Cyclosa bifida

Long-bellied Cyclosa Spider
C. bifida from Australia
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Araneae
Infraorder:	Araneomorphae
Family:	Araneidae
Genus:	Cyclosa
Species:	C. bifida
Binomial name
Cyclosa bifida (Doleschall, 1859)
Synonyms
Epeira bifidaDoleschall, 1859 Epeira macruraThorell, 1877 Cyclosa macrura(Thorell, 1877)

Cyclosa bifida is a species of orb weaver spider in the family Araneidae. It has a wide distribution across South and Southeast Asia, ranging from India to the Philippines and Indonesia, including New Guinea. ^[1]

Taxonomy

The species was first described by Carl Ludwig Doleschall in 1859 as Epeira bifida. ^[2] It was later transferred to the genus Cyclosa by Eugène Simon in 1895. ^[3] The species Epeira macrura, described by Tamerlan Thorell in 1877, was later recognized as a synonym of C. bifida by Thomas Workman in 1896. ^[4]

Distribution

C. bifida has been recorded from a wide range of locations across Asia. ^[1] It is found throughout India, including the Khasi Hills and Jaintia Hills of Assam, the Dooars region of West Bengal, and various other states. ^{[5] [6] [7]} The species extends eastward through Southeast Asia, with confirmed records from Thailand, Laos, the Philippines, and Indonesia, including New Guinea. ^{[8] [9]}

Description

Original drawing by Workman (1896)

C. bifida exhibits pronounced sexual dimorphism. ^[4] Females are considerably larger, with a total body length of 11 mm. The cephalothorax measures 2.7 mm in length. The abdomen is 8.5 mm long with a maximum breadth of 3 mm. The legs show the typical proportions for the genus. ^[4]

Males are much smaller, with a total body length of 3.75 mm. The cephalothorax measures about 1.75 mm in length with a breadth of more than 1 mm. The abdomen is less than 2 mm long with a breadth of 1.2 mm. ^[4]

Habitat and behavior

According to historical observations from Amboina (modern-day Ambon Island), C. bifida constructs large regular webs in dark places near buildings. ^[4] The spider positions itself in the middle of its web and secures it with a flat angular cocoon. In Singapore, webs were found to be perpendicular and measured 5 to 7 inches in diameter, with specific structural characteristics including 40-60 rays, 7-11 turns in the inner spiral, and 40-50 turns in the outer spiral. The spider typically does not position itself at the center of the web but rather sideways, sometimes with a leaf attached to the web as camouflage. ^[4]

References

1. "Cyclosa bifida (Doleschall, 1859)". World Spider Catalog. Retrieved 3 September 2025.
2. Doleschall, L. (1859). "Tweede Bijdrage tot de kennis der Arachniden van den Indischen Archipel". Acta Societatis Scientiarum Indo-Neerlandicae. 5 (5): 1–60.
3. Simon, E. (1895). Histoire naturelle des araignées. Deuxième édition, tome premier. Paris: Roret. pp. 761–1084.
4. Workman, T. (1896). Malaysian spiders. Belfast. pp. 25–104.
5. Tikader, B. K. (1966). "Studies on spider fauna of Khasi and Jaintia Hills, Assam, India". Journal of the Assam Science Society. 9: 139–154.
6. Sen, S.; Dhali, D. C.; Saha, S.; Raychaudhuri, D. (2015). "Spiders (Araneae: Arachnida) of reserve forests of Dooars: Gorumara National Park, Chapramari Wildlife Sanctuary and Mahananda Wildlife Sanctuary". World Scientific News. 20: 1–339.
7. Roy, T. K.; Saha, S.; Raychaudhuri, D. (2017). "On the araneid fauna (Araneae: Araneidae) of the tea estates of Dooars, West Bengal, India". World Scientific News. 67 (1): 1–67.
8. Barrion, A. T.; Litsinger, J. A. (1995). Riceland spiders of South and Southeast Asia. Wallingford, UK: CAB International. p. 700.
9. Chrysanthus, P. (1971). "Further notes on the spiders of New Guinea I (Argyopidae)". Zoologische Verhandelingen. 113: 1–52.