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Mahmood S. Shivji - One of the best experts on this subject based on the ideXlab platform.
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Vertical Movements of Shortfin Mako Sharks Isurus oxyrinchus in the Western North Atlantic Ocean are Strongly Influenced by Temperature
Marine Ecology Progress Series, 2016Co-Authors: Jeremy J. Vaudo, Bradley M. Wetherbee, Anthony D. Wood, Kevin C. Weng, Lucy A. Howey-jordan, Guy M. Harvey, Mahmood S. ShivjiAbstract:Although shortfin mako sharks Isurus oxyrinchus are regularly encountered in pelagic fisheries, limited information is available on their vertical distribution and is primarily restricted to cooler areas of their geographic range. We investigated the vertical movements of mako sharks across differing temperature regimes within the western North Atlantic by tagging 8 individuals with pop-up satellite archival tags off the northeastern United States and the Yucatan Peninsula, Mexico. Depth and temperature records across 587 d showed vertical movements strongly associated with ocean temperature. Temperatures \u3c15°C created a lower depth limit to most diving behaviors, and shifts in depths used coincided with changes in the thermal properties of the vertical habitat. In the warmest water columns, sharks spent 36% of the daytime at depths \u3e150 m compared to only 1% in the coldest water columns. The sharks showed diel diving behavior, with deeper dives occurring primarily during the daytime (maximum depth: 866 m). Overall, sharks experienced temperatures between 5.2 and 31.1°C. When the opportunity was available, sharks spent considerable time in waters ranging from 22 to 27°C, indicating underestimation of the previously reported upper limit of the mako sharks’ preferred temperature. The preference for higher temperatures does not support endothermy as an adaption for niche expansion in mako sharks. The strong influence of thermal habitat on movement behavior suggests potentially strong impacts of rising ocean temperatures on the ecology of this highly migratory top predator
Diego Bernal - One of the best experts on this subject based on the ideXlab platform.
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Aerobic metabolic rates of swimming juvenile mako sharks, Isurus oxyrinchus
Marine Biology, 2007Co-Authors: C. A. Sepulveda, Diego BernalAbstract:The shortfin mako shark, Isurus oxyrinchus, is a highly streamlined epipelagic predator that has several anatomical and physiological specializations hypothesized to increase aerobic swimming performance. A large swim-tunnel respirometer was used to measure oxygen consumption (MO2) in juvenile mako sharks (swimming under controlled temperature and flow conditions) to test the hypothesis that the mako shark has an elevated maintenance metabolism when compared to other sharks of similar size swimming at the same water temperature. Specimen collections were conducted off the coast of southern California, USA (32.94°N and 117.37°W) in 2001-2002 at sea-surface temperatures of 16.0–21.0°C. Swimming MO2 and tail beat frequency (TBF) were measured for nine mako sharks [77–107 cm in total length (TL) and 4.4 to 9.5 kg body mass] at speeds from 28 to 54 cm s−1 (0.27–0.65 TL s−1) and water temperatures of 16.5–19.5°C. Standard metabolic rate (SMR) was estimated from the extrapolation to 0-velocity of the linear regression through the LogMO2 and swimming speed data. The estimated LogSMR (±SE) for the pooled data was 2.0937 ± 0.058 or 124 mg O2 kg−1 h−1. The routine metabolic rate (RMR) calculated from seventeen MO2 measurements from all specimens, at all test speeds was (mean ± SE) 344 ± 22 mg O2 kg−1h−1 at 0.44 ± 0.03 TL s−1. The maximum metabolic rate (MMR) measured for any one shark in this study was 541 mg O2 kg−1h−1 at 54 cm s−1 (0.65 TL s−1). The mean (±SE) TBF for 39 observations of steady swimming at all test speeds was 1.00 ± 0.01 Hz, which agrees with field observations of 1.03 ± 0.03 Hz in four undisturbed free-swimming mako sharks observed during the same time period. These findings suggest that the estimate of SMR for juvenile makos is comparable to that recorded for other similar-sized, ram-ventilating shark species (when corrected for differences in experimental temperature). However, the mako RMR and MMR are apparently among the highest measured for any shark species.
J Mejuto - One of the best experts on this subject based on the ideXlab platform.
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STANDARDIZED CATCH RATES OF SHORTFIN MAKO (Isurus oxyrinchus) CAUGHT BY THE SPANISH SURFACE LONGLINE FISHERY TARGETING SWORDFISH IN THE ATLANTIC OCEAN DURING THE PERIOD 1990-2010
2013Co-Authors: J Mejuto, B. García-cortés, A. Ramos-cartelle, J. M. De La SernaAbstract:SUMMARY Standardized catches per unit of effort (in number and weight) were obtained for the Atlantic shortfin mako (Isurus oxyrinchus) using General Linear Modeling (GLM) procedures based on trip data from the Spanish surface longline fleet targeting swordfish in the North and South Atlantic Ocean over the period 1990-2010. In all cases area was considered to be the most relevant factor in explaining CPUE variability. Area, area* quarter and ratio were the most important factors in the North Atlantic, and area, year and quarter or area* quarter in the South Atlantic. Other factors were also identified as significant but with a minor effect on CPUE variability. Part of the CPUE variability was explained by the targeting criteria or ratio between the two most prevalent species in the catches, especially in the North Atlantic case. The significant models explained between 35% and 44% of CPUE variability. The mean variability of the predicted standardized CPUE between pairs of consecutive years was between 14% and 16% or around +2% when their absolute increments or both positive and negative increments were considered, respectively. RESUME
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movements and environmental preferences of the shortfin mako Isurus oxyrinchus in the southeastern pacific ocean
Marine Biology, 2011Co-Authors: Francisco J Abascal, M Quintans, A Ramoscartelle, J MejutoAbstract:Nine individuals of shortfin mako, Isurus oxyrinchus, were tracked in the southeastern Pacific Ocean, off northern Chile, by means of pop-up satellite archival tags. No common pattern was observed in their trajectories, apart from a movement onshore of all the fish tracked during June–August. The average estimated rate of movement was of c. 27 km day−1. Data were collected and processed for a total of 341 days, including 33 days for one recaptured fish specimen, allowing high-resolution archived data to be downloaded. The fish spent most of their time in the mixed layer but undertook dives down to 888 m. Ambient temperatures ranged between 4.6 and 24.1°C, and the sea surface temperatures recorded ranged from 13.4 to 24.1°C during the study period. No clear diel pattern in depth behavior was observed, but mean vertical distribution was deeper during the daytime. Moreover, a foraging pattern, consisting of rapid descents below the thermocline followed by slower ascents, was generally observed during daylight hours. Dissolved oxygen concentration and water temperature seem to be the main factors affecting the vertical range of the species in the area. This is the first study on electronic tagging of the shortfin mako in the southeastern Pacific Ocean and covers the longest total tracking period reported so far for this species.
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length weight relationships and morphometric conversion factors between weights for the blue shark prionace glauca and shortfin mako Isurus oxyrinchus caught by the spanish surface longline fleet in the atlantic ocean
2008Co-Authors: J Mejuto, M Quintans, F Gonzalez, A CarrocedaAbstract:SUMMARY Length-weight relationships and conversion factors between different weight types are presented for the blue shark (Prionace glauca) and shortfin mako (Isurus oxyrinchus) which are the two of the most prevalent by-catch species in the surface longline fleets. The conversion factors RW-GW and RW-DW obtained for blue shark range, respectively, from 1.1946-1.2219 and 2.4074-2.5052 and from 1.15251.1577 and 1.4369-1.4575 for shortfin mako. Linear equations for conversion between different weight types are also presented for both species. The predicted weights from length-weight relationships obtained using nonlinear modeling do not differ from some of the previous length-weight relationships reported by other authors for both species. RESUME Les relations longueur-poids et les coefficients de conversion entre differents types de poids sont presentes pour le requin peau bleue (Prionace glauca) et le requin taupe bleue (Isurus oxyrinchus) qui sont les especes accessoires dominantes des flottilles palangrieres de surface. Les coefficients de conversion RW-GW et RW-DW obtenus pour le requin peau bleue s’inscrivent, respectivement, dans la gamme de 1,1946-1,2219 et 2,4074-2,5052 et entre 1,1525-1,1577 et 1,4369-1,4575 pour le requin taupe bleue. Des equations lineaires pour la conversion entre les differents types de poids sont egalement presentees pour ces deux especes. Les poids predits a partir des relations longueur-poids obtenues a l’aide de modeles non-lineaires ne different pas de certaines relations longueur-poids anterieures declarees par d’autres auteurs pour ces deux especes. RESUMEN Se presentan relaciones talla-peso y relaciones de conversion entre diferentes tipos de peso para las especies tiburon azul (Prionace glauca) y marrajo dientuso (Isurus oxyrinchus) las cuales son especies de las mas prevalentes como captura incidental en las flotas de palangre de superficie. Los factores de conversion RW-GW y RW-DW para el tiburon azul estarian respectivamente dentro de estrechos rangos 1.1946-1.2219 y 2.4074-2.5052 y entre 1.1525-1.1577 y 1.4369-1.4575 para el marrajo dientuso. Las diferentes ecuaciones de conversion entre diferentes tipos de peso son tambien suministradas para ambas especies. Las predicciones de peso a partir de las relaciones talla-pes, obtenidas usando ajustes no lineales, no difieren de las previamente descritas por otros autores para ambas especies.
Jeffrey B. Graham - One of the best experts on this subject based on the ideXlab platform.
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Functional morphology of the gills of the shortfin mako, Isurus oxyrinchus, a lamnid shark.
Journal of morphology, 2010Co-Authors: Nicholas C. Wegner, Chugey A. Sepulveda, Kenneth R. Olson, Kelly A. Hyndman, Jeffrey B. GrahamAbstract:This study examines the functional gill morphology of the shortfin mako, Isurus oxyrinchus ,t o determine the extent to which its gill structure is conver- gent with that of tunas for specializations required to increase gas exchange and withstand the forceful branchial flow induced by ram ventilation. Mako gill structure is also compared to that of the blue shark, Prio- nace glauca, an epipelagic species with lower metabolic requirements and a reduced dependence on fast, continu- ous swimming to ventilate the gills. The gill surface area of the mako is about one-half that of a comparably sized tuna, but more than twice that of the blue shark and other nonlamnid shark species. Mako gills are also distin- guished from those of other sharks by shorter diffusion distances and a more fully developed diagonal blood-flow pattern through the gill lamellae, which is similar to that found in tunas. Although the mako lacks the filament and lamellar fusions of tunas and other ram-ventilating tele- osts, its gill filaments are stiffened by the elasmobranch interbranchial septum, and the lamellae appear to be sta- bilized by one to two vascular sacs that protrude from the lamellar surface and abut sacs of adjacent lamellae. Vaso- active agents and changes in vascular pressure poten- tially influence sac size, consequently effecting lamellar rigidity and both the volume and speed of water through the interlamellar channels. However, vascular sacs also occur in the blue shark, and no other structural elements of the mako gill appear specialized for ram ventilation. Rather, the basic elasmobranch gill design and pattern of branchial circulation are both conserved. Despite special- izations that increase mako gill area and efficacy relative to other sharks, the basic features of the elasmobranch gill design appear to have limited selection for a larger gill surface area, and this may ultimately constrain mako aerobic performance in comparison to tunas. J. Morphol. 000:000-000, 2010. 2010 Wiley-Liss, Inc.
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Movement patterns, depth preferences, and stomach temperatures of free-swimming juvenile mako sharks, Isurus oxyrinchus , in the Southern California Bight
Marine Biology, 2004Co-Authors: Chugey A. Sepulveda, Suzanne Kohin, C. Chan, Russ Vetter, Jeffrey B. GrahamAbstract:Acoustic telemetry was used to track vertical and horizontal movement patterns and to monitor the stomach temperatures of seven juvenile shortfin mako sharks (Isurus oxyrinchus Rafinesque) in the Southern California Bight from July to November 2002. Makos (80–145 cm fork length, FL) were attracted to the tracking vessel, where they were fed a mackerel containing an acoustic transmitter that reported temperature and pressure. Tracks ranged from 6.8–45.4 h. Collectively, the mako sharks spent 80% of the track record at 0–12 m, 15% at 12–24 m, and 5% at depths >24 m. The average horizontal swimming speed was 2.3 km h−1 or 0.55 FLs s−1, and the greatest distance traveled was 145 km in 45.4 h. For the six tracks >21 h, there was a positive correlation between body size and maximum depth. Makos used more of the water column during daylight hours. Mean stomach temperature was 3.8±1.5°C above ambient, and body size was positively correlated with both maximum and average stomach temperature. Stomach content analyses of four makos captured at the end of tracking verified the occurrence of feeding events as indicated by changes in stomach temperature.
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Hemodynamics and Blood Properties of the Shortfin Mako Shark (Isurus oxyrinchus)
Copeia, 1997Co-Authors: N. Chin Lai, Keith E. Korsmeyer, Steven Katz, David B. Holts, Leeanne M. Laughlin, Jeffrey B. GrahamAbstract:Lamnid sharks are difficult experimental subjects, and knowledge of their cardiovascular system has been largely based on morphological (Tota et al., 1983; Emery et al., 1985), histological (Sanchez-Quintana and Hurle, 1987; De Andres et al., 1990), biochemical (Farrell and Davie, 1991; Dickson et al., 1993), and hematological investigations (Wells and Davie, 1985; Emery, 1986). Because these sharks have a physiological capacity that exceeds other species (Graham et al., 1990), it is important to obtain cardiovascular data in living specimens. This report details in vivo studies of the cardiovascular and blood respiratory properties and the heartregulatory mechanism of shortfin mako sharks (Isurus oxyrinchus) carried out at sea on freshly collected specimens, most of which were subsequently released.
Jeremy J. Vaudo - One of the best experts on this subject based on the ideXlab platform.
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Vertical Movements of Shortfin Mako Sharks Isurus oxyrinchus in the Western North Atlantic Ocean are Strongly Influenced by Temperature
Marine Ecology Progress Series, 2016Co-Authors: Jeremy J. Vaudo, Bradley M. Wetherbee, Anthony D. Wood, Kevin C. Weng, Lucy A. Howey-jordan, Guy M. Harvey, Mahmood S. ShivjiAbstract:Although shortfin mako sharks Isurus oxyrinchus are regularly encountered in pelagic fisheries, limited information is available on their vertical distribution and is primarily restricted to cooler areas of their geographic range. We investigated the vertical movements of mako sharks across differing temperature regimes within the western North Atlantic by tagging 8 individuals with pop-up satellite archival tags off the northeastern United States and the Yucatan Peninsula, Mexico. Depth and temperature records across 587 d showed vertical movements strongly associated with ocean temperature. Temperatures \u3c15°C created a lower depth limit to most diving behaviors, and shifts in depths used coincided with changes in the thermal properties of the vertical habitat. In the warmest water columns, sharks spent 36% of the daytime at depths \u3e150 m compared to only 1% in the coldest water columns. The sharks showed diel diving behavior, with deeper dives occurring primarily during the daytime (maximum depth: 866 m). Overall, sharks experienced temperatures between 5.2 and 31.1°C. When the opportunity was available, sharks spent considerable time in waters ranging from 22 to 27°C, indicating underestimation of the previously reported upper limit of the mako sharks’ preferred temperature. The preference for higher temperatures does not support endothermy as an adaption for niche expansion in mako sharks. The strong influence of thermal habitat on movement behavior suggests potentially strong impacts of rising ocean temperatures on the ecology of this highly migratory top predator
