The taxonomic status of Phyllocheres Humes, 1996 and Neoasterocheres Canário et al., 2017, and three new Asterocheres Boeck, 1859 species (Siphonostomatoida, Asterocheridae) from Brazil

Asterocheridae Giesbrecht, 1899 is the most diverse family of siphonostomatoid copepods associated with marine invertebrates, comprising 342 species in 72 genera. However, some are poorly described, leading to significant taxonomic uncertainties. Therefore, this study aims to revise the taxonomic status of Phyllocheres Humes, 1996, redescribing its type species.

Since the main remaining diagnostic feature of the genus is also shared with Neoasterocheres Canário, Rocha, Neves & Johnsson, 2017, we propose the latter as its junior synonym. Accordingly, we present the combinatio nova for P. breviseta (Canário, Rocha, Neves & Johnsson, 2017), P. dysideae (Humes, 1996), P. enewetakensis (Humes, 1997), P. humesi (Varela, 2012), P. rotundus (Malt, 1991), P. scutatus (Stock, 1966), and P. serrulatus (Humes, 1996), previously included in Neoasterocheres.

In addition, based on our analysis, we also propose the combinatio nova for P. spongus (Johnsson, 2002). Finally, with the well-defined boundaries between Asterocheres and Phyllocheres, we describe three new asterocherid species from Todos-os-Santos Bay to Asterocheres Boeck, 1859, Northeastern Brazil. Asterocheres quiteriae sp. nov. exhibits the following combined diagnostic features: a 21-segmented female antennule, antennal endopod 3- segmented, with armature formula: 0,1,2, mandibular palp 2-segmented, and maxilliped 6-segmented, A. angelicae sp. nov. is characterized by having a 20-segmented female antennule, mandibular palp 1-segmented, and maxilliped 5- segmented, and A. felipae sp. nov. by having 21-segmented female antennule, mandibular palp 2-segmented, maxilliped 5-segmented, and two setae on the second segmental antennal endopod as striking features.