Department of Fisheries Biology and Genetics, Faculty of Fisheries, Aquaculture and Marine Science, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh. Aquatic Bioresource Research Lab, Department of Fisheries Biology and Genetics, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh. .
Aquatic Bioresource Research Lab, Department of Fisheries Biology and Genetics, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh. .
Zootaxa. 2021 Jun 29;4995(1):129-146. doi: 10.11646/zootaxa.4995.1.7.
A new species of giant guitarfish, Glaucostegus younholeei sp. nov., is described from 13 specimens, 730933 mm total length, collected from fish landing center of Bangladesh Fisheries Development Corporation in Cox's Bazar district of Bangladesh. The new species is distinguished from congeners in having the following combination of characters: Body brownish or greyish in color with a narrowly wedge-shaped disc, and long narrow bluntly pointed snout (angle 3140°), and broad oblique nostrils with the narrow anterior opening. Nostrils about half of the mouth width, subequal (0.981.33) to internasal width; ~5557 nasal lamellae; anterior nasal flaps slightly penetrating into internasal space, their interspace 2.20 2.61 in length of the posterior nasal aperture. Orbit very small in adults, diameter 8.1911.62 in preorbital length, 2.252.69 in interorbital space. Rostral ridges almost joined along their entire length; margin of cranium sharply demarcated before eyes. Spiracular folds very short and widely separated. Skin rough, densely covered with small denticles, more coarsely granular on the dorsal surface than ventrally, enlarged between orbits and in a distinct band between nape and first dorsal fin. Tail relatively longer, length 1.151.48 in disc length; dorsal fins narrowly spaced, interspace 1.322.11 in base length of the first dorsal fin. Clasper length in adult male 4.375.70 in total length. Phylogenetic analysis of DNA barcode sequences also shows the clear divergence of Glaucostegus younholeei from other congeneric species obtained from GenBank. A key is provided to the 8 known members including new species of the genus Glaucostegus.
一种新的巨型锯鳐，Younholeei 氏锯鳐，被描述为 13 个标本，总长度为 730933 毫米，来自孟加拉国考克斯巴扎尔区孟加拉渔业发展公司的鱼上岸中心。新物种与同属的其他物种区别在于具有以下特征组合：身体呈棕色或灰色，具有狭窄的楔形盘，长而窄的钝尖鼻（角度 3140°），宽阔的斜鼻孔，狭窄的前开口。鼻孔约占口宽的一半，与鼻间距相等（0.981.33）到鼻间宽度；~5557 个鼻瓣；前鼻瓣略微切入鼻间空间，它们之间的间隔为后鼻孔长度的 2.20 2.61。在成鱼中，眼眶非常小，直径为 8.1911.62 在前眶长，2.252.69 在眶间距离。额嵴几乎沿着全长连接；颅的边缘在眼睛前方明显划定。鳃褶非常短，间隔宽。皮肤粗糙，密布小齿状突起，背面比腹面粗糙，颗粒状较大，眶间和颈背与第一背鳍之间有明显的带。尾巴相对较长，长度为 1.151.48 在盘长；背鳍间隔狭窄，间隔为 1.322.11 在第一背鳍基部长度。成雄的夹距长 4.375.70 在总长中。DNA 条码序列的系统发育分析也显示出 Glaucostegus younholeei 与从 GenBank 获得的其他同属种的明显分化。提供了一个包括新种在内的已知 8 种 Glaucostegus 属成员的关键。
