Thermal histories of brooding lobsters, Homarus americanus, in the Gulf of Maine
Although it is widely accepted that migration by ovigerous lobsters (Homarus americanus Milne Edwards) optimizes thermal conditions for embryonic development, temperatures experienced by freely moving lobsters have never been measured. The precise thermal histories of 30 ovigerous lobsters at large in the Gulf of Maine were recorded to compare thermal conditions experienced during a brooding season. Analysis of both the temperature and movement data revealed a clear difference between lobsters smaller and larger than the size when 50% of individuals are mature (carapace length 93 mm). Although small and large lobsters ultimately experienced a similar number of degree-days above 3.4°C (952.8 for small and 983.6 for large) from 25 September 2002 until 27 July 2003, large lobsters and their embryos experienced less extreme and less variable temperatures. They were exposed to more gradual cooling in the fall and more gradual warming in the spring. These data, which are the first to document the seasonal temperatures experienced by ovigerous lobsters, suggest that migrations do not necessarily increase the number of degree-days experienced by developing embryos, but do reduce the variation in their thermal regime.
KeywordsEmbryonic Development Carapace Length Ovarian Maturation Hourly Temperature Homarus Americanus
Financial support was provided by the Northeast Consortium, Darden Restaurants Foundation, National Fish and Wildlife Foundation, and Davis Conservation Foundation. SCUBA and research assistance were provided by Dan O’Grady, Linda Archambault, Michele Walsh, Sara Ellis, and Town of Friendship lobstermen. Chris Brehme created the GIS map. These experiments comply with the current laws of the USA. This manuscript was improved thanks to comments provided by two anonymous reviewers.
- Anonymous (1993) American lobster. Northeast Fish Sci Cent Ref Doc 93–18:75–107Google Scholar
- Campbell A, Duggan DR (1980) Review of the Grand Manan lobster fishery with an analysis of recent catch and effort trends. Can Tech Rept Fish Aquat Sci 997:1–20Google Scholar
- Comeau M, Savoie F (2002) Movement of American lobster (Homarus americanus) in the southwestern Gulf of St. Lawrence. Fish Bull 100:181–192Google Scholar
- Estrella BT, McKiernan DJ (1989) Catch-per-unit-effort and biological parameters from the Massachusetts coastal lobster (Homarus americanus) resource: description and trends. US Dept Commerce, NOAA Tech Rep NMFS SSRF 81Google Scholar
- Fogarty MJ, Borden DVD, Russell HJ (1980) Movements of tagged American lobster, Homarus americanus, off Rhode Island. Fish Bull 78:771–780Google Scholar
- Herrick FH (1895) The American lobster: a study of its habits and development. Bull US Commun Fish 15:1–252Google Scholar
- Krouse JS (1973) Maturity, sex ratio, and size composition of natural population of American lobster, Homarus americanus, along the Maine coast. Fish Bull 71:165–173Google Scholar
- Krouse JS (1980) Summary of lobster, Homarus americanus, tagging studies in American waters (1898–1978). Can Tech Rep Fish Aquat Sci 932:135–140Google Scholar
- Perkins HC (1972) Development rates at various temperatures of embryos of the northern lobster (Homarus americanus Milne-Edwards). Fish Bull 70:95–99Google Scholar
- Pezzack DS, Tremblay MJ, Hudon C, Miller RJ (1992) The inshore-offshore lobsters issue in southwestern Nova Scotia. Can Manuscr Rep Fish Aquat Sci 2165: 31pGoogle Scholar
- Shiino S (1950) Studies on the embryonic development of Panulirus japonicus (von Siebold). J Fac Fish Univ Mie-Tsu 1:1–168Google Scholar
- Uzmann JR, Cooper RA, Pecci KJ (1977) Migration and dispersion of tagged American lobsters, Homarus americanus, on the southern New England continental shelf. NOAA Tech Rept NMFS SSRF-705, pp 1–92Google Scholar