The Seven-arm Octopus, Haliphron atlanticus Streenstrup, 1861 (Cephalopoda, Alloposidae), in the Fernando de Noronha archipelago, Brazil

Abstract

The rare deep-sea octopus, Haliphron atlanticus is the only known species recognized within the genus. A fragment of H. atlanticus was found in the Fernando de Noronha archipelago, Brazil (South Atlantic). Both phylogenetic reconstruction and pairwise genetic divergence show that the specimen recorded in South Atlantic is closely related to individuals from North Pacific. However, there is a greater divergence among these specimens and a giant octopus from North Atlantic. This evidence suggests that Haliphron is not monospecific, with at least two species, both represented in the Atlantic Ocean.

Observation of a Gelatinous Octopod, Haliphron atlanticus, along the Southern West Mariana Ridge: A Unique Cephalopod of Continental Slope and Mesopelagic Communities

“…This is consistent with the concept that this species may not be entirely independent of continental slope habitats, since most observations and collection records were not far from continental shelves or islands [9,26,27] or were near a seamount [17] or an ocean ridge [60]. The West Mariana Ridge has a variety of seamounts along the ridge, with some reaching <200 m and a few being near the surface (Figure 1(c)), and this pattern extends to the north along the ridge [52].…”

“…The YK17-10 research cruise (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27) May 2017) of the R/V Yokosuka of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) was designed to search for and video-record anguillid eels underwater in their spawning area at the West Mariana Ridge. The manned Shinkai 6500 Submersible of JAMSTEC was used to survey depths of 400-1000 m where eels might be during the daytime, based on the swimming depth data of pop-up tag studies on Japanese eels (Higuchi et al, unpublished manuscript).…”

“…These toothed whales dive down to various deep-depths and feed mostly on squid and fishes using acoustic echolocation hunting techniques [61,62,68,69], including at the depth where the H. atlanticus was seen in the present study. Incomplete predation events by sperm whales on these gelatinous octopods may be how the body parts of large individuals that have been found are produced [27].…”

“…This semigelatinous species can reach 4 meters in total body length (TL) and weigh up to 75 kg [25] and has been caught in trawls pelagically or on the bottom at depths of about 100-3000 m [9]. Specimens of larger H. atlanticus are rare, but their presence has been reported from trawl captures, predator stomach contents (see below), or from body fragments of large individuals that have likely been preyed upon [26,27]. It may not be a particularly rare species though because it may be able to frequently avoid capture by nets [26].…”

“…Haliphron atlanticus is likely widely present in many areas based on its reported occurrences [26,27], which also include collections in marginal sea areas such as the Banda Sea in Indonesia [10], Japan Sea [28,29], South China Sea [30], and Gulf of Mexico [16]. Its detection in the stomach contents of some kinds of large predators also suggests it has a widespread presence.…”