Scaling and development of elastic mechanisms: the tiny strikes of larval mantis shrimp
Scaling and development of elastic mechanisms: the tiny strikes of larval mantis shrimp
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DOI：
10.1242/jeb.235465
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发表时间：
2021-04-01
影响因子：
2.8
通讯作者：
Patek, S. N.
中科院分区：
文献类型：
--
作者：
Harrison, Jacob S.;Porter, Megan L.;Patek, S. N.
小型生物利用闩锁介导的弹簧致动 (LaMSA) 来产生高加速度运动。数学模型预测，随着 LaMSA 系统尺寸的减小，加速度会增加。成年螳螂虾在其猛禽附肢中使用 LaMSA 机制来产生极快的攻击。然而，到目前为止，尚不清楚生活史早期阶段的螳螂虾是否也利用弹性反冲和闩锁介导进行攻击。我们测试了螳螂虾 (Gonodactylaceus falcatus) 幼虫是否使用 LaMSA，并且由于其体型较小，因此能够比其他螳螂虾品种的成虫获得更高的攻击加速度。基于显微镜和运动学分析，我们发现 G. falcatus 幼虫在第四幼虫阶段（即幼虫开始摄食的发育阶段）拥有 LaMSA 的成分，并积极使用 LaMSA。幼虫以高加速度和高速度进行攻击（平均值：4.133x10(5) rad s(-2)、292.7 rad s(-1)；12 个体，25 次攻击），与成虫的数量级相同 - 尽管成虫的附肢长两个数量级。幼虫的撞击速度（平均值：0.385 m s(-1)）比其他物种的类似大小生物的最大游泳速度高出几个数量级。这些发现确定了螳螂虾 LaMSA 机制的发育时间和尺度，并为微小弹性机制中尺度限制的运动学后果提供了见解。
Latch-mediated spring actuation (LaMSA) is used by small organisms to produce high acceleration movements. Mathematical models predict that acceleration increases as LaMSA systems decrease in size. Adult mantis shrimp use a LaMSA mechanism in their raptorial appendages to produce extremely fast strikes. Until now, however, it was unclear whether mantis shrimp at earlier life-history stages also strike using elastic recoil and latch mediation. We tested whether larval mantis shrimp (Gonodactylaceus falcatus) use LaMSA and, because of their smaller size, achieve higher strike accelerations than adults of other mantis shrimp species. Based on microscopy and kinematic analyses, we discovered that larval G. falcatus possess the components of, and actively use, LaMSA during their fourth larval stage, which is the stage of development when larvae begin feeding. Larvae performed strikes at high acceleration and speed (mean: 4.133x10(5) rad s(-2), 292.7 rad s(-1); 12 individuals, 25 strikes), which are of the same order of magnitude as for adults - even though adult appendages are up to two orders of magnitude longer. Larval strike speed (mean: 0.385 m s(-1)) exceeded the maximum swimming speed of similarly sized organisms from other species by several orders of magnitude. These findings establish the developmental timing and scaling of the mantis shrimp LaMSA mechanism and provide insights into the kinematic consequences of scaling limits in tiny elastic mechanisms.