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Factors Affecting Motility Characteristics and Fertilizing Ability of Sea Lamprey Spermatozoa
Author(s) -
Ciereszko Andrzej,
Dabrowski Konrad,
Toth Gregory P.,
Christ Susan A.,
Glogowski Jan
Publication year - 2002
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(2002)131<0193:famcaf>2.0.co;2
Subject(s) - motility , sperm motility , sperm , biology , petromyzon , lamprey , andrology , human fertilization , semen , anatomy , fishery , botany , microbiology and biotechnology , medicine
This study was conducted to determine the basic motility characteristics of the spermatozoa (hereafter, sperm) of sea lampreys Petromyzon marinus using computer‐assisted motility analysis. We determined the effects of NaCl, KCl, and pH on semen motility. We also tested the effects of time after activation and sterilization on sperm motility and fertilizing ability. Sperm motility was inhibited by high osmolality (80 mM NaCl or KCl). There were inverse relationships between the NaCl concentration and straight‐line velocity (VSL; r 2 = 0.97, P < 0.01) and linearity (LIN; r 2 = 0.81, P < 0.05). The duration of sperm motility decreased with increases in pH. Positive linear relationships were obtained between pH and VSL ( r 2 = 0.79, P < 0.01 ) and LIN ( r 2 = 0.78, P < 0.01 ). Sperm motility decreased with time; a 50% decrease in motile cells was observed 4 min after activation; after 10 min, only 7% of the sperm were still motile. Fertilizing ability declined to 27% after a 2‐min exposure and to 0.4% after 4 min. Sperm motility was prolonged in the presence of substances produced by females, either coelomic fluid or egg water. Semen from males treated with bisazir (a sterilant) was similar to that of the control treatment in sperm concentration, motility, and fertilization rate; however, almost no hatched larvae were observed. Our results indicate that sea lamprey sperm are kept immotile by rather high osmolality. The duration of sea lamprey sperm movement is among the longest of freshwater fish. Motility characteristics may be modulated by sodium and potassium ions and pH. A peculiar characteristic of sea lamprey sperm is the presence of oval‐shaped blebs on the tail. These results provide a basis for future evaluation and control of the reproductive function in sea lampreys.