Conrath and Conners: Aspects of the reproductive biology of Enteroctopus dofleini in the Gulf of Alaska 
255 
Figure 1 
Map of sampling locations where North Pacific giant octopuses (Enteroctopus dofleini) were 
collected during 2010-2011 in the central and western Gulf of Alaska from both charter oper- 
ations and the bottom-trawl survey conducted by the Alaska Fisheries Science Center in the 
Gulf of Alaska. The inset on the upper left of the figure shows the location of the sampling 
area in relation to the state of Alaska. The inset on the lower right of the figure provides 
greater detail on the locations where octopuses were sampled during charter operations in 
Chiniak Bay. 
model, and the equation was solved for T=0.5 to yield 
IT 50 . Bootstrapping methods were used to estimate con- 
fidence intervals and the variance of W 5 0 (Efron and 
Tibshirani, 1993). These statistical tests were complet- 
ed with TIBCO Spotfire S+ statistical software , 2 vers. 
8.2 (TIBCO Software, Palo Alto, CA). In addition, for 
maturing and mature female specimens, the histologi- 
cal sections were examined to determine the longest 
ova: 5 large ova in each section were measured with a 
micrometer, and the largest was determined to be the 
maximum ova length (MOL). 
Seasonality 
Seasonality of reproduction in this species was exam- 
ined by noting the presence or absence of spermato- 
phores and well-developed, yolked (stage-3) ovarian 
eggs during each season of the year. Seasons were de- 
fined on the basis of daily measurements of sea-sur- 
2 Reference to trade names or commercial companies is for 
identification purposes only and does not imply endorsement 
by the National Marine Fisheries Service, NOAA. 
face temperatures in Chiniak Bay taken at the Kodiak 
Fisheries Research Center: spring had rising tempera- 
tures (April-June), summer had rising temperatures 
to a maximum ( July-September), fall had falling tem- 
peratures (October-December), and winter tempera- 
tures were steady and coldest (January-March). The 
GSI values for maturing and mature North Pacific gi- 
ant octopuses were averaged by season to determine a 
mean seasonal GSI values for males and females. This 
seasonal examination of gonad growth was limited 
to individuals with developing reproductive tracts 
and, therefore, did not include immature specimens 
that may remain immature for a period of years. The 
mean MOL also was determined for each season of 
the year. A one-way analysis of variance (ANOVA) was 
used to test for significant differences in GSI and fe- 
male MOL values during each season of the year. If 
results were found to significantly differ, the Tukey 
honest significant difference (HSD) test was used to 
compare the GSI and MOL values between individual 
seasons. The ANOVA and Tukey HSD tests were com- 
pleted with R statistical software, vers. 2.15.1 (R Core 
Team, 2012). 
