It would be a mistake to mess with the mermaids on Siren. The Freeform original series made that point very clear in this week’s episode,which featured a vicious mermaid fight between Ryn (Eline Powell) and Katrina (Aylya Marzolf). Unlike preceding mermaid sequences, this battle was in very tight quarters and in full view of both the audience and the human characters.
Source: blastr.com