Davis Aaron M, Sheaves Marcus, Venkataraman Ajay, Betancur-R Ricardo
Centre for Tropical Water and Aquatic Ecosystem Research (TropWATER), Australian Tropical Sciences and Innovation Precinct (ATSIP), James Cook University, Building 145, Townsville, QLD, 4810, Australia.
College of Science and Engineering, James Cook University, Townsville, Australia.
Sci Rep. 2025 Jul 1;15(1):21766. doi: 10.1038/s41598-025-05879-0.
While ontogenetic habitat shifts are a widely appreciated phenomenon across fishes, the macroevolutionary implications of habitat shifts and subsequent ecological opportunity have mainly focused on adult organisms, largely overlooking juvenile life history diversification. The snappers and fusiliers (Lutjanidae) represent a successful tropical teleost radiation exhibiting complex ontogenetic shifts and use of diverse nursery and adult habitats across the marine-freshwater interface. Lutjanids collectively occupy a broad range of environments within the seascape mosaic, including freshwater rivers, estuaries, reefs, and deep offshore slopes. Using an extensive phylogenomic dataset of ~ 110 species, we test models of juvenile and adult habitat evolution across seascape gradients. Evolutionary model fitting and ancestral state reconstructions, conducted independently for juvenile nurseries and adult habitats, both support an ordered, stepwise pattern of habitat transitions, with low-salinity associations evolving only via intermediate coastal habitats. This 'stepping stone' model of marine-freshwater macroevolution saw adoption of low salinity habitats preceded by adaptation to intermediate brackish habitats, rather than random jumps between widely separated seascape components. While our results highlight that ontogenetic shifts have been central to lutjanid diversification, more consistent and transferable research frameworks are required to clarify the ecological and evolutionary implications of lutjanid life history diversity.
虽然个体发育过程中的栖息地转移是鱼类中一种广为人知的现象，但栖息地转移及随后的生态机遇在宏观进化方面的影响主要集中在成年生物上，很大程度上忽视了幼体生活史的多样化。笛鲷科鱼类代表了一类成功的热带硬骨鱼辐射类群，它们表现出复杂的个体发育转变，并在海洋 - 淡水界面利用多种育苗场和成年栖息地。笛鲷科鱼类共同占据了海景观镶嵌体中的广泛环境，包括淡水河流、河口、珊瑚礁和深海近海斜坡。利用一个包含约110个物种的广泛系统发育基因组数据集，我们测试了幼体和成年栖息地在海景观梯度上的进化模型。针对幼体育苗场和成年栖息地独立进行的进化模型拟合和祖先状态重建，均支持一种有序、逐步的栖息地转变模式，低盐度关联仅通过中间的沿海栖息地进化而来。这种海洋 - 淡水宏观进化的“踏脚石”模型表明，低盐度栖息地的采用是在适应中间咸淡水栖息地之后，而不是在广泛分离的海景观成分之间随机跳跃。虽然我们的结果强调个体发育转变是笛鲷科鱼类多样化的核心，但需要更一致且可转移的研究框架来阐明笛鲷科鱼类生活史多样性的生态和进化意义。
