Arvoredo Island is an important area for undefined aggregations of one ray species.

Photographs were taken during surveys conducted annually from 2012–2019, during the austral summer (December–March) (Anderson et al. 2021). Routine underwater visual census surveys (average number of surveys per year = 12) were conducted in the mornings (Anderson et al. 2021, Quimbayo et al. 2022). In February 2014, the first record of a Brazilian Guitarfish aggregation was photographed consisting of 25 individuals, resting on the seabed and dispersed on sandy substrates at the interface of a rocky reef (Anderson et al. 2021). A few individuals were visually estimated to be young-of-the-year (~35 cm total length [TL]), but most were adults ranging from 80–100 cm TL. Size-at-birth for this species is 22–29 cm TL (Vooren et al. 2005). In December 2018, another aggregation of 15 individuals was recorded (Anderson et al. 2021). Individuals were dispersed in small clusters of 2–3 individuals on the sandy substrate. In December 2019, a third and much larger aggregation of the Brazilian Guitarfish was photographed. At least 50 large (mostly ranging from 80–120 cm TL) individuals were counted and photographed clustered on the sandy substrate (Anderson et al. 2021).

In southern Brazil, adult Brazilian Guitarfish migrate to coastal waters at depths of less than 20 m from November–March. Parturition and mating take place in March. Soon after, the males and females return to deeper waters and disperse to depths of 40–150 m over the continental shelf. Neonates and juveniles remain in shallow waters throughout the year (Lessa et al. 1986, Vooren et al. 2005). All aggregations in this area were recorded during the reproductive season of the species in southern Brazil in waters at depths <20 m (Anderson et al. 2021). However, further information is required to understand the nature and function of these aggregations.