Food habits, selectivity, and foraging modes of the school shark Galeorhinus galeus

Lucifora, Luis O.; García, Verónica B.; Menni, Roberto Carlos; Escalante, Alicia H.

doi:10.3354/meps315259

Cited by 61 publications

(59 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies comparing shark diets and prey availability estimates have shown that, during times of high prey abundance, some species (e.g. school shark Galeorhinus galeus and angel shark Squatina dumeril) can be selective predators (Lucifora et al 2006, Baremore et al 2008.…”

Section: Discussionmentioning

confidence: 99%

Predator–prey relationships and foraging ecology of a marine apex predator with a wide temperate distribution

Barnett¹,

Abrantes²,

Stevens³

et al. 2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

The diet of the broadnose sevengill shark Notorynchus cepedianus was investigated over 3 years from 2 coastal locations in south-east Tasmania: the Derwent Estuary and Norfolk Bay. In general, individuals from both locations consumed the same broad dietary categories (sharks, batoids, teleosts and mammals). However, within these categories, species composition differed. Variations in chondrichthyan prey consumed matched estimations of prey abundance: Mustelus antarcticus was the primary prey in Norfolk Bay, where it was also the most abundant prey species; similarly, Squalus acanthias was an important prey and the most abundant in the Derwent Estuary. A decline in the catch rates of N. cepedianus and elasmobranch prey, in particular M. antarcticus over 3 years coincided with declines in dietary occurrence of M. antarcticus. Also, N. cepedianus and M. antarcticus abundances were both higher in Norfolk Bay than the Derwent Estuary. The correlation with diet and estimations of predator and prey relative abundance suggests N. cepedianus may move into coastal areas to exploit regular seasonal abundant resources, but they can also be versatile opportunistic predators that exploit a temporarily abundant resource. KEY WORDS: Shark · Notorynchus cepedianus · Diet · Spatial scale · Mustelus antarcticusResale or republication not permitted without written consent of the publisher

show abstract

Section: Discussionmentioning

confidence: 99%

Predator–prey relationships and foraging ecology of a marine apex predator with a wide temperate distribution

Barnett¹,

Abrantes²,

Stevens³

et al. 2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…Birds can also use different strategies during different stages of the chick-rearing cycle (Deagle et al 2008). Adaptability in foraging strategy is also evident in other marine organisms, such as sharks (Lucifora et al 2006, Baremore et al 2008) and marine mammals (Boyd et al 1994, Skern-Mauritzen et al 2009, Arnould et al 2011. If diverse marine ecosystems such as the northern California Current are undergoing a gradual shift in the prey base, it will be crucial to monitor not only the population levels of predators in the system, but also the ability of predators to buffer those changes through behavioral flexibility.…”

Section: Discussionmentioning

confidence: 99%

Trade-offs in prey quality and quantity revealed through the behavioral compensation of breeding seabirds

Schrimpf¹,

Parrish²,

Pearson³

2012

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Many productive ocean ecosystems are also highly variable, resulting in complex trophic interactions. We analyzed interannual patterns in the diet of a seabird, the common murre Uria aalge, in a region of high oceanographic productivity, the northern California Current, to investigate how these top predators adjust their chick provisioning to cope with environmental variability. Murres relied chiefly on Pacific herring Clupea harengus pallasi and surf smelt Hypomesus pretiosus to provision chicks, although they regularly returned 8 other fish taxa. Provisioning success was measured by the energy return rate to chicks, which in turn was disarticulated into energy per meal (quality) and meal delivery rate (quantity). Parents exhibited 'compensation' during 2 years in which smaller, low quality prey were returned more quickly than in years with normal (i.e. 'good') provisioning. Despite the increased delivery rate, energy return rates were still lower in 'compensation' vs. 'good' years. The lowest energy return rates occurred in 3 'poor' years, during which ocean productivity was also depressed. Our results suggest that murres in this system have the ability to shift provisioning strategies to deal with some variability in prey resources, but not when limited by exceptionally poor environmental conditions.

show abstract

“…Large-sized sharks are particularly jeopardized due to their slow life history, low densities and large home ranges (Compagno, 1990;Cortés, 2000;Frisk et al, 2001;Hutchings et al, 2012). On the Argentinean coast, the group of large-sized sharks targeted by sport and artisanal fishermen comprises: the sand-tiger shark Carcharias taurus Rafinesque, the copper shark Carcharhinus brachyurus (Günther) and the broadnose sevengill shark Notorynchus cepedianus (Péron) (Lucifora, 2003;Cedrola et al, 2011). These species are under intense sport and artisanal fishing since the 50's decade along all its range of distribution in Argentina, Uruguay and Brazil (Chiaramonte, 1998;Cedrola et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Depletion of trophy large-sized sharks populations of the Argentinean coast, south-western Atlantic: insights from fishers' knowledge

Irigoyen

Trobbiani

2016

Neotrop. ichthyol.

View full text Add to dashboard Cite

Globally, sharks are impacted by a wide range of human activities, resulting in many populations being depleted. Trophy large-sized sharks of the Argentinean coast, the sand-tiger Carcharias taurus, the copper Carcharhinus brachyurus and the sevengill shark Notorynchus cepedianus are under intense sport and artisanal fishing since the 50's decade. However, the current and historical information for the assessment of its populations status is scarce. The aim of this work was to analyze the status of conservation of these species through the gathering of expert fishermen knowledge (FK) on semi-structured interviews. Abundance variation perception between the beginning and the end of fishermen careers revealed a critical status for the species study (means variation between -77 and -90 %). Furthermore, a best day´s catch analysis reinforce this result in the case of the sand tiger shark. The school shark Galeorhinus galeus was included on this work with the objective of contrast FK with formal information available of catch-per-unit-effort (CPUE) time series. Both sources of information, despite are not comparable, shows declines ~ -80%. The critical conservation situation of study species needs urgent management action, particularly for the san tiger shark which could became regionally extinct before the reaction of stakeholders occurs.A escala global, los condrictios se encuentran severamente afectados por un amplio rango de actividades antrópicas. Actualmente una gran proporción de poblaciones se encuentran diezmadas y algunas especies son consideradas en peligro de extinción. Los tiburones de gran tamaño y de interés pesquero de la costa Argentina, el escalandrún Carcharias taurus, el bacota Carcharhinus brachyurus y el gatopardo Notorynchus cepedianus se encuentran bajo una intensa presión de pesca desde la década del 50. Sin embargo, la información actual o histórica sobre el estado de conservación de estas especies es muy escasa. El objetivo de este trabajo fue analizar el estado de conservación de estas especies a través de la colecta de conocimiento de pescadores expertos mediante entrevistas semi-estructuradas. La precepción de los pescadores sobre la variación en abundancia entre el principio de sus carreras y el final de las mismas, mostró un estado crítico de las especies de estudio (variación media entre -77 y -90%). Además, un análisis sobre el mejor día de capturas revela un estado particularmente crítico para el eslandrún. El cazón Galeorhinus galeus fue incluido en este trabajo con el objetivo de contrastar los resultados de la percepción de los pescadores con información formal disponible basada en información de Captura por Unidad de Esfuerzo. En ambas fuentes de información, si bien no son comparables, se obtuvo una declinación del 80 % en la abundancia. Adicionalmente, en este trabajo se recabo información sobre los patrones estacionales de ocurrencia de las especies (adultos y neonatos). El crítico estado de conservación de las especies de estudio requiere la aplicación de mediadas de manejo ...

show abstract

Food habits, selectivity, and foraging modes of the school shark Galeorhinus galeus

Cited by 61 publications

References 38 publications

Predator–prey relationships and foraging ecology of a marine apex predator with a wide temperate distribution

Predator–prey relationships and foraging ecology of a marine apex predator with a wide temperate distribution

Trade-offs in prey quality and quantity revealed through the behavioral compensation of breeding seabirds

Depletion of trophy large-sized sharks populations of the Argentinean coast, south-western Atlantic: insights from fishers' knowledge

Contact Info

Product

Resources

About