Marine Reserves and Spiny Lobster: Effects on Male Size and Reproductive Success

海洋保护区和大龙虾：对雄性体型和繁殖成功率的影响

• 批准号: 9730195
• 负责人: Mark Butler
• 金额: $ 27.68万
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 2001-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9730195&HistoricalAwards=false
• 关键词: Marine; Reserves; Spiny; Lobster; Effects

Changes in the abundance, size structure and sex ratio of populations can have large and consequential effects on mating systems, and thus on reproductive output. Yet, we know relatively little about these effects on the large, mobile marine species commonly exploited by humans. These species are generally difficult to observe and their populations are not generally amenable to manipulation at the requisite scale. There is the additional problem that in most cases the unexploited population was poorly, or never, studied and there are no unexploited populations with which to make contemporary contrasts. The advent of marine sanctuaries over the last 30 years and the recovery of exploited populations within some of them, offers opportunities to contrast the effects of changes in population structure on reproductive dynamics at appropriately large scales. Spiny lobsters (Palinuridae) are excellent models for such studies. Spiny lobsters are widely distributed and heavily exploited, and although mobile, their movements are limited enough that their populations respond to the protection afforded by many marine sanctuaries. Male spiny lobsters grow substantially larger than females, and although both male and female size is reduced by exploitation (fishing), male size declines more precipitously. The reproductive output (clutch size) of females is exponentially related to female size, so a shift toward smaller females in exploited areas has clear implications for reproductive potential. Less clear is the effect of reduced male size on lobster reproductive dynamics and this unfamiliarity extends to ecology as a whole. We have evidence from laboratory experiments on two species of spiny lobsters (Caribbean spiny lobster and New Zealand Rock Lobster) that the availability of large males has a large, direct effect on female fecundity. In both species, clutches fertilized by small males are significantly smaller than clutches fertilized by large males. There also is strong evidence for gamete limitation and it applies to two species in separate genera that dwell in very different habitats on opposite comers of the world. Male size effects on mating systems are known in only a few systems, primarily insects, but the population-level consequences are poorly understood. We propose a series of laboratory experiments to describe more fully the mating system of the Caribbean spiny lobster, with special reference to the effect of male size on reproductive success, and then to utilize field studies of exploited and unexploited lobster populations and simulation modeling to investigate the population-level consequences of reduced male size on reproductive dynamics.

种群数量、规模结构和性别比例的变化可能对交配系统产生巨大的后果性影响，从而对生殖产出产生巨大的影响。 然而，我们对这些对人类通常利用的大型移动海洋物种的影响知之甚少。 这些物种通常很难观察，而且它们的种群通常不适合进行必要规模的操纵。 还有一个问题是，在大多数情况下，对未开发人口的研究很少，或者从未研究过，并且没有未开发人口可以与之进行当代对比。 过去 30 年海洋保护区的出现以及其中一些保护区内被剥削种群的恢复，为在适当大的范围内对比种群结构变化对生殖动态的影响提供了机会。 大龙虾（Palinuridae）是此类研究的优秀模型。 大龙虾分布广泛，捕捞严重，虽然可以移动，但它们的活动非常有限，以至于它们的种群只能对许多海洋保护区提供的保护做出反应。 雄性大龙虾长得比雌性大得多，尽管雄性和雌性的体型都因剥削（捕鱼）而缩小，但雄性体型下降得更急剧。 雌性的繁殖产出（产蛋量）与雌性的体型呈指数关系，因此，在开发地区向体型较小的雌性转变对生殖潜力具有明显的影响。 不太清楚的是雄性体型减小对龙虾繁殖动态的影响，这种不熟悉延伸到了整个生态学。 我们从对两种大龙虾（加勒比大龙虾和新西兰岩龙虾）进行的实验室实验中得到的证据表明，大型雄性的可用性对雌性的繁殖力有很大的直接影响。 在这两个物种中，小型雄性受精的窝明显小于大型雄性受精的窝。 还有强有力的证据表明配子限制，它适用于居住在世界两端截然不同的栖息地的不同属的两个物种。 雄性体型对交配系统的影响仅在少数系统（主要是昆虫）中为人所知，但对种群水平的影响却知之甚少。 我们提出了一系列实验室实验，以更全面地描述加勒比大龙虾的交配系统，特别是雄性体型对繁殖成功的影响，然后利用对已开发和未开发的龙虾种群的实地研究和模拟模型来研究雄性体型减小对繁殖动态的种群水平影响。