title: Application of stable isotope analysis for detecting filial cannibalism.
abstract: A novel type of filial cannibalism has been reported in pipefishes, in which the eggs are absorbed through the male's brood-pouch epithelium. The present study explored the applicability of stable isotope analysis for the detection of paternal brood cannibalism in the seaweed pipefish Syngnathus schlegeli. As expected, the δ15N values for liver, which conveys short-term dietary information about the recent reproductive season, were higher in males than in females. In contrast, the δ15N values for muscle, which reflects longer-term feeding habits that span both the reproductive and non-reproductive seasons, did not significantly differ between the sexes. This finding indicates that males occupy a higher trophic position than females only during the reproductive season, and it is probable that this difference is a result of paternal uptake of nutrients from embryos in the brood pouch.
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8528, Japan. Electronic address: atsushi.sogabe@hirosaki-u.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sogabe
authors.affiliation: Center for Marine Environmental Studies, Ehime University, 2-5 Bunkyo-cho, Matsuyama, 790-8577, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Hamaoka
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8528, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fukuta
authors.affiliation: Center for Marine Environmental Studies, Ehime University, 2-5 Bunkyo-cho, Matsuyama, 790-8577, Japan.
authors.forename: Jun-Ya
authors.initials: JY
authors.lastname: Shibata
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8528, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Shoji
authors.affiliation: Center for Marine Environmental Studies, Ehime University, 2-5 Bunkyo-cho, Matsuyama, 790-8577, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Omori
mesh_terms: D000818:Animals; D002190:Cannibalism; D005260:Female; D007553:Isotope Labeling / Q000379:methods*; D008099:Liver / Q000737:chemistry; D008297:Male; D023701:Smegmamorpha / Q000502:physiology*
keywords: Syngnathidae; filial cannibalism; nutrition source; paternal care; stable isotopes