Settlement and early post-settlement survival of sessile marine invertebrates on topographically complex surfaces: the importance of refuge dimensions and adult morphology
Settlement and early post-settlement survival of sessile marine invertebrates on topographically complex surfaces: the importance of refuge dimensions and adult morphology
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固着海洋无脊椎动物在地形复杂的表面上的定居和定居后早期生存：避难所尺寸和成体形态的重要性
DOI：
10.3354/meps137161
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发表时间：
1996
影响因子：
2.5
通讯作者：
D. Wethey
中科院分区：
文献类型：
--
作者：
L. Walters;D. Wethey
我们预测，在低能量环境中，避难所的大小和生长形式都会影响附着在坚硬基质上生活的无根海洋无脊椎动物的沉降和短期沉降后成功（57 d）。对基质有无限依恋的个体应迅速受到其生长形式的保护，从而减少它们在避难所定居的需要，并限制异质基质上任何地点作为避难所的时间长度。另一种选择是，对基质的附着有限的生物应在较长时间内易受死亡原因的影响，因此应定居在高质量的避难所（保护个体免受竞争对手、捕食者或身体干扰事件的场所，直到获得大小避难所或生殖成熟为止）。对4种无脊椎动物进行了地形复杂的孤立海鞘海纹（以下简称海纹）表面和沉降板上均匀间隔的粗糙度元素的测试，结果与上述预测一致，这些粗糙度元素的高度与美国北卡罗来纳州博弗特海纹上发现的粗糙度元素高度（2.0和5.0 rnm）相似。在所有表面上，对基质的附着有限的两种物种，Balanus sp.（无性系，单生）和Bugula neritina（无性系，乔木），几乎全部定居在为个体提供最佳避难所的位置：粗糙元素基部与平面相交处形成的裂缝。此外，当存在不同高度的粗糙度元素（Styela，范围：0.6 ~ 8.8 mm）时，中等尺寸的粗糙度元素(2.0 < X 15。0毫米)的采收率超过72%。无性附着于基质的两种物种（无性附着型Schjzoporella errata）和无性附着型匍匐茎（Tubularia crocea）的定居地点和生存增强地点不太一致。这两个物种中很少有个体定居在海鞘上的粗糙元素上，当他们定居时，他们并不局限于粗糙元素的基部。在板块表面，大多数沉降确实发生在裂缝中，但这两个物种都在短时间内离开了这个位置，并且在这个位置的短期存活率并不总是更高。额外的试验在具有与测试粗糙度元素（2.0和5.0 mm深度）相同最大尺寸的凹坑的板上进行，以查看裂缝和凹坑是否为新定居的个体提供了相同质量的避难所。在沟壑和深坑中，只有海螺的存活率最高。主动选择定居地点的证据来自试验的一致结果，在这些试验中，一些幼虫在Styela上特定尺寸的粗糙元素上和高度侵蚀的地区定居的数量更多。总的来说，这些结果表明，在对异质表面上的避难所质量进行概括时，必须非常谨慎，并且要确定一个地点是否为空间避难所，关键是要考虑：(1)幼虫的尺寸，(2)从定居开始的任何时间点，个体和潜在避难所的相对尺寸，以及(3)个体的生长形式，这与保护其免受生物和非生物死亡来源的需要有关。
We predicted that both refuge dimension and growth form would influence settlement and short-term post-setUement success (57 d) of sessile marine invertebrates that live attached to hard substrata in low energy environments. Individuals with unlimited attachment to the substrata should rapidly be protected by their growth form, thus decreasing their need to settle in refuges and limiting the length of time any locations on heterogeneous substrata act as refuges. Alternatively, organisms with limited attachment to the substrata should remain susceptible to the causes of mortality for a longer time, and as a result should settle in high quality refuges [sites that protect individuals from competitors, predators or physical disturbance events until either a size refuge or reproductive maturity is obtained). Results agreed with these predictions for 4 species of invertebrates examined on both the topographically complex surface of the solitary ascidian Styela plicata (hereafter Styela) and on settlement plates w ~ t h uniformly spaced roughness elements that mimicked the heights of roughness elements (2.0 and 5.0 rnm) found on Styela in Beaufort, North Carollna, USA. On all surfaces, the 2 species with limited attachment to the substrata, Balanus sp. (aclonal, solitary) and Bugula neritina (clonal, arborescent), settled almost exclusively in the location that provided individuals with the best refuge: the crevices formed where the bases of roughness elements intersect with the flat surfaces. Additionally, when roughness elements of various heights were present (Styela, range: 0 6 to 8.8 mm), intermediate size roughness elements (2.0 < X 1 5 . 0 mm) were picked over 72% of the time. Settlement locations and locations where survival were enhanced were less consistent for the 2 species with unlimited attachment to the substrata: a clonal, encrusting form (Schjzoporella errata) and a clonal stolon-mat form (Tubularia crocea). Fewer individuals of these 2 species settled on roughness elements on Styela and when they did, they were not restricted to the bases of the roughness elements. On the plate surfaces, most settlement did occur in crevices, but both species grew away from this location w~thin days and short-term survival was not consistently greater in this location. Additional trials were run on plates with pits of the same maximum dimensions as the tested roughness elements (2.0 and 5.0 mm depth) to see if crevices and pits provide refuges of equal quality for newly settled individuals. Only survival of Balanus sp. recruits was greatest in both crevlces and pits. Evidence for active choice of settlement location comes from consistent results in trials in which some larvae settled in greater numbers on specific size roughness elements on Styela and in areas of high erosion. Overall, these results show that one must be very cautious when generalizing about refuge quality on heterogeneous surfaces, and to determine if a location is a spatial refuge, i t is critical to consider: (1) the dimensions of the larva, (2) the relative dimensions of the individual and potential refuge location at any point in time from the moment settlement occurred, and (3) the growth form of the individual which is related to its need for protection from biotic and abiotic sources of mortality.