Hubbs SeaWorld Research Institute

San Diego, CA, United States

Hubbs SeaWorld Research Institute

San Diego, CA, United States
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Crance J.L.,Hubbs SeaWorld Research Institute | Crance J.L.,National Marine Mammal Laboratory | Bowles A.E.,Hubbs SeaWorld Research Institute | Garver A.,SeaWorld San Diego
Journal of Experimental Biology | Year: 2014

Killer whales (Orcinus orca) are thought to learn their vocal dialect. Dispersal in the species is rare, but effects of shifts in social association on the dialect can be studied under controlled conditions. Individual call repertoires and social association were measured in three adult female killer whales and three males (two juveniles and an adult) during two periods, 2001-2003 and 2005-2006. Three distinct dialect repertoires were represented among the subjects. An adventitious experiment in social change resulted from the birth of a calf and the transfer of two non-focal subjects in 2004. Across the two periods, 1691 calls were collected, categorized and attributed to individuals. Repertoire overlap for each subject dyad was compared with an index of association. During 2005-2006, the two juvenile males increased association with the unrelated adult male. By the end of the period, both had begun producing novel calls and call features characteristic of his repertoire. However, there was little or no reciprocal change and the adult females did not acquire his calls. Repertoire overlap and association were significantly correlated in the first period. In the second, median association time and repertoire similarity increased, but the relationship was only marginally significant. The results provided evidence that juvenile male killer whales are capable of learning new call types, possibly stimulated by a change in social association. The pattern of learning was consistent with a selective convergence of male repertoires. © 2014. Published by The Company of Biologists Ltd.

Alves-Stanley C.D.,University of Central Florida | Worthy G.A.J.,University of Central Florida | Worthy G.A.J.,Hubbs SeaWorld Research Institute | Bonde R.K.,U.S. Geological Survey
Marine Ecology Progress Series | Year: 2010

The endangered West Indian manatee Trichechus manatus has 2 recognized subspecies: the Florida T. m. latirostris and Antillean T. m. manatus manatee, both of which are found in freshwater, estuarine, and marine habitats. A better understanding of manatee feeding preferences and habitat use is essential to establish criteria on which conservation plans can be based. Skin from manatees in Florida, Belize, and Puerto Rico, as well as aquatic vegetation from their presumed diet, were analyzed for stable carbon and nitrogen isotope ratios. This is the first application of stable isotope analysis to Antillean manatees. Stable isotope ratios for aquatic vegetation differed by plant type (freshwater, estuarine, and marine), collection location, and in one instance, season. Carbon and nitrogen isotope ratios for manatee skin differed between collection location and in one instance, season, but did not differ between sex or age class. Signatures in the skin of manatees sampled in Belize and Puerto Rico indicated a diet composed primarily of seagrasses, whereas those of Florida manatees exhibited greater regional variation. Mixing model results indicated that manatees sampled from Crystal River and Homosassa Springs (Florida, USA) ate primarily freshwater vegetation, whereas manatees sampled from Big Bend Power Plant, Ten Thousand Islands, and Warm Mineral Springs (Florida) fed primarily on seagrasses. Possible diet-tissue discrimination values for 15N were estimated to range from 1.0 to 1.5%. Stable isotope analysis can be used to interpret manatee feeding behavior over a long period of time, specifically the use of freshwater vegetation versus seagrasses, and can aid in identifying critical habitats and improving conservation efforts. © Inter-Research 2010,

Jirsa D.,Hubbs SeaWorld Research Institute | Davis A.,Auburn University | Stuart K.,Hubbs SeaWorld Research Institute | Drawbridge M.,Hubbs SeaWorld Research Institute
Aquaculture Nutrition | Year: 2011

Two feeding trials were conducted to initiate the development of a practical soy-based diet for California yellowtail (YT), Seriola lalandi. The first trial evaluated fish meal (FM), FM+solvent-extracted soybean meal (SBM) or FM+soy protein concentrate (SPC)-based diets and a commercial reference diet (Skretting Marine Grower). Final weights (31.8-67.6g), per cent gain (492.8-1059.9%) and feed conversion ratio (1.11-1.59) all followed a similar response in that fish offered the commercial diet performed significantly better than fish maintained on the other diets. The second trial was designed to evaluate the replacement of FM with increasing levels of soy protein. The basal diet contained 400gkg -1 FM and 240gkg -1 SBM. The FM was then reduced to 300gkg -1, 200gkg -1 and 150gkg -1 of the diet using SPC as the replacement protein. Final weight (41.2-64.1g) and per cent gain (110.5-226.5%) followed similar trends with decreases in performance as the FM level was reduced. No gross signs of enteritis were noted, indicating that reduced performance was likely due to nutrient deficiencies or palatability problems rather than an allergic response. Results demonstrate that there is potential to develop reduced FM diets for this species using soy protein. © 2011 Blackwell Publishing Ltd.

Vizcaino-Ochoa V.,Research Center Cientifica Educacion Superior Of Ensenada | Lazo J.P.,Research Center Cientifica Educacion Superior Of Ensenada | Baron-Sevilla B.,Research Center Cientifica Educacion Superior Of Ensenada | Drawbridge M.A.,Hubbs SeaWorld Research Institute
Aquaculture | Year: 2010

The California halibut (Paralichthys californicus) is a good candidate for aquaculture due to its good growth, survival and high commercial value. Several farms in the Western coast of North America are currently evaluating the potential of this species under commercial conditions. However, one of the main problems in the production of juveniles for commercial purposes is the high percentage of malpigmented fish obtained after metamorphosis (up to 80%). This problem seems to be related, among other things, to nutritional deficiencies during the larval period, in particular to the quantities and proportions of highly unsaturated fatty acids (HUFAs) in the diet. As a first approach to reduce malpigmentation, improve growth and determine the requirement for DHA in California halibut late larvae, we evaluated the effect of four levels of dietary DHA (0, 1, 2, and 4% of total fatty acids in the diet) on growth, survival, weaning success and pigmentation. DHA was administered to the larvae through enriched Artemia metanauplii. Larvae standard length and wet weight were taken during the initial stage of Artemia metanauplii supplementation (18 days post hatch, dph); at the beginning of the weaning period (50 dph); and at the end of the experiment (75 dph). We quantified the amounts of total fatty acids in 18 and 50 dph larvae. No significant differences on growth, survival and pigmentation as a result of increasing dietary DHA levels were found in 50 dph recently settled juveniles. However, larvae fed the highest DHA level resulted in the highest growth and survival at the end of the experiment (75 dph). Additionally, highest weaning success was achieved with this treatment. Significantly higher numbers of normally pigmented fish (ca., 33%) were obtained with the highest DHA level at 75 dph compared to the low DHA levels (0 and 5%). However, since this treatment resulted in the highest survival, part of the population had abnormal pigmentation (ca., 30% of the population). Based on a second order polynomial regression, the recommended DHA level in the diet for pre-metamorphic larvae to attain adequate growth and survival as estimated here for recently settled California halibut at 50 dph was 1.21% DHA of total fatty acids (TFA). However, for post-metamorphosis fish (75 dph) highest pigmentation rates, growth and survival are obtained with 2.40% DHA of TFA in the diet during the Artemia feeding period. © 2010 Elsevier B.V. All rights reserved.

Trushenski J.,Southern Illinois University Carbondale | Mulligan B.,Southern Illinois University Carbondale | Jirsa D.,Hubbs SeaWorld Research Institute | Drawbridge M.,Hubbs SeaWorld Research Institute
North American Journal of Aquaculture | Year: 2013

Fish oil sparing has proven difficult for some fish species, especially marine carnivores like White Seabass Atractoscion nobilis that require one or more long-chain polyunsaturated fatty acids (LC-PUFAs). Recent studies have suggested that the use of saturated fatty acid (SFA)-rich lipids instead of C18 polyunsaturated fatty acid-rich (C18 PUFA) lipids may be advantageous in maintaining tissue levels of LC-PUFAs; SFA-rich lipids may also offer a strategic advantage in terms of meeting the LC-PUFA requirements of marine carnivores while minimizing dietary fish oil inclusion. Accordingly, we assessed the performance and tissue fatty acid composition of White Seabass (3.8 ± 0.2 g [mean ± SE]) fed diets containing fish oil or graded levels of C18 PUFA-rich standard soy oil or SFA-rich hydrogenated soy oil (replacing 25, 50, 75, or 100% of dietary fish oil) for 8 weeks. Feed conversion ratio, weight gain, and specific growth rate were not impaired by partial or complete replacement of dietary fish oil with hydrogenated soy oil; however, fish oil sparing with standard soy oil was associated with declining performance. The tissue fatty acid profiles of fish fed the hydrogenated soy oil-based diets were very similar to those of fish fed the fish oil-based feed, but the standard soy oil-based feeds resulted in concomitant loss of n-3 fatty acids and LC-PUFAs. In all cases, the magnitude of the dietary effect was greater among liver and fillet tissues than among brain and eye tissues. These data suggest a limitation, potentially related to LC-PUFA deficiency, associated with replacing fish oil with standard soybean oil, but not with hydrogenated soybean oil. Our data suggest that the LC-PUFA requirements of White Seabass can be effectively reduced by feeding SFA-rich alternative lipids, allowing for a greater level of fish oil sparing without growth impairment or tissue profile modification than is possible with C18 PUFA-rich lipids. © American Fisheries Society 2013.

Bowles A.E.,Hubbs SeaWorld Research Institute | Denes S.L.,Hubbs SeaWorld Research Institute | Shane M.A.,Hubbs SeaWorld Research Institute
Journal of the Acoustical Society of America | Year: 2010

Ultrasonic coded transmitters (UCTs) producing frequencies of 69-83 kHz are used increasingly to track fish and invertebrates in coastal and estuarine waters. To address concerns that they might be audible to marine mammals, acoustic properties of UCTs were measured off Mission Beach, San Diego, and at the U.S. Navy TRANSDEC facility. A regression model fitted to VEMCO UCT data yielded an estimated source level of 147 dB re 1 μPa SPL @ 1 m and spreading constant of 14.0. Based on TRANSDEC measurements, five VEMCO 69 kHz UCTs had source levels ranging from 146 to 149 dB re 1 μPa SPL @ 1 m. Five Sonotronics UCTs (69 kHz and 83 kHz) had source levels ranging from 129 to 137 dB re 1 μPa SPL @ 1 m. Transmitter directionality ranged from 3.9 to 18.2 dB. Based on propagation models and published data on marine mammal auditory psychophysics, harbor seals potentially could detect the VEMCO 69 kHz UCTs at ranges between 19 and >200 m, while odontocetes potentially could detect them at much greater ranges. California sea lions were not expected to detect any of the tested UCTs at useful ranges. © 2010 Acoustical Society of America.

Stuart K.R.,Hubbs SeaWorld Research Institute | Drawbridge M.,Hubbs SeaWorld Research Institute
Aquaculture | Year: 2011

Environmental parameters, such as light intensity and turbidity, have been shown to significantly influence the growth and survival of cultured larval finfish. Here, we study three light intensities (low: 360. lx; medium: 1675. lx; and high: 14,850. lx) and two turbidity conditions (with and without green water) to determine optimum growth and survival for California yellowtail (Seriola lalandi) larvae. The study lasted from 2 thru 16. days post hatch (dph). The high light intensity, green water treatment produced the largest larvae (865 ± 165 μg dry weight; 7.01 ± 0.07. mm notochord length), had the highest survival rate (9.2 ± 3.1%), and had the highest incidence of swimbladder inflation (68.8 ± 3.1%) among all treatments in this study. The low and medium light intensity, clear water treatments produced the smallest larvae (183 ± 60 μg dry weight; 5.58 ± 0.07. mm notochord length) and the lowest survival rate (0-0.10%). These results indicate that light intensity and turbidity are significant factors that affect growth and survival of Seriola lalandi larvae up to 16. dph. © 2011 Elsevier B.V.

Stuart K.R.,Hubbs SeaWorld Research Institute | Drawbridge M.A.,Hubbs SeaWorld Research Institute
Aquaculture Research | Year: 2013

A captive population of California yellowtail (Seriola lalandi) was used to document spawning patterns, including measures of egg production, population fecundity and egg and larval quality from 2007 to 2010. Spawned eggs were also used to document larval development and to develop rearing techniques for aquaculture in the region. Broodstock growth and condition factor were best when feeding rations were maintained at 10-15% body weight week-1 during the warm summer months. A winter ration based on satiation feeding was typically 4% body weight week-1. During the 4-year study period, the only broodstock health issue was an infestation by the parasitic gill fluke Zeuxapta seriolae, which was readily treated. Spawning occurred naturally in the 140 m3 tank when the ambient water temperature reached 16°C and ended when the temperature exceeded 22°C. Egg production reached a maximum in 2010 when 43 spawn events were recorded from a pool of nine females yielding 36.8 million eggs in total. The average female size at this time was 20 kg, which equated to a total annual population fecundity of approximately 226 000 eggs kg-1 female year-1. Larval rearing trials yielded survival rates as high as 5.8% from egg to 50 days post-hatch (dph). Successful larval culture methods included the addition of algae paste for green water culture, rotifers (20 rotifers mL-1) at 2 dph and Artemia (5 Artemia mL-1) at 6 dph. Larvae were transferred from the incubation tank at 10 dph to a shallower tank with 33% greater surface area to accommodate the larvae's strong orientation to surface waters. This research represents the first documentation of successful spawning and larval rearing for S. lalandi in the eastern Pacific. © 2012 Blackwell Publishing Ltd.

Stuart K.R.,Hubbs SeaWorld Research Institute | Drawbridge M.,Hubbs SeaWorld Research Institute
Aquaculture | Year: 2012

Light can have significant impacts on larval growth and survival of many marine fish species. Here, we study the effect of photoperiod on larvae from captive populations of two marine finfish species, California yellowtail (CYT; Seriola lalandi) and white seabass (WSB; Atractoscion nobilis). Two photoperiod treatments were tested: 12. h light and 12. h dark (12-L), and 24. h light and 0. h dark (24-L). CYT larvae were significantly heavier (240. ±. 16. μg dry weight) in the 24-L treatment group than the 12-L group (155. ±. 25. μg dry weight) at 10. dph. Similarly, WSB were significantly heavier (685. ±. 77. μg dry weight) in the 24-L treatment group than the 12-L group (455. ±. 44. μg dry weight) at 18. dph. CYT larvae also had significantly greater survival (16.6. ±. 6.2%) in the 24-L treatment over the 12-L conditions (7.6. ±. 4.9%). In contrast, WSB larvae showed no significant difference in survival between treatments. Food consumption was significantly greater in the 24-L treatment for both species up until 6. dph, after which time no difference was observed. Swim bladder inflation rates were not significantly affected by the photoperiod treatments. These results indicate that photoperiod is a significant factor in early larval performance for both CYT and WSB, although it is unknown if continuous light becomes detrimental as larvae develop. © 2012.

Gruenthal K.M.,Hubbs SeaWorld Research Institute | Drawbridge M.A.,Hubbs SeaWorld Research Institute
Evolutionary Applications | Year: 2012

The evolutionary effects captive-bred individuals that can have on wild conspecifics are necessary considerations for stock enhancement programs, but breeding protocols are often developed without the knowledge of realized reproductive behavior. To help fill that gap, parentage was assigned to offspring produced by a freely mating group of 50 white seabass (Atractoscion nobilis), a representative broadcast spawning marine finfish cultured for conservation. Similar to the well-known and closely related red drum (Sciaenops ocellatus), A. nobilis exhibited large variation in reproductive success. More males contributed and contributed more equally than females within and among spawns in a mating system best described as lottery polygyny. Two females produced 27% of the seasonal offspring pool and female breeding effective size averaged 1.85 per spawn and 12.38 seasonally, whereas male breeding effective size was higher (6.42 and 20.87, respectively), with every male contributing 1-7% of offspring. Further, females batch spawned every 1-5weeks, while males displayed continuous reproductive readiness. Sex-specific mating strategies resulted in multiple successful mate pairings and a breeding effective to census size ratio of ≥0.62. Understanding a depleted species' mating system allowed management to more effectively utilize parental genetic variability for culture, but the fitness consequences of long-term stocking can be difficult to address. © 2012 Blackwell Publishing Ltd.

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