INTROPICA

13-20

Authors: Albeiro Aguado, Hernando Suárez

Was studied the life cycle under laboratory conditions, the damage, density of population of A. riochama Kingsolver on P. juliflora (SW) DC in the urban zone of Santa Marta, (Magdalena, Colombia). The insect was identified, and action of parasitoids natural enemies; was evaluated in 14 sites with trees of P. juliflora. The work was realized in 2002. The life cycle presented four larval instars, with mean duration of 23 days, were recorded parasitoids natural enemies of the Order Hymenoptera and families Pteromalidae, Braconidae, Bethylidae and Chalcididae. The infestation in pods was of 55, 9 % and density population of 1.716 adults by 100 pods.

33-41

Authors: Héctor Martínez-Viloria, Juan Carlos Narváez, Roberto Rivera, Oscar D. Solano

One of the most important artisanal fisheries in northern Colombia is being developed in the deltaic estuarine zone of the Sinú River (ZDERS). Little is known about the impact on the resource caused by fishing gears and even less about those which are not allowed. In order to estimate the selectivity of gillnets or «trasmallos» in this artisanal fishery, selection parameters for five of the main commercial species, Mugil incilis, Eugerres plumieri, Prochilodus magdalenae, Ariopsis bonillai and Centropomus undecimalis, in 2001 and 2002, length frequency data for mesh sizes in the main landing sites were collected. A total of 16427 individuals were caught with mesh sizes from 5.08 to 10.16 cm stretched. It has been determined that gill nets exerts a negative pressure on the studied species when used with mesh sizes of 5.08 and 7.62 cm. Optimal catch length for each species, estimated with different mesh sizes, were found below the mean length of sexual maturity. The same effect was observed with those species reaching big sizes (C. undecimalis, A. bonillai and P. magdalenae) when fished with gill nets whose mesh size was 10.16 cm. Observed Selection factor values were low for E. plumieri and P. magdalenae, and high for M. incilis, A. bonillai and C. undecimalis. Differences in selection factor were attributed to the morphology of each species, tall (E. plumieri and P. magdalenae), oblong (M. incilis and A. bonillai) and long fishes (C. undecimalis). Minimum catch length and mesh sizes for each species are recommended. Some aspects on the sustainable management of the fish resource in the ZDERS fishery are discussed.

59-67

Authors: Leandro Castillo, Jaime Dávila, Nicolás Chaparro, Albert Hernández, Saeko Gaitán, Arturo Acero

This research was carried out from may 2004 to january 2005, with the purpose of evaluating rearing in captivity of fingerlins of New Granada sea catfish Ariopsis sp., an apparently endemic species of the north coast of Colombia and catalogued in the red book as «in extinction danger». Six 3 m3 -floating cages were used and they had a density of 20 animals*m-3 each. Two different diets were tested: a 35% commercial concentrate with 35% of protein (T1 ) and fresh fish (T2) belonging to species of low commercial value in the Ciénaga Grande de Santa Marta (CGSM), such as bocona (Cetengraulis edentulus) and mullet (Mugil sp.). In comparison with other previous experiments, significant mortalities did not occur, in spite of the strong changes in salinity, that oscillated between 5,4 and 19,0; dissolved oxygen and temperature did not show significant variations and they were within the appropiate ranks for fish cultures. In T1 the average initial weight was 38,8 g and the final 198,5 g, whereas survival was 83%; in T2 , the average initial weight was 38,8 g and the final 195.4 g, whereas survival was 79%. Significant differences between treatments were not found after 8 months of culture; it was also observed a relatively slow growth, but this is typical of many cultivated catfishes species. The results aim at giving an economic alternative for the fishermen in the CGSM and helping to preserve the species.

77-86

Authors: Jair Deluque, Shisley Reyes, Tatiana Sierra-Labastidas, William López

It presents the families composition of the macroinvertebrate communities associated to the aquatic macrophytes at the Ciénaga Cerro de San Antonio (Magdalena), after a punctual sampling on April 29 of 2004. Were collected 296 individuals from 17 families of arthropods, molluscs and annelids. The Coleoptera order was the highest relative abundance (38%) and the Ephemeroptera order the lowest (1%).

101-108

Authors: Luis Orlando Duarte, Félix Cuello

The Fisheries Assessment and Ecology Information System (SIEEP) was constructed to validate, standardize and store biotic and abiotic information for ecological, oceanographic and fisheries studies. Since bycatch studies are required in the shrimp trawl fisheries, the SIEEP has been updated to store fisheries and biological data from bycatch samples analysed on board and in laboratory. In addition, the performance of the system was optimized, interfaces for catch, size and reproductive data were included and the performance of the system was optimised. Information of the bycatch assessment in the shrimp trawl fishery of the Colombian Caribbean Sea and information of the experimental trials of bycatch reduction devises in such fishery was the first application of the new version of the system (V. 1.1). A total of 723 tows and 27 scientific cruises were stored. Detailed biological information of 730 taxa, including more than 180000 records of individual size and 84000 records of individual weights, was obtained. An important fraction of the recent data belonged from the southern fishing zone of the Colombian Caribbean Sea which complements data previously collected in the northern fishing zone, thus a valuable informative basis for the integrated management of the fisheries resources is established. The system is a new digital platform for storing data derived from shrimp bycatch monitoring, useful for scientist and institutions related with the study and management of living marine resources. Contributions with data and initiatives for the permanent update of the SIEEP will be appreciated.

109-112

Authors: Rodrigo Turizo-Correa, César Tamarís-Turizo, Guillermo Rueda-Delgado

A continuous water-flow system was adapted to rear stonefly nymphs of the genus Anacroneuria in laboratory, the system includes a combination of rearing cameras and traditional aquaria, this system guarantee a water flow in the rearing cameras; the system and were adapted to the local temperature and oxygen conditions. The system to allow the association of 13 nymphs with your correspond adult, with times of emergency between 1 and 30 days.