Biology Reference
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frequencies have been recorded (Tatarenkov et al., 2009), leaving the 2-3%
fertilization frequency to secondary males. Harrington (1967) has reported
the appearance of < 5% primary males, when the eggs are incubated at <
19
o
C (Fig. 48). However, exposure of post-hatchlings to 28ºC generates
secondary males. Relatively higher water temperatures prevailing in
tropical Belize produce nearly 25% secondary males (Tatarenkov et al.,
2009). Understandably, sex change can be induced in this self fertilizing
hermaphrodite by exposing to different thermal regimes during the early
Fig. 39.
Ontogenetic pathways of sex differentiation in simultaneous hermaphroditic fi shes.
H = hatching, G = Gamete exchanging, Z = sex changing, p♂ = primary male, s♂ = secondary
male, ♀a
+
= female active hermaphrodite, ♂a
+
= male active hermaphrodite
