Cartwright: Description of early life stages of Icelmus borealis 
179 
Figure 2 
Developmental series of northern sculpin ( Icelinus borealis ): (A) preflexion larva, 7.4 mm 
NL, UW 105149, Bering Sea, 54°24.9'N, 165°09.0'W, 140 m depth, 25 April 1997; (B) flexion 
larva, 9.3 mm SL, UW 105129, Bering Sea, 56°27.3'N, 169°28.3'W, 94 m depth, 12 July 
1997; (C) postflexion larva, 15.8 mm SL, LTW 105162, Bering Sea, 56°28.3’N, 169°26.9'W, 
87 m depth, 1 August 1996; (D) transformation larva, 17.9 mm SL, UW 105160, Bering 
Sea, 55°04.4'N, 165°08.0'W, 108 m depth, 26 July 1996; (E) juvenile, 41.7 mm SL, UW 
105152, Gulf of Alaska, 57°15.7'N, 152°53.7'W, 87 m depth, 16 September 1993. Abbrevia- 
tions: NL = notochord length; SL = standard length. Illustrations by R. L. Cartwright. 
the first two or three spines. Rays of the second dorsal 
fin were also pigmented in some specimens. Large, dark 
melanophores were present on the pectoral-fin base, and 
some pigmentation developed on the rays near the base. 
One or two melanophores were present on or near the 
pelvic-fin base. 
Throughout transformation of larvae of I. borealis 
into the juvenile stage, pigmentation continued to in- 
