Sterility and Mutants - Genetic Sex Differentiation in Fish - page 142

Fig. 57. Diagramatic representation of eight parts of the gonads of hermaphroditic tiger puffers,
Takifugu rubripes caught from Bungo Channel (A) and in the Japan Sea off Yamaguchi Prefecture
(B). 1, 2, 5 and 6 = ovary, 3, 4, 7 and 8 = testis (from Suzuki, 1997)
investigations are limited to Odontethes bonariensis (Strussmann et al., 1996)
and T. rubripes (Suzuki 1997). At the experimental level, Kossman (1971)
stripped eggs and sperm form the hermaphroditic carp and successfully
fertilized them. While the abnormals seem not to have attracted the
attention of physiologists, especially endocrinologists, rare occurrence and
non-functional status may have inhibited experimental zoologists from
undertaking detailed studies. Nevertheless, the abnormals may increasingly
become an important resource for studies on sex differentiation. For Schulz
(1996) has reported the regular incidence of 0.02% of abnormals in wild
population of the roach Rutilus rutilus. Unrestricted and indiscriminate
use of pesticides like endosulfan is common in developing countries; the
discrete immersion of post-hatchlings of D. rerio in 1400 ng endosulfan/l
for 14 hours resulted in the production of 44% abnormal hermaphrodites
(Balasubramani and Pandian, 2008a). Secondly, the genome of non
functional/inviable abnormals can be recovered using the newly developed
technique of Shimada and Takeda (2008). These abnormals may provide
excellent opportunities for a better understanding of the high plasticity
encountered in sexuality of fi shes.
Steriles: Contrary to the abnormal hermaphrodites, steriles are those with
gonads of reduced size, where gametogenesis has been blocked (Pifferer et
al., 1994). Whether the steroidogenesis is blocked or not is unknown as yet.
C Strussmann introduced sperm cells into sterile Odontesthes argintinensis