Detailed surface morphology of the ‘lobster louse’ copepod, Nicothoë astaci, a haematophagous gill parasite of the European lobster, Homarus gammarus

• Published in: Journal of invertebrate pathology Vol. 122; pp. 48 - 51
• Main Authors: Davies, Charlotte E., Thomas, Gethin R., Maffeis, Thierry G.G., Wootton, Emma C., Penny, Mark W., Rowley, Andrew F.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2014
• Subjects: Animals; Copepoda - anatomy & histology; Cryo-scanning electron microscopy; Feeding adaptations; Microscopy, Electron, Scanning; Morphology; Nephropidae - parasitology; Nicothoidae; Parasitic copepod; Nicothoidae; Cryo-scanning electron microscopy; Morphology; Feeding adaptations; Parasitic copepod
• ISSN: 0022-2011; 1096-0805
• DOI: 10.1016/j.jip.2014.08.006

[Display omitted] •Nicothoë astaci infests the gills of the European lobster, Homarus gammarus.•The study examines surface morphology of the parasite; chiefly, feeding adaptations.•The edge of the oral disc is lined with numerous setae.•The surface of the disc is covered with numerous small teeth-like structures.•These adaptations aid in parasite feeding via a vacuum plus grip. The ectoparasitic copepod, Nicothoë astaci (the ‘lobster louse’), infests the gills of the European lobster, Homarus gammarus. There have been limited studies on this haematophagous species; therefore knowledge of this parasite is rudimentary. The current study examines the surface morphology of this parasitic copepod, detached from the host, concentrating on adaptations of the suctorial mouthpart, the oral disc. Cryo-scanning electron microscopy revealed structural adaptations that facilitate attachment of these parasites to the gill filaments of their lobster host. The aperture of the feeding channel, through which host haemolymph is drawn, is only ca. 5μm in diameter. The edge of the oral disc is lined with numerous setae, whilst the surface of the disc is covered with large numbers of small (<1μm in diameter) teeth-like structures, which presumably pierce through, and grip, the cuticle lining of the host’s gill. Overall, these structures are thought to provide a ‘vacuum seal’ to assist in pumping of blood, via peristalsis, into the alimentary canal of the copepod host.