Variation in the Sizes of Chthamalid Barnacle Post-Settlement Cyprids on European Shores |
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| Authors: | Ruth M O'Riordan Jane Delany David McGrath Alan A Myers Anne Marie Power Neil F Ramsay Damaso Alvarez Teresa Cruz Federica G Pannacciulli Pedro Range & Giulio Relini |
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| Institution: | Department of Zoology and Animal Ecology, University College Cork, National University of Ireland-Cork, Lee Maltings, Prospect Row, Cork City, Ireland. ; Present address: Dove Marine Laboratory, University of Newcastle, Cullercoats, North Shields, Tyne and Wear NE30 4PZ, England. ; Department of Life Sciences, Galway-Mayo Institute of Technology, Galway, Ireland. ; Present address: Cavanilles Institute of Biodiversity &Evolutionary Biology, University of València, Polìgono de la Coma s/n, 46980 Paterna, València, Spain. ; Unidad de Ecologia, Departmento de Biologia de Organismos y Sistemas, Universidad da Oviedo, 33071-Oviedo, Spain. ; Laboratório de Ciências do Mar, Universidade de Évora, Apartado 190, 7521 Sines Codex, Portugal. ; Laboratori di Biologia Marina ed Ecologia Animale, DIP.TE.RIS, Universitàdi Genova, Via Balbi 5, Genova 16126, Italy. ; Present address: Marine Environment Research Centre, ENEA –Santa Teresa, P.O. Box 224, Pozzuolo di Lerici, 19100-La Spezia, Italy. ; Laboratório Marítimo da Guia, Estrada do Guincho, 2750 Cascais, Portugal. |
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| Abstract: | Abstract. As part of a wider study on the settlement and recruitment of Chthamalus spp. in Europe, this study investigated whether chthamalid cyprids can be separated by length on a European scale. Variation in cyprid length with latitude and temporal variation at selected localities were also examined. The lengths of cyprids collected between 1996 – 1999 on nine rocky shores in Europe are reported. Elminius modestus cyprids were found only at Roscoff, NW France and could be distinguished due to their carapace shape and length. They showed a unimodal length distribution, measuring between 450 and 625 µm, with no variation in length between the two sampling dates (1997 and 1998). Based on carapace shape and length, the remaining cyprids in the collections were identified as one of three chthamalid species, Chthamalus montagui, Chthamalus stellatus or Euraphia depressa. Bimodal length distributions of chthamalid cyprids were seen on some shores, while others had a single small‐sized modal group (representing C. montagui on Atlantic shores and/or E. depressa in the Mediterranean) separated from a few distinctly larger cyprids (C. stellatus). Metamorphs collected simultaneously with cyprid collections were identified as C. stellatus or C. montagui, except at Roscoff, where E. modestus were also found. In southern Portugal, where all metamorphs collected were C. montagui and adult C. montagui were the dominant barnacles, most cyprids measured between 350 and 550 µm long and this size distribution coincides with the distribution expected for C. montagui. Cyprids collected on these four more southerly Portuguese shores had the same modal length class (475 µm) and this remained constant between successive years at Luz and Albufeira, Algarve. The smallest (350 µm long) wild chthamalid cyprids found were from southern Portugal and Italy. In Spain, France and Ireland the smallest chthamalid cyprid was 425 µm long. The results from the present study support the hypothesis that on Atlantic shores cyprids of C. montagui can be separated from those of C. stellatus based on size, although there is some variation in cyprid length with latitude as well as temporal variation at selected localities. |
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| Keywords: | Chthamalid barnacles cyprids settlement Europe |
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