Daniel Margulies

Inter-American Tropical Tuna Commission | IATTC · Early Life History Group

The yellowfin tuna (Thunnus albacares) (YFT) exhibits strong potential as a candidate species for full-life-cycle aquaculture. The Inter-American Tropical Tuna Commission (IATTC) has maintained a spawning population and studied the reproductive biology and early life history of YFT for research purposes at its Achotines Laboratory, Republic of Pana...

In this study we describe the courtship and spawning behaviors of captive yellowfin tuna (Thunnus albacares), their spawning periodicity, the influence of physical and biological factors on spawning and hatching, and egg and early-larval development of this species at the Achotines Laboratory, Republic of Panama, during October 1996 through March 2...

The nutritional condition of first-feeding and late larval/early juvenile scombrids was investigated in waters of the northwestern Panam Bight from May through early November 1988. Wild-caught larvae and juveniles of three taxa, black skipjack tuna (Euthynnus lineatus), bullet and/or frigate tuna (Auxis spp.) and sierra (Scomberomorus sierra), were...

Development of the visual system in larval and early juvenile Euthynnus lineatus, Auxis spp., and Scomberomorus sierra was examined histologically. First‐feeding larvae of all three taxa possess a pure cone retina, with theoretical acuities ranging from 50 min of arc in Scomberomorus sierra to about 60 min of arc in Euthynnus lineatus and Auxis spp...

Ocean acidification is predicted to have a wide range of impacts on fish, but there has been little focus on broad-ranging pelagic fish species. Early life stages of fish are thought to be particularly susceptible to CO2 exposure, since acid-base regulatory faculties may not be fully developed. We obtained yellowfin tuna (Thunnus albacares) from a...

The impacts of climate change are expected to have profound effects on the fisheries of the Pacific Ocean, including its tuna fisheries, the largest globally. This study examined the combined effects of climate change on the yellowfin tuna population using the ecosystem model SEAPODYM. Yellowfin tuna fisheries in the Pacific contribute significantl...

Changes in nutritional constituents and enzyme activities were clarified in yellowfin tuna (YFT, Thunnus albacares) eggs during embryonic development, from eggs immediately after fertilization to hatching. The protein levels in the eggs gradually increased with development until the completion of hatching. In contrast, the triglyceride (TG) and fre...

Pelagic fish embryos are thought to float in or near surface waters for the majority of their development and are presumed to have little to no control over their mobility, rendering these embryos at high risk for damages associated with surface stressors such as ultraviolet radiation (UVR). We recently challenged these long-standing paradigms by c...

RNA, DNA, and protein contents were assessed to evaluate somatic growth in larval and juvenile yellowfin tuna (YFT), Thunnus albacares. The experimental fish were reared at the Achotines Laboratory of the Inter-American Tropical Tuna Commission in Los Santos Province, Republic of Panama. Sampling was carried out from 3 to 33 days after hatching (DA...

Three experiments were conducted to investigate the growth, survival, and standardized cohort biomass of Pacific bluefin tuna, Thunnus orientalis, larvae fed nutritionally enhanced prey during the first week of feeding using two commonly used, commercially available enrichment media, AlgaMac Enrich and Marine Glos. T. orientalis larvae exhibited ex...

To investigate the dietary effect of taurine on the larval stage of tuna species, Pacific bluefin tuna (PBF) and yellowfin tuna (YFT), larvae were reared until 16 days after hatching (dAH) and 14 dAH, respectively, and replicate samples were fed either non-taurine-enriched rotifers (T-0) or rotifers enriched with 800 mg taurine L À1 (T-800). Most P...

To develop techniques for seedling production of yellowfin tuna, the behavior of primordial germ cells (PGCs) and gonadogenesis were examined at 1-30 days post hatching (dph) using morphometric analysis, histological examination, and in situ hybridization. Immediately after hatching, PGCs were located on the dorsal side of the posterior end of the...

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...

Early-stage mortality due to surface water tension-related death and due to sinking to the tank bottom was investigated for yellowfin tuna, Thunnus albacares (YFT), larvae. Different aeration rates and rearing water surface conditions were examined to evaluate the effect on larval survival, swim bladder inflation and growth. The percentage survival...

The genetic population structure of the Pacific bluefin tuna (PBF) Thunnus orientalis and the yellowfin tuna (YFT) T. albacares in the North Pacific Ocean was investigated. The polymorphism of microsatellite (SSR) loci and sequences of mitochondrial DNA control region (mtCR) were analyzed for 71 samples of PBF from Japan and Mexico and 45 samples...

Anthropogenic carbon dioxide (CO2) emissions are resulting in increasing absorption of CO2 by the earth‘s oceans, which has led to a decline in ocean pH, a process known as ocean acidification (OA). Evidence suggests that OA may have the potential to affect the distribution and population dynamics of many marine organisms. Early life history proces...

Effect of water temperature on embryonic development of yellor,vfin tuna was investigated. Eggs were incubated at different water temperatures:22, 24, 26C (Experiment-1) arrd 28, 30, 32C (Experiment-2). Developmental condition was observed and the elapsed time from the 2 or 4 cell stages until hatching was mea-sured. Hatching occurred at 18.58 h fo...

Achotines Laboratory, owned and operated by the Inter-American Tropical Tuna Commission (IATTC), is the only research facility in the world with captive broodstock tuna that have been spawning on a near daily basis for over a decade. Yellowfin tuna eggs, larvae and juveniles resulting from those spawns are used for a variety of studies including in...

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 experi...

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 tuna...

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...

The yellowfin tuna, �Thunnus albacares�, is an important species in tuna fisheries worldwide. At the Inter-American Tropical Tuna Commission (IATTC) Achotines Laboratory in the Republic of Panama captive yellowfin broodstock tuna spawn regularly providing material for early life history studies (Wexler et al 2003; Margulies et al. 2007). Larval rea...

The first CLIOTOP-GLOBEC Working Group 1 on Early Life History meeting was held in the city of Málaga, during October 10-14 under the auspices of the Oceanographic Center of Málaga of the Spanish Institute of Oceanography. Scientists from USA, Japan, Italy and Spain attended the meeting. The report provides an insight to the different research tuna...

Tuna larvae (at flexion, postflexion, and transformation stages) were collected by dip net and light traps at night in the northwestern Panama Bight during the season of reduced upwelling (June-September) of 1990, 1991, 1992, and 1997. The larvae were identified as yellowfin tuna (Thunnus albacares) by mtDNA analysis. Ichthyoplankton data from bong...

Tank experiments were conducted to study the effect of oceanic turbulence on the survival of first feeding larvae of yellowfin tuna. Several levels of turbulence intensity were provided by changing the amount of air bubbles released from air-stones in the tanks containing yellowfin tuna larvae. The results showed that there is an optimal turbulence...

A land-based culture facility for research on yellowfin tuna, Thunnus albacares, was developed at the Achotines Laboratory in the Republic of Panama. Six concrete tanks, and seawater and life support systems were built to maintain a yellowfin broodstock. On average, 50% of the yellowfin caught survived capture and handling, and approximately 30% be...

Mitochondrial DNA genotypes of captive broodstock of yellowfin tuna (Thunnus albacares) were compared with those of their offspring in order to monitor spawning frequency and periodicity. Among 38 broodstock individuals, 27 genotypes were observed, 18 of which established a single individual's identity. Spawned eggs and hatched larvae were collecte...

Previous studies have suggested that adult tunas have only two visual pigments in their retinas - a rod pigment with a wavelength at maximum absorbance (u max) around 485 nm and one with similar u max in both twin and single cones inferred from extraction data. Using microspectrophotometry we confirm the presence of a u max 483 nm visual pigment in...

Restriction fragment length polymorphism found in the S7 ribosomal protein gene introns of yellowfin tuna (Thunnus albacares) was compared between a single pair of parents and their offspring. The sizes of the first intron ( RP1) and second intron ( RP2) amplified by polymerase chain reaction were 810 bp and 1400 bp, respectively. The dam and sire...

The vulnerability of white perch, Morone americana, larvae to yearling bluegill, Lepomis macrochira, predators was examined in relation to larval size, nutritional condition and relative abundance of alternative prey. Short-term (15 min) predation trials were conducted in 381 tanks in the laboratory. Larval vulnerability was measured as the proport...

The size-specific vulnerability of white seabass, Atractoscronnobilis, larvae (2.5-15.0 mm SL) to two types of fish predators-adult northern anchovy, Engraulis mordax, and juvenile white seabass-was examined in laboratory preda­ tion trials. Concurrent analyses were made of the developmental ontogeny of larval visual and mech­ anoreceptive systems....

Optimum temperatures for growth and survival of first-feeding white perch larvae are 15-20°C. Estimation of variability in growth rates of larval white perch in Chesapeake tributaries would make a major contribution to our understanding of white perch recruitment. -from Author

Author Institution: Chesapeake Biological Laboratory, University of Maryland

We report a recent collection of the gilt darter (Percina evides) from the White River drainage in Indiana. The collection represents the second record for this species in Indiana in this century and the first record in 46 years. The gilt darter is threatened with extirpation in Indiana waters. We recommend that the West Fork of the White River be...

This report includes descriptions of projects which were partially funded by the Federal Government, although the Federal contributions are not considered in the funding analyses. This report only considers marine pollution research, development, and monitoring activities. ''Research'' projects include studies, investigations, and surveys to study...