Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/30027
Appears in Collections:Aquaculture Journal Articles
Peer Review Status: Refereed
Title: Endoscopy and Cannulation as Non-Invasive Tools to Identify Sex and Monitor Reproductive Development in Arapaima gigas
Author(s): Torati, Lucas Simon
Lima, Adriana Ferreira
Kirschnik, Luciana Nakaghi Ganeco
Migaud, Herve
Contact Email: herve.migaud@stir.ac.uk
Keywords: Arapaima gigas
Issue Date: Jun-2019
Citation: Torati LS, Lima AF, Kirschnik LNG & Migaud H (2019) Endoscopy and Cannulation as Non-Invasive Tools to Identify Sex and Monitor Reproductive Development in Arapaima gigas. Copeia, 107 (2), pp. 287-296. https://doi.org/10.1643/ot-18-127
Abstract: The lack of tools for sex identification and assessment of gonadal development are hindering our ability to study the reproductive dysfunction of Arapaima gigas in captivity. This study initially aimed to validate a non-surgical endoscopy procedure to identify sex in juveniles and assess stage of ovary development in female broodstock under field operational conditions. Cannulation, assisted through the description of the genital anatomy, made ovarian biopsy possible to describe oocyte development from primary growth to pre-ovulation, providing a first classification scheme for oogenesis in the species including description of the micropyle morphology using scanning electron microscopy. Cannulation was also successfully performed without endoscopic guidance, which allowed monitoring of ovarian development along the reproductive season together with profiling of plasma sex steroids (17β-estradiol [E2] and 11-ketotestosterone [11-KT] in females and males, respectively). The monitoring of our study population showed females paired with males in earthen ponds sexually matured and reached oocyte maturation during the spawning season. However, since no spawning was recorded, eggs had either been resorbed or released and not fertilized by the male. Plasma E2 levels remained high in females, as expected in an asynchronous species during the spawning season with multiple batches of oocytes being recruited. Plasma 11-KT showed a tendency to decrease, suggesting a male reproductive dysfunction or the end of the reproductive season with a lack of synchronization between sexes. In conclusion, endoscopy and cannulation are tools that can be promptly applied to aid sex identification, assessment of reproductive function, and overall broodstock management in wild and captive stocks. These tools will greatly help future studies looking at the effects of environmental, social, and hormonal cues on reproductive development with the aim of developing a spawning induction protocol for the species.
DOI Link: 10.1643/ot-18-127
Rights: reen Open Access, Self-Archiving, Non-Commercial Preprint Servers, and Dissertation Chapter Deposition: Prior to acceptance for publication, Copeia allows authors to deposit manuscripts in non-commercial preprint servers such as bioRxiv. Upon publication of a paper in Copeia, it is important that authors update the article to the accepted version, provide a link from the preprint to their formal publication via its Digital Object Identifier (DOI), and add the following text to their preprint server manuscript: "This article has been accepted for publication in Copeia." Following publication, Copeia allows authors to deposit their accepted manuscript in non-commercial digital repositories associated with their employers as long as a number of conditions are met. Copyright: American Society of Ichthyologists and Herpetologists, 2019 Torati LS, Lima AF, Kirschnik LNG & Migaud H (2019) Endoscopy and Cannulation as Non-Invasive Tools to Identify Sex and Monitor Reproductive Development in Arapaima gigas. Copeia, 107 (2), pp. 287-296. https://doi.org/10.1643/ot-18-127



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