Laboratório de Zooplâncton, Instituto de Oceanografia, Universidade Federal do Rio Grande, Av. Itália, km 8, 96203-000 Rio Grande, RS, Brazil.
Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, trav. 14, 101, 05508-090 São Paulo, SP, Brazil.
An Acad Bras Cienc. 2021 May 28;93(2):e20190574. doi: 10.1590/0001-3765202120190574. eCollection 2021.
Ephyrae are the young scyphozoan jellyfishes that usually passes unnoticed, whereas their adult counterparts play major ecological roles and can negatively affect economic activities when they occur in high densities. We describe, for the first time, wild ephyrae of Lychnorhiza lucerna (Scyphozoa, Rhizostomeae) from the Patos Lagoon Estuary, Southern Brazil. A total of 10 ephyrae were found in salinities between 12 and 33 and temperatures between 16 and 27°C. The presence of digitata, eight oral arms and serrated tips on marginal lobes allowed species determination. Wild ephyrae were morphologically identical to laboratory-cultivated individuals. The youngest individual was about one to two days old, and the most developed one, between 12 and 14 days old. Recruitment of L. lucerna probably initiated during warmer months (December until February) because nine out of ten individuals were found in high temperature (> 20° C) and salinity (> 30) waters. On the other hand, a mid-winter occurrence of a single ephyra (T=16° C, S= 12) demonstrates that the species may support a considerable range of variation in the physical environment. We reinforce the importance of long-term studies to provide information about the species coupling with seasonal cycles and the dynamics of estuarine and coastal areas.
水螅体是年轻的钵水母纲水母,通常不被注意到,而它们的成年同类则在生态中扮演着重要角色,当它们高密度出现时,可能会对经济活动产生负面影响。我们首次描述了来自巴西南里奥格兰德州帕图斯泻湖河口的 Lychnorhiza lucerna(Scyphozoa,Rhizostomeae)野生水螅体。在盐度为 12 到 33,温度为 16 到 27°C 的范围内共发现了 10 个水螅体。存在 digitata、八个口臂和边缘裂片锯齿状尖端可确定物种。野生水螅体在形态上与实验室培养的个体完全相同。最年轻的个体约为一到两天大,最成熟的个体约为 12 到 14 天大。L. lucerna 的繁殖可能在温暖的月份(12 月至 2 月)开始,因为十分之九的个体在高温(>20°C)和高盐度(>30)水域中被发现。另一方面,一个单一水螅体(T=16°C,S=12)在仲冬的出现表明,该物种可能在物理环境中支持相当大的变化范围。我们强调了进行长期研究的重要性,以便提供有关物种与季节性周期以及河口和沿海地区动态耦合的信息。