Estimating population parameters of longsnout seahorses, Hippocampus reidi (Teleostei: Syngnathidae) through mark-recapture

ABSTRACT Estimating population parameters is essential for understanding the ecology of species, which ultimately helps to assess their conservation status. The seahorse Hippocampus reidi is directly exposed to anthropogenic threats along the Brazilian coast, but the species still figures as Data Deficient (DD) at IUCN’s Red List. To provide better information on the ecology of this species, we studied how population parameters vary over time in a natural subtropical environment. By combing mark-recapture models for open and closed populations, we estimated abundance, survival rate, emigration probability, and capture probability. We marked 111 individuals, which showed a 1:1 sex ratio, and an average size of 10.5 cm. The population showed high survival rate, low temporary emigration probability and variable capture probability and abundance. Our models considering relevant biological criteria illuminate the relatively poorly known population ecology and life history of seahorses. It is our hope that this study inspires the use of mark-recapture methods in other populations of H. reidi in a collective effort to properly assess their conservation status.

摘要：种群参数估算对于认知物种种群生态学至关重要，最终可辅助评估物种的保护现状。巴西沿岸海域的吻海马（*Hippocampus reidi*）直接面临人为活动威胁，但该物种在国际自然保护联盟（IUCN）红色名录中仍被归类为数据缺乏（Data Deficient，DD）等级。为获取该物种种群生态学的详实数据，本研究针对自然亚热带环境中的吻海马种群，探究了种群参数随时间的变化规律。本研究结合开放种群与封闭种群的标记重捕模型（mark-recapture model），估算了种群丰度、存活率、迁出概率与捕获概率。本次研究共标记111尾个体，其性别比例为1:1，平均体长为10.5厘米。该种群表现出高存活率、低临时迁出概率，以及波动的捕获概率与种群丰度。本研究构建的模型纳入相关生物学准则，阐明了目前认知相对匮乏的海马种群生态学与生活史特征。我们期望本研究能够推动标记重捕方法在其他吻海马（*Hippocampus reidi*）种群中的应用，通过集体协作精准评估该物种的保护现状。