Fisheries, Aquaculture and Coasts Centre, Institute for Marine and Antarctic Studies Tasmania, University of Tasmania, Private Bag 49, Hobart, TAS 7001, Australia.
J Fish Biol. 2012 Apr;80(5):966-90. doi: 10.1111/j.1095-8649.2012.03242.x.
The large size, high trophic level and wide distribution of Hexanchiformes (cow and frilled sharks) should position this order as important apex predators in coastal and deep-water ecosystems. This review synthesizes available information on Hexanchiformes, including information not yet published, with the purpose of evaluating their conservation status and assessing their ecological roles in the dynamics of marine ecosystems. Comprising six species, this group has a wide global distribution, with members occurring from shallow coastal areas to depths of c. 2500 m. The limited information available on their reproductive biology suggests that they could be vulnerable to overexploitation (e.g. small litter sizes for most species and suspected long gestation periods). Most of the fishing pressure exerted on Hexanchiformes is in the form of commercial by-catch or recreational fishing. Comprehensive stock and impact assessments are unavailable for most species in most regions due to limited information on life history and catch and abundance time series. When hexanchiform species have been commercially harvested, however, they have been unable to sustain targeted fisheries for long periods. The potentially high vulnerability to intense fishing pressure warrants a conservative exploitation of this order until thorough quantitative assessments are conducted. At least some species have been shown to be significant apex predators in the systems they inhabit. Should Hexanchiformes be removed from coastal and deep-water systems, the lack of sympatric shark species that share the same resources suggests no other species would be capable of fulfilling their apex predator role in the short term. This has potential ecosystem consequences such as meso-predator release or trophic cascades. This review proposes some hypotheses on the ecology of Hexanchiformes and their role in ecosystem dynamics, highlighting the areas where critical information is required to stimulate research directions.
六鳃鲨目（牛鲨和皱鳃鲨）体型庞大、营养级高、分布广泛，应将其定位为沿海和深海生态系统中的重要顶级掠食者。本综述综合了六鳃鲨目现有的信息，包括尚未发表的信息，目的是评估其保护状况，并评估其在海洋生态系统动态中的生态作用。该目由六个物种组成，全球分布广泛，成员从浅海沿海地区到约 2500 米深处都有分布。关于其生殖生物学的有限信息表明，它们可能容易受到过度捕捞的影响（例如，大多数物种的幼仔数量较少，怀疑妊娠期较长）。对六鳃鲨目鱼类施加的大部分捕捞压力是以商业副渔获物或娱乐性捕捞的形式出现的。由于关于生活史和渔获量和丰度时间序列的信息有限，大多数地区的大多数物种都没有进行全面的种群和影响评估。然而，当六鳃鲨目物种被商业捕捞时，它们无法长期维持有针对性的渔业。由于高强度捕捞压力的潜在高脆弱性，在进行全面的定量评估之前，应对该目进行保守的开发利用。至少有一些物种已被证明是它们栖息系统中的重要顶级掠食者。如果六鳃鲨目从沿海和深海系统中移除，缺乏与它们共享相同资源的同域鲨鱼物种，这表明短期内没有其他物种能够替代它们在短期担任顶级掠食者的角色。这可能会对生态系统产生影响，例如中型捕食者释放或营养级联。本综述提出了一些关于六鳃鲨目生态学及其在生态系统动态中的作用的假设，突出了需要关键信息的领域，以激发研究方向。
