Environmental Influence on Maturity Stage Spatial Distribution of Whitemouth Croaker (Micropogonias furnieri) Along an Estuarine Gradient

JAUREGUIZAR, A.J; MILITELLI, M I; GUERRERO, RA

Campeche

Congreso; International Conference on Coastal Ecosystems (ICCE): Towards and Integrated Knowledge for an Ecosystem Approach for Fisheries; 2006

The maturity stage distribution of the whitemouth croaker (Micropogonias furnieri) and it relationship to environmental factors was evaluated from 194 stations sampled between 1994, 95, 96, 97, 98, 99 and 2003 during spring within the Rio de la Plata estuary (36º S, 56º W). A canonical correspondence analysis (CCA) was used to define maturity stage spatial distribution of whitemouth croaker and to estimate their association with environmental factors (depth, temperature and salinity of surface and bottom waters, horizontal gradient of bottom salinity and bottom temperature, and vertical stratification). Results indicated that bottom salinity has a major influence on the spatial distribution pattern of M. furnieri maturity stage from spent and resting stage, associated to high salinities, to immature and gravid (with hydrated oocytes) and running stage, associated to low salinity, across developing and partially spent stage. Although immature stage, and gravid and running stage are associated to similar bottom salinities, the gravid and running stage were associated to high bottom salinity horizontal gradient. That distinct preferences for different bottom salinities and bottom salinity horizontal gradient by the various maturity stage of this species results in a differential distribution pattern along the main axis of the estuary.