Thrissina belvedere sp. nov. is described from 14 specimens collected in Ha Long Bay, northern Vietnam. The new species is closely related to Thrissina chefuensis (Günther 1874) (redescribed herein), both species having a short upper jaw with the posterior tip slightly shortened to the posterior margin of the preopercle, an indistinct black blotch on the nape (but not on the dorsum just before the dorsal-fin origin), and similar numbers of scutes on the ventral edge of the body. However, the former is characterized by higher total gill-raker counts on the first, second, third, and fourth gill arches, and the third gill arch posterior face (59–66, 53–59, 33–37, 25–29, 7–10 respectively vs. 50–57, 44–52, 29–35, 23–27, and 5–8 in T. chefuensis), fewer branched anal-fin rays [24–27 vs. 24–30 (usually 27–29)], a deeper body (body depth 25.6–27.9% SL vs. 21.9–26.0%, the distance between the dorsal and anal fin origins 29.6–31.7% SL vs. 26.1–30.2%, and the caudal-peduncle depth 10.5–11.7% SL vs. 8.8–10.6%).

中文翻译：

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Thrissina belvedere，一种来自越南北部下龙湾的新 thryssa 和 Thrissina chefuensis (Günther 1874) (Clupeiformes: Engraulidae) 的重新描述

Thrissina belvedere sp. 十一月 从在越南北部下龙湾收集的 14 个标本中描述。这个新种与 Thrissina chefuensis (Günther 1874) 密切相关（在此重新描述），这两个物种都有一个短的上颌，后尖略微缩短至前鳃盖骨的后缘，颈背上有一个模糊的黑色斑点（但不是在背鳍起点之前的背部），以及身体腹侧边缘的相似数量的鳞片。然而，前者的特点是第一、第二、第三和第四鳃弓和第三鳃弓后面的鳃耙总数较高（59-66、53-59、33-37、25-29、 7-10 分别与 50-57、44-52、29-35、23-27 和 5-8 在 T.chefuensis 中），较少的分支肛鳍射线 [24-27 与 24-30（通常 27 –29)]，更深的主体（主体深度 25.6–27.9% SL vs.