Profiling of methyl farnesoate in relation to female reproductive cycle in the freshwater crab, Travancoriana schirnerae Bott, 1969 (Crustacea: Gecarcinucidae)

ABSTRACT

The sesquiterpenoid, methyl farnesoate, produced by the mandibular organ of decapod crustaceans has a variety of functions including the regulation of moulting, reproduction, morphogenesis, behaviour and osmoregulation. This study used gas chromatography and mass spectrometric analysis to measure the haemolymph concentration of methyl farnesoate during various developmental stages of the ovary of the edible freshwater crab Travancoriana schirnerae. The results revealed exceptionally low methyl farnesoate titres in the haemolymph during the avitellogenic and previtellogenic periods (5.7 ± 0.7 and 12.8 ± 1.3 ng/mL, respectively), reaching a peak in the early vitellogenic period (91.8 ± 3.8 ng/mL), followed by a significant fall during the middle and late vitellogenic stages (32.1 ± 2.3 and 22.1 ± 1.6 ng/mL, respectively). The progressive increase and decrease in the haemolymph titre of methyl farnesoate in accordance with the stages of the ovarian cycle clearly indicated the role of this hormone in growth and maturation of the ovary. Furthermore, administration of methyl farnesoate can be exploited as an alternate method to the traditional eyestalk ablation practised for inducing ovarian maturation and spawning.

KEYWORDS:

• Gas chromatography-mass spectrometry
• haemolymph
• ovarian development
• pre-reproductive season
• reproductive season

Acknowledgments

The Gas Chromatography-Mass Spectrometry facilities provided by the Sophisticated Analytical Instrument Facility, Indian Institute of Technology, Madras is gratefully acknowledged. The authors acknowledge with thanks the anonymous reviewers for the valuable comments/suggestions they received in improving the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Kerala State Council for Science, Technology and Environment [grant number P 115/2016/KSCSTE] dt. 03-05-2016.