Parrish et a!.: Movements of cultured and wild juvenile Pristipomoides filamentosus in a nursery habitat 
239 
Table 2 
The identification number and substrate type of the 4 sites on the windward Oahu slope where receivers 
were deployed in 2007. Also shown is the distance in kilometers of each receiver from the nursery, num- 
ber of tagged juvenile crimson jobfish (Pristipomoides filamentosus) that were detected, mean number 
of days when those fish were present at each site, and mean bottom temperature at each site. For “Days 
present” the mean, standard deviation (SD), and range are given for each site. There were 2 substrate 
types: rock ledge and soft bottom. 
Days present Temp. (°C) 
Receiver 
Substrate 
Nursery (km) 
No. fish 
Mean (SD) 
Range 
Mean (SD) 
1 
Rock 
4.0 
5 
6.0 (9.9) 
0.25-23.5 
21.8 (1.0) 
2 
Soft 
1.5 
17 
1.5 (2.0) 
0.25-8.3 
21.8 (1.0) 
3 
Rock 
1.8 
8 
17.8 (25.2) 
0.25-61.0 
21.0 (1.0) 
4 
Soft 
3.3 
8 
0.6 (0.4) 
0.25-2.0 
21.8 (1.0) 
ter during the day and in deeper water at night, shift- 
ing between adjacent areas (<300 m separation) that 
differed slightly in depth ( ~ 10 m). For both tracks, the 
area of daytime activity was twice the size of the area 
of activity at night. 
This commuting behavior could explain the bimodal 
pattern seen for the tagged fish in our study before 
they left the nursery. If these fish also shifted deeper 
at night, some of them would be out of detection range 
until morning when they returned to the shallower 
portion of their home range and were more active. 
Looking at the patterns in the movements of the 4 wild 
fish that persisted in the nursery for multiple weeks, 2 
fish (tags 1834 and 1850) appeared to have both their 
areas of activity during day and night mostly inside 
the detection area of the receivers in the nursery (Fig. 
5). In contrast, the pattern of a third fish (tag 1835) 
indicates that the area of activity during the day was 
within the detection range of the receiver and the area 
of nighttime activity was outside that range. Some drift 
in the home range of individual fish can occur, as was 
observed for the fourth wild fish (tag 1844) that stayed 
at the nursery for multiple weeks, but the extent to 
which the size or location of home ranges are subject 
to change over time is unknown. 
As the wild fish departed the nursery and ranged 
farther out on the slope, they used both soft bottom 
and rock ledge habitats before emigrating away. Al- 
though the size of the fish at the sites on the slope did 
not statistically differ by habitat type of sites, a few 
of the larger fish (mean: 25.5 cm FL [SD 5.4]) clearly 
persisted for more than a month at sites with rock 
ledges. Crimson jobfish at this size are at the lower 
end of the size range of subadults documented to ag- 
gregate around relief features (Okamoto 1 ). Presumably, 
this shift in habitat use occurs because the fish grow 
to a size where they need to change their diet or for- 
aging strategy. Studies of stomach contents of crimson 
jobfish have shown a transition from a juvenile diet of 
mostly benthic invertebrates (DeMartini et al., 1996) 
to an adult diet of mostly large plankton, including 
jellies and salps (Haight et al., 1993b). Maturing and 
adult fish use high-relief habitat more than juveniles 
do — they exploit the increased water flow around relief 
features to improve their level of success in encounter- 
ing and feeding on drifting plankton over their level of 
success at low-relief habitats. Future tagging work in 
the Kaneohe nursery should include receivers deployed 
in nearby locations with adult crimson jobfish assem- 
blages to see if some of the emigrating juveniles make 
a direct transition to adult habitat. 
Considerations for stock enhancement 
Although we have no explanation for the behavioral dif- 
ference seen between the 2 batches of tagged fish, the 
patterns observed for wild and cultured fish are similar 
to findings from other marine fish studies. Simultane- 
ous releases of tagged cultured and wild individuals 
generally have shown that cultured fish tend to move 
away sooner and farther than wild fish (D’Anna et al., 
2004; Yokota et al., 2007; Fairchild et al., 2009; Lino et 
al., 2009). Future studies with releases of tagged juve- 
nile crimson jobfish might include a staged release pro- 
cess (Fairchild et al., 2010) that would give fish time 
to acclimate to the nursery and, therefore, make them 
more likely to use the habitat like wild fish. However, 
if cultured fish were to continue to leave the nursery 
directly, and there were no means to verify their sur- 
vivorship after they have left, the use of larger fish 
(>30 cm FL) that are old enough to skip the nursery 
stage and join subadults or adults should be considered 
for enhancement efforts. Stock enhancement studies on 
shallower Hawaiian species have shown that the size 
of release is an important variable in the success of 
stocking efforts (Leber, 1995; Leber et al., 1998; Leber 
et al., 2005). Finally, it is possible that being reared, or 
even just being held for a time in captivity and fed, can 
accelerate the ontogentic shift from the nursery stage 
to subadult phase in the life history of the crimson job- 
