{"title":"坦桑尼亚桑给巴尔水域的章鱼胞囊(Gray,1849 年)的食性和食物组成","authors":"Amini I. Hamad, Christopher A. Muhando","doi":"10.4314/wiojms.v22i2.5","DOIUrl":null,"url":null,"abstract":"The octopus fishery in Zanzibar is an essential activity of coastal communities. To assist with developing fisheries management plans, baseline information on the feeding of Octopus cyanea (Gray, 1849) was collected in relation to sex and maturity stages. The feeding habits and diet composition of 543 O. cyanea were studied over a period of 12 months at Paje, Kizimkazi, Chwaka Bay and Nungwi. Samples at each site were collected on two days per month during spring tide. Digestive tract contents revealed that O. cyanea preyed on 36 species of crustaceans, molluscs and fishes, with crabs a major prey item. The number of prey species in a single stomach ranged from one to six. O. cyanea in Zanzibar is therefore a generalist predator with a mixed diet. The octopus gonadosomatic index (GSI) indicated a peak breeding season in June to October, which correlated with low prey consumption. Mature octopuses ingested a small amount of food from mainly small sessile prey. Females consumed less food than males of similar maturity stages, suggesting that they ate less or had higher digestion rates. The information is useful for developing fisheries management plans for the octopus fishery in Zanzibar.","PeriodicalId":510876,"journal":{"name":"Western Indian Ocean Journal of Marine Science","volume":"67 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Feeding habits and diet composition of Octopus cyanea (Gray, 1849) in Zanzibar waters, Tanzania\",\"authors\":\"Amini I. Hamad, Christopher A. Muhando\",\"doi\":\"10.4314/wiojms.v22i2.5\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The octopus fishery in Zanzibar is an essential activity of coastal communities. To assist with developing fisheries management plans, baseline information on the feeding of Octopus cyanea (Gray, 1849) was collected in relation to sex and maturity stages. The feeding habits and diet composition of 543 O. cyanea were studied over a period of 12 months at Paje, Kizimkazi, Chwaka Bay and Nungwi. Samples at each site were collected on two days per month during spring tide. Digestive tract contents revealed that O. cyanea preyed on 36 species of crustaceans, molluscs and fishes, with crabs a major prey item. The number of prey species in a single stomach ranged from one to six. O. cyanea in Zanzibar is therefore a generalist predator with a mixed diet. The octopus gonadosomatic index (GSI) indicated a peak breeding season in June to October, which correlated with low prey consumption. Mature octopuses ingested a small amount of food from mainly small sessile prey. Females consumed less food than males of similar maturity stages, suggesting that they ate less or had higher digestion rates. The information is useful for developing fisheries management plans for the octopus fishery in Zanzibar.\",\"PeriodicalId\":510876,\"journal\":{\"name\":\"Western Indian Ocean Journal of Marine Science\",\"volume\":\"67 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2023-11-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Western Indian Ocean Journal of Marine Science\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.4314/wiojms.v22i2.5\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Western Indian Ocean Journal of Marine Science","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4314/wiojms.v22i2.5","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
桑给巴尔的章鱼渔业是沿海社区的一项重要活动。为了协助制定渔业管理计划,我们收集了有关章鱼(Octopus cyanea,Gray,1849 年)摄食与性别和成熟阶段的基线信息。在 Paje、Kizimkazi、Chwaka Bay 和 Nungwi,对 543 只 O. cyanea 的摄食习惯和食物组成进行了为期 12 个月的研究。每个地点的样本都是在春潮期间每月两天采集的。消化道内容物显示,O. cyanea捕食了 36 种甲壳类、软体动物和鱼类,其中螃蟹是主要的猎物。一个胃中的猎物种类从 1 种到 6 种不等。因此,桑给巴尔的 O. cyanea 是一种混合食物的食肉动物。章鱼性腺指数(GSI)表明,章鱼的繁殖旺季在 6 月至 10 月,这与猎物消耗量低有关。成熟章鱼主要从小型无梗猎物中摄取少量食物。雌性章鱼消耗的食物少于成熟阶段相似的雄性章鱼,这表明它们吃得更少或消化率更高。这些信息有助于制定桑给巴尔章鱼渔业管理计划。
Feeding habits and diet composition of Octopus cyanea (Gray, 1849) in Zanzibar waters, Tanzania
The octopus fishery in Zanzibar is an essential activity of coastal communities. To assist with developing fisheries management plans, baseline information on the feeding of Octopus cyanea (Gray, 1849) was collected in relation to sex and maturity stages. The feeding habits and diet composition of 543 O. cyanea were studied over a period of 12 months at Paje, Kizimkazi, Chwaka Bay and Nungwi. Samples at each site were collected on two days per month during spring tide. Digestive tract contents revealed that O. cyanea preyed on 36 species of crustaceans, molluscs and fishes, with crabs a major prey item. The number of prey species in a single stomach ranged from one to six. O. cyanea in Zanzibar is therefore a generalist predator with a mixed diet. The octopus gonadosomatic index (GSI) indicated a peak breeding season in June to October, which correlated with low prey consumption. Mature octopuses ingested a small amount of food from mainly small sessile prey. Females consumed less food than males of similar maturity stages, suggesting that they ate less or had higher digestion rates. The information is useful for developing fisheries management plans for the octopus fishery in Zanzibar.