ALBERT

Description: Incirrate octopods (those without fins) are among the larger megafauna inhabiting the benthic environments of all oceans, commonly in water depths down to about 3,000 m. They are known to protect and brood their eggs until the juveniles hatch, but to date there is little published information on octopod deep-sea life cycles and distribution. For this study, three manganese-crust and nodule-abundant regions of the deep Pacific were examined by remote operated-vehicle and towed camera surveys carried out between 2011 and 2016. Here, we report that the depth range of incirrate octopods can now be extended to at least 4,290 m. Octopods (twenty-nine individuals from two distinct species) were observed on the deep Ka'ena and Necker Ridges of the Hawaiian Archipelago, and in a nodule-abundant region of the Peru Basin. Two octopods were observed to be brooding clutches of eggs that were laid on stalks of dead sponges attached to nodules at depths exceeding 4,000 m. This is the first time such a specific mineral-biota association has been observed for incirrate octopods. Both broods consisted of approximately 30 large (2.0-2.7 cm) eggs. Given the low annual water temperature of 1.5°C, it is likely that egg development, and hence brooding, takes years [Robison et al. (2014), doi:10.1371/journal.pone.0103437]. Stalked-sponge fauna in the Peru Basin require the presence of manganese nodules as a substrate, and near total collapse of such sponge populations was observed following the experimental removal of nodules within the DISCOL (DISturbance and COLonisation) area of the Peru Basin [Bluhm (2001), doi:10.1016/S0967-0645(01)00070-4]. Stalked fauna are also abundant on the hard substrates of the Hawaiian archipelago. The brooding behavior of the octopods we observed suggests that, like the sponges, they may also be susceptible to habitat loss following the removal of nodule fields and crusts by commercial exploitation.

Description: All information is related to the cruise POLARSTERN PS79 - ANTXXVIII-4 to the Antarctic Peninsula between March and April 2012. Animals were collected, identified and labelled by Dr. Christoph Noever during the 2012 cruise. In laboratory all animals were re-examined by Richard Schwarz.

Description: All information is related to the cruise POLARSTERN PS79 - ANTXXVIII-4 to the Antarctic Peninsula between March and April 2012. Additional samples of Megaleledone setebos came from POLARSTERN cruises ANTVII-4 (1989), PS 82 (2014) and PS 96 (2016). Animals were collected, identified and labelled by Dr. Christoph Noever during the 2012 cruise. In laboratory all animals were re-examined by Richard Schwarz.

Description: The data files contain biological information (sex, sizes, weights, etc.) from Antarctic octopod species collected during Polarstern cruises (Alfred Wegener Institute). The data is part of Richard Schwarz his Ph.D. thesis on age and growth of deep-sea and Antarctic octopods.

Description: The data involves annotations with the MBARI VARS annotation software of pelagic HD video transects obtained by the pelagic in situ observations system PELAGIOS. PELAGIOS is a newly developed towed camera system for deep-sea biological exploration and performance of video transects for diversity and distribution data. The data was collected in 2015 during cruise MSM49 on R/V MARIA S. MERIAN, from 20 to 950 m, during day (187 minutes) and night (292 minutes) transects on the northwestern slope of Senghor Seamount (17°14.2'N, 22°00.7'W; bottom depth of approximately 1000 m). The annotated organisms include fishes, crustaceans and gelatinous zooplankton. One file includes the transect length at each depth at day or night and another file has all individual annotated taxa observed at a particular depth at day or night. The Figure 4 is made with this data. A third file involves the data we used to make Figure 3 which is the comparison between the observations of Poeobius observed in PELAGIOS and UVP5 to calculate sample volume.

Description: All information is related to the cruise POLARSTERN PS79 - ANTXXVIII-4 to the Antarctic Peninsula between March and April 2012. Animals were collected, identified and labelled by Dr. Christoph Noever during the 2012 cruise. In laboratory all animals were re-examined by Richard Schwarz.