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Las Tablas, Panama

Zink I.C.,University of Miami | Benetti D.D.,University of Miami | Douillet P.A.,Ecomicrobials LLC | Margulies D.,Inter American Tropical Tuna Commission | Scholey V.P.,Achotines Laboratory
North American Journal of Aquaculture | Year: 2011

The effects of adding a probiotic Bacillus spp. blend on shipping bag water quality and survival of yolk sac larvae of yellowfin tuna Thunnus albacares during a 24-h mock shipment were investigated. To better detect effects on water quality, the trial was designed without the utilization of available chemical water quality or temperature modulators. Shipping water salinity (30.7-31.0) and temperature (24.0-26.7°C) reflected conditions utilized during larval rearing. Probiotic incorporation (15 mL/L, about 1.5 × 10 6 colony-forming units/mL) resulted in significantly lower final concentrations of total ammonia nitrogen and un-ionized ammonia in comparison with the control. Significantly higher final mean dissolved oxygen concentration observed in the probiotic treatment could have resulted from stress reduction. Although no statistical difference was detected in larval survival upon termination of the trial, improvements in water quality (reduced total ammonia nitrogen and increased dissolved oxygen) resulting from incorporation of Bacillus probiotics would yield added levels of safety during shipping and would reduce the chances of negative results while incurring minimal increases in shipping costs. © American Fisheries Society 2011. Source

Kim Y.-S.,Kinki University | Delgado D.I.,Aquatic Resources Authority of Panama | Cano I.A.,Achotines Laboratory | Sawada Y.,Kinki University
Fisheries Science | Year: 2015

Effects of temperature and salinity on hatching rate and normal larval rate at hatching, and survival of fasting larvae after hatching (survival activity index; SAI) were investigated using spontaneously spawned eggs of captive yellowfin tuna (Thunnus albacares, YFT). Within the range of experimental temperatures, 23–35 °C, at 32 psu salinity, hatching and normal larval rates and SAI were highest at 23 and 26 °C. In the experiment exploring the most suitable salinity within the range 23–38 psu, 35 and 38 psu gave the highest hatching rate and normal larval rate; however, SAI was highest at 26 psu. The results of multi-factor experiments in each temperature (23, 26, and 29 °C) with each salinity (32, 35, and 38 psu) indicated interactive effects of temperature and salinity on the three indices and within the experimental ranges gave an optimal combination of 23 °C and 38 psu for YFT hatching and survival. © 2015, Japanese Society of Fisheries Science. Source

Buentello J.A.,Texas A&M University | Pohlenz C.,Texas A&M University | Margulies D.,Achotines Laboratory | Scholey V.P.,Achotines Laboratory | And 4 more authors.
Aquaculture | Year: 2011

The yellowfin tuna (YFT, Thunnus albacares) is a circumtropical/subtropical marine species that supports major fisheries throughout its range. Tuna ranching - an activity that currently relies on fish captured from the wild - has rapidly expanded, thus placing even greater pressure on wild tuna stocks worldwide. Although captive propagation of tunas has proven feasible, hatchery technologies for YFT need improvement to increase larval survival. The onset of exogenous feeding is a critical phase during which digestive processes develop rapidly. Therefore, the present research was undertaken to examine size-dependent changes in YFT fertilized eggs and in 23, 25 and 34. mm (total length) early juveniles with respect to the development of digestive capacity, biochemical composition and amino acid (AA) profiles as indicators of larval nutritional requirements for AAs. To this end, the activities of alkaline and acid phosphatases, pepsin, trypsin, chymotrypsin, aminopeptidase, lipase and α-amylase were determined spectrophotometrically. Activities of the analyzed enzymes were greater in the YFT than in similar-age/size marine fish of other species. In YFT, enzyme activities progressively increased as fish grew, resulting in significantly different (P< 0.0001) enzyme profiles among size classes. With the exception of acid phosphatase, all enzymes displayed a precocious increase in specific activity concurrent with somatic growth. Proximate composition and AA patterns were generally similar within juveniles but distinctly different (P≤ 0.001-0.05) from that of eggs. Histidine, taurine and alanine were the most prevalent AAs in the free pool; whereas, arginine's free pool concentration increased substantially from egg to juvenile stages (2.2 to 12.7. nmol/mg, respectively). These results support the hypothesis of precocious digestive capacity for scombrid fish. Observed AA patterns suggest that strategies for feeding larval and juvenile YFT in aquaculture should incorporate higher levels of specific AAs during early development to support rapid growth and diminish the threat of starvation or cannibalism. Although this information is useful for understanding feeding processes in juvenile YFT, more research is necessary to fully characterize these processes in the various stages from egg to juvenile, leading to the development of balanced diets that would allow for early weaning from live prey. © 2010 Elsevier B.V. Source

Wexler J.B.,Inter American Tropical Tuna Commission | Wexler J.B.,Achotines Laboratory | Margulies D.,Inter American Tropical Tuna Commission | Margulies D.,Achotines Laboratory | Scholey V.P.,Achotines Laboratory
Journal of Experimental Marine Biology and Ecology | Year: 2011

We determined the optimal water temperature and oxygen ranges for survival, development, and growth of yellowfin tuna (Thunnus albacares) eggs and yolk-sac and first-feeding larvae by conducting a series of experiments between 2004 and 2006 at the Achotines Laboratory on the Pacific coast of the Republic of Panama.Based on the results of our experiments, yolk sac and first-feeding yellowfin larvae exhibited lethal limits for their survival at temperatures less than 21°C and greater than 33°C. Embryos hatched alive at all temperatures tested except 36°C; however, larvae were malformed after hatching at temperatures <20°C and ≥ 34°C. Egg and larval development were significantly slower at mean incubation temperatures <23°C. Mean egg diameters were significantly greater at mean incubation temperatures <26°C compared with those incubated at temperatures >27°C. Within the temperature range for survival and normal development, mean specific growth rates in weight for larvae after 2. days of feeding maintained at mean temperatures of 21.3°C, 26.6°C, 27.5°C, and 31.5°C were 1.8%, 20.9%, 27.2%, and 45.0%, respectively. The optimal range of temperatures for rapid growth and moderate to high survival in first-feeding larvae was from about 26° to 31°C.Lethal conditions (100% mortality) for larvae after hatching and shortly after the onset of first feeding occurred at dissolved oxygen concentrations of <2.2mgO 2L 1 (<34% oxygen saturation) at temperatures between 26° and 29°C. Significantly lower survival first occurred for first-feeding larvae when the larvae were exposed to dissolved oxygen concentrations of 2.65mgO 2L -1 (40.4% oxygen saturation).Based on our experimental results, critical depths for survival of yolk-sac and first-feeding yellowfin larvae within the Panama Bight of the Pacific Ocean would occur at depths less than 30. m during the upwelling season and at depths less than 50. m during the reduced upwelling season, based on temperature alone. Limiting oxygen levels may occur at depths greater than 30. m during the upwelling season and greater than 50. m during the reduced upwelling season. © 2011 Elsevier B.V. Source

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