Yellow sac spider | Cheiracanthium Sp.
Cheiracanthium sp. (Family: Miturgidae Simon, 1885)
Common Name: Yellow sac spider
Size: Female 9-11 mm, Male 6-8 mm
Distribution: India
Family identification features: Cephalothorax longer than wide, red brown to dark brown in colour; eight eyes in tworows; sternum oval and flat, apex with obtuse angle; labium long and usually truncated anteriorly; maxillae enlarged with or without lateral notch. Chelicerae strong with teeth on fang furrow. Legs prograde, with two claws and claw tufts or with three claws. Claw tuft varies from weak to dense; scopulae dense; two rows of tarsal trichobothria; trochanters shallow to deeply notched; tibiae of front legs with paired setae; long and sturdy legs in females, longer and slender in males. Abdomen oval with markings, bands, chevrons or spots. Posterior spinnerets two segmented, distal segment distinctly conical, apical segment either as long as or shorter than basal segment; anterior spinnerets conical in shape; colulus present. Cribellum entire or divided with anoval or elongated area of densely spaced calamistral setae in some genera. Epigyne complex, with a small median plate with anterior extensions and heavily sclerotised internal ducts. Male palp with distally expanded retrotibial apophysis and prolateral embolus. A total of 29 species of 3 genera are reported from India so far.
Genus identification features: Eyes smaller, relative to distance between them. Posterior row scarcely longer than anterior. Posterior median eyes further from posterior laterals than from each other. Trapezium formed by four median eyes relatively narrow in front as in Clubiona. Eyes of lateral pairs very close. Sternum broader, not attenuated in front. Inner row with two teeth far removed from fang. Legs relatively longer and slender, first leg longer than fourth. No dorsal spines on femora I and II, no ventral spines on tibiae III. Male palp of tibia noticeably longer and more slender. Bulb with sexual organs not reaching the end of the tarsus, at the basal end of which is a long spur extending back over the tibia.
The genus Cheiracanthium was previously placed in the family Clubionidae and is very similar in appearance and habitat to Clubiona. Both spiders are small, about 10 mm in length and have a similar body shape, straw colour and make similar silk sac retreats, hence the common name of sac spider. The legs and cephalothorax are similarly coloured but sometimes the cephalothorax and legs might be slightly darker. However, Clubiona has a brown to maroon face and chelicerae with the first and fourth pairs of legs of similar size. Cheiracanthium,on the other hand, has a black face and chelicerae, with the first pair of legs noticeably longer than the fourth pair and these they use for detecting and capturing prey. A total of 26 species are reported from India so far.
Natural History: These free living spiders are commonly found in the sac-like retreats made up of green leaves. Different types of sacs are used for resting, mating and breeding. While the eggs are developing, thefemale encloses herself with the eggs and guards them. Sac spiders are fast and aggressive, nocturnal and commonly occur in vegetation. Some species construct retreat in the corners of room walls and live as synanthropic spiders.
Contributed By : Sudhikumar A.V.
Common Name: Yellow sac spider
Size: Female 9-11 mm, Male 6-8 mm
Distribution: India
Family identification features: Cephalothorax longer than wide, red brown to dark brown in colour; eight eyes in tworows; sternum oval and flat, apex with obtuse angle; labium long and usually truncated anteriorly; maxillae enlarged with or without lateral notch. Chelicerae strong with teeth on fang furrow. Legs prograde, with two claws and claw tufts or with three claws. Claw tuft varies from weak to dense; scopulae dense; two rows of tarsal trichobothria; trochanters shallow to deeply notched; tibiae of front legs with paired setae; long and sturdy legs in females, longer and slender in males. Abdomen oval with markings, bands, chevrons or spots. Posterior spinnerets two segmented, distal segment distinctly conical, apical segment either as long as or shorter than basal segment; anterior spinnerets conical in shape; colulus present. Cribellum entire or divided with anoval or elongated area of densely spaced calamistral setae in some genera. Epigyne complex, with a small median plate with anterior extensions and heavily sclerotised internal ducts. Male palp with distally expanded retrotibial apophysis and prolateral embolus. A total of 29 species of 3 genera are reported from India so far.
Genus identification features: Eyes smaller, relative to distance between them. Posterior row scarcely longer than anterior. Posterior median eyes further from posterior laterals than from each other. Trapezium formed by four median eyes relatively narrow in front as in Clubiona. Eyes of lateral pairs very close. Sternum broader, not attenuated in front. Inner row with two teeth far removed from fang. Legs relatively longer and slender, first leg longer than fourth. No dorsal spines on femora I and II, no ventral spines on tibiae III. Male palp of tibia noticeably longer and more slender. Bulb with sexual organs not reaching the end of the tarsus, at the basal end of which is a long spur extending back over the tibia.
The genus Cheiracanthium was previously placed in the family Clubionidae and is very similar in appearance and habitat to Clubiona. Both spiders are small, about 10 mm in length and have a similar body shape, straw colour and make similar silk sac retreats, hence the common name of sac spider. The legs and cephalothorax are similarly coloured but sometimes the cephalothorax and legs might be slightly darker. However, Clubiona has a brown to maroon face and chelicerae with the first and fourth pairs of legs of similar size. Cheiracanthium,on the other hand, has a black face and chelicerae, with the first pair of legs noticeably longer than the fourth pair and these they use for detecting and capturing prey. A total of 26 species are reported from India so far.
Natural History: These free living spiders are commonly found in the sac-like retreats made up of green leaves. Different types of sacs are used for resting, mating and breeding. While the eggs are developing, thefemale encloses herself with the eggs and guards them. Sac spiders are fast and aggressive, nocturnal and commonly occur in vegetation. Some species construct retreat in the corners of room walls and live as synanthropic spiders.
Contributed By : Sudhikumar A.V.
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