Report of the Inter-American Tropical Tuna Commission for the year 1995

ENGLISH: The Inter-American Tropical Tuna Commission (IATTC) operates under the authority and direction of a convention originally entered into by Costa Rica and the United States. The convention, which came into force in 1950, is open to adherence by other governments whose nationals fish for tropical tunas and tuna-like species in the eastern Pacific Ocean. Under this provision Panama adhered in 1953, Ecuador in 1961, Mexico in 1964, Canada in 1968, Japan in 1970, France and Nicaragua in 1973, Vanuatu in 1990, and Venezuela in 1992. Ecuador withdrew from the IATTC in 1968, Mexico in 1978, and Canada in 1984. The IATTC held its 55th meeting in La Jolla, California, USA, on June 13-15, 1995. SPANISH: La Comisión Interamericana del Atún Tropical (CIAT) funciona bajo la autoridad ydirección de un convenio suscrito originalmente por Costa Rica y los Estados Unidos de América. El convenio, vigente desde 1950, está abierto a la afiliación de cualquier país cuyos ciudadanos pesquen atunes tropicales y especies afines en el Océano Pacífico oriental. Bajo esta estipulación, la República de Panamá seafilióen 1953, Ecuadoren 1961, México en 1964, Canadáen 1968,Japónen 1970, FranciayNicaragua en 1973, Vanuatu en 1990, y Venezuela en 1992. Ecuador se retiró de la CIAT en 1968, México en 1978, y Canadá en 1984. La CIAT celebró su 55a reunión en La Jolla, California (EE.DU.) del 13 al15 de junio de 1995. (PDF contains 336 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1996

ENGLISH: The Inter-American Tropical Tuna Commission (IATTC) operates under the authority and direction of a convention originally entered into by Costa Rica and the United States. The convention, which came into force in 1950, is open to adherence by other governments whose nationals fish for tropical tunas and tuna-like species in the eastern Pacific Ocean. Under this provision Panama adhered in 1953, Ecuador in 1961, Mexico in 1964, Canada in 1968, Japan in 1970, France and Nicaragua in 1973, Vanuatu in 1990, and Venezuela in 1992. Ecuador withdrew from the IATTC in 1968, Mexico in 1978, and Canada in 1984. The IATTC held its 57th meeting in La Jolla, California, USA, on October 21-23, 1996. SPANISH: La Comisión Interamericana del Atún Tropical (CIAT) funciona bajo la autoridad y dirección de un convenio suscrito originalmente por Costa Rica y los Estados Unidos de América. El convenio, vigente desde 1950, está abierto a la afiliación de cualquier país cuyos ciudadanos pesquen atunes tropicales y especies afines en el Océano Pacífico oriental. Bajo esta estipulación, la República de Panamá seafilióen 1953, Ecuador en 1961, México en 1964, Canadá en 1968, Japón en 1970, Francia y Nicaragua en 1973, Vanuatu en 1990, y Venezuela en 1992. Ecuador se retiró de la CIAT en 1968, México en 1978, y Canadá en 1984. La CIAT celebró su 57a reunión en La Jolla, California (EE.DU.) del 21 a123 de octubre de 1996. (PDF contains 360 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1997

ENGLISH: The Inter-American Tropical Tuna Commission (IATTC) operates under the authority and direction of a convention originally entered into by Costa Rica and the United States. The convention, which came into force in 1950, is open to adherence by other governments whose nationals fish for tropical tunas and tuna-like species in the eastern Pacific Ocean (EPO). Under this provision Panama adhered in 1953, Ecuador in 1961, Mexico in 1964, Canada in 1968, Japan in 1970, France and Nicaragua in 1973, Vanuatu in 1990, Venezuela in 1992, and EI Salvador in 1997. Mexico withdrew from the IATTC in 1978 and Canada in 1984. The 58th meeting of the IATTC was held in San Jose, Costa Rica, on June 3-4, 1997. SPANISH: La Comisión Interamericana del Atún Tropical (CIAT) funciona bajo la autoridad y dirección de un convenio suscrito originalmente por Costa Rica y los Estados Unidos de América. El convenio, vigente desde 1950, está abierto ala afiliación de cualquier país cuyos ciudadanos pesquen atunes tropicales y especies afines en el Océano Pacifico oriental (OPO). Bajo esta estipulación, la República de Panamá seafilió en 1953, Ecuador en 1961, México en 1964, Canadá en 1968, Japón en 1970, Francia y Nicaragua en 1973, Vanuatu en 1990, Venezuela en 1992, y El Salvador en 1997. México se retiro de la CIAT en 1978, y Canadá en 1984. La CIAT celebró su 58' reunión en San Jose de Costa Rica el 3 y 4 de junio de 1997. (PDF contains 310 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1998

ENGLISH: The Inter-American Tropical Tuna Commission (IATTC) operates under the authority and direction of a convention originally entered into by Costa Rica and the United States. The convention, which came into force in 1950, is open to adherence by other governments whose nationals fish for tropical tunas and tuna-like species in the eastern Pacific Ocean (EPO). Under this provision Panama adhered in 1953, Ecuador in 1961, Mexico in 1964, Canada in 1968, Japan in 1970, France and Nicaragua in 1973, Vanuatu in 1990, Venezuela in 1992, and El Salvador in 1997. Canada withdrew from the IATTC in 1984. The 60th meeting of the IATTC was held in La Jolla, California, USA, on February 7, 1998. SPANISH: La Comisión Interamericana del Atún Tropical (CIAT) funciona bajo la autoridad y dirección de un convenio suscrito originalmente por Costa Rica y los Estados Unidos de América. El convenio, vigente desde 1950, está abierto ala afiliación de cualquier país cuyos ciudadanos pesquen atunes tropicales y especies afines en el Océano Pacifico oriental (OPO). Bajo esta estipulación, la República de Panamá seafilió en 1953, Ecuador en 1961, México en 1964, Canadá en 1968, Japón en 1970, Francia y Nicaragua en 1973, Vanuatu en 1990, Venezuela en 1992, y El Salvador en 1997. México se retiro de la CIAT en 1978, y Canadá en 1984. La 60a reunión de la CIAT tuvo lugar el 7 de febrero de 1998. (PDF contains 358 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1999

ENGLISH: The Inter-American Tropical Tuna Commission (IATTC) operates under the authority and direction of a convention originally entered into by Costa Rica and the United States. The convention, which came into force in 1950, is open to adherence by other governments whose nationals fish for tropical tunas and tuna-like species in the eastern Pacific Ocean (EPO). Under this provision Panama adhered in 1953, Ecuador in 1961, Mexico in 1964, Canada in 1968, Japan in 1970, France and Nicaragua in 1973, Vanuatu in 1990, Venezuela in 1992, and El Salvador in 1997. Canada withdrew from the IATTC in 1984. The 63rd meeting of the IATTC was held in Guayaquil, Ecuador, on June 8-10,1999. SPANISH: La Comisión Interamericana del Atún Tropical (CIAT) funciona bajo la autoridad y dirección de un convenio suscrito originalmente por Costa Rica y los Estados Unidos de América. El convenio, vigente desde 1950, está abierto ala afiliación de cualquier país cuyos ciudadanos pesquen atunes tropicales y especies afines en el Océano Pacifico oriental (OPO). Bajo esta estipulación, la República de Panamá seafilió en 1953, Ecuador en 1961, México en 1964, Canadá en 1968, Japón en 1970, Francia y Nicaragua en 1973, Vanuatu en 1990, Venezuela en 1992, y El Salvador en 1997. México se retiro de la CIAT en 1978, y Canadá en 1984. La 63a reunión de la CIAT tuvo lugar del 8 al 10 de junio de 1999 en Guayaquil (Ecuador). (PDF contains 184 pages.)

Proceedings of the first world meeting on bigeye tuna

The annual catches of big eye are exceeded by those of only two other species of tuna, skipjack, Katsuwonus pelamis, and yellowfin, Thunnus albacares. However, because most of the bigeye caught are consumed fresh, whereas most of the skipjack and yellowfin caught are canned, the economic value of big eye exceeds that of any other species of tuna. Despite its importance, less is known of the biology of bigeye than of the biology of any of the other principal market species of tunas. Historically, bigeye have been harvested mostly by longlines, which take only medium to large fish. During recent years, however, greater amounts of small bigeye have been caught by purse seines and other surface gear. This is a matter of concern for several reasons. First, long line fishermen are concerned that the harvesting of small bigeye will decrease the amounts of medium to large bigeye available to them. Second, since small bigeye are canned, rather than eaten fresh, consumers are concerned about the possible decrease in the supply of high-quality fresh fish. Third, economists are concerned about the possible economic loss associated with harvesting fish at less than their maximum economic value. Fourth, biologists are concerned about the possibility that harvesting of small bigeye could decrease the overall catches of that species. These concerns cannot be properly addressed until more knowledge of the biology of big eye is available. The purposes of the meeting were to review and discuss the information available and to make recommendations for further research.

Estimating the underwater shape of tuna longlines with micro-bathythermographs

An estimation method for the three-dimensional underwater shape of tuna longlines is developed, using measurements of depth obtained from micro-bathythermographs (BTs) attached to the main line at equally spaced intervals. The shape of the main line is approximated by a model which consists of a chain of unit length lines (folding-rule model), where the junction points are placed at the observed depths. Among the infinite number of possible shapes, the most likely shape is considered to be the smoothest one that can be obtained with a numerical optimization algorithm. To validate the method, a series of experimental longline operations were conducted in the equatorial region of the eastern Pacific Ocean, using 13 or 14 micro-BTs per basket of main line. Concurrent observations of oceanographic conditions (currents and temperature structure) were obtained. The shape of the main line can be calculated at arbitrary times during operations. Shapes were consistent with the current structure. On the equator, the line was elevated significantly by the Equatorial Undercurrent. It is shown that the shape of main line depends primarily upon the vertical shear and direction of the current relative to the gear. Time sequences of calculated shapes reveals that observed periodic (1-2 hours) oscillations in depth of the gear was caused by swinging movements of the main line. The shortening rate of the main line is an important parameter for formulating the shape of the longline, and its precise measurement is desirable.

Organization, functions, and achievements of the Inter-American Tropical Tuna Commission

ENGLISH: The Inter-American Tropical Tuna Commission (IATTC) operates under the authority and direction of a Convention originally entered into by the governments of Costa Rica and the United States. The Convention, which came into force in 1950, is open to the adherence by other governments whose nationals participate in the fisheries for tropical tunas in the eastern Pacific Ocean. The member nations of the Commission now are t in addition to Costa Rica and the United States, Canada, France, Japan, Mexico, Nicaragua, and Panama.This report is a description of the organization, functions, and achievements of the Commission. It has been prepared to provide in a convenient format answers to requests for information concerning the Commission. It replaces a similar, earlier report (Carroz, 1965), which is now largely outdated. SPANISH: La Comisión Interamericana del Atún Tropical (CIAT) funciona bajo la autoridad y dirección de un Convenio firmado originalmente por los gobiernos de Costa Rica y los Estados Unidos de America. El Convenio, que entro en vigencia en 1950, se encuentra libre para que otros gobiernos cuyos ciudadanos participen en la pesca de atunes tropicales en el Océano Pacifico oriental se afilien a el. Las naciones miembros de la Comisión, además de Costa Rica y los Estados Unidos, son Cañada, Francia, Japón, México, Nicaragua y Panamá. Este informe es una descripción de la organización, funciones y resultados de la Comisión. Ha sido preparado para suministrar en forma conveniente respuestas a preguntas sobre la Comisión. Reemplaza un informe anterior similar (Carroz 1965), que ya es anticuado en su mayor parte.

Exploratory fishing for tunas and tuna tagging in the Marquesas, Tuamotu, Society, Pitcairn, and Gambier Islands

The Marquesas Islands are located in the Pacific Ocean at about 9 degrees south latitude and 140 degrees west longitude (Figure 1). It has been demonstrated by tagging (Anonymous, 1980b) that skipjack tuna, Katsuwonus pelamis, which occur in the northeastern Pacific Ocean have migrated to the Hawaiian Islands and Christmas Island in the central Pacific and also to the area between the Marshall and Mariana islands in the western Pacific. The Tuamotu, Society, Pitcairn, and Gambier islands, though the first two are not as close to the principal fishing areas of the eastern Pacific Ocean as are the Marquesas Islands, and the last two are small and isolated, are of interest for the same reasons that the Marquesas Islands are of interest, and thus skipjack should be tagged in those islands for the same reason that they should be tagged in the Marquesas Islands. The organizations which participated in the Marquesas Islands tagging and other scientific activities were the Inter-American Tropical Tuna Commission (IATTC), the South Pacific Commission (SPC), the Centre National pour l'Exploitation des Oceans (CNEXO), the Office de la Recherche Scientifique et Technique Outre-Mer (ORSTOM), the Service de la Peche de la Polynesie Francaise (SPPF), and the Service de l'Economie Rural (SER).

Organization, functions, and achievements of the Inter-American Tropical Tuna Commission

ENGLISH: The Inter-American Tropical Tuna Commission (IATTC) operates under the authority and direction of a Convention originally entered into by the governments of Costa Rica and the United states. The Convention, which came into force in 1950, is open to the adherence by other governments whose nationals participate in the fisheries for tropical tunas in the eastern Pacific Ocean. The member nations of the Commission now are France. Japan, Nicaragua. Panama, and the United States. This report is a description of the organization, functions. and achievements of the Commission. It has been prepared to provide in a convenient format answers to requests for information concerning the Commission. It replaces similar, earlier reports (Carroz, 1965; Spec. Rep., 1), which are now largely outdated. SPANISH: La Comisión Interamericana del Atún Tropical (CIAT) funciona bajo la autoridad y dirección de un Convenio firmado originalmente por los gobiernos de Costa Rica y los Estados Unidos de America. El Convenio, Que entre en vigencia en 1950, se encuentra libre para Que otros gobiernos cuyos ciudadanos participan en la pesca de los atunes tropicales en el Océano Pacifico oriental se afilien a 61. Las naciones actuales que son miembros de la Comisión son: Francia, Japón, Nicaragua, Panamá y los Estados Unidos. Este informe es una descripci6n de la organización, funciones y resultados de la Comisión. Se ha preparado para suministrar en forma conveniente, informaci6n sobre la Comisión. Este informe renueva otros anteriores similares (Carroz, 1965; CIAT, Inf. Esp., 1) que en su mayor parte determinados.

Symposium on World tuna fisheries: commemorating the 50th anniversary of the establishment of the Inter-American Tropical Tuna Commission

The Inter-American Tropical Tuna Commission (lA TTC) came into existence in 1950, after its convention, signed by representatives ofCosta Rica and the United States in 1949, was ratified. It was the first international tuna organization, and only the third international fisheries organization, whose staff has had the responsibility for performing scientific research, the others being the International Pacific Halibut Commission, established in 1923, and the International Pacific Salmon Fisheries Commission, established in 1937. The current members of the IATTC are Costa Rica, Ecuador, EI Salvador, France, Guatemala, Japan, Mexico, Nicaragua, Panama, the United States, Vanuatu, and Venezuela. The first Director ofthe IATTC was Dr. Milner B. Schaefer, who was in that position from 1950 to 1963. He was followed by Dr. John L. Kask (1963-1969), Dr. James Joseph (1969-1999), and Dr. Robin L. Allen (1999-present). The success ofthe IATIC showed that it was possible to carry out research and management on an international, high-seas fishery successfully. Since then other international organizations for tuna management, including the International Commission for the Conservation of Atlantic Tunas (1969), the Forum Fisheries Agency (1979), the Commission for the Conservation of Southern Bluefin Tuna (1994), and the Indian Ocean Tuna Commission (1996), were established. Appropriately, the 50th anniversary celebration was held in Costa Rica, one of the two charter members of the IATTC. Persons who have held important positions in international fishery management in various parts ofthe world spoke at the celebration. Their presentations, except for that describing the Indian Ocean Tuna Commission, are reproduced in this volume.

Population structure of Pacific yellowfin tuna

ENGLISH: The population structure and production of Pacific yellowfin tuna, Thunnus albacares, were examined by studying most of the basic data available on stock assessment, as well as other data, for the period 1965 to 1972. The data were obtained mainly from the Japanese longline fishery in the Pacific Ocean east of about 1200E and from the purse-seine fishery in the eastern Pacific east of about 140oW. Data from genetic studies of subpopulations were not used due to their preliminary nature. It was concluded that the concept of "semi-independent" subpopulations proposed by Kamimura and Honma (1963) and Royce (1964) defines the population structure of Pacific yellowfin. At least three stocks (i.e. western, central and eastern), relatively independent of each other, are thought to exist, but the actual number and location of subpopulations is still unclear. Possible north-south separations, indicated to some extent by genetic studies and tagging, could be neither substantiated nor rejected on the basis of this study. Finally, unless some major change in the fishing technology occurs, it is doubtful if any significant sustainable increase in yellowfin production from the Pacific is possible. The greatest potential for increase, if any, appears to be based on changing the size structure of yellowfin in the catch from the central Pacific. SPANISH: Se examino la estructura de la población y la producción del atún aleta amarilla del Pacifico Thunnus albacares para estudiar la mayoría de los datos básicos que se tenían sobre el avalúo de la población, como también otra información correspondiente al periodo de 1965·1972. Los datos fueron obtenidos principalmente de las pescas palangreros japonesas del Océano Pacifico al este de los 1200 E y de las pescas con redes de cerco del Pacifico oriental, al este de los 140oW. No se emplearon los datos de estudios genéticos de las subpoblaciones porque eran mas bien preliminares. Se concluyo que el concepto propuesto por Kamimura y Honma (1963) y Royce (1964) de subpoblaciones "semiindependientes" define la estructura de la población del aleta amarilla en el Pacifico. Se cree que existen por 10 menos tres existencias (e.d. la occidental, central y oriental), relativamente independientes la una de la otra, pero no se conoce con certeza cuantas subpoblaciones hay y donde se encuentran. La posible separación norte-sur, indicada, hasta cierto punto, por los análisis genéticos y del marcado, no puede ni confirmarse ni rechazarse basados en este estudio. Finalmente, a no ser que ocurra algún gran cambio en la tecnología pesquera es dudoso que sea posible obtener un aumento constante e importante en la producción del aleta amarilla del Pacifico. El potencial mayor de aumento, si es que existe alguno, parece que se basa en el cambio de la estructura de talla en la captura del aleta amarilla del Pacifico central. (PDF contains 169 pages.)

Organization, functions, and achievements of the Inter-American Tropical Tuna Commission

This report is a description of the organization, functions, and achievements of the IATTC. It has been prepared to provide, in a convenient format, answers to requests for information concerning the IATTC. It replaces similar, earlier reports (Carroz, 1965; IATTC Spec. Rep., 1 and 5), which are now largely outdated. In order to make each section of the report independent of the others, some aspects of the IATTC are described in more than one section. For example, work on the early life history of tunas financed by the Overseas Fishery Cooperation Foundation of Japan is mentioned in the subsection entitled Finance, the subsection entitled Biology of tunas and billfishes, and the section entitled RELATIONS WITH OTHER ORGANIZATIONS. Due to space constraints, however, it is not possible to describe the IATTC's activities in detail in this report. Additional information is available in publications of the IATTC, listed in Appendix 6, and in its web site, www.iattc.org. Many abbreviations are used in this report. The names of the organizations or the terms are written out the first time they are used, and, for convenience, they are also listed in the Glossary.

Early life history studies of Yellowfin tuna, Thunnus albacares. I. Food selection of Yellowfin tuna, Thunnus albacares, larvae reared in the laboratory. II. Age validation and growth of Yellowfin tuna, Thunnus albacares, larvae reared in the laboratory

English: Food selection of first-feeding yellowfin tuna larvae was studied in the laboratory during October 1992. The larvae were hatched from eggs obtained by natural spawning of yellowfin adults held in sea pens adjacent to Ishigaki Island, Okinawa Prefecture, Japan. The larvae were fed mixed-prey assemblages consisting of size-graded wild zooplankton and cultured rotifers. Yellowfin larvae were found to be selective feeders during the first four days of feeding. Copepod nauplii dominated the diet numerically, by frequency of occurrence and by weight. The relative importance of juvenile and adult copepods (mostly cyclopoids) in the diet increased over the 4-day period. Rotifers, although they comprised 31 to 40 percent of the available forage, comprised less than 2.1 percent of the diet numerically. Prey selection indices were calculated taking into account the relative abundances of prey, the swimming speeds of yellowfin larvae and their prey, and the microscale influence of turbulence on encounter rates. Yellowfin selected for copepod nauplii and against rotifers, and consumed juvenile and adult copepods in proportion to their abundances. Yellowfin larvae may select copepod nauplii and cyclopoid juveniles and adults based on the size and discontinuous swimming motion of these prey. Rotifers may not have been selected because they were larger or because they exhibit a smooth swimming pattern. The best initial diet for the culture of yellowfin larvae may be copepod nauplii and cyclopoid juveniles and adults, due to the size, swimming motion, and nutritional content of these prey. If rotifers alone are fed to yellowfin larvae, the rotifers should be enriched with a nutritional supplement that is high in unsaturated fatty acids. Mouth size of yellowfin larvae increases rapidly within the first few days of feeding, which minimizes limitations on feeding due to prey size. Although yellowfin larvae initiate feeding on relatively small prey, they rapidly acquire the ability to add relatively large, rare prey items to the diet. This mode of feeding may be adaptive for the development of yellowfin larvae, which have high metabolic rates and live in warm mixed-layer habitats of the tropical and subtropical Pacific. Our analysis also indicates a strong potential for the influence of microscale turbulence on the feeding success of yellowfin larvae. --- Experiments designed to validate the periodicity of otolith increments and to examine growth rates of yellowfin tuna larvae were conducted at the Japan Sea-Farming Association’s (JASFA) Yaeyama Experimental Station, Ishigaki Island, Japan, in September 1992. Larvae were reared from eggs spawned by captive yellowfin enclosed in a sea pen in the bay adjacent to Yaeyama Station. Results indicate that the first increment is deposited within 12 hours of hatching in the otoliths of yellowfin larvae, and subsequent growth increments are formed dailyollowing the first 24 hours after hatching r larvae up to 16 days of age. Somatic and otolith gwth ras were examined and compared for yolksac a first-feeding larvae reared at constant water tempatures of 26�and 29°C. Despite the more rapid develo of larvae reared at 29°C, growth rates were nnificaifferent between the two treatments. Howeve to poor survival after the first four days, it was ssible to examine growth rates beyond the onset of first feeding, when growth differences may become more apparent. Somatic and otolith growth were also examined for larvae reared at ambient bay water temperatures during the first 24 days after hatching. timates of laboratory growth rates were come to previously reported values for laboratory-reared yelllarvae of a similar age range, but were lower than growth rates reported for field-collected larvae. The discrepancy between laboratory and field growth rates may be associated with suboptimal growth conditions in the laboratory. Spanish: Durante octubre de 1992 se estudió en el laboratorio la seleccalimento por larvaún aleta amarillmera alimentación. Las larvas provinieron de huevos obtenidosel desove natural de aletas amarillas adultos mantenidos en corrales marinos adyacentes a la Isla Ishigaki, Prefectura de Okinawa (Japón). Se alimentó a las larvas con presas mixtas de zooplancton silvestre clasificado por tamaño y rotíferos cultivados. Se descubrió que las larvas de aleta amarilla se alimentan de forma selectiva durante los cuatro primeros días de alimentación. Los nauplios de copépodo predominaron en la dieta en número, por frecuencia de ocurrencia y por peso. La importancia relativa de copépodos juveniles y adultos (principalmente ciclopoides) en la dieta aumentó en el transcurso del período de 4 días. Los rotíferos, pese a que formaban del 31 al 40% del alimento disponible, respondieron de menos del 2,1% de la dieta en número. Se calcularon índices de selección de presas tomando en cuenta la abundancia relativa de las presas, la velocidad de natación de las larvas de aleta amarilla y de sus presas, y la influencia a microescala de la turbulencia sobre las tasas de encuentro. Los aletas amarillas seleccionaron a favor de nauplios de copépodo y en contra de los rotíferos, y consumieron copépodos juveniles y adultos en proporción a su abundancia. Es posible que las larvas de aleta amarilla seleccionen nauplios de copépodo y ciclopoides juveniles y adultos con base en el tamaño y movimiento de natación discontinuo de estas presas. Es posible que no se hayan seleccionado los rotíferos a raíz de su mayor tamaño o su patrón continuo de natación. Es posible que la mejor dieta inicial para el cultivo de larvas de aleta amarilla sea nauplios de copépodo y ciclopoides juveniles y adultos, debido al tamaño, movimiento de natación, y contenido nutritivo de estas presas. Si se alimenta a las larvas de aleta amarilla con rotíferos solamente, se debería enriquecerlos con un suplemento nutritivo rico en ácidos grasos no saturados. El tamaño de la boca de las larvas de aleta amarilla aumenta rápidamente en los primeros pocos días de alimentación, reduciendo la limitación de la alimentación debida al tamaño de la presa. Pese a que las larvas de aleta amarilla inician su alimentación con presas relativamente pequeñas, se hacen rápidamente capaces de añadir presas relativamente grandes y poco comunes a la dieta. Este modo de alimentación podría ser adaptivo para el desarrollo de larvas de aleta amarilla, que tienen tasa metabólicas altas y viven en hábitats cálidos en la capa de mezcla en el Pacífico tropical y subtropical. Nuestro análisis indica también que la influencia de turbulencia a microescala es potencialmente importante para el éxito de la alimentación de las larvas de aleta amarilla. --- En septiembre de 1992 se realizaron en la Estación Experimental Yaeyama de la Japan Sea- Farming Association (JASFA) en la Isla Ishigaki (Japón) experimentos diseñados para validar la periodicidad de los incrementos en los otolitos y para examinar las tasas de crecimiento de las larvas de atún aleta amarilla. Se criaron las larvas de huevos puestos por aletas amarillas cautivos en un corral marino en la bahía adyacente a la Estación Yaeyama. Los resultados indican que el primer incremento es depositado menos de 12 horas después de la eclosión en los otolitos de las larvas de aleta amarilla, y que los incrementos de crecimiento subsiguientes son formados a diario a partir de las primeras 24 horas después de la eclosión en larvas de hasta 16 días de edad. Se examinaron y compararon las tasas de crecimiento somático y de los otolitos en larvas en las etapas de saco vitelino y de primera alimentación criadas en aguas de temperatura constante entre 26°C y 29°C. A pesar del desarrollo más rápido de las larvas criadas a 29°C, las tasas de crecimiento no fueron significativamente diferentes entre los dos tratamientos. Debido a la mala supervivencia a partir de los cuatro primeros días, no fue posibación, uando las diferencias en el crecimiento podrían hacerse más aparentes. Se examinó también el crecimiento somático y de los otolitos para larvas criadas en temperaturas de agua ambiental en la bahía durante los 24 días inmediatamente después de la eclosión. Nuestras estimaciones de las tasas de crecimiento en el laboratorio fueron comparables a valores reportados previamente para larvas de aleta amarilla de edades similares criadas en el laboratorio, pero más bajas que las tasas de crecimiento reportadas para larvas capturadas en el mar. La discrepancia entre las tasas de crecimiento en el laboratorio y el mar podría estar asociada con condiciones subóptimas de crecimiento en el lab