Effect of oestradiol-17β immersion treatments on sex reversal of mud loach, Misgurnus mizolepis (Günther)

Abstract

Mud loach, Misgurnus wizolepis (Gunther), were sex reversed using the immersion technique. Fry were raised in water containing 50, 100 or 200 |ig oestradiol-17P 1"^ for 1, 2 or 3 weeks. Survival rates decreased as dose and duration of treatment increased: in most instances they were significantly (P < 0.05) lower than those of the controls. Growth rates were unaffected except for fish in the 200 ^ig r^ treatments. The 200 (Xg T^ treatments for 2 and 3 weeks produced monosex female populations. The 100 ng 1~^ treatment for 3 weeks produced 99% females and 1% intersex individuals. Histologically, ovaries of sex-reversed fish were similar to those of normal females. Morphologically, however, they were different in that the ovaries of sex-reversed flsh were not connected to the genital pore. The hormone treatments affected the size and morphology of the pectoral Uns, which exhibit sexual dimorphism in mud loach.

Effects of estradiol-17β on survival, growth performance, gonadal structure and sex ratio of the tiger puffer,Takifugu rubripes (Temminck & Schlegel, 1850), fingerlings

“…Atlantic salmon ( Salmo salar ; Hunter & Donaldson, ), coho salmon, Oncorhynchus tshawytscha (Sower, Dickhoff, Flagg, Mighell, & Mahnken, ), and bluegill sunfish, Lepomis macrochirus (Wang et al., ), treated frequently with high doses of estradiol showed high mortality rates and growth depression, indicating that high doses of estradiol exert toxic effects. Estradiol‐17β doses above a threshold level have been reported to negatively affect the survival of many fish species, such as coho salmon ( Oncorhynchus tshawytscha ; Hunter, Solar, Baker, & Donaldson, ), zebra cichlid ( Cichlasoma nigrofasciatum ; George & Pandian, ) and mud loach ( Misgurnus mizolepis ; Kim, Nam, & Jo, ).…”

Effects of immersion of larvae in oestradiol-17β on feminization, structural changes of gonad and growth performance in the Far Eastern catfish Silurus asotus (Linnaeus)

“…Reduced viability and depressed growth of the fish treated at a high concentration of exogenous steroid have already been reported, regardless of the treatment methods by immersion into steroid‐containing water (Hunter et al . 1986; Kim et al . 1997; Nam, Noh & Kim 1998) or administration of steroid supplemented diets (Gannam & Lovell 1991; Kavumpurath & Pandian 1994).…”

“…The morphological changes of genital characters of the fish that had been exposed to exogenous steroid have also been reported for other fish including rainbow trout, O. mykiss (Walbaum) (Feist et al . 1995), mud loach, Misgurnus mizolepis (Günther) (Kim et al . 1997), and European seabass, Dicentrarchus labrax (Linnaeus) (Chatain, Saillant & Peruzzi 1999).…”

“…An immersion technique was used for administrating the hormone to larvae (Kim et al 1997). Groups of 180 larvae were allocated to replicate tanks (1.2 Q 0.6 Q 0.5 m = L Q W Q H) containing 0, 50, 100 or 200 mg L ±1 oestradiol-17b.…”

Production of all-female diploid and triploid far eastern catfish, Silurus asotus (Linnaeus): survival and growth performance

“…Metaphase chromosome spreads were also prepared from 22 putative triploid fish and 12 diploid fish as described by Kim, Nam & Park (1995). To examine the gonad development of all‐female triploid fish, histological analysis of gonads from 3‐month‐old diploid and triploid individuals was performed according to the method described by Kim, Nam & Jo (1997).…”