Larval dispersion rather than adult migration generally leadsto the worldwide expansion of fishes. Species of the genus Gymnocanthus have expanded geographically while undergoing allopatric speciation. Of this genus, while G. tricuspisinhabits the Arctic Ocean and surrounding area, G. herzensteini and G. intermedius occuraround northern Japan. Larval early life histories of G. herzensteini and G. intermedius from northern Japan and G. tricuspis from Unalaska Island were investigatedto estimate their dispersal potential during larval stages. The larval and juvenile abundances of G. herzensteini and G. intermedius were highest in May in shallow sandy bottoms below 7 m in depth, and the body sizes were 9.7-34.6 mm NL/SL in G. herzensteini and 8.4-46.7 mm NL/SL in G. intermedius. Two egg masses of G. tricuspis (1.92 ± 0.08 mm in diameter) and hatched larvae (6.20 ± 0.19 mm NL) were collected inMarch. Compared with other sculpins in previous studies, the body sizes of G. herzensteini and G. intermedius at hatch are large and at settlement are small, whileboth hatch and settlement sizes of G. tricuspis aremuch larger. Counting micro-incrementsbetween the hatch check and settlement marks in G. herzensteini and G. intermedius demonstrated that the pelagic larval durations for two weeks with an immature body suggests that these species cannot disperse widely during the pelagic phase, while pelagic larvae of Arctic species such as G. tricuspis with long PLDs could disperse. This article is protected by copyright. All rights reserved.

中文翻译：

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Gymnocanthus 属两种同域杜鹃的分散与沉降

幼体的扩散而不是成体的迁移通常会导致鱼类在世界范围内的扩张。Gymnocanthus 属的物种在经历异域物种形成的同时在地理上扩大了。在该属中，虽然 G. tricuspis 栖息在北冰洋和周边地区，但 G. herzensteini 和 G. intermedius 出现在日本北部附近。研究了来自日本北部的 G. herzensteini 和 G. intermedius 以及来自 Unalaska 岛的 G. tricuspis 的幼虫早期生活史，以估计它们在幼虫阶段的传播潜力。G. herzensteini 和 G. intermedius 的幼虫和幼体丰度在 5 月在 7 m 深度以下的浅沙底最高，体型在 G. herzensteini 为 9.7-34.6 mm NL/SL 和 8.4-46.7 mm NL/ G. intermedius 中的 SL。G. tricuspis 的两个卵块 (1.92 ± 0. 08 毫米直径) 和孵化的幼虫 (6.20 ± 0.19 毫米 NL) 在 3 月收集。与以往研究中的其他杜鹃相比，G. herzensteini和G. intermedius在孵化时的体型大而沉降时较小，而G. tricuspis的孵化和沉降尺寸要大得多。计算 G. herzensteini 和 G. intermedius 的孵化检查和沉降标记之间的微增量表明，未成熟身体的远洋幼虫持续两周表明这些物种在远洋阶段不能广泛分散，而北极物种的远洋幼虫如因为具有长 PLD 的 G. tricuspis 可以分散。本文受版权保护。版权所有。herzensteini和G. intermedius在孵化时大而在沉降时小，而G. tricuspis的孵化和沉降尺寸都大得多。计算 G. herzensteini 和 G. intermedius 的孵化检查和沉降标记之间的微小增量表明，未成熟身体的远洋幼虫持续两周表明这些物种在远洋阶段不能广泛分散，而北极物种的远洋幼虫如因为具有长 PLD 的 G. tricuspis 可以分散。本文受版权保护。版权所有。herzensteini和G. intermedius在孵化时大而在沉降时小，而G. tricuspis的孵化和沉降尺寸都大得多。计算 G. herzensteini 和 G. intermedius 的孵化检查和沉降标记之间的微增量表明，未成熟身体的远洋幼虫持续两周表明这些物种在远洋阶段不能广泛分散，而北极物种的远洋幼虫如因为具有长 PLD 的 G. tricuspis 可以分散。本文受版权保护。版权所有。intermedius 证明，具有未成熟身体的远洋幼虫持续两周表明这些物种在远洋阶段不能广泛扩散，而具有长 PLD 的北极物种（如 G. tricuspis）的远洋幼虫可以扩散。本文受版权保护。版权所有。intermedius 证明，具有未成熟身体的远洋幼虫持续两周表明这些物种在远洋阶段不能广泛分散，而具有长 PLD 的北极物种（如 G. tricuspis）的远洋幼虫可以分散。本文受版权保护。版权所有。