Taxonomy and description of spider

1. Phylum : Arthropoda
Subphylum : Chelicerata
Class : Arachnida
SPIDER

3. 1. Spiders are poisonous, predaceous and fluid
feeding terrestrial carnivores. They found all over
the world.
Body
 The body of spider has two divisions,
prosoma(cephalothorax) and
opisthosoma(abdomen), the two being connected
together by a short and narrow pedicel.
 Prosoma is dorsally covered by carapace and
ventrally by two chitinous plates, namely small
labium and a large sternum.
 Dorsally, prosoma bears 8 or more simple eyes and
ventrally it bears the mouth and 6 pairs of
appendages. The appendages are chelicerae,

4.  Chelicerae are provided with poison glands and pedipalps, in
male serve as palpal organs for transferring sperms. The
walking legs are7 segmented.
 The 7 segments are from base tip coxa, trochanter, femer,
patella, tibia, metatarsus and tarsus(web spinning).

5.  Opisthosoma is soft, ovoid and apodous, except for spinnerets
and book lungs.
 Anteriorly on its ventral side, is a transvers epigastric groove
and gonopores. In female gonopores are covered by
epigynum. A pair of tracheal spiracles are present on each
side of gonopore.
 At the posterior end of opisthosoma is a group of 6 or 8
spinnerets or spinning organs. Spinnerets make silk threads
from the viscous secretion of the silk glands. Silk threads are
used for spinning web, making cocoons, binding the captives
etc.

7.  Most species of spider are nocturnal. The small wolf
spider chase their prey and overtake them by sheer
speed.
 Jumping spiders which have largest eyes and keenest
vission among spiders
 Crab spiders lurk among flower petals, or fallen
flowers, in wait of their prey.
 Some spiders exhibit protective colouration and
mimicry.

8.  Spiders mostly feed on insects. Exceptional species
are known to prey habitually or occassionally on
small vertebrates, such as fishes, lizards etc.
 Spiders are welknown for their unusual powers to
survive prolonged fasts
 Resliratory organ include bokk lungs and trachea.
Excretory organs are malpighian tubules and coxal
glands
 Only few species are dangerous to men (
eg:Latrodectus)
 Spiders have powers to regenerate their lost leg.
 Show sexual dimorphisam, male is much smaller
than female

11.  Spiders are remarkable for their elaborate courtship.
Some times the female will suck inthe body juice of
male after mating
 In some slecies the female abandons the egg cocoon,
but in others she carries the coccoon attached to her
spinnerets and still in others she guards the cocoon.