Males and females have a single hump on the back of the abdomen, giving it a triangular outline in side view.
In the described male and female, the head has four projections, each tipped with a short spine. The abdomen is mottled brown and beige.
Eriauchenus andriamanelo has especially long forelegs relative to its body. In the 2018 study, the first femur was 5.38–6.48 times carapace length in five males and 3.80–4.25 times in five females. Body-length ranges overlapped, while foreleg proportions differed in the specimens examined.
The described male holotype came from Montagne d’Ambre in northern Madagascar in 2001, while the described female specimen came from Lokobe on Nosy Be. Their first femora measured 10.0 and 6.59 mm, respectively. The researchers separated detailed descriptions of particular specimens from measurements of variation among multiple individuals, documenting morphology across collections from different places.
An extinction-risk assessment has not been added yet.
At Ankarafantsika National Park, where this spider has been collected, fire and dry-forest recovery are conservation concerns. Kew’s research project describes studying natural recovery after severe burns and developing restoration guidance for forest managers and local communities. Its planned work combines aerial and ground surveys, native-tree horticulture, and community seedling production.