title: Effects of environmental factors on sperm motility and fertilization rate of Phascolosoma esculenta.
abstract: The study investigated the effects of environmental factors (salinity, pH, ions and activation media) on sperm motility (activation rate, duration of quick movement, and lifespan) and fertilization rate of Phascolosoma esculenta. The results showed that spermatozoa in the coelom and nephridium are able to move quickly. The optimal salinity was 14.64 to 43.35 and the optimal pH was 6.46 to 9.53 for sperm activation and motility, whereas the ranges for fertilization were narrower (18.56 to 30.3 for salinity and 6.46 to 8.61 for pH). Of the ions studied, Na+ was indispensable for sperm motility and fertilization, and Ca2+ and Mg2+ were necessary for fertilization. P. esculenta sperm could not fertilize eggs and have short lifespans in 200 to 600 mmol/L NaCl and KCl solutions. Furthermore, they could not be activated or move in 200 to 600 mmol/L CaCl2, MgSO4, and sucrose solutions.
authors.affiliation: Ningbo University School of Marine Sciences Ningbo, Zhejiang 315211 China.
authors.forename: Z
authors.initials: Z
authors.lastname: Sheng
authors.affiliation: Ningbo University School of Marine Sciences Ningbo, Zhejiang 315211 China Zhejiang Institute of Freshwater Fisheries Huzhou, Zhejiang 313001 China.
authors.forename: J-H
authors.initials: JH
authors.lastname: Jiang
authors.affiliation: Ningbo University School of Marine Sciences Ningbo, Zhejiang 315211 China.
authors.forename: C-H
authors.initials: CH
authors.lastname: Jin
authors.affiliation: Ningbo University School of Marine Sciences Ningbo, Zhejiang 315211 China.
authors.forename: S-J
authors.initials: SJ
authors.lastname: Xu
authors.affiliation: Ningbo University School of Marine Sciences Ningbo, Zhejiang 315211 China.
authors.forename: J-Q
authors.initials: JQ
authors.lastname: Zhu
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002122:Calcium Chloride / Q000378:metabolism / Q000494:pharmacology; D004777:Environment; D005306:Fertilization / Q000187:drug effects; D005399:Fishes / Q000378:metabolism / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000378:metabolism; D008278:Magnesium Sulfate / Q000378:metabolism / Q000494:pharmacology; D008297:Male; D054712:Salinity; D012623:Seawater / Q000737:chemistry*; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism / Q000494:pharmacology; D013081:Sperm Motility / Q000187:drug effects; D013395:Sucrose / Q000378:metabolism / Q000494:pharmacology
chemical_list: D012965:Sodium Chloride; D013395:Sucrose; D008278:Magnesium Sulfate; D012964:Sodium; D008274:Magnesium; D002122:Calcium Chloride; D002118:Calcium
keywords: Phascolosoma esculenta; environmental factors; fertilization rate; sperm motility