Gulf toadfish (Opsanus beta) are exceptionally capable of switching from excreting ammonia as their primary nitrogenous waste to excreting predominantly urea in distinct pulses across the gill. Previous studies suggest that these urea pulses may be used for intraspecific chemical communication. To determine whether pulsatile urea excretion communicates reproductive status, toadfish were sexed using ultrasound and delivered conspecific-conditioned seawater (CC-SW) that previously housed a conspecific of the opposite sex, a conspecific chemical alarm cue (avoidance control), or a prey cue (attraction control). Swim behavior, attraction to or avoidance of the cues, and changes in the pattern of pulsatile urea excretion were monitored during and after delivery. Gulf toadfish did not spend more time in zones that were delivered CC-SW or prey cue. However, male toadfish spent significantly more time swimming after the delivery of female cues than control seawater (SW). In contrast, toadfish did not appear to have an immediate avoidance response to the conspecific alarm cue. Additionally, significantly more toadfish pulsed within 7 h of CC-SW and prey cue delivery compared to control SW, and pulse frequency was 1.6 times greater in response to CC-SW than control SW. These results, in combination with increased urea production and excretion the during breeding season, suggest that toadfish may use pulsatile urea excretion to communicate with conspecifics when exposed to chemosensory cues from the opposite sex.

中文翻译：

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墨西哥蛤To鱼是否使用多尿素排泄物以化学方式传达生殖状态？

海湾蟾蜍鱼（Opsanus beta）具有出色的能力，可以从ammonia作为主要的含氮废物排泄到to以明显的脉冲形式排泄主要为尿素。先前的研究表明，这些尿素脉冲可用于种内化学通讯。为了确定脉动性尿素排泄是否传达了生殖状态，蟾蜍通过超声进行了性别定性，并输送了特定条件的海水（CC-SW），该海水之前曾容纳过异性的特定物种，特定的化学警报提示（避免控制）或猎物提示。 （吸引力控制）。在分娩过程中和分娩后监测游泳行为，对线索的吸引或回避以及搏动尿素排泄方式的变化。墨西哥蛤to没有在投放CC-SW或猎物的地区花费更多的时间。然而，与控制海水（SW）相比，雄性蟾蜍在雌性线索传播后花费的游泳时间明显更多。相反，蟾蜍似乎没有对特定警报提示立即回避。此外，与对照SW相比，在CC-SW和猎物提示递送的7小时内脉冲蟾蜍的数量要多得多，对CC-SW的响应脉冲频率是对照SW的1.6倍。这些结果，加上在繁殖季节尿素产量增加和排泄，表明蟾蜍在暴露于异性的化学感应信号时，可能会利用搏动性尿素排泄与特定物种进行交流。蟾蜍鱼似乎对特定警报提示没有立即回避的反应。此外，与对照SW相比，在CC-SW和猎物提示递送的7小时内脉冲蟾蜍明显更多，并且对CC-SW的响应脉冲频率是对照SW的1.6倍。这些结果，加上在繁殖季节尿素产量增加和排泄，表明蟾蜍在暴露于异性的化学感应信号时，可能会利用搏动性尿素排泄与特定物种进行交流。蟾蜍鱼似乎对特定警报提示没有立即回避的反应。此外，与对照SW相比，在CC-SW和猎物提示递送的7小时内脉冲蟾蜍的数量要多得多，响应CC-SW的脉冲频率比对照SW高1.6倍。这些结果，加上在繁殖季节尿素产量增加和排泄，表明蟾蜍在暴露于异性的化学感应信号时，可能会利用搏动性尿素排泄与特定物种进行交流。