Haline tolerance of stomatopod larvae (Crustacea) in Sontecomapan lagoon, southern Gulf of Mexico

descriptionin this study, we analyzed the haline tolerance of the stomatopod (crustacea) larvae collected in an estuary from the southern gulf of mexico. the chosen study area was the sontecomapan lagoon, which shows great variability in the salinity gradient throughout the year. the sontecomapan estuary was visited five times (june 2018, october 2019, may 2021, november 2021, and june 2022) and zooplankton samples were collected with a conical net (50 cm mouth diameter and 333 µm mesh size); to measure the volume of filtered water a flowmeter was attached to the net mouth. during the fieldwork, the number of sampling stations varied between 11 and 20, depending on weather conditions and logistic facilities. sampling grid comprised the lagoon and the adjacent marine zone. in total, 69 samples were obtained, all of them fixed in a 4% formaldehyde solution and neutralized with sodium borate. besides, at each sampling station, salinity was measured with a ysi brand salinometer, with a precision of 0.01. in the laboratory, stomatopod larvae were sorted from each sample and morphologically examined based on the criteria of ahyong et al. (2014). afterward, the standardized number of larvae (individuals per 1000 m3 of filtered water), was plotted over a salinity gradient graphic to examine the larvae distribution and their salinity tolerance. results indicated the presence of two kinds of larvae at different developmental stages: antizoea and alima. the morphological characteristics of the antizoea larvae correspond to the superfamily lysiosquilloidea, whereas those of the alima larvae, match with the superfamily squilloidea. the antizoea larvae were recorded in salinities as low as 21.9 psu and the alima at 23.2 psu. the occurrence of alima larvae, a late developmental stage, suggests the presence of an adult population in the sontecomapan lagoon, perhaps squilla empusa, the commonest squilloid species in the western atlantic. the tolerance to salinity conditions of stomatopod larvae is indicative of their potential to enter into estuaries. sampling localitythe sontecomapan lagoon is a ramsar site (number 1342) located within los tuxtlas biosphere reserve, between 18.51 – 18.57° n and 94.99 – 95.04° w, in the southern gulf of mexico. the lagoon has an irregular shape and permanent connection with the sea through a narrow channel; it is 7 km long and, on average, 1.5 m depth. the lagoon exhibits variable salinity gradients throughout the year depending on seawater intrusion, the tides, and discharges of rivers, such as coxcoapan, las palmas, and basura. sampling date expedition sonte 1: june 2018. expedition sonte 2: october 2019. expedition sonte 3: may 2021. expedition sonte 4: november 2021. expedition sonte 5: june 2022.structure of the information data are organized in five excel sheets containing 9 columns: column 1: expedition column 2: year column 3: month column 4: sampling station column 5: longitude in decimal degrees column 6: latitude in decimal degrees column 7: salinity (psu) column 8: antizoea density (individuals per 1000 m3) column 9: alima density (individuals per 1000 m3)

本研究中，我们对墨西哥湾南部某河口采集的甲壳类十足目幼虫的盐度耐受性进行了分析。所选研究区域为索特科班潟湖，该潟湖全年盐度梯度变化显著。索特科班潟湖于2018年6月、2019年10月、2021年5月、2021年11月和2022年6月共进行了五次访问，并使用口径为50厘米、网目尺寸为333微米的锥形网收集浮游生物样本；为测量过滤水的体积，将流速计连接到网口。在野外工作中，采样站点的数量介于11至20个之间，具体取决于天气条件和后勤设施。采样网格包括潟湖及其相邻的海域。总计获得了69个样本，所有样本均用4%甲醛溶液固定，并用硼酸钠中和。此外，在每个采样站点，使用YSI品牌盐度计测量盐度，精度为0.01。在实验室中，根据Ahyong等（2014）的标准，对每个样本中的十足目幼虫进行分类，并从形态学上进行了检查。随后，将标准化的幼虫数量（每1000立方米过滤水中的个体数）绘制在盐度梯度图上，以考察幼虫的分布及其盐度耐受性。结果显示，存在两种不同发育阶段的幼虫：抗足幼虫和艾米幼虫。抗足幼虫的形态特征与多足亚科相符，而艾米幼虫则与梭形亚科相匹配。抗足幼虫的记录盐度低至21.9 psu，艾米幼虫为23.2 psu。艾米幼虫这一晚期发育阶段的出现，暗示索特科班潟湖中存在成年种群，可能是最常见于大西洋西部的梭形物种梭鱼。十足目幼虫对盐度条件的耐受性表明了其进入河口的可能性。采样地点：索特科班潟湖是拉姆萨尔公约（编号1342）指定地点，位于洛斯图克斯拉斯生物圈保护区之内，纬度介于18.51°至18.57°N，经度介于94.99°至95.04°W，墨西哥湾南部。该潟湖形状不规则，通过一条狭窄的水道与海洋保持永久性连接；其长度为7公里，平均深度为1.5米。潟湖的盐度梯度全年变化，取决于海水入侵、潮汐和河流（如科克斯科班、拉斯帕尔马斯和巴斯ura）的排放。采样日期：

索特科班探险1：2018年6月。
索特科班探险2：2019年10月。
索特科班探险3：2021年5月。
索特科班探险4：2021年11月。
索特科班探险5：2022年6月。
信息结构：
数据组织在五个Excel表中，包含9列：
列1：探险
列2：年份
列3：月份
列4：采样站点
列5：十进制度数经度
列6：十进制度数纬度
列7：盐度（psu）
列8：抗足幼虫密度（每1000立方米个体数）
列9：艾米幼虫密度（每1000立方米个体数）