630 
Fishery Bulletin 95(3), 1997 
Figure 1 
Panjet-injected alcian blue dye mark between the pelvic fins of a juvenile sablefish. 
after 189 days and were frozen prior to analysis. Flat- 
fish were held for 90 d in six 70-L flow-through tanks 
on their preferred bottom type (mud substrate for 
soles [Moles and Norcross, 1995], sand substrate for 
halibut). For each flatfish species, control and marked 
fish were held in separate tanks. Sablefish were held 
indoors and were provided about 8 h of fluorescent 
light daily, whereas flatfish were held outdoors un- 
der an awning with 12 h of fluorescent light daily. 
Sablefish wei e fed ad libitum, and flatfish were fed 
10% of their initial body weight per day throughout 
the study. The substrates in the flatfish tanks were 
initially frozen three days to kill meiofauna and 
macrofauna Mark recognition for sablefish was 
checked abou every 3 weeks, flatfish about every 4 
weeks. Blue marks were viewed under fluorescent 
light, orange marks under fluorescent and ultravio- 
let (UV) light. Mark retention was rated subjectively 
as acceptable (retained) or unacceptable (not re- 
tained) by the same person each time the fish were 
checked. Fish lengths were recorded at the begin- 
ning and end of the study: fork length (FL) for sable- 
fish, total length (TL) for flatfish. Because we were 
obtaining additional data (histological) from flatfish, 
we also recorded flatfish weights when we recorded 
their lengths. Differences in acceptable mark retention 
were tested with a chi-square test, and differences in 
fish size and growth rate were tested with a btest. 
Absolute growth rate in length of flatfish was cal- 
culated as 
L = TL 2 - (7^/90X10), 
where L = absolute growth in length; 
TL 2 = total length at 90 days; and 
TL l = total length at day 1 (beginning of the 
study). 
Instantaneous growth rate in weight of flatfish was 
calculated as 
W = (log e W 2 - log e Wj)/90, 
where W = instantaneous rate of increase in weight; 
W 2 = weight at 90 days; and 
W j = weight at day 1 (beginning of the study). 
All flatfish were examined for histological changes. 
Fish were examined for gross pathology at 50x with 
a dissecting microscope. Gill and liver tissues were 
