Laonice species (Polychaeta, Spionidae) from the Whittard Canyon (NE Atlantic) with descriptions of two new species

• Published in: Journal of the Marine Biological Association of the United Kingdom
• Main Authors: Sikorski, Andrey, Gunton, Laetitia M., Pavlova, Lyudmila
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2017
• Subjects: Aquatic Science; North Atlantic
• Online Access: http://dx.doi.org/10.1017/s0025315417000480; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315417000480

Four species of Laonice (Annelida: Spionidae) were collected from the lower bathyal depths (3300–3700 m) in the Whittard Canyon, NE Atlantic. Two are herewith described as new species: Laonice whittardensis sp. nov. and Laonice natae sp. nov. The other two are Laonice blakei Sikorski & Jirkov, 1988 and Laonice magnacristata Maciolek, 2000. Laonice whittardensis has genital pouches appearing from chaetiger 3, prostomium free of peristomium and bidentate hooks. Laonice natae belongs to the subgenus Appelloefia nov. with prostomium distinct from the peristomium, more than two vertical rows of capillaries in several anterior chaetigers, genital pouches present on a limited number of segments or totally absent. However, the absence of pronounced anterior widening of the body together with anterior branchiae, which are remarkably (nearly twice) longer than the notopodial postchaetal lobes, the narrow lanceolate notopodial postchaetal lobes, the pronounced pointedness of all postchaetal lobes (both notopodial and neuropodial) in the anterior half of body at least, and absence of genital pouches and the size of the body all distinguish L. natae from other species belonging to this subgenus. An identification key to all nine known deep-water (>400 m depth) Laonice species in North Atlantic is given and four previously recognized sub-generic groups are formally named: Laonice, Sarsiana subgen. nov., Appelloefia subgen. nov., Norgensia subgen. nov.