Journal
<p>Amphidromous gobies are usually nest spawners.<br />
Females lay a large number of small eggs under stones<br />
or onto plant stems, leaves or roots while males take care of<br />
the clutch until hatching. This study investigates the breeding<br />
pattern and paternal investment of Sicyopterus lagocephalus<br />
in a stream on Reunion Island. In February 2007<br />
and January 2010, a total of 170 nests were found and the<br />
presence of a goby was recorded at 61 of them. The number<br />
of eggs in the nests ranged from 5,424 to 112,000 with an<br />
average number of 28,629. We showed that males accepted a<br />
single female spawning in the nest and cared for the eggs<br />
until hatching. The probability for a nest to be guarded<br />
increased with the number of eggs within it, suggesting that<br />
paternal investment depends on a trade-off between the<br />
reproductive value of the current reproduction and future<br />
nesting events. We showed that large nest stones were<br />
occupied by large males (TL [80 mm), whereas smaller<br />
males (TL \50 mm) were found under smaller cobbles,<br />
probably because of male–male competition for available<br />
nests. Our results suggest that the male’s choice relies upon a<br />
similarity to the female size, while the female’s choice was<br />
based on both body and nest stone sizes.</p>
