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Papers by Pablo Intriago

Research Square (Research Square), Mar 6, 2024

Journal of Invertebrate Pathology

bioRxiv (Cold Spring Harbor Laboratory), Aug 30, 2023

Multiple PCR analyzes were performed using 19 different primer sets to open and broaden the searc... more Multiple PCR analyzes were performed using 19 different primer sets to open and broaden the search spectrum for shrimp pathogens. In addition, multiple primer pairs for 10 pathogens were compared to see if there were differences in selectivity or sensitivity among them. Some pathogens that did not present histological lesions were detected. The most important outcome was thatthe selection of appropriate primers was the most critical factor in obtaining reliable results. We found high variability in results among primers, and we learned it was prudent to seasonally assess them for the best set selection. It is important to understand that a PCR positive test result alone does not confirm the presence of a viable pathogen or a disease state. Nor, as might be expected, does it mean that the positive PCR test results will be necessarily accompanied by histological lesions characteristic of the targeted pathogen. However, the use of appropriately selected primer sets can reveal whether t...

Aquaculture International

During January 1984, sorne upwelling water was found in the euphotic zone along the coast of Ecua... more During January 1984, sorne upwelling water was found in the euphotic zone along the coast of Ecuador from 1°20'S to 2°30'S. This water was characterized by a relatively low surface temperature of 23°C and the presence of Mesodinium rubrum. The concentration of chlorophyll a was between 0.50 and 1.37 mg/m 3 • Levels of phosphate, nitrate, ammonia and silicate fluctuated between < 0.03 to 0.35 I-Lg-at P0 4-P/I, 0.6 to 3.5 I-Lg-at NOTN/I, 1.0 to 6.0 I-Lg-at NH 4-N/l, and 4.0 to 10.3 I-Lg-at Si0 4-SiIl respectively. In February-March of the same year, a large scale " red tide " bloom of M. rubrum developed, with dense patches, covering an area of one hundred square miles, though the organism was spread over more than two hundred miles along the coast. The maximum number of cells was 7.6 x 10 6 cells/l within and 100 x 10 3 cells/l outside the patches. The sea surface tempe rature was 26°C. The concentration of chlorophyll a varied between 0.5 and 140 mg/m 3 • Nutrient content was similar to that of the previous month. Large concentrations of diatoms and dinoflagellates were most abundant concentrations of up to 600 X 10 3 cells/l and 400 x 10 3 cells/l respectively. Microflagellates were an important component of the phytoplankton community, with concentrations of 100 x 10 3 cells/l extending along the coast from 0° to 3°20'S.

Journal of Aquaculture Research & Development, 2012

The nitrogen flow together with dissolved nutrients and other parameters are described in a large... more The nitrogen flow together with dissolved nutrients and other parameters are described in a large shrimp maturation operation in Ecuador. In summary, only 8.9% of the nitrogen input ended in animal tissue. Nitrate-N and dissolved organic nitrogen (DON) accounted for more than 95% of the nitrogen pool. The nitrogen dynamics in the system is driven by a nitrification based trickling filter attached population and a free living heterotrophic carbon limited in the sump. The average nitrification rate of TAN (total ammonia nitrogen) averaged 44.81 gd-1. The trickling filters worked as a nitrifier body and also reducing the organic load. There is also some evidence that the trickling filters might have also play some role in denitrification. Nitrate never reached high concentrations (<3.7 mg L-1 nitrate-N), hence did not present a danger to the productivity of the system. In general either inorganic or organic phosphorous did not undergo any major change during the study. BOD values in the sump were low averaging 1.1 mg L-1 d-1 more likely as a result of the carbon limitation of the system. A combination of low C:N ratio and high load of organic nitrogen in the trickling filter could be part of the key factors running this system. The semi closed recirculating system presented in this study has been used since 2004 providing a steady yield of nauplii without the seasonal effects typical of open system and without the accumulation of deleterious amount of waste nitrogen or the presence of pathogens. The present study demonstrates the feasibility of using a simple and inexpensive semi closed recirculating systems in a large commercial scale.

RÉSUMÉ Roberto JIMENEZ, Pablo INTRIAGO Instituto Nacional de Pesca, Casilla 5918, Guayaquil, Ecua... more RÉSUMÉ Roberto JIMENEZ, Pablo INTRIAGO Instituto Nacional de Pesca, Casilla 5918, Guayaquil, Ecuador. Received 24/7/85, in revised form 24/2/87, accepted 3/3i87. During January 1984, sorne upwelling water was found in the euphotic zone along the coast of Ecuador from 1°20'S to 2°30'S. This water was characterized by a relatively low surface temperature of 23°C and the presence of Mesodinium rubrum. The concentration of chlorophyll a was between 0.50 and 1.37 mg/m3• Levels of phosphate, nitrate, ammonia and silicate fluctuated between < 0.03 to 0.35 I-Lg-at P04-P/I, 0.6 to 3.5 I-Lg-at NOTN/I, 1.0 to 6.0 I-Lg-at NH4-N/l, and 4.0 to 10.3 I-Lg-at Si04-SiIl respectively. In February-March of the same year, a large scale " red tide " bloom of M. rubrum developed, with dense patches, covering an area of one hundred square miles, though the organism was spread over more than two hundred miles along the coast. The maximum number of cells was 7.6 x 106 cells/l within and ...

Thesis (Ph. D.)--University of Wales (U.C.N.W., Bangor:Ocean Sciences), 1990.

Journal of General Microbiology, 1991

The total fatty acid content of the estuarine Ffexibacter sp. strain Inp and the relative proport... more The total fatty acid content of the estuarine Ffexibacter sp. strain Inp and the relative proportions of its constituent fatty acids were affected by growth temperature and salinity. Whilst both the proportion and concentration of the polyunsaturates were markedly stimulated by increases in salinity, the total amount of fatty acid per mg cell protein decreased. The highest concentration of fatty acid per mg cell protein did not coincide with the highest percentage of polyunsaturated fatty acids, which occurred when the bacterium was grown on glucose. The presence of an inverse relationship between C16: lw5 and C18: lw9 are regarded as evidence that two Merent pathways exist for the biosynthesis of unsaturated fatty acids in FZexikter strain Inp.

Revista de ciencias del mar y limnologia

… of the Special …, Jan 1, 1995

Journal of General Microbiology, Jan 1, 1992

The mechanism of unsaturated fatty acid biosynthesis in two estuarine strains of Ffexibucter was ... more The mechanism of unsaturated fatty acid biosynthesis in two estuarine strains of Ffexibucter was investigated. Addition of cyclic AMP (CAMP) inhibited the incorporation of radiolabelled acetate into fatty acids of lateexponential phase cultures of strain Inp2. Cerulenin selectively inhibited the incorporation of radioactive acetate into the major fatty acid, 16:l. When Ffexibacter strain Inp3 was grown in a medium of high osmotic strength, polyunsaturated fatty acids were present, but they were absent from cultures grown in media with an osmotic strength close to that of sea water. Addition of cAMP to cultures growing at high osmotic strength suppressed the formation of polyunsaturated fatty acids; the uncoupler 2,4-dinitrophenol had a similar effect. The findings are discussed in the context of the suggestion made by Intriago and Floodgate (Journal of General Microbiology 137, 1503-1509,1991) that Ffexibucter strains possess both the anaerobic and aerobic pathways for unsaturated fatty acid biosynthesis, the activity of the latter being modulated by the intracellular concentration of CAMP. Present address: Aqualab, PO Box 09-01-5738, Guayaquil, Ecuador. Fax 4 284409. Abbreviations: DNP, 2,4-dinitrophenol; UFA, unsaturated fatty acid; PUFA, polyunsaturated fatty acid; p.p.t., parts per thousand (salinity). 0001-6740 0 1992 SGM

Oceanol. Acta, Jan 1, 1987

Aquaculture, Jan 1, 1993

Artemia sp. were grown to pre-adult on diets consisting of bacteria, bacteria plus algae, and alg... more Artemia sp. were grown to pre-adult on diets consisting of bacteria, bacteria plus algae, and algae alone. There was little difference in survival among Artemia grown on these diets, but significant differences in length and dry weight were observed. Artemia fed with Flexibacter strain ...