Embryonic development is a vulnerable and key period during the life cycle of an oviparous elasmobranch. Captivity studies are difficult to carry out on non-coastal species; hence, embryonic development can be analysed from samples collected from the seabed. Here, embryonic development of three shelf and deep-water skates from the southwest Atlantic Ocean, Bathyraja brachyurops, B. macloviana and Amblyraja doellojuradoi was studied. Egg cases containing embryos in different stages were collected from 84 to 1006 m depth in the northern part of the Argentinean continental shelf and continental slope (36°S-41°S), including the Mar del Plata Canyon (38° S). Common development patterns were observed among the three species and also with other skate species previously studied. Anatomical structures and embryo features were similar among species in initial, early and middle stages. Advanced and pre-hatching embryos showed species-specific differences regarding pigmentation and spinulation. This study sheds light on the identification of neonates of shelf and deep-water species, which could be useful to recognize specific nursery areas in the deep ocean. In addition, this embryological comparative study expands the existing database on the different chondrichthyan lineages, thus making a step forward towards understanding of their phylogenetic relationships.

在卵生性弹性分支的生命周期中，胚胎发育是一个脆弱且关键的时期。很难对非沿海物种进行圈养研究；因此，可以从海底采集的样品中分析胚胎发育。在这里，西南大西洋，Bathyraja brachyurops，B。macloviana和Amblyraja doellojuradoi的三架深水滑冰鞋的胚胎发育被研究了。在阿根廷大陆架北部和大陆斜坡（36°S-41°S），包括马德普拉塔峡谷（38°S），从84至1006 m深度收集了包含不同阶段胚胎的卵盒。在这三个物种之间以及之前研究过的其他滑冰物种中，观察到了共同的发育模式。在初始，早期和中期，物种的解剖结构和胚胎特征相似。孵化前和孵化前的胚胎在色素沉着和旋转方面表现出物种特异性差异。这项研究为识别架子和深水物种的新生儿提供了启示，这对于识别深海中的特定苗圃地区可能是有用的。此外，