67 
NOAA 
National Marine 
Fisheries Service 
Fishery Bulletin 
established 1881 
Spencer F. Baird 
First U S. Commissioner 
of Fisheries and founder 
of Fishery Bulletin 
Embryo development in golden king crab 
{Lithodes aequispinus ) 
Email address for contact author: chris.long@noaa.gov 
Resource Assessment and Conservation Engineering Division 
Kodiak Laboratory 
Alaska Fisheries Science Center 
National Marine Fisheries Service, NOAA 
301 Research Court 
Kodiak, Alaska 99615 
Abstract— The golden king crab 
(. Lithodes aequispinus) is a commer- 
cially important species in Alaska 
waters with an asynchronous repro- 
ductive cycle and lecithotrophic lar- 
vae. In this study, we qualitatively 
and quantitatively describe embryo 
development for this species. Six fe- 
male multiparous golden king crab 
were captured from the Aleutian 
Islands, Alaska, and mated in the 
laboratory. Their embryos were pho- 
tographed on average once every 9 
days throughout embryogenesis. We 
describe 13 stages of embryo devel- 
opment on the basis of both visual 
observations and embryo morpho- 
metries from 1241 measured embry- 
os. Embryo development was simi- 
lar to that of other cold-water crab 
species, with the exceptions that 
1) golden king crab did not have a 
diapause and 2) that the average 
percentage of the area occupied by 
the yolk at hatching, at about 40%, 
was much higher than that of other 
species. Both of these differences 
likely are attributable to the fact 
that the larvae are lecithotrophic 
and, therefore, do not need to syn- 
chronize hatch time with planktonic 
food availability but do need energy 
reserves to develop to the first crab 
stage. This study increases our un- 
derstanding of the reproductive biol- 
ogy of the golden king crab and pro- 
vides a baseline for future studies of 
embryo development. 
Manuscript submitted 3 February 2015. 
Manuscript accepted 5 November 2015. 
Fish. Bull. 114:67-76 (2016). 
Online publication date: 25 November 2015. 
doi: 10.7755/FB.114.1.6 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
W. Christopher Long (contact author) 
Scott B. Van Sant 
The golden king crab ( Lithodes ae- 
quispinus) is an important fishery 
species in Alaska waters; the an- 
nual harvest of the Aleutian Islands 
stock has averaged around 5-6 mil- 
lion lb since 1996 (NPFMC, 2015). 
In North American waters, golden 
king crab are distributed primarily 
along the upper portion of the con- 
tinental slope, on seamounts, and in 
fjords in the Gulf of Alaska and to 
southern British Columbia, along the 
Aleutian Islands, and in the Bering 
Sea (Butler and Hart, 1962; Sloan, 
1985; Donaldson and Byersdorfer, 
2005). They have been harvested in 
the Bering Sea since the early 1980s, 
and the harvest levels there have 
been among the most stable for any 
crab species or stock (Orensanz et al., 
1998; NPFMC, 2015). 
Female golden king crab reach 
maturity, on average, at a carapace 
length (CL) of about 98-111 mm, 
depending on the stock and latitude 
(Jewett et al., 1985; Somerton and 
Otto, 1986). The reproductive cycle 
of golden king crab is not an annual 
event and is probably asynchronous 
in many areas (Hiramoto, 1985; 
Otto and Cummiskey, 1985; Somer- 
ton and Otto, 1986; Paul and Paul, 
2000, 2001). Like all lithodids, female 
golden king crab must molt before 
mating (Paul and Paul, 2001), after 
which they extrude a clutch of up 
to 27,000 eggs (Jewett et al., 1985). 
Golden king crab have lower fecun- 
dities than similar-size red ( Para - 
lithodes camtschaticus) and blue 
( Paralithodes platypus ) king crabs 
(Haynes, 1968; Somerton and Macin- 
tosh, 1985; Swiney et al., 2012). They 
have much larger embryos because 
their larvae are lecithotrophic and 
therefore are supplied with greater 
energy reserves than are the larvae 
of red and king crab (Shirley and 
Zhou, 1997; Paul and Paul, 1999). 
For golden king crab, the brooding 
duration is about 362 days, and the 
time between the completion of lar- 
val hatching and extrusion of a new 
clutch is about 194 days; however, 
these parameters have been esti- 
mated only in the laboratory at tem- 
peratures that were higher than the 
temperatures experienced by crab 
in the field and are likely underes- 
timates (Paul and Paul, 2001). After 
hatching, larvae pass through 3 zoeal 
stages and 1 glaucothoe stage before 
they molt to the first benthic crab 
stage (Shirley and Zhou, 1997; Paul 
and Paul, 1999). 
One of the current gaps in our 
understanding of the biology of the 
golden king crab is the process of 
embryo development. The embryos 
of both the red king crab (Nakani- 
