Enteroctopus dofleini(GPO, Giant Pacific Octopus) Wülker, 1910

DWhatley

Cthulhu
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#1
Chapter 19 (BSAI) Octopus Complex 2007Alaska Fisheries Science Center
November 2007

Study findings on regulating octopus catch in Alaskan waters (Bering Sea). Long and somewhat repetitive but interesting report on trying to determine if and how to regulate Alaskan octopuses. Much of the data came from observers like Greg

Abstracts from the Giant Pacific Octopus Symposium And Workshop, Seattle Aquarium March 2012
 

GPO87

Sepia elegans
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#3
HOLD IT! There was a GPO workshop in Seattle? Why was I not informed/ asked to be the guest of honour? Surely my name gives me some sort of entitlement. :roll: Hmmm, perhaps it's because I was the 87th in line.... I'll have to do something about that.

Very cool find, D. I'll have to keep my eyes open to see if this becomes an annual thing!
 

DWhatley

Cthulhu
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#4
The post is dated 8/17 but it does not say when the workshop took place. Still worth investigating though as it might give you a an official reason to go home for a visit :grin:
 

DWhatley

Cthulhu
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#5
A COMPLEX PATTERN OF POPULATION STRUCTURE IN THE NORTH PACIFIC GIANT OCTOPUS ENTEROCTOPUS DOFLEINI Patrick D. Barry,Sherry L. Tamone, David A. Tallmon

Abstract

We investigated the population structure of the North Pacific giant octopus, Enteroctopus dofleini (Wülker, 1910) in Alaskan waters. Octopuses were collected from five locations (Dutch Harbor [DH; n = 45], Kachemak Bay [KB; n = 45], Prince William Sound [PWS; n = 18], Glacier Bay [GB; n = 33], and Stephen's Passage [SP; n = 39]). All samples were sequenced at the cytochrome oxidase I (COI) locus of the mitochondrial genome. We identified two major mtDNA haplogroups. Sequence divergence ranged from 0.2 to 2.9%. Haplotypes were not distributed evenly among the sampled populations, producing an enigmatic pattern of population structure. We observed no genetic differentiation between DH, KB and GB, or between PWS and SP. FST was extremely high for all other pairwise comparisons, ranging from 0.871–0.948. We did not observe an isolation-by-distance pattern or a strong clinal gradient in haplotype frequencies, as typically detected in other marine species. Strong genetic drift, serial bottlenecks or sweepstakes events may contribute to the pattern observed. The high level of sequence divergence observed at the COI locus could also suggest cryptic species within the E. dofleini complex, with limited geographical overlap of populations and gene flow. Additional samples were contributed by researchers from British Columbia [n = 1], Seaside, Oregon [n = 4], Neah Bay, Washington [n = 2], Puget Sound, Washington [n = 1], and Kodiak Island, Alaska [n = 2)] While sample sizes were low for these locations, prompting their exclusion from population based analyses, all individuals were of the predominate haplotype found in Alaska.
 

DWhatley

Cthulhu
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#6
Not scientific but the video is the best I have seen to demonstrate how octopuses can fit through very small spaces.
[video]http://www.liveleak.com/view?i=68e_1364664200[/video]
 

DWhatley

Cthulhu
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#9
Multiple Paternity and Preliminary Population Genetics of Giant Pacific Octopuses, Enteroctopus dofleini, in Oregon, Washington and the Southeast Coast of Vancouver Island, BC Shawn Larson , Catherine Ramsay, James A. Cosgrove 2015 (pdf)

Abstract: A total of 77 giant Pacific octopus, Enteroctopus dofleini, tissue samples were collected from the Oregon Coast (OR), Neah Bay Washington (NB), Puget Sound Washington (PS) and the southeast coast of Vancouver Island, British Columbia, Canada (BC) for genetic analyses. A suite of eight variable microsatellite markers developed from giant Pacific octopuses were amplified in these samples to determine population diversity, structure, relatedness and paternity. The majority of loci met Hardy-Weinberg equilibrium expectations within each population. We found moderate genetic diversity (average observed heterozygosity = 0.445, range = 0.307–0.515 and average expected heterozygosity = 0.567, range = 0.506–0.696) and moderate population structuring with distinct separation of groups (FST values ranged from 0.101 between BC and PS to 0.237 between BC and NB). Several egg strings from the BC population were collected from three female octopus dens for relatedness and paternity analyses. Results suggest strong support for multiple paternity within one egg clutch with progeny sired by between two to four males.
 

DWhatley

Cthulhu
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#10
RETROSPECTIVE REVIEW OF MORTALITY IN GIANT PACIFIC OCTOPUS (ENTEROCTOPUS DOFLEINI)
Kathryn E. Seeley , D.V.M., Leigh A. Clayton , D.V.M., Dipl. A.B.V.P. (Avian, Reptile/Amphibian), Catherine A. Hadfield , M.A., VetM.B., Dipl. E.C.Z.M., Dipl. A.C.Z.M., Dillon Muth , D.V.M., Joseph L. Mankowski , D.V.M., Ph.D., Dipl. A.C.V.P., andKathleen M. Kelly , D.V.M., Ph.D., Dipl. A.C.V.P. 2016 (subscription - Journal of Zoo and Wildlife Medicine)

Abstract
The giant Pacific octopus (Enteroctopus dofleini) is a popular exhibit species in public display aquaria, but information on health and disease is limited. This retrospective review evaluates time in collection and describes antemortem clinical signs and pathology of giant Pacific octopuses in an aquarium setting. Between March 2004 and December 2013, there were 19 mortalities: eight males, 10 females, and one individual whose sex was not recorded. Average time spent in collection for all octopuses was 375 ± 173 days (males 351 ± 148 days, females 410 ± 196 days). Ten (52.6%) of the octopuses were sexually mature at the time of death, six (31.6%) were not sexually mature, and reproductive status could not be determined in three octopuses (15.8%). Minimal changes were noted on gross necropsy but branchitis was histologically evident in 14 octopuses, often in conjunction with amoeboid or flagellate parasites. Senescence, parasitism, and husbandry were all important contributors to mortality and should be considered when caring for captive octopuses.
 

DWhatley

Cthulhu
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#13
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

Abstract:
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.
 

DWhatley

Cthulhu
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#15
Assessment of the Octopus Stock Complex in the Gulf of Alaska
Olav A. Ormseth and M. Elizabeth Conners Alaska Fisheries Science Center 2017

Study recommends to reducing the bycatch limit of E. dofleini to 13 percent of it 2016 tone limit. A review of the sampling may be in order to determine why the huge result difference.

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
 

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