Gulf of Nicoya Mouth is an important reproductive area for three shark and three ray species. Neonates and pregnant females (embryos or egg capsules inside) are regularly caught in trawl fisheries operating within this area which infers the use of the area as a nursery (Clarke et al. 2011; Clarke et al. 2014; Clarke et al. 2016; Azofeifa-Solano et al. 2021; Clarke et al. unpubl. data 2022).

Neonate and gravid female Brown Smoothhound, Rasptail Skate, and Southern Banded Guitarfish were recorded on-board shrimp trawlers through visual appearance or dissections. These species reach maturity at ~37–60 cm total length (TL). Neonates possessed an open umbilical scar, no evidence of calcified claspers, and clasper tip not reaching the distal end of the pelvic fins. Large females were dissected, and pregnancy was determined by the presence of developing egg capsules or embryos. Between March 2010–August 2012, these individuals were more abundant in shallow areas (<50 m), showing that this area provides an advantage for the early life stages of these species (Clarke et al. 2014; Azofeifa-Solano et al. 2021). There is ongoing research which uses a similar methodology, where shrimp trawl fishery catches are analysed visually or through dissection. Preliminary results highlight that catches include neonate and some gravid female Sicklefin Smoothhound, Pacific Angelshark, and Chilean Torpedo. These species reach maturity at ~55–66 cm TL (Pérez-Jiménez & Sosa-Nishizaki 2008), >103 cm TL (Osaer et al. 2015), and ~50 cm TL (Last et al. 2016), respectively. Neonates possessed an open umbilical scar, no evidence of calcified claspers, and clasper tip not reaching the distal end of the pelvic fins. Large females were dissected, and pregnancy was determined by the presence of developing embryos (Clarke et al. unpubl. data 2022).