Nutritional ecology of nominally herbivorous fishes on coral reefs
Nutritional ecology of nominally herbivorous fishes on coral reefs
复制标题
DOI：
10.3354/meps296129
复制
发表时间：
2005-01-01
影响因子：
2.5
通讯作者：
Clements, KD
中科院分区：
文献类型：
--
作者：
Crossman, DJ;Choat, JH;Clements, KD
名义上食草的棘鱼（外科鱼类）和叉尾目（鹦嘴鱼）通常被认为是一个“同质”的功能群，消耗和寄生藻类。最近的研究表明，许多这些鱼类消耗碎屑。本研究的目的是调查饮食营养成分的目标，这些和其他鱼类的摄食行为，饮食和短链脂肪酸（SCFA）。我们进行了一系列的物种，包括食草动物，食藻动物，杂食动物和食草动物从澳大利亚东北部的营养分析。我们计算了总蛋白质氨基酸（TAA），碳水化合物和脂质的同化效率，并测量了沿着肠的肠液中的TAA。营养物质的同化相似，他们的饮食比例，与食草动物同化的TAA的比例高，中等比例的脂肪和碳水化合物很少。杂食动物同化了中等比例的TAA和碳水化合物，以及低比例的脂质。食藻动物同化TAA和脂类的比例较低，但碳水化合物的比例较高。食腐的sacrids和acanthurids显着不同的食藻动物，同化高比例的TAA，低比例的碳水化合物和中等比例的脂质。所有物种的肠液中TAA水平在前肠最高，后肠最低。具有最高TAA值的肠段在饮食组之间进行了比较，并遵循与TAA同化相似的趋势。食浮游动物的TAA浓度较高，杂食动物的TAA浓度居中，食藻动物的TAA浓度最低。最高的肠液TAA浓度被发现在食藻的scarids和棘，并显着高于在藻类。前肠液TAA与后肠SCFA值呈显著负相关。食腐动物的TAA水平最高，但SCFA水平最低。食浮游生物物种有高水平的TAA和低到中等水平的SCFA。杂食动物的TAA和SCFA水平均处于中等水平。食藻动物的TAA水平较低，但SCFA水平较高。这表明，珊瑚礁上的食藻鱼类和非食藻鱼类所针对的食物资源存在重大差异。
Nominally herbivorous acanthurids (surgeonfishes) and scarids (parrotfishes) have often been considered a 'homogeneous' functional group that consumes and digests algae. Recent work demonstrates that many of these fishes consume detritus. The objective of this study was to investigate the composition of dietary nutrients targeted by these and other fishes in terms of feeding behaviour, diet and short chain fatty acids (SCFA). We undertook a nutritional analysis of a range of species including detritivores, algivores, omnivores and planktivores from north eastern Australia. We calculated assimilation efficiencies for total protein amino acids (TAA), carbohydrate and lipid, and measured TAA in gut fluid along the intestine. Nutrients were assimilated similarly to their dietary proportions, with planktivores assimilating a high proportion of TAA, a moderate proportion of lipid and little carbohydrate. Omnivores assimilated moderate proportions of TAA and carbohydrate, and a low proportion of lipid. Algivores assimilated a low proportion of TAA and lipid, but a high proportion of carbohydrate. Detritivorous scarids and acanthurids differed significantly from algivores, assimilating a high proportion of TAA, a low proportion of carbohydrate and a moderate proportion of lipid. TAA levels in gut fluid of all species were highest in the anterior and lowest in the posterior intestine. Gut segments with highest TAA values were compared between dietary groups and followed a similar trend to TAA assimilation. Planktivores had high concentrations of TAA, while omnivores had intermediate, and algivores the lowest, concentrations. The highest gut fluid TAA concentrations were found in detritivorous scarids and acanthurids, and were significantly higher than in algivores. A significant negative correlation was found between anterior intestinal fluid TAA and posterior intestinal SCFA values. Detritivores had the highest levels of TAA but the lowest levels of SCFA. Planktivorous species had high levels of TAA and low to intermediate levels of SCFA. Omnivores had moderate levels of both TAA and SCFA. Algivores had low levels of TAA but high levels of SCFA. This indicates that there are major differences in the food resources targeted by detritivorous and algivorous fish species on coral reefs.