title: Acute hypoxic exposure affects gamete quality and subsequent fertilization success and embryonic development in a serpulid polychaete.
abstract: Hypoxia likely compromises the reproductive success of those marine organisms carrying out external fertilization because their gametes and embryos are inevitably exposed to the external environment. Hydroides elegans, a dominant serpulid polychaete in Hong Kong waters, can spawn throughout the year but the number of recruits drops during summer when hypoxia commonly occurs. This study attempted to explain such observation by investigating the gamete quality, including sperm motility, egg size, complexity and viability, after 1-h hypoxic exposure (1 mg O2 l(-1)). In addition, how gamete quality affects fertilization success and embryonic development was examined. After 1-h hypoxic exposure, sperm motility was significantly reduced, compromising fertilization success. Although the eggs remained viable, more malformed embryos and retarded embryonic development were observed. We interpreted that the harmful effect of hypoxia on embryonic development was attributed to the teratogenicity and induced oxidative stress, ultimately causing the reduction in recruitment during summer.
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Hong Kong, China; State Key Laboratory in Marine Pollution, City University of Hong Kong, Hong Kong, China.
authors.forename: P K S
authors.initials: PK
authors.lastname: Shin
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Hong Kong, China.
authors.forename: J Y S
authors.initials: JY
authors.lastname: Leung
authors.affiliation: Department of Biology, Hong Kong Baptist University, Hong Kong, China.
authors.forename: J W
authors.initials: JW
authors.lastname: Qiu
authors.affiliation: School of Life Sciences, Chinese University of Hong Kong, New Territories, Hong Kong, China.
authors.forename: P O
authors.initials: PO
authors.lastname: Ang
authors.affiliation: Department of Biology, Hong Kong Baptist University, Hong Kong, China.
authors.forename: J M Y
authors.initials: JM
authors.lastname: Chiu
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: V
authors.initials: V
authors.lastname: Thiyagarajan
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Hong Kong, China; State Key Laboratory in Marine Pollution, City University of Hong Kong, Hong Kong, China. Electronic address: bhsgche@cityu.edu.hk.
authors.forename: S G
authors.initials: SG
authors.lastname: Cheung
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D004625:Embryo, Nonmammalian; D047108:Embryonic Development; D005260:Female; D005306:Fertilization; D005854:Germ Cells / Q000502:physiology; D006723:Hong Kong; D008297:Male; D010063:Ovum / Q000502:physiology; D011077:Polychaeta / Q000196:embryology / Q000502:physiology*; D012098:Reproduction / Q000502:physiology; D012623:Seawater / Q000737:chemistry*; D013081:Sperm Motility
keywords: Embryonic development; Fertilization success; Gametes; Hydroides elegans; Hypoxia; Malformation