Marine Science Institute, The University of Texas at Austin, Port Aransas, Texas, United States of America.
PLoS One. 2011;6(5):e19576. doi: 10.1371/journal.pone.0019576. Epub 2011 May 25.
Hermaphroditism, associated with territoriality and dominance behavior, is common in the marine environment. While male sex-specific coloration patterns have been documented in groupers, particularly during the spawning season, few data regarding social structure and the context for these color displays are available. In the present study, we define the social structure and male typical behavior of rock hind (Epinephelus adscensionis) in the wild. In addition, we detail the captive conditions and time period necessary to induce the onset of the sex-specific coloration and sexual change. At six oil production platform locations in the Gulf of Mexico, rock hind social group size and typical male rock hind social behavior were documented. We observed a rapid temporary color display in rock hind that could be turned on and off within three seconds and was used for confronting territory intruders and displays of aggression towards females. The male-specific "tuxedo" pattern consists of a bright yellow tail, a body with alternating dark brown and white patches and a dark bar extending from the upper mandible to the operculum. Identification and size ranges of male, female and intersex fish collected from oil platforms were determined in conjunction with gonadal histology. Rock hind social order is haremic with one dominant male defending a territory and a linear dominance hierarchy among individuals. In five captive experiments, the largest remaining female rock hind displayed the male specific color pattern within 32d after dominant male removal from the social group. To our knowledge, this is the first evidence in a grouper species of color patterning used to display territoriality and dominance outside of spawning aggregations. The behavioral paradigm described here is a key advance that will enable mechanistic studies of this complex sex change process.
雌雄同体现象与领地性和支配行为有关，在海洋环境中很常见。虽然在石斑鱼中已经记录了雄性特有的颜色模式，尤其是在繁殖季节，但关于社会结构和这些颜色表现的背景的资料很少。在本研究中，我们定义了野生岩石 hind（Epinephelus adscensionis）的社会结构和雄性典型行为。此外，我们详细介绍了在圈养条件下诱导出现特有的性别颜色和性转变所需的时间。在墨西哥湾的六个石油生产平台地点，记录了岩石 hind 的社会群体大小和典型雄性岩石 hind 的社会行为。我们观察到岩石 hind 有一种快速的临时颜色显示，可以在三秒钟内打开和关闭，用于对抗领地入侵者和对雌性的攻击展示。雄性特有的“晚礼服”图案由亮黄色的尾巴、身体上交替的深褐色和白色斑块以及从上颌延伸到鳃盖的黑色条纹组成。与性腺组织学一起确定了从石油平台收集的雄性、雌性和雌雄同体鱼类的识别和大小范围。岩石 hind 的社会秩序是后宫制，有一个占主导地位的雄性保护一个领地，个体之间存在线性支配等级。在五个圈养实验中，最大的剩余雌性岩石 hind 在从社会群体中移除主导雄性后的 32 天内显示出雄性特有的颜色模式。据我们所知，这是在石斑鱼物种中首次发现用于展示领地性和支配地位的颜色模式，而不是在繁殖群中。这里描述的行为范式是一个关键的进展，将使这种复杂的性别转变过程的机制研究成为可能。
