Swim bladder measurements of Cyclothone species from the BATHYPELAGIC cruise to the Northeast Atlantic Ocean

This dataset contains the values of swim bladder length, height, width, angle, volume, equivalent spherical radius and aspect ratio in Cyclothone spp. measured during the Bathypelagic cruise (from 24th May to 23rd June 2018). Samples were obtained with MOCNESS-1 m² (with a 0.2 mm mesh size) zooplankton net during day and night hauls carried out from the surface to 1800 m depth. MOCNESS samples were preserved in 5% buffered formalin. Standard length (SL, ±0.01 mm) and swim bladder (Sw, ±0.001 mm) on each specimen were measured at the land-based laboratory. A stereo microscope fitted with an ocular micrometer was used to obtain the swim bladder length height, width, and swim bladder angle (θ). The longitudinal axis was set as the reference line for the angle (θ =0) with positive values over the reference line. Swim bladder volumes were approximated using the formula for a prolate spheroid, the equivalent spherical radius was estimated following the equation of Strasberg (1953) and the aspect ratio was calculated as the ratio of the height to the longitudinal semi-axis.

本数据集收录了2018年5月24日至6月23日深渊带巡航（Bathypelagic cruise）期间，对圆罩鱼属（Cyclothone spp.）个体测得的鳔长度、高度、宽度、角度、体积、等效球半径及宽高比数据。样本通过网孔尺寸0.2毫米的MOCNESS-1平方米浮游生物网（MOCNESS-1 m²）采集，作业为覆盖表层至1800米水深的昼夜拖网采样；采集所得样本经5%缓冲福尔马林固定保存。在陆地实验室中，研究人员对每尾标本的标准体长（Standard Length，SL，精度±0.01毫米）及鳔（swim bladder，Sw，精度±0.001毫米）开展测量：使用配备目镜测微尺的体视显微镜获取鳔的长度、高度、宽度与鳔角度（θ），以标本纵轴作为角度参考线（θ=0），参考线上方的角度取值为正。鳔体积采用长椭球（prolate spheroid）公式近似计算，等效球半径依据Strasberg（1953）提出的公式估算，宽高比则以鳔高度与纵向半轴的比值计算得出。