We tested whether body patterns distinguished two haplotypes of large octopus in Prince William Sound Alaska. Live octopuses were photographed in captivity and assigned to a morphotype based on whether longitudinal mantle folds (a characteristic body pattern feature of the giant Pacific octopus (GPO), Enteroctopus dofleini (Wülker 1910)) were present (the GPO morphotype, N = 14) or absent (a novel morphotype, N = 6). Novel morphotype octopuses were distinguished without exception from GPO morphotype octopuses by the presence of a lateral mantle frill and the absence of longitudinal mantle folds, ventral mantle texture below the lateral frill, and patch and groove patterning. Additional traits could be used in combination to reliably characterize the novel morphotype. The genetic haplotypes of these octopuses were determined from nucleotide sequence data from two microsatellite loci and a portion of the OCDE gene. The GPO morphotype was identified with E. dofleini based on the match of body pattern traits to published descriptions of that species and the match of its genetic haplotype to published sequences of E. dofleini. Novel morphotype body patterns did not match descriptions of any species from the eastern north Pacific, while its genetic haplotype matched that of a recently sequenced undescribed octopus. The GPO and novel morphotypes are sister clades, and body pattern traits reliably identified individuals to morphotype and haplotype. Body pattern traits can be used in field identification of live octopuses allowing population assessments, by-catch frequency estimates, and other studies of both octopus types. We offer the common name of the frilled giant Pacific octopus for the novel morphotype, and based on genetic and morphological data suggest this clade is a new species of large Pacific octopus in the genus Enteroctopus. A full species description remains to be done.
Whoa this is unbelievably cool! A new species of GPO hiding in plain sight? How is this not front page news all over the internet? Let me see if I can remedy that . . .Body Patterns of the Frilled Giant Pacific Octopus, a New Species of Octopus from Prince William Sound, AK American Malacological Bulletin 35(2):134-144. 2017
Nathan Hollenbeck, David Scheel
Catch history Since there has been only a limited market for octopus and no directed fishery in federal waters, there is limited data available for documenting catch history. Historical rates of incidental catch would not necessarily be indicative of future fishing patterns if octopuses were increasingly retained for market catch. Estimates of incidental catch suggest substantial year-to-year variation in abundance, which would result in large annual fluctuations in harvest. This large interannual variability is consistent with anecdotal reports (Paust 1988, 1997) and with life-history patterns for E. dofleini.
Executive Summary At least seven species of octopus are found in the Gulf of Alaska (GOA). For management purposes, all octopus species are grouped into a single assemblage. Neither the relative abundances of the various species or the species composition of the commercial catch are well documented, but research indicates that the giant Pacific octopus Enteroctopus dofleini is the most abundant octopus species in shelf waters and makes up the bulk of octopus catches in commercial fisheries. Octopuses are taken as incidental catch in trawl, longline, and pot fisheries throughout the GOA; a portion of the catch is retained or sold for human consumption or bait. The highest octopus catch rates are from Pacific cod pot fisheries in the central and western GOA (NMFS statistical areas 610 and 630). Through 2010, octopuses were managed as part of the “other species” complex, with catch reported only in the aggregate along with sharks, squids, and sculpins. In 2011, the GOA Fishery Management Plan was amended to provide separate management for sharks, sculpins, squids, and octopuses. In compliance with the reauthorized Magnuson-Stevens Act, each complex has its own annual catch limit. Harvest recommendations for the octopus complex are made using a modified Tier 6 approach, where the overfishing level (OFL) is calculated by multiplying the best available estimate of octopus biomass by the best estimate of natural mortality for E. dofleini. Catch limits for octopus for 2011-2014 were set using the average biomass from the last 3 surveys. Beginning in 2015, a random-effects (RE) model is used to provide a minimum biomass estimate