Same but different: aquatic prey capture in paedomorphic and metamorphic Alpine newts
Same but different: aquatic prey capture in paedomorphic and metamorphic Alpine newts
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DOI：
10.1186/s40851-019-0140-4
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发表时间：
2019-07-26
影响因子：
2.7
通讯作者：
Grell, Julia
中科院分区：
文献类型：
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作者：
Heiss, Egon;Grell, Julia
幼虫形态描述了幼虫特征在成年阶段的保留，并且在蝾螈中广泛存在。蝾螈表现出兼性幼态性，幼态性和变态性成虫在同一种群中共存。先前的研究表明，尽管形态和猎物捕获性能存在差异，但幼形和变态的钝口蝾螈之间的猎物捕获运动学并没有差异。然而，目前尚不清楚跨形态类型的猎物捕获运动学的刻板印象是否仅限于钝口蝾螈，或者也可以在其他蝾螈类群中发现。在这里，我们对幼态和变态蝾螈的猎物捕获行为进行了双平面高速记录，只发现不同形态之间存在微小的运动学差异，这表明不同形态之间的刻板印象是蝾螈中更普遍的特征。然后，我们比较了头骨和下鳃骨骼的解剖结构，以及颈直肌的生理横截面积（PCSA），颈直肌是增强吸食能力的主要肌肉。除了摄食器的总体形态差异外，不同形态类型的颈直肌 PCSA 也存在显着差异，在儿童形态中是其两倍。因此，儿童型可以发挥更强大的吸力打击，这反过来可能是儿童型比变体更能有效捕获难以捉摸的猎物的关键因素之一。
Paedomorphosis describes the retention of larval characters in adult stages and is widespread amongst salamanders. Salamandrid newts exhibit facultative paedomorphosis, where paedomorphic and metamorphic adult forms coexist in the same population. Previous studies have shown that prey capture kinematics do not differ between paedomorphic and metamorphosed ambystomatid salamanders, despite diverging morphology and prey capture performance. It remained unclear, however, whether the stereotypy of prey capture kinematics across morphotypes is restricted to ambystomatids, or can be found in other salamander groups too. Here, we performed biplanar high-speed-recordings of the prey capture behavior in paedomorphic and metamorphic salamandrid newts and only found minor kinematic differences across morphotypes, suggesting that stereotypy across morphotypes is a more general feature within salamanders. We then compared anatomy of skull and hyobranchial skeleton, along with the physiological cross sectional area (PCSA) of the rectus cervicis muscle, the main muscle empowering suction feeding. Besides the overall morphological differences of the feeding apparatus, the PCSA of the rectus cervicis also differs significantly between morphotypes, being twice as large in paedomorphs. Accordingly, paedomorphs can exert more powerful suction strikes, which in turn may be one of the key factors why paedomorphs are more efficient in capturing elusive prey compared to metamorphs.