El ictioplancton constituye un componente importante en las comunidades planctónicas y comprende los huevos, larvas, postlarvas y, algunas veces, los juveniles de peces (Ciechomski, 1981; Matsuura & Olivar, 1999). Su relevancia radica en que proporcio

The taxonomy, spatial distribution, and abundance patterns of ichthyoplankton collected in September 2005 from the coastal zone of Gorgona Island National Natural Park in the Colombian Pacific Ocean were analyzed. The ichthyoplankton in the study area was collected with oblique tows using a minibongo net (30 cm; 250 μm mesh). The tows were made from variable depths depending on the stations but never exceeding 50 m. A sampling grid with 24 stations was used. Fish larvae abundance was between 69 and 16,837 larvae•1000 m-3. Larval stages of 35 species belonging to 14 families were identified. Gobiidae (35%) and Sciaenidae (15%) were the most abundant and frequent families. Lythrypnus sp. (8,519 larvae•1000 m-3) and Sciaenidae spp. (6,553 larvae•1000 m-3) were the most abundant and frequent species. The analysis of larval spatial distribution suggested a tendency to aggregate towards the south of the study zone, approximately 5 km offshore. Significant differences were detected in the ichthyoplankton abundances between the eastern and the western zones of the study area (Mann-Whitney, p = 0.000062). However, no significant relationship was observed between ichthyoplankton abundance and average temperature (Spearman, R =-0.346), salinity (Spearman, R = 0.227), and water transparency (Spearman, R = 0.10).

Este trabajo presenta resultados de los análisis del ictioplancton obtenidos mediante arrastres superficiales en 23 estaciones de muestreo durante la campaña oceanográfica Pacífico XXXVIII ERFEN XXXVI en la cuenca del océano Pacífico colombiano, CPC. Se identificaron los estadios larvales de 19 especies pertenecientes a 18 familias, en su mayoría de interés para la pesca. Se destacó por su abundancia la familia Photichthyidae, seguida de la familia Hemiramphidae, que presentó la más amplia distribución. Se determinó la distribución y abundancia de huevos mediante el análisis gráfico de mapas de dispersión espacial y se evaluó la relación entre la distribución y abundancia de larvas de peces con la temperatura, salinidad, oxígeno, clorofila-a y variación nictimeral. El comportamiento de las variables físico-químicas no evidenciaron cambios anómalos, considerándose éste período como normal. No se detectaron diferencias significativas para la abundancia del ictioplancton entre el día y la noche (Mann Whitney, P=0.2974). Sin embargo, la distribución y abundancia de las larvas en la zona costera y oceánica estuvo influenciada por la clorofila-a, la temperatura y la salinidad. Teniendo en cuenta el error de muestreo asumido por el uso de una red cónica simple y el tipo de arrastre, se considera que la abundancia de las larvas de peces fue subestimada.

The density, taxonomic composition, and spatial and temporal distribution of the estuarine ichthyoplankton of Bahía Málaga (Pacific coast of Colombia) are described, as well as the relationship between biological parameters and some physicochemical variables. Samples were collected at 12 stations along the principal navigation canal; these samples were taken in four areas following the design of Barletta-Bergan. Surface sweeps were carried out with a conical-cylindrical net (mesh size 500 µm, mouth diameter 0.6 m, length 3.5 m). Salinity and temperature were measured before each sweep. A total of 69019 larvae/1000 m³, representing 23 families, 36 genera and 40 species were collected during monthly sampling from September, 2009 to February, 2010. Carangidae (39.0%) was the most abundant family, followed by Sciaenidae (27.1%) and Engraulidae (20.1%). The most frequent families were Sciaenidae (26.6%), followed by Carangidae (22.8%) and Engraulidae (14.7%) which are important families in larval fish assemblages in tropical estuaries. Eighty percent of total density was provided by six species, of which Seriola morphotype 1 (Carangidae) and Cetengraulis mysticetus (Engraulidae) were the most abundant and dominant. No correlation was found between density and salinity (Spearman, R = 0.23) or temperature (Spearman, R = 0.51). Analysis of spatial and temporal variations of larval density shows significant differences among the months sampled (Anova, p = 0.0029; p < 0.05), but not among areas (Anova, p = 0.078), suggesting that Bahía Málaga offers adequate conditions for the presence of fish larvae.