About Avicularia juruensis Mello-Leitão, 1923
Avicularia juruensis was first described by Mello-Leitão in 1923. For adult females, the carapace measures approximately 19 mm long by 17 mm wide, and the abdomen measures approximately 24 mm long by 17 mm wide. Adult males have smaller bodies: the carapace is roughly 15 mm in both length and width, and the abdomen is noticeably shorter and narrower, at approximately 17 mm long by 12 mm wide. The fourth leg is slightly longer than the first leg, and both the first and fourth legs are longer than the second and third (middle) legs. In the measured specimens, the first leg was 53 mm long in a female and 56 mm long in a male, while the fourth leg was 58 mm long in the female and 60 mm long in the male. The eyes are arranged in two rows of four eyes each. The anterior (front) row is slightly curved forward, and the posterior (back) row is slightly curved backward. The abdomen bears type II urticating hairs (setae); these hairs reach up to about 1 mm long in males and 0.7 mm long in females. Mature females have two long, well-separated spermathecae, which are expanded in the middle to around 1.5 times the width of their end portions. Mature males have a globular palpal bulb with a small subtegulum and a well-developed protrusion on the tegulum. The embolus, which forms the tip of the palpal bulb, is approximately 5 mm long. On the prolateral (forward-facing) side of the first leg's tibia, there is an unbranched protrusion called an apophysis. Like other species in the genus Avicularia, juvenile A. juruensis have a different colour pattern from adults. Juveniles do not have any metallic sheen; they have black tarsi that contrast with the lighter rest of the leg, and a reddish upper abdominal surface marked with a central longitudinal black stripe and separate transverse black stripes. Adults lose the abdominal stripes and develop a metallic sheen. There are two distinct colour morphotypes of A. juruensis. Morphotype 1 has a golden and pink sheen, a whitish carapace, whitish leg rings, and longer light brown hairs evenly distributed over shorter darker hairs. Males of this morphotype generally do not have whitish hair tips on the upper surface of the abdomen. Morphotype 1 was previously classified as the separate species A. urticans. Morphotype 2 has an intense purple sheen and yellower leg rings. Females of this morphotype have long reddish brown hairs on the front and sides of the upper abdomen, overlying shorter darker hairs. Males of this morphotype have white-tipped hairs evenly distributed across the upper abdomen. Morphotype 1 is more commonly found in Brazil, while morphotype 2 is more common in Ecuador and Peru, though this distribution pattern is not absolute. Avicularia juruensis is distributed across central South America, occurring in Colombia, Ecuador, Peru, and Brazil. In Brazil, it is found in the states of Amazonas, Acre, and Pará. Like other members of its genus, it is arboreal and constructs silken retreats.
