Luminosity micrograph (a), and photo micrograph (b), displaying the change
  in otolith microstructure associated with sex change (arrow) in a fish from the
wild.

 

Figure 1. (a) Parapercis cylindrica; female front, male back. (b) Mean otolith increment-width profiles ± S.E. for experimental fishes. Non-sex changing control females; blue, monogamous sex-changers; grey, polygynous sex-changers; black. All increment profiles significantly different (p < 0.05) according to repeated-measures ANOVA. (c-e); photomicrographs of the gonads (g) and otoliths (o) from experimental fishes in the laboratory. All initial sizes = 85 mm TL. (c) Control non-sex changing female displaying active oogenesis and regular otolith increments (d) Monogamous sex-changer displaying partial gonad-transition and otolith-increment discontinuity (arrow). (e) Polygynous sex-changer displaying complete gonad-transition and otolith-increment discontinuity (arrow). DO; developing oocytes, MO; mature oocytes, DPO; degenerating previtelogenic oocytes, ROC; remnant oocyte constituents, AB; atretic body, FOL; former ovarian lumen, Spc; spermatocytes, Spz; spermatozoa, PSS; peripheral sperm sinus.

Free copyright is granted for use of these images in conjunction with ARC Centre of Excellence news stories