Stoddard Philip K, Markham Michael R
Philip K. Stoddard is a professor, and Michael R. Markham is a research associate, in the Department of Biological Sciences at Florida International University in Miami. They study the evolution, neurobiology, and behavior of communication.
Bioscience. 2008;58(5):415-425. doi: 10.1641/B580508.
Electric fish produce weak electric fields to image their world in darkness and to communicate with potential mates and rivals. Eavesdropping by electroreceptive predators exerts selective pressure on electric fish to shift their signals into less-detectable high-frequency spectral ranges. Hypopomid electric fish evolved a signal-cloaking strategy that reduces their detectability by predators in the lab (and thus presumably their risk of predation in the field). These fish produce broad-frequency electric fields close to the body, but the heterogeneous local fields merge over space to cancel the low-frequency spectrum at a distance. Mature males dynamically regulate this cloaking mechanism to enhance or suppress low-frequency energy. The mechanism underlying electric-field cloaking involves electrogenic cells that produce two independent action potentials. In a unique twist, these cells orient sodium and potassium currents in the same direction, potentially boosting their capabilities for current generation. Exploration of such evolutionary inventions could aid the design of biogenerators to power implantable medical devices, an ambition that would benefit from the complete genome sequence of a gymnotiform fish.
电鱼会产生微弱的电场，以便在黑暗中感知周围环境，并与潜在的配偶和竞争对手进行交流。具有电感应能力的捕食者的窃听行为对电鱼施加了选择压力，促使它们将信号转移到较难被探测到的高频频谱范围。Hypopomid电鱼进化出了一种信号伪装策略，在实验室环境中，这种策略降低了它们被捕食者探测到的可能性（因此在自然环境中，它们被捕食的风险可能也会降低）。这些鱼会在身体附近产生宽频电场，但这些不均匀的局部电场会在空间中合并，从而在一定距离处抵消低频频谱。成年雄性电鱼会动态调节这种伪装机制，以增强或抑制低频能量。电场伪装背后的机制涉及能产生两种独立动作电位的发电细胞。独特的是，这些细胞使钠电流和钾电流沿相同方向流动，这可能增强了它们产生电流的能力。探索此类进化创新有助于设计为可植入医疗设备供电的生物发电机，而这一目标将受益于裸背电鳗科鱼类的完整基因组序列。
