Pm. Pankhurst et P. Butler, DEVELOPMENT OF THE SENSORY ORGANS IN THE GREENBACK FLOUNDER, RHOMBOSOLEA-TAPIRINA, Marine and freshwater behaviour and physiology, 28(1-2), 1996, pp. 55-73
Plastic resin histology and scanning electron microscopy were used to
examine the development of the sense organs in greenback flounder from
day 1 after hatching to early stage juveniles. A functional cone reti
na was present at the time of first feeding. Twin cones and rods devel
oped later. There were two pairs of superficial neuromasts on the head
of 1-day-old fish, with rapid proliferation of superficial neuromasts
on the head and trunk thereafter. Lateral line canals first appeared
on the head late in larval development, but trunk canals were still no
t present in early stage juveniles. The labyrinth initially contained
2 otolith organs with a full compliment of labyrinth organs present in
late stage larvae. The olfactory organs were superficial cups of cili
ated sensory epithelium in 1-day-old fish. These gradually sank into t
he rostral dermis, becoming enclosed except for anterior and posterior
openings (nares) in juvenile fish. Metamorphosis, which involves migr
ation of the left eye to the right side, and a change in posture of 90
degrees, has implication for central processing of sensory informatio
n.