Dudgeon Steve, Benes Kylla M, Krueger Stacy A, Kübler Janet, Mroz Paul, Slaughter Christin T
Department of Biology, California State University, Northridge, CA 91330-8303, USA.
J Mar Biol Assoc U K. 2009 Feb 1;89(1):83-88. doi: 10.1017/S0025315408001343.
Recent studies of hydrozoans suggest that metabolic factors associated with the physiology of gastrovascular fluid transport play a role in regulating morphogenetic development of colonies. In that context, the objective of this study was to develop a system to experimentally control diets of hydrozoans in culture that could be used to test effects of specific compounds. This diet delivery system consisted of a known concentration of homogenate of brine shrimp nauplii that was solidified in a 1% agar block cut to the size of, and containing the equivalent of, a single, 2-day old brine shrimp nauplius larva. We tested the utility of this system by comparing the frequencies of ingestion, and rates of gastrovascular transport and growth following feeding, between polyps of Podocoryna carnea fed either a single brine shrimp nauplius (controls) or an agar cube including brine shrimp homogenate. Polyps fed experimental diets showed similar rates of gastrovascular transport (6 and 12 h after feeding) and growth (24 h after feeding) to those of polyps fed a brine shrimp nauplius suggesting that no significant artefacts existed associated with these response variables. However, the frequency of ingestion of experimental foods by polyps was much less than that by control polyps. These results imply that this system of delivery of experimental diets has potential as a means to manipulate physiological state and assay the effects on morphogenesis of hydrozoan colonies, but must first overcome limitations of low ingestion frequency.
最近对水螅虫的研究表明，与胃血管液体运输生理相关的代谢因素在调节群体的形态发生发育中起作用。在此背景下，本研究的目的是开发一种系统，用于在培养中实验性地控制水螅虫的饮食，该系统可用于测试特定化合物的效果。这种饮食递送系统由已知浓度的卤虫无节幼体匀浆组成，该匀浆凝固在切成单个2日龄卤虫无节幼体大小且含有其等量物质的1%琼脂块中。我们通过比较喂食单个卤虫无节幼体（对照组）或包含卤虫匀浆的琼脂块后，卡氏柄杯螅息肉的摄食频率、胃血管运输速率和生长速率，来测试该系统的效用。喂食实验性饮食的息肉在胃血管运输（喂食后6小时和12小时）和生长（喂食后24小时）方面显示出与喂食卤虫无节幼体的息肉相似的速率，这表明与这些反应变量相关不存在显著的假象。然而，息肉对实验性食物的摄食频率远低于对照息肉。这些结果意味着这种实验性饮食递送系统有潜力作为一种手段来操纵生理状态并测定对水螅虫群体形态发生的影响，但必须首先克服低摄食频率的限制。
