Preliminary observations of gastropod predation in the western Niger Delta
Preliminary observations of gastropod predation in the western Niger Delta
复制标题
尼日尔三角洲西部腹足动物捕食的初步观察
DOI：
10.1016/0031-0182(66)90010-1
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发表时间：
1966
期刊：
影响因子：
--
通讯作者：
R. Reyment
中科院分区：
文献类型：
--
作者：
R. Reyment
对西部尼日尔三角洲部分地区的微型底栖动物进行的定向调查表明，当地有丰富的钻腹足类。除了大量的腹足类和腹足类物种，钻头攻击其他钻腹足类，舟足类，介形类，在罕见的情况下，甚至有孔虫。可以确定的是，一般有孔钻的尺寸和猎物的大小之间的相关性差，从而表明，即使是大钻头将选择小受害者。Ostreais攻击优先于任何其他形式和pelecypods比腹足类或介形类更理想。大部分的捕食是由于naticids，虽然muricids是丰富的在该地区正在考虑。在该地区的主要部分，仅发现钻头袭击了介形类中的Bythocypris，Cytherella和CorpionallyCosta。然而，一个来自拉各斯附近的样本表明，当地的害虫不仅攻击这些已知的属，而且还攻击豆科花介属、布莱氏花介属、半花介属，甚至像花介属这样的小种类。在某些情况下，钻孔是甲壳总长度的三分之二或更多。已观察到所有物种的较大幼虫阶段都被钻过。从整体上看，对盘足类和介形类的攻击强度没有表现出规律性。而扇叶扇贝、小厚壳蛤、长喙丽达蛤、十字蛤、光叶蛤蜊和圆腹蛤蜊等，所有物种对本土药物的敏感程度大致相同。统计分析表明，介形类和盘形类的左右瓣同样受到钻头的青睐。它还表明，有变化的孔的形状从样品到样品，这被认为是可能归因于部分壳厚度。在一些样本中发现的洞的外部和内部尺寸的变化范围可能与捕食动物群组成的变化有关。钻头更喜欢钻取盘足类瓣膜和许多介形类贝壳的中央区域，尽管人们的兴趣集中在像Bythocypris这样的细长形式的后缘或前缘。统计分析表明，在定位中心领域内的孔有一定的偏见。
An orientatory investigation of the microbenthos of parts of the western Niger Delta has indicated that drilling gastropods are locally abundant. In addition to a large number of pelecypod and gastropod species, drills attack other drilling gastropods, scaphopods, ostracods and, in rare cases, even foraminifers. It could be ascertained, that there is generally poor correlation between the dimensions of the hole drilled and the size of the prey, thus suggesting that even large drills will select small victims.Ostreais attacked preferentially to any other forms and pelecypods are more desired than gastropods or ostracods. Most of the predation is due to naticids, although muricids are abundant in the area under consideration. In the main part of the area, the drills have only been found to have attackedBythocypris, Cytherellaand occasionallyCostaamong the ostracods. However, one sample from near Lagos showed that naticids there attacked not only these genera noted but alsoLeguminocythereis, Bradleya, Hemicythereand even such a small form asCytheropteron. In some cases, the hole drilled is two thirds or more of the total length of the carapace. Larger larval stages of all species have been observed to have been drilled. Taken as a whole, the intensity of attack with respect to pelecypods and ostracods does not display regularity. However, a group comprisingPecten flabellum, Crassatella paeteli, Leda rostrata, Venerupis decussata, Mactra nitida, andArcasp., shows approximately the same degree of susceptibility to naticids for all species. The statistical analysis suggests that right and left valves of ostracods and pelecypods are equally favored by the drills. It is also shown, that there is variation in the shape of the hole from sample to sample and this is thought to be possibly ascribable in part to the shell thickness. The ranges of variation found in some samples for the outer and inner dimensions of the hole may be connected with shifts in the composition of the predator fauna. The drills prefer to bore the central area of the pelecypod valve and many ostracod shells, although interest is concentrated to the posterior or anterior margin of such an elongated form asBythocypris. Statistical analysis indicated a certain bias in locating the hole within the central field.