Relationships between growth, survival, physiology and behaviour — A multi-criteria approach to Haliotis tuberculata phenotypic traits

Abstract

00000International audienceAbalone growth rate is often identified among important traits to improve through selective breeding. However, the rapid success of some selective breeding plans has sometimes led to negative effects in some aquaculture species due to trade-offs. One of them is the loss of homeostasis of selected animals which results in the inability to resist the stress experienced during the rearing process. In this context, this study aimed to analyze the phenotypic relationships between growth, and physiological and behavioural traits in Haliotis tuberculata under stressful conditions. Eleven traits related to growth, immunity, reproduction and behaviour were recorded under laboratory conditions. A total of 120 adults from wild or farm origin were first monitored during a 3-week stress period (high density and acute stress handling) during winter, followed by 6 months on-growing in sea-cages. Relationships between parameters were analyzed using a multi-factorial approach. Wild and farm stocks could only be discriminated on behaviour traits, confirming that the French abalone industry is in the beginning of the domestication process. After 3 weeks of chronic stress, the righting latency of an abalone was linked to better survival and faster growth. Abalones having the best growth after 6 months were characterized by higher activity during the previous winter period, whereas an early gonad maturation reduced the growth in summer. Our results provide a basis for the establishment of a multi-trait breeding program to improve the growth rate while controlling the evolution of physiological and behavioural traits.ăStatement of relevanceăThe relationships of behavioural and physiological variables with survival and weight gain after application of important stressors were studied in order to provide a better understanding of Haliotis tuberculata biology during early domestication stage. This paper will give information on new targets and tools for selective breeding

Anti-predator response of Haliotis tuberculata is modified after only one generation of domestication

“…Another hypothesis could be a lower energy level in offspring from the weight-selected broodstock compared to offspring from wild abalone. Two other results from the experiment allow us to refute this hypothesis: abalone from weight-selected parents ingested the same quantity of algae per gram of abalone as those in other treatments during the 1 mo diurnal rhythm measurements, and no differences were observed during the righting test, which is a good indirect indicator of meta bolic and energetic status (Baldwin et al 2007) as well as of subsequent abalone survival (Lachambre et al 2017b). The third hypothesis, and probably the most plausible, is a change in the stimulus threshold re quired to trigger a response to a dangerous situation (i.e.…”

“…Farm-rearing conditions such as high stocking density (Travers et al 2010) and handling during grading practices (Hooper et al 2011) imply that even the progeny from wild parents, studied at 3 yr of age, had already been subjected to inadvertent selection. The selection processes during captive rearing probably ex plain an important part of the differences observed between farmed abalone and wild H. tuberculata, where abalone from the farm showed a reduced retraction in reaction to finger contact and quicker immune recovery after a stress compared to wild abalone (Lachambre et al 2017a) and spent less time moving at night than wild abalone (Lachambre et al 2017b). In contrast to the experiments described above, the progeny in our experiment were bred in the same environment and were reared under common conditions.…”

“…To measure phagocytosis efficiency, a protocol adapted from Travers et al (2008) was followed using 2 replicates of 25 µl of haemo lymph. Procedures described in Lachambre et al (2017b) were applied with the following modifications: analyses were performed on a FACSVerse flow cytometer (Becton Dickinson) equipped with 3 lasers (405, 488 and 640 nm), a universal loader and a flow sensor to estimate the sample volume analysed. The immunological parameters were calculated using BD FAC-Suite software v.1.0.6.…”

“…However, the effect of domestication on behaviour has rarely been studied (Robinson et al 2013). A first series of experiments on this species showed that wild abalone spent about twice as much time moving during the day, took longer to right themselves after being turned up side down (Lachambre et al 2017b) and responded more to touching the foot (Lachambre et al 2017a) compared to farmed abalone. However, because wild and farmed abalone were not raised in the same conditions, it was not possible differentiate developmental from genetic effects.…”

Transcriptome based SNP discovery and validation for parentage assignment in hatchery progeny of the European abalone Haliotis tuberculata

“…Abalone production is an emerging industry in Europe, and is mainly based on the European abalone Haliotis tuberculata (Huchette and Clavier, 2004), although Haliotis discus hannai and Haliotis rufescens have been introduced to Ireland (Hannon et al, 2013) and Iceland (Jonasson et al, 1999) respectively for aquaculture production. H. tuberculata takes between 3 and 4 years to reach a minimal commercial size of 30g, and no intentional selective process has yet been initiated (Lachambre et al, 2017). This slow growth leads to high production costs and increases the risk of accidents during the production cycle.…”