Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
Instituto do Mar, Universidade Federal de São Paulo, Santos, São Paulo, Brazil.
PeerJ. 2023 Feb 20;11:e14712. doi: 10.7717/peerj.14712. eCollection 2023.
Cyatholaimidae is a common and diverse family of mainly marine nematodes, potentially, with a large number of species to be discovered. The taxonomy of the group is marked by a lack of information about the evolutionary history of the characters and of detailed descriptions of morphological structures that may be taxonomically relevant. Two new species of the family are described from a sublittoral region in Southeastern Brazil, emphasizing the importance of the distribution and morphology of pore complex and pore-like structures present on the cuticle. The taxonomic importance of the cuticle ornamentation and spicule shape for the species, as well as the precloacal supplements structures of species, are discussed. sp. nov. differs from other species of the genus by the presence of eight longitudinal rows of pore complex on the cuticle and by the shape of the copulatory structure. sp. nov. differs from the most similar species, Wieser, 1954, by the smaller number of turns of the amphidial fovea, the shorter tail and the beginning of the cuticle lateral differentiation (3/4 of the pharynx length . end of the pharynx, respectively). We also obtained the SSU rDNA sequence from sp. nov., which is closely related to sp. (MN250093) by about 91%. Updated tabular keys to species identification of each genus ( and ) are included, containing morphometric data, characters related to cuticle ornamentation, and copulatory structures.
Cyatholaimidae 是一个主要生活在海洋中的线虫科，具有丰富的多样性，可能有大量的物种有待发现。该类群的分类学特点是缺乏关于特征进化历史的信息，以及关于可能具有分类学意义的形态结构的详细描述。本文从巴西东南部的潮间带地区描述了两个该科的新种，强调了研究表皮上的孔复合体和似孔结构的分布和形态的重要性。本文讨论了种的表皮装饰和刺形状、以及种的肛前补充结构在分类学上的重要性。种 sp. nov. 与该属的其他种不同，其表皮上有八行纵向的孔复合体，交配结构的形状也不同。种 sp. nov. 与最相似的种，Wieser, 1954 不同，主要表现在以下几个方面：感受器窝的匝数较少、尾较短、表皮侧向分化开始（在 3/4 的咽长处. 咽的末端）。我们还从种 sp. nov. 中获得了 SSU rDNA 序列，该序列与 sp. (MN250093) 的相似度约为 91%。本文还包括了每个属（和）的物种鉴定的表格式关键特征，包含形态测量数据、与表皮装饰有关的特征和交配结构。
