Comparative embryonic development patterns in three deep-water skates from the southwest Atlantic

VAZQUEZ, DIEGO MARTÍN; DÍAZ DE ASTARLOA, JUAN MARTÍN; GABBANELLI, VALERIA; MABRAGAÑA, EZEQUIEL

DEEP-SEA RESEARCH. PART 1. OCEANOGRAPHIC RESEARCH PAPERS

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2020 vol. 161

0967-0637

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 analysedfrom samples collected from the seabed. Here, embryonic development of three shelf and deep-water skates fromthe southwest Atlantic Ocean, Bathyraja brachyurops, B. macloviana and Amblyraja doellojuradoi was studied. Eggcases containing embryos in different stages were collected from 84 to 1006 m depth in the northern part of theArgentinean 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 previouslystudied. Anatomical structures and embryo features were similar among species in initial, early andmiddle stages. Advanced and pre-hatching embryos showed species-specific differences regarding pigmentationand spinulation. This study sheds light on the identification of neonates of shelf and deep-water species, whichcould be useful to recognize specific nursery areas in the deep ocean. In addition, this embryological comparativestudy expands the existing database on the different chondrichthyan lineages, thus making a step forward towardsunderstanding of their phylogenetic relationships.