TY - JOUR AU - Kupriyanova, Elena K. PY - 2006/12/30 Y2 - 2024/03/28 TI - Fertilization success in Galeolaria caespitosa (Polychaeta: Serpillidae): gamete characteristics, role of sperm dilution, gamete age, and contact time JF - Scientia Marina JA - Sci. mar. VL - 70 IS - S3 SE - Articles DO - 10.3989/scimar.2006.70s3309 UR - https://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/136 SP - 309-317 AB - <p align=justify>Variability in gamete traits and the factors affecting fertilization success were studied in a common gregarious broadcast-spawning serpulid polychaete <em>Galeolaria caespitosa</em>. Variability of egg size and sperm velocity were not related to the adult size. High sperm concentrations (10<sup>7</sup>-10<sup>8 </sup>sperm. ml<sup>-1</sup>) were required to achieve fertilization rates of 60-80%. The gamete contact time required to achieve high fertilization rates (70-80%) in <em>G. caespitosa</em> did not exceed 5 minutes of gamete exposure given sufficiently high sperm concentrations. This suggests that attachment of sperm to the egg takes place very rapidly, and a short-term exposure to highly concentrated sperm is a common feature of fertilization ecology of this gregarious species. A sharp decline in fertilization rates at high sperm concentrations usually attributable to polyspermy was not observed. Sperm were motile for up to 6 hours after activation; however, swimming velocity and fertilization success decreased after 2 hours. Eggs of <em>G. caespitosa</em> were fertilizable up to 10 hours after spawning, but the number of embryos resulting from fertilizations by fresh sperm decreased after 2 hours. The gamete traits of G. caespitosa appear to have evolved to enable this sessile organism to reproduce under conditions of high population density and increased risk of polyspermy. </p> ER -