Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, Departamento de Plancton y Ecología Marina, Av. Instituto Politécnico Nacional s/n, Col. Playa Palo de Santa Rita, La Paz, Baja California Sur, C.P. 23096, Mexico..
Zootaxa. 2021 Feb 26;4938(2):zootaxa.4938.2.1. doi: 10.11646/zootaxa.4938.2.1.
Sea spiders (Class Pycnogonida Latreille, 1810) are chelicerate arthropods, with an extraordinarily reduced body armed with eight to twelve elongated legs. A literature review of taxonomic and ecological studies of pycnogonids from Mexico identified 49 nominal species (~3.6% out of 1,335 species described worldwide). This low species richness is likely caused by limited taxonomic research and intermittent sampling and research efforts initially carried out by foreign scientists (1893-1996) and later by Mexican scientists. The present study investigates the latitudinal gradient of species richness of the pycnogonids associated with nine marine docks located between Cabo San Lucas (22°53'N) and Santa Rosalía (26°58'N) along the west coast of the Gulf of California, 22°53'N Mexico and provides a detailed morphological re-description of each nominal species using light and scanning electron microscopy. Nine nominal pycnogonid species and one unidentified species in the genus Tanystylum were collected and identified from the biological samples collected between 2011-2017. The highest pycnogonid species richness was recorded at Bahía de La Paz (seven species, 24°14'N) and the lowest species richness at Cabo San Lucas (one species) without an evident latitudinal species richness gradient. Anoplodactylus californicus Hall, 1912 and Ammothella spinifera Cole, 1904 were the most abundant species (52% of the total number of individuals). Tanystylum occidentale (Cole, 1904) and Nymphon apheles Child, 1979 were new geographical records for Mexico and Ammothella symbia Child, 1979 and A. californicus were new records for Baja California Sur state. Adding these new geographical records of pycnogonids increased the species richness previously recorded at Baja California Sur from 20 to 24 nominal species and for Mexico, the species richness increased from 49 to 51 nominal species.
海蜘蛛（Class Pycnogonida Latreille, 1810）是一种具螯肢的节肢动物，身体极度缩小，长有 8 到 12 对细长的腿。对墨西哥的 Pycnogonida 分类学和生态学研究的文献回顾确定了 49 个名义种（全世界描述的 1335 种中的约 3.6%）。这种低的物种丰富度可能是由于分类学研究有限，以及最初由外国科学家（1893-1996 年）和后来的墨西哥科学家进行的间歇性采样和研究工作造成的。本研究调查了与加利福尼亚湾西海岸九个海洋码头相关的 Pycnogonida 的纬度梯度，这些码头位于卡波圣卢卡斯（22°53'N）和圣罗莎莉亚（26°58'N）之间，墨西哥 22°53'N，并使用光镜和扫描电子显微镜对每个名义种进行了详细的形态重新描述。从 2011-2017 年采集的生物样本中收集并鉴定了九个名义 Pycnogonid 种和一个 Tanystylum 属的未识别种。在拉巴斯湾（Bahía de La Paz，24°14'N）记录到的 Pycnogonid 物种丰富度最高（七种，24°14'N），而在卡波圣卢卡斯（Cabo San Lucas）记录到的物种丰富度最低（一种），没有明显的纬度物种丰富度梯度。Anoplodactylus californicus Hall, 1912 和 Ammothella spinifera Cole, 1904 是最丰富的物种（个体总数的 52%）。Tanystylum occidentale（Cole, 1904）和 Nymphon apheles Child, 1979 是墨西哥的新地理记录，Ammothella symbia Child, 1979 和 A. californicus 是下加利福尼亚州的新记录。增加这些海蜘蛛的新地理记录，使下加利福尼亚州之前记录的物种丰富度从 20 种增加到 24 种，使墨西哥的物种丰富度从 49 种增加到 51 种。
