Punta del Diablo is an important reproductive area for one shark and two ray species.

Between 2020–2025, pregnant Sandtiger Shark and young-of-the-year (YOY) were recorded from opportunistic reports from artisanal fishers using gillnets in the area. A total of three documented reports of pregnant females (with distended abdomens) in November 2020 and October 2022, and two YOY (estimated based on size) in December 2023 and January 2025 were recorded in Punta del Diablo measuring <1 m total length (TL; AC Milessi unpubl. data 2025). Size-at-birth for the species is 85–105 cm TL (Ebert et al. 2021). Additionally, between 2022–2024, a total of 45 formal interviews were conducted with artisanal fishers using gillnets and longlines in the area and adjacent waters (La Paloma) (AC Milessi unpubl. data 2025). Of these, 23 fishers reported capturing pregnant Sandtiger Sharks during October–December each year, a pattern they have observed since the fishery began in the mid-1940s. Pregnant females represent approximately 30% of the captures during the months when they were present (AC Milessi unpubl. data 2025). On average, neonates and YOY account for approximately 10% of the total annual catch of the species between December–March (AC Milessi unpubl. data 2025). Santiger Shark pregnant females, neonates, and YOY have been reported along the Uruguayan coast around rocky areas (Silveira et al. 2018; Mayer et al. 2025), however, Punta del Diablo and La Paloma areas have been consistently reported during consecutive years as areas where pregnant females are captured between October–November and YOY are captured during summer months (Mayer et al. 2025).

Between August 2006 and November 2013, scientific surveys onboard the artisanal shrimp fishery were carried out to sample species incidentally captured (Pereyra 2017). Fishing sets (n = 207) were carried out randomly in the area year-round across the surveyed years. Sampling was conducted with a bottom trawl with a 9 m horizontal mouth and mesh size of 25 mm (Pereyra 2017). Each trawl was 15 minutes long (seabed time), with an average trawl speed of 1.6 knots (Pereyra 2017). Skate catches were identified to species level, weighed, measured (TL), sexed, and maturity status was determined based on macroscopic evaluation of the reproductive systems (Pereyra 2017).

A total of 1,397 Bignose Fanskates (748 males and 649 females) were captured, with 1,312 individuals measuring between 8.7–57 cm TL (Pereyra 2017). Among them, 32 neonates (2.4%) measured 9–11 cm TL, and 146 YOY (11.1%) measured 12–23 cm TL (Pereyra 2017). The size-at-birth for the species in the region is 4.9–10.9 cm TL (Oddone & Vooren 2004). Juveniles, ranging from 24–45 cm TL, made up the majority with 1,043 individuals (79.5%) (Pereyra 2017). Neonates were present year-round except during winter (Pereyra 2017). A winter spawning season was proposed for the area, based on the presence of neonates in spring and the incubation period of the species (four months) (Pereyra 2017).  Adult males and females were more frequent in the area between spring and summer, however, they were captured in low numbers, which may indicate that copulation occurs in deeper areas (>15 m) (Pereyra 2017).

During these same surveys, a total of 231 (91 males, 140 females) Smallnose Fanskates were captured, with 222 individuals measuring between 8.9–77 cm TL (Pereyra 2017). Among them, 58 neonates (26.1%) measured 9–19 cm TL, and 59 YOY (26.6%) measured 20–30 cm TL (Pereyra 2017). The size-at-birth for the species in the region is 8–20 cm TL (Jañez & Sueiro 2007). Overall, 59 individuals (26.6%) were considered juveniles measuring 31–57 cm TL (Pereyra 2017). Neonates were present throughout spring and summer (Pereyra 2017). A late autumn until early spring spawning season was proposed for the area, based on the presence of neonates and the incubation period of the species (four months) (Pereyra 2017). This spawning season coincides with the presence of adult males and females in the area (Pereyra 2017).