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Efficacy of estradiol in feminising the eastern mosquitofish, Gambusia holbrooki: advance towards developing a genetic control option

Version 2 2024-09-19, 06:08
Version 1 2023-05-21, 02:39
journal contribution
posted on 2024-09-19, 06:08 authored by NH Norazmi-Lokman, Gary Purser, Jawahar PATIL

As a first step towards developing genetic option to control pest populations of Gambusia holbrooki, this study investigated the efficacy of oestradiol (E2) to feminise the species. The oestrogen was administered orally via food to neonates (Experiment 1) or embryos through gravid females (Experiment 2) at dosage between 50 and 400 mg kg–1 of feed. Two control groups consisted of (C1) normal feed and (C2) feed mixed with 70% ethanol. In Experiment 1, 100% feminisation was observed at all E2 concentrations except at 400 mg kg–1 where no treated individuals survived. There was a significantly (P < 0.05) lower mean survival rate (MSR) of all E2-treated juveniles than of controls (C1: 71.73 ± 22.86%; C2: 70.02 ± 18.26%), with 50 mg kg–1 showing the best MSR (66.38 ± 12.34%). In Experiment 2, 100% feminisation was achieved at E2 concentrations of 200–400 mg kg–1 food, with the best MSR (59.33 ± 12.54%) at 200 mg kg–1 concentration, which was, however, significantly lower than in control groups (C1: 79.96 ± 20.33%; C2: 77.09 ± 10.32%). The reproductive output and gestation period of gravid females were not affected by E2 exposure. The outcomes provide a framework for reliable sex reversal (feminisation) in this fish, paving way for developing genetic strategies to manage and eradicate this pest fish.

History

Publication title

Marine and Freshwater Research

Volume

72

Issue

11

Pagination

1657-1666

ISSN

1323-1650

Department/School

Fisheries and Aquaculture, Ecology and Biodiversity, Sustainable Marine Research Collaboration

Publisher

C S I R O Publishing

Publication status

  • Published

Place of publication

150 Oxford St, Po Box 1139, Collingwood, Australia, Victoria, 3066

Rights statement

Journal compilation copyright CSIRO 2021

Socio-economic Objectives

180302 Control of pests, diseases and exotic species in fresh, ground and surface water

UN Sustainable Development Goals

3 Good Health and Well Being