Abstract

Abstract:

New records of early life stages of cephalopods are presented based on planktonic collections carried out around Easter Island (Rapa Nui; 27°7′S, 109°21′W) and at the nearby Apolo Seamount (located at ~7 nautical miles southwest from Easter Island) during March and September 2015 and March 2016. A total of 13 individuals were collected, comprising four families (Octopodidae, Ommastrephidae, Chtenopterygidae, and Enoploteuthidae) and five potential genera/types (Octopus sp., Chtenopteryx sp., rhynchoteuthion paralarvae, and two undetermined Enoploteuthid paralarvae). Cephalopod mantle lengths (ML) ranged from 0.8 to 4.5 mm, with 65% of them (mainly Octopodidae) corresponding to newly hatched paralarvae of ~1 mm ML, and 35% to rhynchoteuthion and early stages of oceanic squids of around 1.5–4.5 mm ML. These results provide the first records on composition and presence of early stages of cephalopods around a remote Chilean Pacific Island, while also providing a morphological and molecular basis to validate the identity of Octopus rapanui (but not Callistoctopus, as currently recorded), Ommastrephes bartramii and Chtenopteryx sp. around Rapa Nui waters. Despite adult Octopodidae and Ommastrephidae having been previously recorded at these latitudes, the current findings provide evidence to suggest that the northwest side of Easter Island, and one of the nearby seamounts, may provide a suitable spawning ground for benthic and pelagic species of cephalopods inhabiting these areas. For Chtenopterygidae and Enoploteuthidae, this is the first record for the Rapa Nui ecoregion.

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