McInerney Emma P, Silla Aimee J, Byrne Phillip G
School of Earth, Atmospheric and Life Sciences, University of Wollongong, NSW, Australia.
Conserv Physiol. 2019 Mar 13;7(1):coz009. doi: 10.1093/conphys/coz009. eCollection 2019.
Dietary carotenoids are expected to improve vertebrate growth and development, though evidence for beneficial effects remains limited. One reason for this might be that few studies have directly compared the effects of carotenoids from different classes (carotenes versus xanthophylls) at more than one dose. Here, we tested the effect of two doses of dietary β-carotene and lutein (representing two different carotenoid classes) on the growth and development of larval southern corroboree frogs (). Individuals were supplemented with either β-carotene or lutein at one of two doses (0.1 mg g, 1 mg g), or given a diet without carotenoids (control). Each dietary treatment included 36 replicate individuals, and individuals remained on the same diet until metamorphosis (25-39 weeks). We measured larval survival, larval growth (body length), time to metamorphosis, metamorphic body size (mass and SVL), and body condition. Lutein had no detectable effect on larval growth and development. However, larvae receiving a high dose (1 mg g) of β-carotene metamorphosed significantly faster than all other dietary treatments, despite no significant differences in growth rate. This result indicates that β-carotene supplementation in has positive effects on development independent of growth effects. Our study provides new evidence for differential effects of carotenoid class and dose on vertebrate development. From a conservation perspective, our findings are expected to assist with the recovery of by expediting the generation of frogs required for the maintenance of captive insurance colonies, or the provision of frogs for release. More broadly, our study highlights the potential for dietary manipulation to assist with the management of threatened amphibian species worldwide.
膳食类胡萝卜素有望促进脊椎动物的生长发育，不过其有益效果的证据仍然有限。造成这种情况的一个原因可能是，很少有研究在超过一种剂量的情况下，直接比较不同类别类胡萝卜素（胡萝卜素与叶黄素）的效果。在此，我们测试了两种剂量的膳食β-胡萝卜素和叶黄素（代表两种不同的类胡萝卜素类别）对南方胃育蛙幼体生长发育的影响。给个体补充两种剂量（0.1毫克/克、1毫克/克）之一的β-胡萝卜素或叶黄素，或者给予不含类胡萝卜素的饮食（对照）。每种饮食处理包括36个重复个体，个体在变态（25 - 39周）前一直保持相同饮食。我们测量了幼体存活率、幼体生长（体长）、变态时间、变态时的身体大小（体重和吻肛长）以及身体状况。叶黄素对幼体生长发育没有可检测到的影响。然而，接受高剂量（1毫克/克）β-胡萝卜素的幼体变态速度明显快于所有其他饮食处理组，尽管生长速率没有显著差异。这一结果表明，南方胃育蛙补充β-胡萝卜素对发育有积极影响，且与生长影响无关。我们的研究为类胡萝卜素类别和剂量对脊椎动物发育的不同影响提供了新证据。从保护角度来看，我们的研究结果有望通过加快维持圈养保险种群所需青蛙的培育，或为放归提供青蛙，来帮助南方胃育蛙的恢复。更广泛地说，我们的研究突出了通过饮食调控来协助全球受威胁两栖动物物种管理的潜力。
