Current and Future Assisted Reproductive Technologies for Fish Species

Abstract

The Food and Agriculture Organization of the United Nations (FAO) estimates that in 2012 aquaculture production of fish will meet or exceed that of the capture fisheries for the first time. Thus, we have just turned the corner from a predominantly hunting gathering approach to meeting our nutritional needs from fish, to a farming approach. In 2012, 327 finfish species and five hybrids were covered by FAO aquaculture statistics, although farming of carps, tilapias, salmonids, and catfishes account for most of food-fish production from aquaculture. Although for most major species at least part of production is based on what might be considered domesticated animals, only limited production in most species is based on farming of improved lines of fish or is fully independent of wild seedstock. Consistent with the infancy of most aquaculture industries, much of the development and implementation of reproductive technologies over the past 100 years has been directed at completion of the life cycle in captivity in order to increase seed production and begin the process of domestication. The selection of species to farm and the emphasis of selective breeding must also take into account other ways to modify performance of an animal. Reproductive technologies have also been developed and implemented to affect many performance traits among fishes. Examples include technologies to control gender, alter time of sexual maturation, and induce sterilization. These technologies help take advantage of sexually dimorphic growth, overcome problems with growth performance and flesh quality associated with sexual maturation, and genetic containment. Reproductive technologies developed to advance aquaculture and how these technologies have been implemented to advance various sectors of the aquaculture industry are discussed. Finally, we will present some thoughts regarding future directions for reproductive technologies and their applications in finfish aquaculture.

Genetic basis and biotechnological manipulation of sexual dimorphism and sex determination in fish

“…As mentioned above, fish genetic breeding scientists have performed a lot of studies in some aquaculture fish species with growth and size dimorphism between females and males. Through these studies, sex-linked genetic markers or X chromosome-linked and Y chromosome-linked genetic markers and the markerassisted sex control breeding biotechnology have been successfully exploited, and thereby provided convenient and practical technological approaches for sex control breeding application in fish [12,158,159]. In the past five years, only Chinese scientists have successfully produced many mono-sex novel varieties in some farmed fish species, such as Yellow catfish "all-male No.1", all-female "North flounder No.1", all-female "North flounder No.2" and Tilapia "Luxiong No.1".…”

Identification of Sex-Specific Markers Reveals Male Heterogametic Sex Determination in Pseudobagrus ussuriensis

“…Additionally, many aquaculture fish species have been observed to have significant sexual dimorphism between males and females in growth rate and body size (Kobayashi et al 2013). Therefore, the understanding of sex determination mechanism in these fishes is very important and useful for exploiting sex manipulation biotechnologies to thereby develop sex control breeding (Cnaani and Levavi-Sivan 2009;Gui and Zhu 2012;Mei and Gui 2015;Weber and Lee 2014). Recently, some sex determination genes have been identified in some farmed fish species, such as rainbow trout (Oncorhynchus mykiss) (Yano et al 2012) and halfsmooth tongue sole (Cynoglossus semilaevis) (Chen et al 2014); however, the sex determination mechanism has been unknown in most of the farmed fish species.…”

Reproduction biotechnologies in germplasm banking of livestock species: a review

“…With the rapid expansion in global aquaculture, there has been an increased emphasis on the development of reproductive technologies directed towards increased production efficiency in fish farming (Weber & Lee, 2014). While procedures for sperm cryopreservation have been developed for most major aquaculture species, successful sperm management for many species is currently constrained by the high variability of sperm cryo-resistance, a lack of appropriate biosecurity safeguards, and the absence of cryopreservation technologies sufficiently validated for large-scale aquaculture (Martínez-Páramo et al , 2017).…”