UMR 8187, Laboratoire d'Océanologie et de Géosciences (LOG), Université de Lille, ULCO, CNRS, 59000, Lille, France.
Sorbonne Université, UFR 927, 75005, Paris, France.
Sci Rep. 2021 Nov 22;11(1):22720. doi: 10.1038/s41598-021-02243-w.
For species in the deep sea, there is a knowledge gap related to their functional traits at all stages of their life cycles. Dynamic energy budget (DEB) theory has been proven to be an efficient framework for estimating functional traits throughout a life cycle using simulation modelling. An abj-DEB model, which compared with the standard DEB model includes an extra juvenile stage between the embryo and the usual juvenile stages, has been successfully implemented for the deep-sea Atlantic woodeater Xylonora atlantica. Most of the core and primary parameter values of the model were in the range of those found for shallow marine bivalve species; however, in comparison to shallow marine bivalves, X. atlantica required less energy conductance and energy to reach the puberty stage for the same range of body sizes, and its maximum reserve capacity was higher. Consequently, its size at first reproduction was small, and better survival under starvation conditions was expected. A series of functional traits were simulated according to different scenarios of food density and temperature. The results showed a weak cumulative number of oocytes, a low growth rate and a small maximum body size but an extended pelagic larval duration under deep-sea environmental conditions. Moreover, DEB modelling helped explain that some male X. atlantica individuals remain dwarfs while still reproducing by changing their energy allocation during their ontogenetic development in favour of reproduction. The estimation of functional traits using DEB modelling will be useful in further deep-sea studies on the connectivity and resilience of populations.
对于深海物种，其在整个生命周期的各个阶段的功能特征方面存在知识空白。动态能量预算（DEB）理论已被证明是一种通过模拟建模估算整个生命周期功能特征的有效框架。与标准 DEB 模型相比，一种额外包含胚胎和通常的幼体阶段之间的幼体阶段的 abj-DEB 模型，已成功应用于深海大西洋木虾 Xylonora atlantica。该模型的大多数核心和主要参数值都在浅海双壳类物种的范围内；然而，与浅海双壳类相比，X. atlantica 在相同的体型范围内需要较少的能量传导和达到青春期的能量，其最大储备能力更高。因此，它的首次繁殖体型较小，预计在饥饿条件下的生存能力更好。根据不同的食物密度和温度场景，模拟了一系列功能特征。结果表明，在深海环境条件下，累积卵母细胞数量较弱，生长速度较低，最大体型较小，但浮游幼体持续时间较长。此外，DEB 建模有助于解释某些雄性 X. atlantica 个体仍然保持矮小，但通过改变其个体发生发育过程中的能量分配，有利于繁殖，仍然可以进行繁殖。使用 DEB 建模估算功能特征将有助于进一步研究深海种群的连通性和恢复力。
