On some new species of Stenheliinae Brady, 1880 (Copepoda, Harpacticoida, Miraciidae) from north-western Mexico, with the proposal of Lonchoeidestenhelia gen. nov.

Quarterly sampling campaigns during 2019 to study the diversity of meiofauna in a polluted estuary in northwestern Mexico revealed the subfamily Stenheliinae Brady, 1880 as one of the most important contributors to the diversity of benthic harpacticoids. Two new stenheliin species are described here. One of them was assigned to the, so far, monotypic genus Lonchoeidestenheliagen. nov. defined by the autapomorphic modified proximal outer spinules on the sigmoid process of the male P2ENP2. The other species was assigned to Willenstenhelia Karanovic and Kim, 2014. Lonchoeidestenheliagen. nov. shares the armature formula of the P1 EXP2 with Stenhelia, Anisostenhelia, and Beatricella, but seems to bear a sister-group relationship with the former two genera by the loss of one inner seta on the P2–P3 EXP3, the presence of two outer spine-like elements on the male P5EXP, and the displacement of the outer spine and medial and inner distal setae of P2ENP3, to an apical and subapical inner position, respectively, but is more closely related to Anisostenhelia by the overall shape of the male P2ENP2. Willenstenhelia reductasp. nov. is attributed to a group of species composed of Wi. minuta, Wi. urania, and Wi. terpsichore characterized by the strongly reduced inner seta of the female P5 baseoendopod, but differs in the discrete female P5 baseoendopods and in the presence of one outer seta only on that segment. Willenstenhelia reductasp. nov. is defined here by the autapomorphic loss of the outermost seta of the female P5 baseoendopod.