The egg is pelagic, globular, small, its diameter 0•45-0•50mm long, with a single oilglobule measuring 0•07mm in diameter. It takes about 36 hours to hatch after fertilization at water temperatures 22•6-23•9°C. Newly hatched larvae (Fig. 3) are 1•1mm long, provided with 7 black chromatophores equidistantly along the dorsal median line, the foremost one is located at the cervical flexure. No pigment is present at the caudal end. The yolk-sac is projected forwards, forming a lump embracing an oil-globule with a black chromatophore, on its anterior surface. The number of myotomes is about 25 pairs. The larva sixteen hours old after hatching is 1•4mm long with 11 black chromatophores along dorsal median line. The anus is situated a little posterior to the middle of the ventral side of body. The ventral part of body and yolk-sac are not furnished with the black chromatophores.
The egg of the present species is smaller than those of
Halichoeres poecilopterus and
Labrus sp. The newly hatched larva is distinguished from others as shown in the following key for Japanese species of Labridae.
a. Black chromatophores of dorsal surface arranged in two rows…………
H. poecilopterus. a'. Black chromatophores of dorsal surface arranged in one row
b. With one black chromatophore above anus……………………………
Labrus. sp. b'. Without black chromatophore above anus
c. Oil-globule with a black chromatophore on its anterior surface……………
T. cupido. c'. Oil-globule with a black chromatophore on its posterior surface
d. Black chromatophores of the back 8…………………………………
Labrus sp. d'. Black chromatophores of the back comparatively small, 18 in number……
Labrus sp.
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