Reproductive strategies of benthic macroinvertebrates at the Argentine shelf-break front, southwestern Atlantic Ocean

The Argentine shelf-break front is of high ecological and economic importance and supports diverse benthic communities and key life-history processes of several commercial species. This study provides the first comprehensive synthesis of reproductive traits among benthic invertebrates inhabiting this area of the southwestern Atlantic Ocean (80-120 m depth). Information was compiled for 126 epibenthic species belonging to Porifera, Cnidaria, Annelida, Mollusca, Brachiopoda, Echinodermata, Arthropoda, Bryozoa, and Chordata (> 1 cm) from published sources, aiming to identify the dominant reproductive strategies that sustain populations persistence over time. Species-specific reproductive data were available for only 47% of the taxa, and for only five species (~ 4%) such information derived from specimens collected at the shelf-break front itself. Despite data gaps and the need for extrapolation from related taxa or regions, this synthesis reveals predominant reproductive patterns among benthic invertebrates and provides essential baseline knowledge for ecosystem-based management. Approximately 68% of the species are gonochoric, although most sponges and all ascidians are hermaphroditic, while 43% can reproduce asexually or have the ability of regeneration. Internal fertilization predominates (71%), while all bivalves and polychaetes reproduce by external fertilization. Parental care, defined as any kind of protection of embryos through incubation or encapsulation, occurs in 61% of the species, being universal among crustaceans and frequent in gastropods (89%). Indirect development characterizes 82% of the species, of which 59% produce lecithotrophic larvae and 33% planktotrophic larvae. Understanding reproductive modes and dispersal capacities is crucial to assess connectivity, resilience, and vulnerability of benthic communities in the Argentine shelf-break front.