NSW Department of Primary Industries, Port Stephens Fisheries Institute, Taylors Beach, NSW, Australia.
Department of Earth and Environmental Sciences, Macquarie University, Sydney, NSW, Australia.
Vet Med Sci. 2021 Jan;7(1):240-250. doi: 10.1002/vms3.333. Epub 2020 Aug 9.
The carcass of a critically endangered, juvenile female grey nurse shark (Carcharias taurus, Rafinesque 1810) was recovered from a south-eastern Australian beach and subjected to necropsy. The 1.98-m-long shark exhibited advanced cachexia with its total weight (19.0 kg) and liver weight (0.37 kg) reduced by 60% and 89%, respectively, compared with a healthy individual of the same length. Marked tissue decomposition was evident preventing histopathology and identification of a definitive cause of death. At necropsy, the abdominal organs were abnormally displaced and showed marked reductions in size compared with a healthy individual of the same size. Importantly, a hook-shaped enterolith (HSE), with a rough surface and cream in colour, was found within the spiral valve of the intestine and is to the authors' knowledge, the first description of such in any marine animal. X-ray diffractometry showed that the HSE comprised the minerals monohydrocalcite (Ca[CO₃].H₂O; ~70 wt%) and struvite (Mg [NH ] [PO ]. [H O] ; ~30 wt%). A CT scan showed concentric lamellate concretions around a 7/o offset J-hook that formed the nidus of the HSE. Nylon fishing line attached to the hook exited the HSE and was evident in the abdominal cavity through a perforation in the intestinal wall where the posterior intestinal artery merges. The most parsimonious reconstruction of events leading to enterolithiasis and secondary cachexia in this shark was the consumption of a hooked fish and subsequent hook migration causing perforations of the cardiac stomach wall followed by the thin, muscular wall of the apposed, sub-adjacent intestine.
一条极度濒危的幼年雌性灰护士鲨（Carcharias taurus，Rafinesque 1810）的尸体在澳大利亚东南部的海滩上被发现，并进行了解剖检查。这条 1.98 米长的鲨鱼患有晚期恶病质，其总重量（19.0 公斤）和肝脏重量（0.37 公斤）分别比同长度的健康个体减少了 60%和 89%。明显的组织分解使组织病理学检查和确定明确的死亡原因变得困难。在解剖时，腹部器官位置异常，与同尺寸的健康个体相比，大小明显缩小。重要的是，在肠的螺旋瓣内发现了一个钩状的肠结石（HSE），其表面粗糙，呈奶油色。据作者所知，这是在任何海洋动物中首次描述这种肠结石。X 射线衍射分析表明，HSE 由一水碳酸钙（Ca[CO₃].H₂O；70wt%）和鸟粪石（Mg [NH ] [PO ]. [H O]；30wt%）组成。CT 扫描显示，HSE 周围有同心层状的凝结物，形成 HSE 的核心是一个 7/o 偏移的 J 形钩。系在钩子上的尼龙钓鱼线从 HSE 中伸出，并通过肠壁上的穿孔在腹腔中可见，该穿孔位于后肠动脉合并处。导致这条鲨鱼发生结石病和继发性恶病质的最合理的事件重建是，它吞食了一条带有钩子的鱼，随后钩子移动导致心脏胃壁穿孔，然后是相邻、毗邻的薄而肌肉发达的肠道穿孔。
