Onisimus normani Sars 1891

• Main Authors: Vader, Wim, Johnsen, Jan Roger, Tandberg, Anne Helene S.
• Format: Text
• Language: unknown
• Published: Zenodo 2020
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Malacostraca; Amphipoda; Uristidae; Onisimus; Onisimus normani; Barents Sea; Greenland; Pacific; Norway; Tromso; Andfjorden; Northern Norway; University of Tromso
• Online Access: https://dx.doi.org/10.5281/zenodo.5633966; https://zenodo.org/record/5633966

Key to the ‘ normani -group’ The ‘ normani -group’ within Onisimus is characterized by a partly cleft telson, a completely constricted uropod 2, and a peculiar 1 st epimeral plate, with an anterodistal hook (Vader et al . 2005). The group consists of O. normani , O. turgidus , and 2 or 3 taxa closely related to O. turgidus , but strongly deviating in the arrangement of the setal teeth on the outer plate of maxilla 1. Material belonging to these taxa has been found in the W Atlantic Ocean, near Greenland and in the NW Pacific (Johnsen 2001). Most (or possibly all) species in this group appear to be obligate associates of sea anemones, a trait absent in all other Onisimus species. In Norwegian waters there are two species in this group, O. normani in W Norway north to Andfjorden, and O. turgidus in N Norway and the Barents Sea. They can be distinguished as follows: 1. Pereopod 1 palm oblique, propodus subrectangular. Uropod 2 inner ramus with small setae in constriction; uropod 1 outer ramus without spines on inner margin............................................................................................................................................................... Onisimus normani Sars, 1891 – Pereopod 1 palm strongly oblique, propodus triangular. Uropod 2 inner ramus with large spine in constriction; uropod 1 outer ramus with spines on inner margin.... Onisimus turgidus (Sars, 1879) : Published as part of Vader, Wim, Johnsen, Jan Roger & Tandberg, Anne Helene S., 2020, Onisimus turgidus (Sars, 1879) (Amphipoda, Uristidae), an overlooked amphipod from sea anemones in Northern Norway, pp. 34-50 in European Journal of Taxonomy 724 on page 36, DOI: 10.5852/ejt.2020.724.1155, http://zenodo.org/record/5627470 : {"references": ["Vader W., Johnsen J. R. & Berge J. 2005. Studies on the genus Onisimus Boeck, 1871 (Crustacea, Amphipoda, Lysianassoidea, Uristidae), Part I. The brevicaudatus and sextonae species groups. Organisms, Diversity & Evolution 5: 161 - 164, Electr Suppl. 7: 1 - 48. https: // doi. org / 10.1016 / j. ode. 2004.08.002", "Johnsen J. R. 2001. The taxonomy of Onisimus. MSc thesis, University of TromsO, Norway.", "Sars G. O. 1879. Crustacea et Pycnogonida nova in itinere 2 do et 3 tio expeditionis norvegicae anno 1877 & 78 collecta (Prodromus descriptionis). Archiv for Mathematik og Naturvidenskaber 4: 427 - 476."]}