Phylum- Annelida

• Body shape-marked out into metameres/ segments(latin-annulus or little ring).

• Habitat-aquatic, terrestrial, free-living, rarely parasite

• Locomotory organs-body wall has longitudinal & circularmuscles. Aquatic annelids likeNeries possess lateralappendages, Parapodia for swimming.

• Circulatory system-closed.

• Excretory system-nephridia help in osmoregulation.

• Nervous system-paired ganglia connected by lateralnerves to a double ventral nerve cord.

• Reproduction- some unisexual(Neries) ,some bisexual(Earthworm, Leech).

• Eg-Nereis, Pheretima (Earthworm),Hirudinaria(blood sucking leech)

Phylum- Arthropoda

• Largest phylum (includes insects).

•Segmentation-present.

•Skeleton-exoskeleton is of Chitin.

•Body division-head, thorax, abdomen.

•Locomotion-by jointed appendages.

•Respiration-by gills, book gills, book lungs, tracheal system.

•Circulatory system-open.

•Sensory organs-antennae, compound & simple eye,statocysts/balance organs are found.

•Excretion-through malphigian tubules.

•Reproduction-dioecious Fertilisation-usuallyinternal (oviparous) with direct or indirect development.

•Eg- Economically useful- Apis(honeybee),Bombyx (silkworm),Laccifer (lac insect)

•Vectors- Anopheles, Culex, Aedes (Mosquitoes)

• Gregarious pest-Locusta(locust).

• Living fossil-Limulus (king crab)

Phylum- Mollusca (2nd largest phylum)

• Habitat-terrestrial or aquatic(marine/ freshwater).

• Body division-covered by calcareous shell & isunsegmented with a distinct head, muscular foot, visceralhump.

• Special structure-soft & spongy layer of skin forms amantle over the viscera hump.

• Respiration & excretion-space between hump & mantle(mantle cavity) have feather like gills which performrespiration & excretion.

• Sense organ-anterior head has sensory tentacles.

• Feeding organ-mouth have file like rasping organ calledradula.

• Reproduction-usually dioecious & oviparous with indirectdevelopment.

• Eg- pila (apple snail), pinctada(pearl oyster)Sepia(cuttle fish),Loligo(squid),Octopus (devil fish), Aplysia(sea hare),Dentalium (tusk shell),Chaetuplura (chiton)

Phylum- Echinodermata (Spiny-bodied)

• Habitat-all marine.

• Endoskeleton-Calcareous ossicles.Show retrogressive metamorphism (larvae is bilateralsymmetrical but adult is radial).

• Digestive system-complete with mouth on ventral/ lower& anus on dorsal/ upper side.

• Water vascular system-help in locomotion, capture &transport of food, respiration.

• Excretory system-absent Reproduction-dioecious.

• Fertilisation-usually external with indirect development(free swimming larvae).

• Eg- Asterias (starfish),Echinus(sea urchin), Antedon(sealily),Cucumaria (sea cucumber) &Ophiura (brittle star).

Phylum- Hemichordata

• Earlier was considered as a sub- phylum under Chordatabut now placed separately under non-chordata.

• Habitat-worm like marine organisms

• Body shape & division-body is cylindrical & containsanterior proboscis, a collar & a long trunk. Proboscisgland is present.

• Circulatory system-open Respiration-by gills

• Excretory organ-proboscis gland

• Reproduction-dioecious animals

• Fertilisation-external with indirect development

• Eg-Balanoglossus& Saccoglossus