Journal of Molluscan Studies Advance Access published 5 June 2014 Journal of The Malacological Society of London Molluscan Studies Journal of Molluscan Studies (2014) 1–13. doi:10.1093/mollus/eyu024 PHYLOGENETICS OF THE GASTROPOD GENUS NUCELLA (NEOGASTROPODA: MURICIDAE): SPECIES IDENTITIES, TIMING OF DIVERSIFICATION AND CORRELATED Downloaded from PATTERNS OF LIFE-HISTORY EVOLUTION PETER B. MARKO1,AMYL.MORAN1, NATALYA K. KOLOTUCHINA2 AND NADEZHDA I. ZASLAVSKAYA2,3 http://mollus.oxfordjournals.org/ 1Department of Biology, University of Hawaii at Manoa, Honolulu, HI 96822, USA; 2A. V. Zhirmunsky Institute of Marine Biology, Far East Branch, Russian Academy of Sciences, Vladivostok, Russia; and 3Far Eastern Federal University, Vladivostok, Russia Correspondence: P. Marko, e-mail:
[email protected] (Received 3 October 2013; accepted 20 February 2014) ABSTRACT Despite the importance of Nucella as a model system in numerous fields of biology, no phylogenetic ana- at University of Hawaii Manoa Library on September 3, 2015 lysis of the genus, including every widely recognized species, has been conducted. We have analysed about 4,500 bp of DNA from six different genes (three mitochondrial, three nuclear) from each taxon in the genus. Our results showed western Pacific N. heyseana and N. freycinetii as distinct and distantly related, but found no evidence that N. elongata is distinct from N. heyseana. We also resolved N. heyseana as the closest living relative of the North Atlantic N. lapillus and, using the fossil record for calibration, inferred a minimum separation time between Atlantic and Pacific lineages of at least 6.2 Ma, slightly pre-dating the opening of the Bering Strait. Comparative analyses showed egg size to be evolutionarily labile, but also revealed a highly significant negative relationship between egg size and the nurse-egg- to-embryo ratio.