Control of puberty in farmed fish

Abstract

Puberty comprises the transition from an immature juvenile to a mature adult state of the reproductive system, i.e. the individual becomes capable of reproducing sexually for the first time, which implies functional competence of the brain-pituitary-gonad (BPG) axis. Early puberty is a major problem in many farmed fish species due to negative effects on growth performance, flesh composition, external appearance, behaviour, health, welfare and survival, as well as possible genetic impact on wild populations. Late puberty can also be a problem for broodstock management in some species, while some species completely fail to enter puberty under farming conditions. Age and size at puberty varies between and within species and strains, and are modulated by genetic and environmental factors. Puberty onset is controlled by activation of the BPG axis, and a range of internal and external factors are hypothesised to stimulate and/or modulate this activation such as growth, adiposity, feed intake, photoperiod, temperature and social factors. For example, there is a positive correlation between rapid growth and early puberty in fish. Age at puberty can be controlled by selective breeding or control of photoperiod, feeding or temperature. Monosex stocks can exploit sex dimorphic growth patterns and sterility can be achieved by triploidisation. However, all these techniques have limitations under commercial farming conditions. Further knowledge is needed on both basic and applied aspects of puberty control to refine existing methods and to develop new methods that are efficient in terms of production and acceptable in terms of fish welfare and sustainability.

A Comprehensive Transcriptome Provides Candidate Genes for Sex Determination/Differentiation and SSR/SNP Markers in Yellow Catfish

“…Sex dimorphic growth pattern has been found in many species of teleost fish (Gui 2007;Mei and Gui 2014), and the significant growth difference between female and male and its application implications have been noted in some farmed fish (Taranger et al 2010;Gui and Zhou 2010;Gui and Zhu 2012;Kobayashi et al 2013;Liu et al 2013a). Yellow catfish (Pelteobagrus fulvidraco), one of the important freshwater fish species in Asia, has been widely cultured for its delicious flesh and high nutritive value (Huang et al 1999).…”

Effects of photoperiod on reproduction of Siamese fighting fish Betta splendens

“…This fact is explained by the gonadal development of females during the successive periods of reproduction (Lubzens et al, 2010;Taranger et al, 2010).…”

Effect of Combining Different Photoperiod Regimes on the Sexual Maturation of Male Sea Bass (Dicentrarchus labrax L.) During the First Two Years of Life

“…Numerous studies have provided relevant information related to genetic, hormonal and environmental approaches for controlling sexual maturation in farmed finfish [1][2][3]. In particular, environmental tools based on manipulating the photoperiod have been investigated, demonstrating their potential application in aquaculture [1,4,5,6]. However, since differences between indoor and outdoor conditions can exist, their utility on a commercial scale needs to be examined [7,8].…”

“…In this regard, while temperature can affect reproductive development, photoperiod is thought to be the main environmental cue for many seasonal breeders [1,4]. In fact, it is well documented that photoperiod plays an important role in the control of gonadal maturation in farmed fish species such as salmonids, gadoids, breams, bass and flatfish [5,4,6].…”