ENVIS Technical Report: 89,  July 2015

Biodiversity, Ecology, Energy, Landscape Dynamics & Hydrology of Agastya Foundation Campus, Kuppam
   Ramachandra T. V.*      Harish R.Bhat  Bharath H. Aithal Rao G. R. Sudarshan P.Bhat
                                                   Vinay S.                          Ganesh Hegde                          Gouri Kulkarni                          Vishnu D. Mukri
Energy and Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012
*Corresponding author: cestvr@ces.iisc.ac.in, energy@ces.iisc.ac.in [080-22933099]
Spiders (ARANEIDS)

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae (Spiders)

Suborder

Mygalomorphae and Araneomorphae

Spiders with more than 41000 species occur almost everywhere in the globe. They are able to live in all climate zones, in or on water, air and ground. Spiders are related to scorpions, pseudoscorpions, harvestmen, ticks and mites, all are ARACHNIDS, 8-legged animals. These arachnids are generally predators (catch live prey), except for some parasites (ticks and some mites). Spiders come in many different sizes, shapes and colours, and exist everywhere. Spiders are known for their venom and silk.

    • VENOM is used in attack and defense: to catch live food, and to protect against predators, parasites, and aggressive relatives. Most spider venom is completely harmless to humans, and only very few spider species can be lethal to people.
    • SILK: Spiders are unique for possessing silk glands; 3 pairs of spinnerets used for silk production. Spider silk is an elastic, strong and sometimes adhesive material. Spiders use silk for many purposes: to protect their young, catch food, make homes and move around. They are the only animals that use silk in almost every part of their daily lives. Silks differ depending on the temperature and speed at which they are spun, on the spider’s diet, and on the purpose of the silk.

Suborder

Araneomorphae

Family

Agelenidae (FUNNEL WEB SPIDERS)

Genus

Agelena (2 genera have been reported from India)

Species

515 species worldwide, 10 are reported from India

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Morphological characters:

8 eyes, hairy bodies and long legs, oval abdomens (rear part) with elongated last pair of spinnerets.

Habitat preference

grasslands, meadows, gardens and house walls.

Web

irregular and flat sheet-like web, with a tube extending from one edge to a retreat; the funnel in which the spider awaits for prey.

Prey preference:

walking and jumping insects.

 

Suborder

Araneomorphae

Family

Eresidae

Genus

Stegodyphus is the only genus reported from India

Species

100 species, 4 of which are reported from India

Morphological characters:

8-eyes, robust looking spiders with a square cephalothorax (head region), body covered with hair, giving a velvet appearance.

Habitat preference:

ground or bushes, shrubs and trees

Web:

sock-like silken retreat in the ground, or sheet webs on bushes, shrubs and trees connected to a small tubular or large irregular retreat

Prey preference:

insects

3 species are social, live in groups like ants, take care of common young, catch prey and feed together, and maintain the web together. Colonies of one of these species are easy to spot in bushes and trees around Agastya campus.

 

Suborder

Araneomorphae

Family

Araneidae (ORB WEAVERS)

Genus

Argiope, Araneus, Cyclosa, Cyrtophora, Gasteracantha and others (29 genera are reported from India)

Species

3000 species worldwide, 154 are reported from India

Morphological characters:

8-eyes with long hairy legs, very large abdomen (rear end of the body), that are brightly colored with various patterns, and sometimes irregularly shaped

Habitat preference:

grasslands, meadows, gardens, forests

Web:

an orb web is a circularly shaped web, constructed in a spiral way. The web is made of silk which spiders developed for the specific purpose of trapping flying insects, and it can reach great sizes. Spiders sometimes add decorations in form of denser silk in different patterns, or leaves, branches or stones

Prey preference:

flying insects

 

Suborder

Araneomorphae

Family

Oxyopidae (LYNX SPIDERS)

Genus

Oxyopes, Peucetica and others (4 genera are reported from India)

Species

430 species worldwide, 69 of which are reported from India

Morphological characters:

8-eyes with slender abdomens and extremely spiny legs.

Habitat preference:

plants, flowers and shrubs

Web:

these are actively hunting spiders without a catching web. They chase or ambush prey. Some hide in flowers and jump to catch flying insects.

Prey preference:

Lynx spiders are important in agricultural systems as biological control agents, as they feed on pest insects

 

 

Suborder

Araneomorphae

Family

Thomisidae (CRAB SPIDERS)

Genus

Thomisus and others (38 genera are reported in India)

Species

2120 species worldwide, 164 are reported in India

Morphological characters:

8-eyes, squat shaped spiders, which move sideways. The first 2 pairs of legs are larger, stouter and spinier than the last 2 pairs. Many species are pink, yellow or white and camouflage the flowers they occupy

Habitat preference:

Gardens and meadows, mainly on flowers, but sometimes on tree barks.

Web:

These spiders have no catching web as they ambush prey.

Prey preference:

Mainly pollinators (flying insects visiting flowers)

 

Suborder

Araneomorphae

Family

Sparassidae (GIANT CRAB SPIDERS)

Genus

Heteropoda, Olios and others (11 genera are reported from India)

Species

1093 species worldwide, 85 are reported from India

Morphological characters:

8-eyes, medium to large sized spiders with long legs and are often camouflaged. They run sideways and are active during the night.

Habitat preference:

ground litter or dry leaves and tree trunks

Web:

they build silken retreats, but do not spin webs

Prey preference:

Cockroaches

 

Suborder

Araneomorphae

Family

Salticidae (JUMPING SPIDERS)

Genus

Carhotus, Salticus and others (66 genera are reported from India)

Species

5300 species worldwide, 192 of which are reported in India

Morphological characters:

8 eyes in 2 rows (4+4) with an excellent eyesight, two of their eyes are conspicuously large; small to medium sized very hairy spiders of various colors They are active during the day.

Habitat preference:

Litter, grassland, bushes, trees, rocks and under stones

Web:

They make a silk safety line while jumping and moving around, but do not spin a web.

Prey preference:

They actively stalk and attack insects, like ants, or other spiders.

 

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