NOTE Thedinga et at: Mark retention and growth of jet-injected marine fish 
631 
Figure 2 
Panjet-injected alcian blue dye mark on the ventral lateral margin of a yellowfin sole. 
excised and fixed in 10% buffered seawater. Tissues 
were then placed in 70% ethanol for two days, dehy- 
drated in a graded ethanol series, cleared in xylene, 
embedded in paraffin, and sectioned at 6 p. Sections 
were stained with hematoxylin and eosin and exam- 
ined for lesions and evidence of wound healing. 
Results 
For sablefish, mark retention varied with mark color 
and method of detection. Retention of marks was sig- 
nificantly higher (P<0.001) for alcian blue dye ( 100%) 
than for fluorescent orange acrylic paint when or- 
ange marks were viewed under fluorescent light but 
was similar (P=0.99) when orange marks were 
viewed under UV light (Fig. 3). Retention of orange 
marks viewed under fluorescent light was 100% af- 
ter 21 days but decreased to less than 20% after 84 
days. Retention of orange marks viewed under UV 
light, however, decreased only to 92% after 84 days 
and remained at that level throughout the remain- 
der of the study. 
Mean length at the end of the study was similar 
(P=0.24) between blue-marked sablefish (280 mm) 
Table 1 
Mean fork length of jet-injected and control juvenile sable- 
fish at time of injection and after 33 weeks. Fish were in- 
jected with alcian blue dye and fluorescent orange acrylic 
paint. Standard error is in parentheses. 
Mean fork length (mm) 
Initial After 33 weeks 
Blue 212(0.80) 280(1.07) 
Orange 212(0.96) 270(1.18) 
Control 218(1.16) 288(1.48) 
and controls (288 mm) (Table 1). Despite the poten- 
tial for tank-linked effect due to holding the marked 
fish in a separate tank, mean length of the orange- 
marked sablefish (270 mm) was not significantly dif- 
ferent from that of the controls (288 mm) (P=0.06) 
(Table 1). Mortality was zero. 
For all flatfish, mark retention was 100% through- 
out the study, and growth was similar between 
marked and control fish (Table 2). The instantaneous 
rate of increase in length and weight at the end of 
