Schuchert Peter
Muséum d'histore naturelle, Route de Malagnou 1, 1211 Geneva, Switzerland; Email:
Zootaxa. 2013 Feb 8;3613:101-24. doi: 10.11646/zootaxa.3613.2.1.
The current status of Plumularia lagenifera Allman, 1885, a common thecate hydroid of the west coast of the USA and Canada, is problematic as it is difficult to distinguish from the near cosmopolitan and very variable Plumularia setacea. Type material of P. lagenifera and newly collected material of P. lagenifera and P. setacea from the region of the type locality of the former was used to compare it to P. setacea from the Atlantic. Measurements of a number of morphological traits were made and analysed using principal components analyses. Type material of the Californian Plumularia palmeri Nutting, 1900 was also included in the comparisons and confirmed the view of earlier workers that it is indistinguishable from P. setacea. Additionally, South African material referred to P. lagenifera by Millard (1975) was compared to the material from the NE Pacific. Plumularia lagenifera remains difficult to separate from P. setacea. The convex outer wall of the hydrotheca offers the only operational character to distinguish P. lagenifera from P. setacea, which always has straight or even concave hydrothecae. For morphological and biogeographic reasons, South African P. lagenifera sensu Millard (1975) should be referred to P. gaimardi (Lamouroux, 1924).
1885年命名的柱状羽螅（Plumularia lagenifera Allman）是美国和加拿大西海岸常见的具鞘水螅虫，其现状存在问题，因为它很难与分布几乎遍及全球且变异很大的刚毛羽螅（Plumularia setacea）区分开来。利用柱状羽螅的模式标本以及从其模式产地附近新采集的柱状羽螅和刚毛羽螅标本，与来自大西洋的刚毛羽螅进行比较。对一些形态特征进行了测量，并使用主成分分析进行分析。1900年命名的加利福尼亚羽螅（Plumularia palmeri Nutting）的模式标本也被纳入比较，证实了早期研究者的观点，即它与刚毛羽螅无法区分。此外，将米勒德（1975年）归为柱状羽螅的南非标本与东北太平洋的标本进行了比较。柱状羽螅仍然很难与刚毛羽螅区分开。具鞘水螅的凸外壁是将柱状羽螅与刚毛羽螅区分开来的唯一可用特征，刚毛羽螅的具鞘水螅总是直的甚至是凹的。出于形态学和生物地理学原因，米勒德（1975年）所指的南非柱状羽螅应归为盖马尔迪羽螅（Plumularia gaimardi (Lamouroux, 1924)）。
