phylum arthropoda visual bee

Topics:TREIA PE BENITO

&JHODEL BILLOD

1. ARTHROPODA

2. ECHINODERMATA

Gk. “arthros”– joint + “podos”– foot

PHYLUM ARTHROPODA

GENERAL CHARACTERISTICS

• Common throughout marine, freshwater, terrestrial, and even aerial environments

• Body usually segmented and jointed externally (divided into 3 major parts: head, thorax,

abdomen) with appendages that are equipped for feeding, sensory reception, defense, and

locomotion; with hardened exoskeleton containing chitin and molted at intervals

Complete digestive tract

(mandible-chewing or proboscis- sucking) with a dorsal heart and a

ventral nervous system

Sensory organs include antennae and hairs, simple and compound

eye

Reproduces (mostly sexually), one to several larval stage

The muscle system is more or less assisted by hydraulics originated from the blood pressure created by the heart

Respiration through gills, trachea, book lungs or body surface

With open circulatory system. Haemolymph that contains haemocyanin, a copper-based oxygen-carrying protein

REPRESENTATIVE ORGANISMS: Ants, Butterfly, Grasshopper, Beetles, Lobsters, Spiders etc.

SUBPHYLUM TRILOBITOMORPHA• CLASS TRILOBITA – Trilobites

SUBPHYLUM CHELICERATA• CLASS ARACHNIDA – Spiders, Scorpions, Ticks

• CLASS MEROSTOMATA – Horseshoe crabs• CLASS PYCNOGONIDA – Sea spiders

• CLASS CEPHALOCARIDA – Horseshoe shrimp

• CLASS MAXILLOPODA – Barnacles, andFish lice

• CLASS MALACOSTRATA – Lobsters, Crabs, and Shrimps

SUBPHYLUM MARIAPODA• CLASS CHILOPODA – Centipedes• CLASS DIPLOPODA - Millipedes

SUBPHYLUM HEXAPODA• CLASS INSECTA – InsectsSUBPHYLUM CRUSTACEA

• Class Branchiopoda – Brine shrimp

CLASS CRUSTACEA Lobsters, Crabs and Shrimps

CLASS INSECTAAnts, Beetles and Bugs

CLASS MEROSTOMATA Horseshoe crabs

MAJOR PARTS OF AN INSECT

• Insects that have piercing and sucking mouthparts are called BUGS while BEETLES are insects distinguished as those having forewings

modified into hard wing cases that cover and protect the hind wings and abdomen!

CLASS ARACHNIDA Spiders, Ticks and Scorpions

CLASS CHILOPODA Centipedes

CLASS DIPLOPODA Millipedes

CLASS TRILOBITA Trilobites

Metamorphosis

Metamorphosis refers to the stages in

development of an insect. This stages are : eggs, larva, pupa, and

adult

• Metamorphosis consisting of all these three stages is described as complete metamorphosis or holometabola.

HOLOMETABOLA

• Some insects undergo incomplete metamorphosis or hemimetabola when the larva stage is not conspicuous.

HEMIMETABOLA

• In other insects. The young that from the egg undergoes little or no structural changes, as they grow older. Such pattern of development is called ametabolab.

AMETABOLA

LIFE CYCLES OF SOME INSECTS

LIFE CYCLE OF A DRAGONFLY(CLASS INSECTA ORDER ODONATA)

LIFE CYCLE OF A FRUIT FLY

(CLASS INSECTA ORDER DIPTERA)

LIFE CYCLE OF A BUTTERFLY

(CLASS INSECTA ORDER LEPIDOPTERA)

LIFE CYCLE OF A GRASSHOPPER

(CLASS INSECTA ORDER ORTHOPTERA)

PHYLUM ECHINODERMATA

• Echinoderms are chiefly marine invertebrates. They have bodies

covered with spines. Their bodies are composed of calcuim

• They have a water vascular system , which function for locomotion, respiration, and feeding. The tips of the tube feet contain most of the organism’s sensory neurons. The tube feet are used to attach to objects, for protection, as well as to obtain food.

● Sexual reproduction in echinoderms usually involves the release of gametes by separate males and females into the seawater.●The radial adults develop by

metamorphosis from bilateral larvae.

● The radial appearance of most adult echinoderms is the result of a secondary adaptation to a sessile lifestyle.- Their larvae are clearly bilateral and even

echinoderm adults are not truly radial in their anatomy.

● All 7,000 or so species of echinoderms are marine.

● They are divided into six classes:

Asteroidea (sea stars) Ophiuroidea (brittle stars) Echinoidea (sea urchins and sand dollars) Crinoidea (sea lilies and feather stars) Holothuroidea (sea cucumbers)

CLASS ASTEROIDEA(SEA STARs) Example : Asterias

forbesi

Class Main characteristics

Asteroidea(Starfish@ sea star)

•Five arms (sometimes more).• Bear tube feet, which act like a suction disc, part of water vascular system.• Mouth generally lower (oral) surface of body, anus on upper (aboral) surface.

CLASS HOLOTHUROIDEA(SEA CUCUMBER)

Example : Holothuria floridana

Class Main characteristics

Holothuroidea(Sea cucumber)

• Elongated.• Lack spines.• Hard endoskeleton is reduced.• Five rows of tube feet, part of water vascular system.• Some of the tube feet around the mouth are developed as feeding tentacles.

CLASS CRINOIDEA

E.g. Featherstar

Class Main characteristics

Crinoidea(Sea Lilies)

• Attached to the substratum by stalked.• As a group, they use their arms in suspension-feeding.• The arms circle the mouth.

• This is the oldest and most primitive of all classes of echinoderms.

• The sea lily is attached to the substratum by a long stalk and thus sessile.

• Sea lily is star-shaped, and posses long feather arms around the mouth (oral) which is on the upper side, and has no spine in its body wall.

CLASS ECHINOIDEA

E.g Sea Urchin

Class Main characteristics

Echinoidea(Sea urchin & sand dollars)

• Have no arms.• Have 5rows of tube feet that function in slow movement.• Sea urchins are roughly spherical while san dollars are flattened & disc shape.

• Sea urchin has no arm, but has five bands of tube feet.

• Its body is spherical, and is covered with long spines.

• The plates of the endoskeleton are fused to form a rigid structure.

• The mouth is on the oral surface, and the intestine is long and coiled.

Keyhole urchin's body is covered with skin, muscle tissue, and short, fine spines that are used for burrowing. Rows of tube

feet extend through holes forming the five "petals" on the top side.

CLASS OPHIUROIDEA E.g. Ophiothrixsp

Class Main characteristics

Ophiuroidea(Brittle star)

• Distinct central discs, & the arms are long & flexible.• Their tube feet lack suckers & move by serpentine lashing of the arms.

Role of Echinodermata

• Star fish- Threaten the coral reef.• Crown-of-thorns starfish (animal with

venomous spines).• The only real predator of the dark starfish is

the triton. But triton are being over-harvested, allowing the starfish to increase its numbers.

• Because the main food of the crown-of-thorns starfish is coral, and the starfish population continues to grow, the coral reef ecosystem is being thrown out of balance.