What is Arthropod?

ARTHROPODAGreek. arthros joint + podos foot

1What is an Arthropod?

ArthropodsLargest phylum of animals1 million species (some estimates say up to 20 million)Includes mainly terrestrial bugs3 out of every 4 animals are arthropods

3The five branches of the arthropod tree

5 Characteristics of Arthropod

Bilateral (left/right) symmetryit could be divided into matching halves by drawing a line down the center.the right half of an arthropod is a mirror image of its left half (bi= two,latus= side).

all of these lines meet in the middle, dividing it up like a birthday cake. That is called radial symmetry. Other animals are not symmetrical at all their bodies cannot be divided into similar halves with a straight line.Segmented bodyall arthropods have bodies that are internally and externally segmented.They will have a body made up of more than one part. Each body segment tends to repeat the same suite of structures often with slight variations down the length of the animal.

Hard exoskeletonexternal skeletonit protects the arthropods body. made ofchitin, a substance produced by many non-arthropods as well. It is produced by the "skin and then hardens into a protective outer-covering.

Jointed legsAll arthropods (arthro= joint,pod= foot) have jointed limbs.In most of the leg, the exoskeleton is hard, but at the joints it is softer and bendable.The limb can be controlled by contracting muscles connected to the exoskeleton on both sides of the joint.

Many pairs of limbsAll arthropods inherited multiple limbs from that ancestor.The ancestral arthropod had many body segments with one pair of limbs on each segment.

SizeWhat Is Different about Each of These Animals?ColorShapeMethod of Movement

Facts about ArthropodsAncestral arthropods were the first land animals.Arthropods are a highly successful group of animalsthey account for over three quarters of all currently known living and fossil organisms. During their life cycle, arthropods undergo a transformation called metamorphosis.

COMPLETE METAMORPHOSISFacts about ArthropodsArthropods employ a variety of reproductive methods.Arthropods have an open circulatory system.When arthropods grow, they must molt their exoskeleton.SHRIMPit is marine crustacean;longantennaeand legs; thin and semi-transparent exoskeleton; has lamellar gills; fan-like tail;The average shrimp will only live for one to two years.;

There are more than 2000 species of Shrimps around the world.

HABITAT OF THE SPECIES :The shrimp lives on the river beds and ocean floors around the world, filtering sand and particles in the water.

Shrimp are widespread, and can be found near the seafloor of most coasts and estuaries, as well as in rivers and lakes.

EGGSNAUPLIUSPROTOZOAMYSISPOSTLARVAJUVENILESUB-ADULTSADULTS

POSTLARVATheir actual size is typically between 0.1 and 2 inches in length.This beak also serves as a stabilizer when swimming backwards and forwards in the water.Shrimp mainly feed on algae and other plant particles along with tinyfishand plankton in the water.FEEDINGshrimps feed on other small crustaceans, finfish, mollusks, polychaetes, ophiuroids and other slow-moving benthic organisms.Shrimps are omnivorous animalsand therefore ingest and variety of both plant andanimals species.

REPRODUCTIONA single female shrimp is capable of producing a large number of offspring.

One shrimp can lay up to one million eggs in a single session.

PRAWNSare marine crustaceans that resembles a large shrimp.belong to one decapod family, Penaeidae/ Palaemonidaeare invertebrates Life span: 2-4 years Skin: Shell (composed mainly of protein, calcium carbonate and a stiffening agent, called chitin) Main Prey: Fish, insects, planktons are able to change colour "swims" by quickly pulling its abdomen in toward its carapace (body) are protandrous hermaphroditesreproduce via eggsUndergoes a process called moulting so they can growAdults grow to about 200 mm longHABITAT: found in calmer waters Prawns live in sub tidal sandy and rocky habitatsDietPrawns eat plant material, decaying organic matter, micro-organisms, small shellfish and worms. King prawns are sensitive to light so they bury themselves during the day and feed actively at night. Tiger prawns tend to be active day and night.PredatorsHuman, fish, squid

BASIC ANATOMY:

LIFE CYCLE

They mature at about six to eight months of age, and spawning occurs in offshore waters. King prawns tend to spawn throughout the year while tiger prawns mainly spawn during spring and summer. A single prawn can spawn more than once in any one year. The female releases hundreds of thousands of eggs.REPRODUCTION When prawns mate, the female must be soft shelled (newly moulted). The male inserts a sperm capsule (spermatophore) into the female. This remains inside the female reproductive organ until the prawn is ready to release her eggs (spawn) at which time the eggs are fertilised.

PRAWNS VS SHRIMPSPrawns are typically larger than shrimps.Prawns have branching gills.

have claws on three pairs of their legsShrimp are generally smaller than prawns.Shrimp feature lamellar gills, which are plate-like in structure.

have claws only on two pairs of legs.

31PRAWNS VS SHRIMPS