The black-foot abalone (pāua), Haliotis iris, is a unique and valuable species to New Zealand with cultural importance for Māori. Abalone are marine gastropods that can display a high level of phenotypic variation, including slow-growing or ‘stunted’ variants. This investigation focused on identifying factors that are associated with growth performance, with particular interest in the slow-growing variants. Tissue alterations in H. iris were examined using histopathological techniques, in relation to growth performance, contrasting populations classified by commercial harvesters as ‘stunted’ (i.e., slow-growing) and ‘non-stunted’ (i.e., fast-growing) from four sites around the Chatham Islands (New Zealand). Ten adults and 10 sub-adults were collected from each of the four sites and prepared for histological assessment of condition, tissue alterations, presence of food and presence of parasites. The gut epithelium connective tissue, digestive gland, gill lamellae and right kidney tissues all displayed signs of structural differences between the slow-growing and fast-growing populations. Overall, several factors appear to be correlated to growth performance. The individuals from slow-growing populations were observed to have more degraded macroalgal fragments in the midgut, increased numbers of ceroid granules in multiple tissues, as well as increased prevalence of birefringent mineral crystals and haplosporidian-like parasites in the right kidney. The histopathological approaches presented here complement anecdotal field observations of reduced seaweed availability and increased sand incursion at slow-growing sites, while providing an insight into the health of individual abalone and sub-populations. The approaches described here will ultimately help elucidate the drivers behind variable growth performance which, in turn, supports fisheries management decisions and future surveillance programs.

黑脚鲍 (pāua)（ Haliotis iris ）是新西兰独特且有价值的物种，对毛利人具有重要的文化意义。鲍鱼是海洋腹足动物，可以表现出高水平的表型变异，包括生长缓慢或“发育不良”的变异体。这项调查的重点是确定与生长性能相关的因素，特别关注生长缓慢的变体。使用组织病理学技术检查虹膜组织的变化与生长性能的关系，对比商业收割机将四种虹膜分类为“发育不良”（即生长缓慢）和“非发育不良”（即生长快速）的群体。查塔姆群岛（新西兰）周围的地点。从四个地点各收集了 10 只成虫和 10 只亚成虫，并准备对状况、组织改变、食物存在和寄生虫存在进行组织学评估。肠道上皮结缔组织、消化腺、鳃片和右肾组织都显示出缓慢生长和快速生长群体之间结构差异的迹象。总体而言，有几个因素似乎与增长绩效相关。据观察，来自生长缓慢群体的个体中肠中降解的大型藻类碎片更多，多个组织中的蜡样颗粒数量增加，并且右肾中双折射矿物晶体和单孢子虫样寄生虫的患病率增加。这里提出的组织病理学方法补充了生长缓慢地点海藻可用性减少和沙子入侵增加的实地观察，同时提供了对单个鲍鱼和亚群健康状况的深入了解。 这里描述的方法最终将有助于阐明可变增长绩效背后的驱动因素，这反过来又支持渔业管理决策和未来的监测计划。