable of reversing its movement in a backward direction Phylum Annelida

Feeding habit of oligochaetes  Terrestrial oligochaetes like earthworm are scavengers and feed upon decaying organic matter, especially of plant origin.  While aquatic oligochaetes, feed on micro- algae or protozoans and other microscopic animals. PhylumAnnelida

Questions?? Phylum Annelida

Group Members:  PATIENCE MUDEKUNYE  NOEL NGARAKANA  TRACY MTSHIYA  FADZAI D DERA  KUDZAI K KUTSEZA  TONDERAI TAMIREPI  TABITHE CHIKOWORE  TARIRO SHOKO  ALICE MPOSI  ANNATORIA SANTINGA Phylum Annelida