Fish ART & sperm performance

• In species with alternative reproductive tactics (ART), parasitically spawning males have larger testes and greater sperm numbers as an evolved response to a higher degree of sperm competition. But do they also have higher sperm performance? We used sand gobies to test if it differs between breeding-coloured and sneaker-morph males. We compared sperm motility, velocity, longevity, morphometrics and gene expression of testes between the two morphs. We found 109 transcripts differentially expressed between the morphs. Notably, several mucin genes were upregulated in breeding-coloured males and two ATP-related genes were upregulated in sneaker-morph males. There was partial evidence of higher sperm velocity in sneaker-morph males, but no difference in sperm motility. Sand gobies have remarkably long-lived sperm, with almost no decline in motility and velocity over 22 hours, but again, this was equally true for both morphs. Sperm length did not differ between morphs and did not correlate with sperm velocity for either morph. Thus, other than a clear difference in testes gene expression, we found only modest differences between the two male morphs, confirming previous findings that increased sperm performance as an adaptation to sperm competition does not appear to be a primary target of evolution.

Subject headings

NATURVETENSKAP  -- Biologi -- Evolutionsbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Evolutionary Biology (hsv//eng)

NATURVETENSKAP  -- Biologi -- Genetik (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Genetics (hsv//eng)

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

Keyword

Lärarutbildning och pedagogisk yrkesverksamhet

Teacher Education and Education Work

Publication and Content Type

ref (subject category)

kon (subject category)