Although researchers have examined numerous marine organisms’ compensatory characteristics to minimize predation pressure, few have investigated the defensive mechanisms of polychaetes, despite their diversity. Thus, our study’s aim was to evaluate the palatability and defensive strategies, both chemical and structural, in the polychaetes Branchiomma luctuosum, Perinereis anderssoni, Phragmatopoma caudata, Eurythoe complanata, and Timarete sp. Another twofold aim was to determine, by comparing our results with the literature, any latitudinal difference in the defensive strategies of E. complanata and to assess defensive mechanisms and palatability in relation to individuals’ mobility, overtness, body regionalization, and color. Specimens were collected at Boa Viagem and Itaipu Beaches in Niterói, Rio de Janeiro, Brazil. In assays, a generalist consumer, the hermit crab Calcinus tibicen, was used to evaluate palatability and defenses. In palatability assays of live tissue of the polychaetes, consumers were offered a fresh piece of each polychaete to gauge their acceptance or rejection; in artificial food assays to test extracts of the polychaetes, artificial bait containing extracts of the polychaetes was offered to crabs to identify any chemical defense. Although the extracts of B. luctuosum, E. complanata, P. caudata (i.e., opercular crown), and Timarete sp. were not palatable to the consumers, extracts of P. anderssoni and P. caudata (i.e., body) were. Moreover, the opercular crown of P. caudata and the branchial crown of B. luctuosum showed evidence of structural and chemical defenses. The results corroborate past findings, suggesting no latitudinal variation in the defensive strategies of E. complanata. In general, less motile and more exposed species, aposematic or dark in color, exhibited greater investment in defensive strategies and unpalatability.

中文翻译：

---

巴西热带巴西海滩上五个安妮利德多毛羚的适口性和物理化学防御

尽管研究人员已经研究了许多海洋生物的补偿特性以最大程度地降低捕食压力，但是尽管它们具有多样性，但很少有人研究多壳动物的防御机制。因此，我们的研究目的是评估在多毛cha科的io科，Perinereis anderssoni，Cragatopoma caudata，Eurythoe complanata和Timarete sp。的适口性和防御策略，包括化学和结构方面。另一个双重目的是，通过将我们的结果与文献进行比较，来确定沙棘肠球菌的防御策略在纬度上的差异。并评估与个人流动性，公开性，身体区域性和肤色有关的防御机制和适口性。在巴西里约热内卢尼泰罗伊的Boa Viagem和Itaipu海滩采集了标本。在化验中，通才的消费者，隐居蟹Calcinus tibicen被用来评估适口性和防御能力。在多毛cha的活组织的适口性测定中，向消费者提供了每个多毛a的新鲜块，以衡量他们的接受或拒绝。在用于测试多毛鱼提取物的人工食品试验中，向多毛蟹提供了包含多毛鱼提取物的人工诱饵，以鉴定任何化学防御作用。尽管B. luctuosum，E. complanata，P. caudata（即，冠状冠）和Timarete sp。对消费者而言不是美味，而P. anderssoni和P. caudata（即身体）的提取物则是可口的。此外，的鳃冠P.矾和鳃冠B. luctuosum显示结构和化学防御的证据。结果证实了以前的发现，表明在大肠杆菌的防御策略中没有纬度变化。通常，活动性较低，暴露程度较高的物种（无定性或深色）在防御策略和难吃性方面表现出更大的投资。