''Poecilotheria subfusca'', or the ivory ornamental, is a spider in the

tarantula Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. , 1,040 species have been identified, with 156 genera. The term "tarantula" is usually used to describe members of the family Theraphosidae, although ...

family, Theraphosidae. It is endemic to

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

. , the

World Spider Catalog The World Spider Catalog (WSC) is an online searchable database concerned with spider taxonomy. It aims to list all accepted families, genera and species, as well as provide access to the related taxonomic literature. The WSC began as a series of ...

regarded ''Poecilotheria bara'' as a

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

. Other sources, particularly in the pet trade, have treated highland and lowland forms as distinct species, with the lowland forms being ''P. bara''.

Description

The female is larger than the male, having a body length of 8–9 cm. Males are 6–7 cm. The species can distinguished from others in the genus due to its large black

opisthosoma The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma (cephalothorax). It is a distinctive feature of the subphylum Chelicerata (arachnids, horseshoe crabs and others). Although it is similar in most respects to a ...

and the folium having three linked dark spots, that end halfway down the opisthosoma. The female has a

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

that dorsally is dark brown with pale edges and has a starburst appearance. The

chelicerae The chelicerae () are the mouthparts of the subphylum Chelicerata, an arthropod group that includes arachnids, horseshoe crabs, and sea spiders. Commonly referred to as "jaws", chelicerae may be shaped as either articulated fangs, or similarly ...

are creamy colored. All four leg pairs are identical. The

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...

is blackish brown with a cream band, the

patella The patella, also known as the kneecap, is a flat, rounded triangular bone which articulates with the femur (thigh bone) and covers and protects the anterior articular surface of the knee joint. The patella is found in many tetrapods, such as m ...

is creamy and the

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

have two parallel lines of oblong spots. Ventrally the body is pale brownish with much darker

maxillae The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

. Dorsally, the male is pale brown all over the body with inconspicuous markings. Ventrally, it is similar to the female. All leg pairs are metallic brown in color.

Behaviour

Compared to other ''Poecilotheria'' species, this species is very agile and jumpy and can bite when provoked. The spider has been observed to have a possibly mutualistic relationship with frogs such as '' Ramanella nagaoi'', sharing tree holes of which some were observed to contain eggs and/or juveniles from the spider, frog, or both. As observed between frog '' Chiasmocleis ventrimaculata'' and tarantula ''

Xenesthis immanis ''Xenesthis immanis'', the Colombian lesser black tarantula, is a terrestrial bird spider (tarantula) originating from Colombia. It is a relatively large spider with a body length reaching 6–7 cm and a length width reaching 19-22 cm. ...

'', the spider may protect the frog from predators while the frog protects the spider's eggs from ants.

References

{{Taxonbar, from1=Q2273938 subfusca Spiders of Asia Endemic fauna of Sri Lanka Spiders described in 1917