Hormonal sex reversal of
Atlantic halibut (Hippoglossus hippoglossus L.)
Ch.I. Hendry, D.J. Martin-Robichaud, T.J. Benfey-2003
Aquaculture, 219(4): 769-781
Abstract:
Atlantic halibut (Hippoglossus hippoglossus
L.) females grow larger and mature later than males, making monosex
(all-female) culture economically advantageous. The objective of this
research was to develop methods for the production of monosex populations of
halibut through the use of sex steroids. Six hundred postlarval halibut,
mean size 30.0 mm fork length (FL), were divided evenly among eight tanks
and fed a formulated diet supplemented with either 17a-methyldihydrotestosterone
(MDHT; 1 and 5 ppm) or 17b-estradiol
(E2; 10 ppm) for 45 days. Fish were then further reared on a
standard halibut diet until sex ratios could be determined through
histological and macroscopic observations. The MDHT treatments yielded
97–100% males, while the E2 treatment yielded a 70–74% female
population. This demonstrates that the direct feminization of halibut can be
achieved, and also allows for the evaluation of indirect feminization
through the crossing of hormonally masculinized females
("neomales") to normal females.
(St. Andrews Biological Station, Fisheries and Oceans
Canada, 531 Brandy Cove Road, St. Andrews, New Brunswick, Canada E5B 2L9,
e-mail: chendry@gov.nf.ca)