Genotypic stability and physiological tolerance in the dog‐whelk ( Nucella lapillus)

• Published in: Journal of Zoology
• Main Authors: Berry, R. J., Crothers, J. H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1970
• Subjects: Dog whelk; Nucella lapillus
• Online Access: http://dx.doi.org/10.1111/j.1469-7998.1970.tb01266.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1970.tb01266.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1970.tb01266.x; https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1970.tb01266.x

Populations of dog‐whelks living on fully marine shores are in genotypic equilibrium: variation is produced during zygote formation in proportion to the exposure of the shore to wave action, and this variation is eliminated during life. However, populations collected on the Somerset coast where the salinity of the Bristol Channel begins to be reduced by land‐water from the River Severn show no such regular pattern. Out of 15 samples (a total of 4711 individuals) 13 showed signs of temporary extinction or of disruptions of growth apparently caused by periodic food shortages. It is concluded that dog‐whelks from the Bristol Channel live in a colonizing situation in which they are struggling to survive rather than extending their range by increasing their physiological tolerance.