Reproductive biology of Garra regressus and Garra tana (Cypriniformes: Cyprinidae) from Lake Tana, Ethiopia

<p>The reproductive biology of <em>Garra regressus </em>and<em> Garra tana </em>was investigated by collecting monthly samples (January to December 2006) from the southern Gulf of Lake Tana, where these species are endemic. <em>Garra regressus</em> has an extended breeding time from April to October while <em>G. tana</em> breeds throughout the year with a peak from March to July. The mean size at maturity in both the species was not significantly different between the sexes, but <em>G. tana</em> had a significantly lower mean size at maturity than <em>G. regressus</em> in female specimens. Absolute fecundity estimates for <em>G. regressus</em> ranged from 580.8–1800, while those for <em>G. tana</em> ranged from 538.9–2968. Egg size frequency distribution revealed that <em>G. regressus</em> is a multiple spawner, while <em>G. tana</em> is a single spawner. The sex ratio in the total catch of <em>G. regressus</em> was found to be skewed in favour of females (Chi-square, P&lt; 0.05), while those for <em>G. tana</em> was not significantly different from 1:1. The mean size at maturity was not significantly different between the sexes for <em>G. tana</em>.</p><div>