Abstract
A new genus, Arktourella gen. nov., is proposed to accommodate a new member of the harpacticoid family Normanellidae, A. margarethae gen. et sp. nov., from a polluted estuary in north-western Mexico. The new genus was attributed to the laophontoidean family Normanellidae on account of the lack of outer spinous processes on the second antennulary segment, one abexopodal seta on the antennary allobasis, four setae on the one-segmented antennary exopod, endopod of first swimming leg two-segmented with first segment elongated and with two distal elements on second segment, endopods of second to fourth legs two-segmented, distal setae on the male second endopodal segment of second and third legs reduced, and outer spine of the male second endopodal segment of third leg fused to segment. The new, so far monotypic genus, differs from the other normanellid genera in the presence of four elements on the third exopodal segment of the first leg, and two outer spines on the third exopodal segment of second to fourth legs. No synapomorphies were observed for Arktourella gen. nov. and Normanella, but they are unique within the Normanellidae in that the mandibular basis and endopod are not fused. Maximum parsimony analysis and Bayesian inference using 59 morphological characters to assess the relationships between the genera of the family Normanellidae confirmed the affinity of Arktourella gen. nov. and Normanella, and their sister group relationship with Sagamiella. Paranaiara and Pseudocletodes were shown consistently to be closely related and are the sister taxa of Normanella-Arktourella gen. nov.-Sagamiella. Arktourella gen. nov., Paranaiara and Pseudocletodes share the presence of a large spinulose spine on the fifth and sixth segments of the female antennule, but its significance is not clear. Additionally, we propose a key to the genera of the Normanellidae.
References
Bodin, P. (1968) Copépodes harpacticoïdes des étages bathyal et abyssal du Golfe de Gascogne. Mémoires du Muséum National d´Histoire Naturelle, Series A, 55, 1–107.
Huys, R. (1990a) A new family of harpacticoid copepods and an analysis of the phylogenetic relationships within the Laophontoidea T. Scott. Bijdragen tot de Dierkunde, 60, 79–120. https://doi.org/10.1163/26660644-06002002
Huys, R. (1990b) Adenopleurella, new genus, Proceropes, new genus, Sarsocletodes Wilson (ex Laophontidae) and Miroslavia Apostolov (ex Cletodidae): representatives of a new family (Copepoda: Harpacticoida). Journal of Crustacean Biology, 10, 340–363. https://doi.org/10.1163/193724090X00140
Huys, R. & Boxshall, G.A. (1991) Copepod evolution. The Ray Society, London, 468 pp.
Huys, R. & Lee, W. (1999) On the relationships of the Normanellidae and the recognition of Cletopsyllidae grad. nov. (Copepoda, Harpacticoida). Zoologischer Anzeiger, 237, 267–290.
Huys, R. & Willems, K.A. (1989) Laophontopsis Sars and the taxonomic concept of the Normanellinae (Copepoda: Harpacticoida): a revision. Bijdragen tot de Dierkunde, 59, 203–227. https://doi.org/10.1163/26660644-05904002
Itô, T. & Takashio, T. (1980) Canthocamptus mirabilis Sterba (Cpepoda, Harpacticoida) from Hokkaido, northern Japan. Annotationes Zoologicae Japonenses, 53, 210–219.
Kihara, T. & Huys, R. (2009) Contributions to the taxonomy of the Normanellidae (Copepoda, Harpacticoida): description of a new genus from the Brazilian continental shelf and re-assignment of Pseudocletodes vararensis Scott & Scott, 1893 (ex Nannopodidae). Zootaxa, 38, 1–38. https://doi.org/10.11646/zootaxa.2233.1.1
Lang, K. (1934) Marine harpacticiden von der Campbell-Insel und einigen anderen südlichen Inseln. Acta Universitatis Lundensis, New Series, Avd. 2, 30 (14) (=Kungl. Fysiografiska Sällskapets Handlingar, 45 (14), 1–56.
Lang, K. (1936) Copepoda Harpacticoida. Bock, S. (Ed.), Further Zoological Results of the Swedish Antarctic Expedition 1901-1903 under the direction of Dr. Otto Nordenskjöld. 3 (3). P. A. Norstedt & Söner, Stockholm, pp. 1–68.
Lang, K. (1944) Monographie der Harpacticiden (vorläufige Mitteilung). Almqvist & Wiksells Boktryckeri AB, Uppsala, 39 pp.
Lang, K. (1948) Monographie der Harpacticiden. Vols. 1 & 2. Nordiska Bokhandeln, Stockholm, 1682 pp.
Lee, W. & Huys, R. (1999) New Normanellidae (Copepoda: Harpacticoida) from western Pacific cold seeps including a review of the genus Normanella. Cahiers de Biologie Marine, 40, 203–262.
Maddison, W.P. & Maddision, D.R. (2019) Mesquite: a modular system for evolutionary analysis. Version 3.61. Available from: https://www.mesquiteproject.org (accesed 24 August 2021)
Marinov, T. (1977) Kharpaktikoidi ot tsentralnata chast na iztochnoto kraibrezhie na Atlanticheskiya okean [Harpacticoida from the Eastern Central Atlantic Coast]. Izvestiya na Instituta Okeanografiya I Ribno Stopanstvo, Varna, 15, 83–98. [in Bulgarian with English and Russian summary]
Marinov, T. & Apostolov, A. (1985) Copépodes harpacticoïdes de l’Océan Atlantique. 1. Espèces des cotes du Sahara espagnol. Cahiers de Biologie Marine, 26, 165–180.
Monard, A. (1935a) Étude sur la faune des harpacticoïdes marins de Roscoff. Travaux de la Station Biologique de Roscoff, 13, 5–88.
Monard, A. (1935b) Les harpacticoïdes marins de la région de Salammbô. Bulletin de la Station Océanographique de Salammbô, 34, 1–94.
Nicholls, A.G. (1941) A revision of the families Diosaccidae Sars, 1906 and Laophontidae T. Scott, 1905 (Copepoda, Harpacticoida). Records of the South Australian Museum, 7, 65–110.
Nicholls, A.G. (1945) Marine Copepoda from Western Australia. III. Littoral harpacticoids from Port Denison. Journal of the Royal Society of Western Australia, 29, 1–16.
Philippi, A. (1840) Zoologische Bemerkungen (Fortsetzung). Archiv für Naturgeschichte, 6, 181–195.
Por, F.D. (1959) Harpacticoide noi (Crustacea, Copepoda) din Mîlurile Mării Negre. Studii Si Cercetări de Biologie Seria Biologie Animalia, 11, 347–368.
Rambaut, A. (2018) FigTree v1.4.4. Available from: http://tree.bio.ed.ac.uk/software/figtree/ (accessed date 24 August 2021)
Rohal, M., Thistle, D. & Easton, E.E. (2016) Extraction of metazoan meiofauna from muddy deep-sea samples: operator and taxon effects on efficiency. Journal of Experimental Marine Biology and Ecology, 502, 105–110. https://doi.org/10.1016/j.jembe.2017.01.006
Ronquist, F., Teslenko, M., van der Mark, P., Ayres, D.L., Darling, A., Höhna, S., Larget, B., Liu, L., Suchard, M.A. & Huelsenbeck, J.P. (2012) Mrbayes 3.2: Efficient bayesian phylogenetic inference and model choice across a large model space. Systematic Biology, 61, 539–542. https://doi.org/10.1093/sysbio/sys029
Sars, G.O. (1903) Copepoda Harpacticoida. Parts I & II. Misophriidae, Longipediidae, Cerviniidae, Ectinosomidae. An account of the Crustacea of Norway with short descriptions and figures of all the species, 5, 1–28.
Sars, G.O. (1905) Copepoda Harpacticoida. Parts VII & VIII. Idyidae (continued), Thalestridae (part). An account of the Crustacea of Norway with short descriptions and figures of all the species, 5, 81–108.
Sars, G.O. (1908) Copepoda Harpacticoida. Parts XXIII & XXIV. Laophontidae (continued). An account of the Crustacea of Norway with short descriptions and figures of all the species, 5, 257–276.
Sars, G.O. (1909) Copepoda Harpacticoida. Parts XXV & XXVI Laophontidae (concluded), Cletodidae (part). An account of the Crustacea of Norway with short descriptions and figures of all the species, 5, 277–304.
Scott, T. (1905) On some new and rare Crustacea from the Scottish seas. Reports of the Fishery Board for Scotland, 23, 141–153.
Scott, T. & Scott, A. (1893) On some new or rare Crustacea from Scotland. Annals and Magazine of Natural History, Series 6, 15, 237–246. https://doi.org/10.1080/00222939308677614
Stĕrba, O. (1968) Neue Harpacticoidea (Crustacea, Copepoda) aus dem asiatischen Teil der Paläarktis. Zoologischer Anzeiger, 180, 50–68.
Vervoort, W. (1964) Free-living Copepoda from Ifaluk Atoll in the Caroline Islands with notes on related species. Bulletin of the United States National Museum, 236, 1–431. https://doi.org/10.5479/si.03629236.236.1
Willey, A. (1930) Harpacticoid Copepoda from Bermuda. Part I. Annals and Magazine of Natural History, Series 10, 6, 81–114. https://doi.org/10.1080/00222933008673192
Willey, A. (1935) Harpacticoid Copepoda from Bermuda. Part II. Annals and Magazine of Natural History, Series 10, 15 (85), 50–100. https://doi.org/10.1080/00222933508654944