3.3. Gonadosomatic female indices
The trend of the OGI and GI indices during the period of study
was similar, reaching a minimum in November, with a gradual
increase in the following months, little variation in May, and
reaching the highest value in June. The general tendency of the
Guerra index (M) was the opposite, with high values in the first
months of sampling and low values in the last. In this case the
highest value was reached in November and the minimum in
March (Table 2). Unlike the OGI and GI indices, the M index
reached the lowest values corresponding to the highest maturity
stages.
In Fig. 2, the percentage of immature females (M1), females
with developing gonads (M2) and mature females (M3) are
shown for each month of sampling. During the period of study,
no post-spawning females (M4) were found. We observed 50%
of mature females in January and more than80%in the following
months, with the highest percentage (96%), of mature females
corresponding to March. In this period (November–June), taking
into account both gonadosomatic indices and monthly
percentage of mature females, the greatest female reproductive
development was found between February and June (both
included).