Size related dietary shifts of Epinephelus marginatus in a western Mediterranean littoral ecosystem: an isotope and stomach content analysis
Size related dietary shifts of Epinephelus marginatus in a western Mediterranean littoral ecosystem: an isotope and stomach content analysis
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DOI：
10.1111/j.1095-8649.2002.tb01741.x
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发表时间：
2002-07
影响因子：
2
通讯作者：
O. Reñones;N. Polunin;R. Goñi
中科院分区：
文献类型：
--
作者：
O. Reñones;N. Polunin;R. Goñi
来自地中海西部巴利阿里群岛的暗色石斑鱼 Epinephelus marginatus 的饮食主要由甲壳类动物、软体动物和鱼类组成，但饮食成分随体型大小而变化。较小的暗色石斑鱼（<300 mm L T）主要以甲壳类动物为食，尤其是短尾目动物，占已识别猎物的 46%。随着暗色石斑鱼的生长，头足类动物变得越来越重要，占亚成体和成体标本中发现的猎物的 10% 至 40%。最大的暗色石斑鱼主要以鱼类为食，占已识别猎物的 40.9%。这些饮食变化伴随着对越来越大的猎物的积极选择和营养生态位的扩大。暗色石斑鱼白肌的 δ 15 N 值范围为 8.8 至 13.1‰，δ 15 N 变化的 71% 可以通过暗色石斑鱼大小的差异来解释。 δ 13 C 值范围为 - 17.9 至 - 15.9‰，未检测到体型大小对 δ 13 C 的显着影响。胃含量和 13 C 值表明，从 1 岁起，E. marginatus 的饮食就以底栖食物网为基础。从幼体到大型雄性记录的 δ 15 N 富集度为 c。 3.8‰。总体而言，肠道内容物和稳定同位素数据之间存在良好的一致性，表明后者可能可用作不允许对鱼类进行采样的海洋保护区的营养研究工具。
The diet of the dusky grouper Epinephelus marginatus, from the Balearic Islands, western Mediterranean, consisted primarily of crustaceans, molluscs and fishes, but diet composition varied with body size. The smaller dusky groupers (<300 mm L T ) fed primarily on crustaceans, and particularly on brachyurans, which accounted for 46% of the prey identified. As dusky groupers grew, cephalopods became increasingly important and constituted 10 to 40% of the prey identified in subadult and adult specimens. The largest dusky groupers fed primarily on fishes that represented 40.9% of prey identified. These shifts in diet were accompanied by a positive selection of increasingly large prey and by an expansion of trophic niche. δ 15 N values of dusky grouper white muscle ranged from 8.8 to 13.1‰ and 71% of the variation in δ 15 N was explained by differences in dusky grouper size. δ 13 C values ranged from - 17.9 to - 15.9‰, and no significant body size effect on δ 13 C was detected. Stomach content and 13 C values indicated that from 1 year old, the diet of E. marginatus was based on the benthic food web. The enrichment in δ 15 N registered from juvenile to large males was c. 3.8‰. Overall, there was good agreement between gut content and stable isotope data indicating that the latter may be useful as a tool in trophic studies in marine protected areas where sampling for fishes is not allowed.