ABSTRACT

The culture of endemic New Zealand black-footed abalone (Haliotis iris) represents a growing aquaculture industry, which is potentially threatened by pathogens and parasites. To identify and characterise health risks, a targeted sampling event was conducted of healthy- and unhealthy-looking abalone (shell deformities, tissue damage and brown creamy substance/fluid in tissues) at a land-based farm. Histological analysis showed signs of ill health, including disrupted and swollen gills with haemocytosis, ceroid material and parasites, and muscle tissues with focal haemocytosis with parasites. For the first time in H. iris, detailed histological observations, followed by confirmatory in situ hybridisation (ISH) resulted in the identification of Perkinsus olseni (5% prevalence). Scyphidia-like ciliates (56%), Sphenophrya-like ciliates (5%), unidentified disintegrated ciliates (26%), intracellular bacterial microcolonies (IMCs) (9%), apicomplexan-like cells (1%) and bacteria (2%) were also identified across organs. There was a significant association between the presence of P. olseni and IMCs. Immunological tissue responses (haemocytosis and ceroid material) and gill pathology were evaluated semi-quantitatively and were significantly associated with P. olseni. Gross abalone appearance was also significantly associated with P. olseni and unidentified disintegrated ciliates. These findings indicate the types of pathogens and parasites found in cultured H. iris for future health assessment studies of this important aquaculture species.

摘要

新西兰特有黑足鲍（Haliotis iris）的养殖代表了水产养殖业的不断发展，但该行业可能受到病原体和寄生虫的威胁。为了识别和描述健康风险，在一个陆上农场对健康和不健康的鲍鱼（壳畸形、组织损伤和组织中的棕色奶油状物质/液体）进行了有针对性的采样活动。组织学分析显示健康状况不佳的迹象，包括鳃破裂和肿胀，伴有血细胞增多、蜡状物质和寄生虫，以及肌肉组织伴有局灶性血细胞增多和寄生虫。首次在H. iris中进行了详细的组织学观察，随后进行了验证性原位杂交 (ISH)，结果鉴定出Perkinsus olseni（5% 患病率）。Scyphidia样纤毛虫 (56%)、Sphenophrya样纤毛虫 (5%)、不明分解纤毛虫 (26%)、细胞内细菌微菌落 (IMC) (9%)、顶端复合体样细胞 (1%) 和细菌 (2%) ）也被跨器官识别。P. olseni的存在与 IMC 之间存在显着关联。半定量评估了免疫组织反应（血细胞增多和蜡状物质）和鳃病理学，并且与奥尔森原虫显着相关。鲍鱼的整体外观也与P. olseni显着相关和不明的分解纤毛虫。这些发现表明了在养殖虹膜中发现的病原体和寄生虫的类型，以供未来对这一重要水产养殖物种的健康评估研究。