Comparison of single- and multi-trait approaches to identify best wild candidates for aquaculture shows that the simple way fails

Abstract

in agriculture, diversifying production implies picking up, in the wild biodiversity, species or populations that can be domesticated and fruitfully produced. two alternative approaches are available to highlight wild candidate(s) with high suitability for aquaculture: the single-trait (i.e. considering a single phenotypic trait and, thus, a single biological function) and multi-trait (i.e. considering multiple phenotypic traits involved in several biological functions) approaches. Although the former is the traditional and the simplest method, the latter could be theoretically more efficient. However, an explicit comparison of advantages and pitfalls between these approaches is lacking to date in aquaculture. Here, we compared the two approaches to identify best candidate(s) between four wild allopatric populations of Perca fluviatilis in standardised aquaculture conditions. our results showed that the single-trait approach can (1) miss key divergences between populations and (2) highlight different best candidate(s) depending on the trait considered. In contrast, the multi-trait approach allowed identifying the population with the highest domestication potential thanks to several congruent lines of evidence. nevertheless, such an integrative assessment is achieved with a far more time-consuming and expensive study. therefore, improvements and rationalisations will be needed to make the multi-trait approach a promising way in the aquaculture development. The emergence of agriculture is one of the most important evolutions in human history. It was enabled by wild species domestication 1. Domestication is the process in which groups of individuals are bred in a human-controlled environment and modified across succeeding generations from their wild ancestors, in ways these become more useful to humans who increasingly control their food supply and reproduction 2. This process ranges from the first trials of acclimatisation to the setting up of selective breeding programmes 3. The main wave of domestication for fishes only started at the beginning of the twentieth century to develop aquaculture (i.e. the farming of aquatic organisms), notably to mitigate provisioning service disruptions due to fishery collapse 3. Aquaculture is the fastest-growing food production sector in the world and now provides about 50% of the world's aquatic food consumption 3. However, the aquaculture development has been criticised, notably because of its negative consequences on environments and its potential unsustainable development 3,4,6. Despite the numerous attempts to domesticate new fish species, one of the main weaknesses of today's aquaculture is its low species diversity

Split it up and see: using proxies to highlight divergent inter-populational performances in aquaculture standardised conditions

“…We obtained this conclusion by performing a retrospective study (i.e. after having performed bioassays) and P. fluviatilis populations of interest have been highlighted in previous studies [ 33 , 44 ]. For this species, the population prioritisation might be mainly useful to integrate wild specimens from highlighted populations to improve current fish stocks since European perch is already produced.…”

“…[ 33 , 67 ]), and behaviour (e.g. [ 44 , 49 ]). This makes the species an appropriate test-case to assess the relevance of alternative proxies to highlight KTA differentiation among wild populations.…”

“…We consider a part of the life cycle (larval stage) of seven allopatric populations of the European perch ( Perca fluviatilis ) as a test case. We evaluate a set of KTA considered as important for the larval production of this species [ 7 , 33 , 44 ]: (i) growth traits (here growth rate, final growth heterogeneity, initial and final lengths) [ 45 ], (ii) development (survival rate, deformity rate, swim bladder inflation rate) and nutrition (yolk sac volume) traits [ 46 , 47 ], (iii) behavioural traits that are aggressiveness [ 48 ], inter-individual distances which reflect group structure [ 49 ], and swimming activity [ 50 ]. First, we evaluate these KTA expressions in the seven European perch populations.…”

Does transcriptome of freshly hatched fish larvae describe past or predict future developmental trajectory?

“…The results provide novel insights into larval biology and emphasize phenotypic heterogeneity as a bottleneck toward the improvement of the aquaculture sector [28]. Hence, we profiled the quality of larvae by combining a "multitrait" zootechnical approach [29] and a transcriptome analysis.…”

A workflow to design new directed domestication programs to move forward current and future insect production

“…It is worth noting that key traits 1) are involved in different biological functions (behavior, growth/development, homeostasis, nutrition, reproduction) and 2) are not necessarily correlated among each other, implying that expression of a trait cannot be inferred from other traits ( Toomey et al, 2020b ). This means that species domestication potential must be assessed by a multifunction and multitrait integrative framework ( Figure 1 ).…”