Al-Sabi Mohammad Nafi Solaiman, Ibrahim Mustafa M, Al-Hizab Fahad, Al-Jabr Omar A, Al-Shubaythi Salem, Huffman David G
Department of Microbiology, College of Veterinary Medicine, King Faisal University, P.O. Box: 400, Al-Ahsa 31982, Saudi Arabia.
Animal Health Research Institute, Dokki, Giza 12618, Egypt.
Saudi J Biol Sci. 2022 Dec;29(12):103430. doi: 10.1016/j.sjbs.2022.103430. Epub 2022 Aug 27.
From January 2017 - December 2019, 75 out of 850 (8.8 %) great hammerhead sharks from the Arabian Gulf had skin lesions of black irregular discolorations on the ventral surface of the head. The lesions consisted of pencil-like lineations often advancing forward by about 2 mm in back-and-forth looped scribbles often forming a relatively linear bands of about 5-7 cm wide. Similar lesions were also found in the blacktip reef shark from the same area within the same period, and consisted of straight to irregular black lines, extended indiscriminately across the skin of the sharks. Microscopic examination of the skin revealed the presence of dark-brown eggs exhibiting the spindle or ellipsoidal eggs characteristic of sp. The morphometrics of eggs from both hosts were similar (62.9-89.9 μm long and 29.3-56.1 μm wide). The eggshells were smooth with polar plugs protruding or not, with an abruptly truncated crown-like or shoulder-like collar surrounding the plug. The eggs were only found in the epidermal layer of the skin. Based on the unique morphometrics of the eggs, we report a new species, named: n. sp.. This appears to be the first report of from either the great hammerhead shark or the blacktip reef shark, and the third reported in sharks from the Arabian Gulf. It is also one of few species reported from connecting waters of the greater Indian Ocean. This new finding contributes to our understanding of the diversity and ubiquity of sp. in marine creatures.
2017年1月至2019年12月期间，阿拉伯湾850条大锤头鲨中有75条（8.8%）头部腹面出现黑色不规则变色的皮肤损伤。这些损伤由铅笔状线条组成，通常以来回环状涂鸦的方式向前推进约2毫米，常形成一条宽约5 - 7厘米的相对线性带。同期在同一区域的黑鳍礁鲨身上也发现了类似损伤，由笔直至不规则的黑线组成，随意延伸穿过鲨鱼皮肤。对皮肤的显微镜检查发现存在深褐色的卵，呈现出 属物种特有的纺锤形或椭圆形卵的特征。两种宿主的卵的形态测量数据相似（长62.9 - 89.9微米，宽29.3 - 56.1微米）。卵壳光滑，极体塞突出或不突出，在塞体周围有一个突然截断的冠状或肩状环。这些卵仅在皮肤的表皮层中发现。基于这些卵独特的形态测量数据，我们报告了一个新物种，命名为： 新种。这似乎是大锤头鲨或黑鳍礁鲨中首次关于 属的报告，也是阿拉伯湾鲨鱼中第三次报告的 属。它也是在大印度洋连接水域报告的少数物种之一。这一新发现有助于我们了解 属在海洋生物中的多样性和普遍性。
