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.

种群的丰度、大小结构和性别比例的变化会对交配系统产生重大影响，从而影响生殖产出。 然而，我们对这些对人类通常利用的大型移动的海洋物种的影响知之甚少。 这些物种一般难以观察，其种群一般不适合在必要的规模上进行操纵。 还有一个问题是，在大多数情况下，对未受剥削人口的研究很少，或从未进行过研究，而且没有未受剥削人口可与当代人口进行对比。 过去30年来海洋保护区的出现以及其中一些保护区内被开发种群的恢复，提供了在适当的大尺度上对比种群结构变化对生殖动态的影响的机会。 棘龙虾（Palinuridae）是这种研究的极好模型。 多刺龙虾分布广泛，被大量捕捞，虽然它们是移动的，但它们的活动受到限制，以至于它们的种群受到许多海洋保护区的保护。 雄性多刺龙虾长得比雌性大得多，尽管雄性和雌性的体型都因捕捞而缩小，但雄性的体型下降得更快。 雌性的生殖输出（窝卵数）与雌性的大小呈指数关系，因此在开发区向较小的雌性转移对生殖潜力有明显的影响。 不太清楚的是减少男性的大小对龙虾繁殖动力学的影响，这种不熟悉延伸到整个生态学。 我们有证据从实验室实验中的两种多刺龙虾（加勒比多刺龙虾和新西兰岩龙虾）的可用性大的男性有一个大的，直接影响女性生育力。 在这两个物种中，由小雄性受精的离合器显着小于由大雄性受精的离合器。 也有强有力的证据表明配子限制，它适用于两个物种在不同的属，居住在非常不同的栖息地在世界的两端。 雄性大小对交配系统的影响仅在少数系统中已知，主要是昆虫，但对种群水平的影响知之甚少。 我们提出了一系列的实验室实验，以更充分地描述交配系统的加勒比多刺龙虾，特别是男性的大小对繁殖成功的影响，然后利用实地研究的开发和未开发的龙虾种群和模拟建模，调查人口水平的后果减少男性的大小对生殖动态。