|Changes in temperature tolerance of Balanus balanoides during its life-cycle|
|Crisp, D.J.; Ritz, D.A. (1967). Changes in temperature tolerance of Balanus balanoides during its life-cycle. Helgol. Wiss. Meeresunters. 15(1-4): 98-115. dx.doi.org/10.1007/BF01618612|
|In: Helgoländer Wissenschaftliche Meeresuntersuchungen. Biologische Anstalt Helgoland: Hamburg. ISSN 0017-9957, more|
|Also published as |
- Crisp, D.J.; Ritz, D.A. (1967). Changes in temperature tolerance of Balanus balanoides during its life-cycle, in: Kinne, O. et al. (Ed.) (1967). Vorträge und Diskussionen. Erstes Europäisches Symposion über Meeresbiologie = Papers and discussions. First European Symposium on Marine Biology = Rapports et discussions. Premier symposium européen sur biologie marine. Helgoländer Wissenschaftliche Meeresuntersuchungen, 15(1-4): pp. 98-115. dx.doi.org/10.1007/BF01618612, more
1. The barnacle Balanus balanoides exhibits little seasonal variation in upper lethal temperatures in North Wales.
2. There are marked seasonal changes in resistance to sub-zero temperatures, the lower lethal varying from –6.0° C in June to –17.6° C in January.
3. Exceptional tolerance to cold is acquired between December and January and is lost between February and April. Although these dates coincide with oviposition and naupliar liberation respectively, it was found that cold tolerance did not necessarily depend upon, or accompany, the normal breeding cycle.
4. Cold tolerance was not acquired by animals kept cold in the laboratory during winter, nor was it lost in animals kept in the laboratory during spring. There was no evidence that changes in nutrition or in the light régime led to loss of cold tolerance.
5. The cyprids were considerably less resistant to both high and low temperatures than the overwintering adults and the late-stage embryos. There was a marked increase in resistance at metamorphosis.
6. The appearance of cold tolerance in the adult coincides with a period of ldquophysiological hibernationrdquo, involving loss of certain tissues, diminished feeding activity, respiration and biosynthesis. The metabolic inactivity of the animal may be a factor promoting the greatly increased tolerance to cold that we have observed, while the composition of the body fluids may also be modified during the winter in such a way as to protect the tissues.