Ricardo Bassini-Silva
Mites form a “string of pearls” on a spider from the Sparassidae family
Unprecedented discovery in Rio de Janeiro, a key territory for the study of spiders and their parasites.
A group of Brazilian scientists were recently shocked to detect, in a zoological collection, a juvenile spider with what appeared to be a “string of pearls” around its body.
According to the study dedicated to the case, in October International Journal of Acarologythis is a very rare case of parasitism: around the animal there were not pearls, but a group of parasitic mites, swollen after feeding on its body fluids.
The discovery will represent only the second time parasitic spider mites have been documented in Brazil. It is also the first record, in the country, of this specific family of mites, until now unknown in Brazilian fauna.
The curious case was detected during the observation of a small juvenile spider, which had been dead for a long time. When the investigator Ricardo Bassini-Silvafrom the Butantan Institute, noticed the larvae grouped near the pedicel — the joint between the abdomen and the cephalothorax — he knew he was looking at something special.
This area has a thinner chitin thickness, which makes it easier for parasites to pierce and suck in fluids, making it a vulnerable point for infestation, says .
The mites have been found in juveniles of three families of spiders, all just a few millimeters long. The mites themselves were even smaller and, so far, have only been observed in the larval stage. In several species of mites, this stage is parasitic: the larvae feed on the host for a limited period, detach and begin to live independently when they reach the adult stage.
The spiders analyzed had been collected in the vicinity of caves in the state of Rio de Janeiroin an area close to where, years before, the first Brazilian case of parasitic spider mites had been recorded.
The study authors emphasize that Brazil, with more than 3,000 species of spiders described in its tropical forests, continues to be a key territory for cataloging biodiversity — not just predators, as is now the case, but also the specialized parasites that depend on them.
