CHEMICAL DEFENSES OF THE TROPICAL ASCIDIAN ATAPOZOA SP AND ITS NUDIBRANCH PREDATORS NEMBROTHA SPP
CHEMICAL DEFENSES OF THE TROPICAL ASCIDIAN ATAPOZOA SP AND ITS NUDIBRANCH PREDATORS NEMBROTHA SPP
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DOI：
10.3354/meps059109
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发表时间：
1990-01-01
影响因子：
2.5
通讯作者：
FENICAL, W
中科院分区：
文献类型：
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作者：
PAUL, VJ;LINDQUIST, N;FENICAL, W
海鞘 Atapozoa sp.在整个热带印度太平洋的浅礁栖息地中很常见。对来自菲律宾中部、苏拉威西岛北部（印度尼西亚）、帕劳群岛、夸贾林环礁和蚂蚁环礁（波纳佩附近）的收集品进行了检查，以确定是否存在次生代谢物。在大多数情况下，裸鳃类软体动物 Nembrotha spp。被发现以海鞘为食。像许多多科裸鳃亚目动物一样，它们似乎通过饮食获得防御化学物质。海鞘类和裸鳃类动物都含有大量的一系列联吡咯次级代谢产物，以前被描述为 Tambjamines。不同的坦巴明和相关的、高度蓝色的四吡咯的浓度在海鞘类和裸鳃类动物的收藏中有所不同。总体而言，裸鳃亚目动物中的坦巴明和四吡咯浓度较高，并且是 Nembrotha spp 分泌的粘液的主要成分。当被激怒时。 Tambjamine A 和四吡咯存在于裸鳃类动物中，但在 Atapozoa 中未检测到含量。在关岛的 2 个珊瑚礁上进行实地测定，测试了海鞘和裸鳃类提取物以及分离的代谢物对各种肉食性鱼类的摄食威慑作用，这两个珊瑚礁在测定过程中摄食的鱼类类型不同。粗提物、坦巴明、坦巴明 C、坦巴明 F 和四吡咯的混合物在天然浓度或低于自然浓度下都是显着的摄食抑制剂。 Tambjamine A 和 E 在自然浓度下单独测试时没有威慑作用；然而，当测试低于自然浓度时，坦巴明 E 和 F 的 1:1 混合物具有威慑作用。因此，有证据表明海鞘及其裸鳃类捕食者都使用坦巴贾明作为针对捕食者的化学防御。
The ascidian Atapozoa sp. is common in shallow reef habitats throughout the tropical IndoPacific. Collections from the central Philippine Islands, northern Sulawesi (Indonesia), Palau, Kwajalein, and Ant Atoll (near Ponape) were examined for the presence of secondary metabolites. In most cases, nudibranch molluscs Nembrotha spp. were found feeding on the ascidians. Like many dorid nudibranchs, these appear to obtain their defensive chemicals through their diet. Both ascidians and nudibranchs contained large quantitites of a series of bipyrrole secondary metabolites previously described as the tambjamines. Concentrations of the different tambjamines and a related, highly blue-pigmented tetrapyrrole varied among collections of the ascidians and nudibranchs. Overall, concentrations of tambjamines and tetrapyrrole were higher in the nudibranchs, and were the major components of the mucus exuded by Nembrotha spp. when irritated. Tambjamine A and the tetrapyrrole were present in the nudibranchs but did not occur in detectable amounts in Atapozoa. The ascidian and nudibranch extracts and isolated metabolites were tested as feeding deterrents toward a variety of carnivorous fishes in field assays on 2 Guam reefs that differed in the types of fishes that fed during the assays. The crude extract, mixtures of tambjamines, tambjamine C, tambjamine F, and the tetrapyrrole were all significant feeding deterrents at or below natural concentrations. Tambjamines A and E were not deterrent when tested alone at natural concentrations; however, a 1:1 mixture of tambjamines E and F was deterrent when tested below natural concentrations. Evidence is thus presented that both the ascidian and its nudibranch predators use the tambjamines as chemical defenses against predators.