Bigman Jennifer S, Pardo Sebastián A, Prinzing Tanya S, Dando Marc, Wegner Nicholas C, Dulvy Nicholas K
Department of Biological Sciences, Earth to Ocean Research Group, Simon Fraser University, Burnaby, British Columbia, Canada.
Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
J Morphol. 2018 Dec;279(12):1716-1724. doi: 10.1002/jmor.20879. Epub 2018 Nov 14.
Fish gill surface area varies across species and with respect to ecological lifestyles. The majority of previous studies only qualitatively describe gill surface area in relation to ecology and focus primarily on teleosts. Here, we quantitatively examined the relationship of gill surface area with respect to specific ecological lifestyle traits in elasmobranchs, which offer an independent evaluation of observed patterns in teleosts. As gill surface area increases ontogenetically with body mass, examination of how gill surface area varies with ecological lifestyle traits must be assessed in the context of its allometry (scaling). Thus, we examined how the relationship of gill surface area and body mass across 11 shark species from the literature and one species for which we made measurements, the Gray Smoothhound Mustelus californicus, varied with three ecological lifestyle traits: activity level, habitat, and maximum body size. Relative gill surface area (gill surface area at a specified body mass; here we used 5,000g, termed the 'standardized intercept') ranged from 4,724.98 to 35,694.39 cm (mean and standard error: 17,796.65 ± 2,948.61 cm ) and varied across species and the ecological lifestyle traits examined. Specifically, larger-bodied, active, oceanic species had greater relative gill surface area than smaller-bodied, less active, coastal species. In contrast, the rate at which gill surface area scaled with body mass (slope) was generally consistent across species (0.85 ± 0.02) and did not differ statistically with activity level, habitat, or maximum body size. Our results suggest that ecology may influence relative gill surface area, rather than the rate at which gill surface area scales with body mass. Future comparisons of gill surface area and ecological lifestyle traits using the quantitative techniques applied in this study can provide further insight into patterns dictating the relationship between gill surface area, metabolism, and ecological lifestyle traits.
鱼类鳃的表面积因物种和生态生活方式而异。以往的大多数研究只是定性地描述鳃表面积与生态的关系，并且主要集中在硬骨鱼类上。在这里，我们定量研究了鳃表面积与软骨鱼类特定生态生活方式特征之间的关系，这为评估硬骨鱼类中观察到的模式提供了独立的参考。由于鳃表面积在个体发育过程中随体重增加，因此必须在异速生长（尺度变化）的背景下评估鳃表面积如何随生态生活方式特征而变化。因此，我们研究了文献中11种鲨鱼以及我们测量的一个物种——加利福尼亚星鲨的鳃表面积与体重之间的关系，是如何随三种生态生活方式特征变化的：活动水平、栖息地和最大体型。相对鳃表面积（特定体重下的鳃表面积；这里我们使用5000克，称为“标准化截距”）范围为4724.98至35694.39平方厘米（平均值和标准误差：17796.65±2948.61平方厘米），并且因物种和所研究的生态生活方式特征而异。具体而言，体型较大、活跃的海洋物种比体型较小、活动较少的沿海物种具有更大的相对鳃表面积。相比之下，鳃表面积随体重变化的速率（斜率）在物种间通常是一致的（0.85±0.02），并且在活动水平、栖息地或最大体型方面没有统计学差异。我们的结果表明，生态可能会影响相对鳃表面积，而不是鳃表面积随体重变化的速率。未来使用本研究中应用的定量技术对鳃表面积和生态生活方式特征进行比较，可以进一步深入了解决定鳃表面积、新陈代谢和生态生活方式特征之间关系的模式。
