First records of Chionodraco hamatus nests in coastal areas of Terra Nova Bay (Ross Sea): a potential nesting area for the species?

Abstract

Nests of the ice sh Chionodraco hamatus were documented for the rst time at about 500 m depth at Terra Nova Bay (Victoria Land, western Ross Sea), in an area included in the Antarctic Specially Protected Area (ASPA) No. 173 and in the portion with more stringent protection of the largest established marine protected area of the world, the Ross Sea Region Marine Protected Area (RSRMPA). Nest building and eggs guarding are common parental care behaviours in the Antarctic ice shes (Channichthyidae). Prior to present work, nest building behaviour for C. hamatus was observed only in the frame of aquarium experiments.Here we report on the observation of ve nests of C. hamatus by remote underwater video systems in November 2021, during an Italian Antarctic expedition. The nests, consisting of gravel and small stones, were circular and bowl-shaped with a consistent diameter of about 30-40 cm. Nest building behaviour, with the ice sh individual alternating radial turns in clockwise and counter-clockwise movements was also recorded in situ for the rst time. By considering the occurrence of the ice sh nests, as well as biotic and abiotic features of the locality, the existence of a C. hamatus nesting area is hypothesised. If con rmed, the occurrence of an ice sh nesting area in Silver sh Bay would further strengthen the ecological value of the ASPA 173. Furthermore, documenting nesting ice sh in nearshore coastal areas of the RSRMPA reinforces the relevance of the MPA itself and provides an important focus for future research and monitoring in the area.