[eng] Mullus surmuletus Linné, 1758 is one of the most important target species of Iberian
Peninsula fisheries, including the Balearic Islands, where the official registers of annual
catch vary between 100 and 400 tones. However, in the last 7 years, annual catches have
been decreasing and now they oscillate between 60 and 100 tonnes. Despite its economic
relevance, some of its reproductive aspects are still unknown. The objective of the present
study is to characterise the reproductive ecology of M. surmuletus including the
reproductive cycle and strategy, fecundity, population distribution and size-at-maturity.
This study was based in the analysis of 1998 individuals obtained with two different
fishing gears, trammel and trawling, captured between 13 and 518 m depth (mostly at
depths inferior to 100 m), covering an entire year of sampling. The population structure
of this species showed a marked bathymetric pattern, with the presence of larger
individuals at shallower waters (< 50 depth), as well as a marked sex ratio segregation
between shallow and deeper waters. Macroscopic and microscopic analyses of the gonads
as well as Gonado Somatic Index showed a seasonal reproductive cycle with the presence
of spawning females from March to May, while males spawn from January to May. The
size-at-maturity was 14,4 cm for females and 12,2 cm for males. The size-frequency
distribution of oocyte diameter showed an asynchronic ovarian organisation. The
counting of mature oocytes in females just prior to spawn showed a total fecundity of
approximately 335000 ± 75000 oocytes per female.