Biology Reference
In-Depth Information
A
B
C
D
E
F
G
H
I
J
K
L
Figure 6.2 Development of lateralized swimming posture andmorphological asymmetry
during flatfishmetamorphosis. Bilaterally symmetrical premetamorphic Southern flounder
larvae (Paralichthys lethostigma) swimwith an upright posture in the light (A). Migration of
one eye to the opposite side of the head is accompanied by a transition to a tilted posture
during metamorphic climax (B), and by the end of metamorphosis flounder swim on one
side (C). Asymmetric remodeling of the skull (visualized in vivo by the fluorescent calcium-
binding stain, calcein) accommodates eye translocation (D-H) in P. lethostigma.After
metamorphosis, dextral flatfish, such as this hogchoker (Trinectes maculatus), have a
pigmented “eyed” (right) side (I) and a nonpigmented “blind” (left) side (J). Some flatfish
species, such as P. lethostigma, can metamorphose with either sinistral (K) or dextral (L)
morphology and behavior. Figure panels A
-
H are reproduced with permission from
Schreiber (2006)
.
and distinct ecological gradients of lateral polymorphism have also been de-
scribed for the congeneric European flounder (
P. flesus
)(
Russo et al., 2012
).
Though breeding experiments suggest that the direction of asymmetry in
populations of polymorphic flatfish is under genetic control (
Boklage,
1984; Hashimoto et al., 2002; Policansky, 1982a, 1982b
), environmental
