Habitat use plasticity by the dog snapper (Lutjanus jocu) across the Abrolhos Bank shelf, eastern Brazil, inferred from otolith chemistry

Author(s):  
Rafael Menezes ◽  
Perimar E.S. Moura ◽  
Alexandre C.A. Santos ◽  
Leonardo E. Moraes ◽  
Mario V. Condini ◽  
...  
2021 ◽  
Vol 240 ◽  
pp. 105953
Author(s):  
Esteban Avigliano ◽  
Nadia M. Alves ◽  
M. Rita Rico ◽  
Claudio O. Ruarte ◽  
Luciana D’Atri ◽  
...  

2016 ◽  
Vol 98 (5) ◽  
pp. 1081-1086 ◽  
Author(s):  
Israel S. Maciel ◽  
Rodrigo H. Tardin ◽  
Sheila M. Simão

Ninety-six field trips were conducted between summer 2010 and 2012 in order to understand the occurrence and habitat use of Bryde's whale (Balaenoptera edeni) in the Cabo Frio region, South-eastern Brazil. Bryde's whales were present in the study area between November and July, being observed during all seasons, but occur more frequently during the autumn (Nindividuals = 16) and spring (Nindividuals = 13), followed by summer (Nindividuals = 5) and winter (Nindividuals = 2), respectively. Bryde's whales were observed in water depths ranging from 20.1–100 m. Furthermore, during 2240 min of video recordings, the most frequent behaviour observed was foraging (40.2%; 900 min). Travelling comprised 28.1% (630 min) of observations, while in 33.1% (710 min) behaviour could not be determined. Taking into account the pattern of occurrence, the use of deeper bathymetric bins and the frequency observed, the foraging behaviour of Bryde's whales observed in our study seems to be associated to prey dynamics. Our data show that the study area is frequently used for foraging by this species in Brazilian waters.


2020 ◽  
Vol 7 ◽  
Author(s):  
Filipe Martinho ◽  
Beatriz Pina ◽  
Margarida Nunes ◽  
Rita P. Vasconcelos ◽  
Vanessa F. Fonseca ◽  
...  

2020 ◽  
Vol 77 (5) ◽  
pp. 1927-1940
Author(s):  
Pamela Toledo ◽  
Edwin J Niklitschek ◽  
Audrey M Darnaude ◽  
Félix P Leiva ◽  
Chris Harrod ◽  
...  

Abstract Partial migration, where migrant and resident organisms coexist within the same population, has been found in many fishes. Although it seems obvious that different life cycles exploit habitats and food webs differently, few assessments about the trophic consequences of partial migration are available. To unveil part of this complexity, we combined otolith chemistry with stable isotope analyses data for hind-casting Merluccius australis habitat use and diet composition at age. By providing detailed information about lifetime variability in diet, trophic position, and prey demand of four M. australis life-cycle types, we show that these groups feed differentially in estuarine and oceanic habitats throughout their ontogeny. Although trophic positions were similar between habitats for juvenile and subadults, substantial differences between life-cycle types were found regarding lifetime diet and trophic demand. Thus, the more abundant and heavily exploited oceanic stock of M. australis was heavily dependent of estuarine habitats within the Patagonian Fjords System, where it consumes large biomasses of Macruronus magellanicus, Pasiphaea, Sprattus fuegensis, and Euphausiidae at earlier stages. We show ignoring trophic consequences of partial migration and life-cycle diversity may produce highly biased results, both in terms of prey and habitat use, which appears critical for multispecies and ecosystem management approaches.


2018 ◽  
Vol 16 (2) ◽  
Author(s):  
Ana C. G. Mai ◽  
Mauricio L. dos Santos ◽  
Valéria M. Lemos ◽  
João P. Vieira

ABSTRACT Two sympatric species of marine mullets, Mugil curema and M. liza, use the rio Tramandaí Estuary as nursing grounds. When two closely related species are sympatric, various mechanisms may permit their coexistence, including spatial or temporal segregation that results in the divergent use of the resources for which they compete. To investigate the spatial segregation, we used otolith chemistry inferred through laser ablation-inductively coupled plasma mass spectrometry. Our results indicate that in the rio Tramandaí Estuary, M. curema is associated with high salinity waters and can be classified as a Marine Migrant in the Marine Estuarine-opportunist subcategory. Mugil liza is associated with lower salinity and can be classified as a Marine Migrant in the Estuarine Dependent subcategory. The intra-specific variation in estuarine habitat use indicates that the migratory behaviors in mullets are far more complex than previously known.


Author(s):  
Victor Uber Paschoalini ◽  
Genyffer Cibele Troina ◽  
Laura Busin Campos ◽  
Marcos César de Oliveira Santos

Abstract We investigated the habitat use and feeding ecology of 10 cetacean species encountered along the south-eastern coast of Brazil (24–26°S) using carbon (δ13C) and nitrogen (δ15N) stable isotopes. Hierarchical cluster analysis distinguished two main groups based on their isotopic patterns. One group included migratory baleen whales (Megaptera novaeangliae and Eubalaena australis) with the lowest δ13C and δ15N values, reflecting baseline isotopic values of their Subantarctic feeding grounds and consumption of lower trophic level prey. Resident species and those occasionally occurring in Brazilian coastal waters highly differed from the migratory whales in their isotopic values. In this group, Tursiops truncatus had the highest δ13C and δ15N values, indicating coastal habits and relatively higher trophic position. Similar δ13C values were observed in Sotalia guianensis, Pontoporia blainvillei, Orcinus orca and Steno bredanensis. However, the former two species had lower δ15N values than the latter two, indicating different trophic positions. The relatively lower δ13C values observed in Stenella frontalis suggest greater influence of pelagic prey in their diet. Furthermore, the lower δ13C values observed in Delphinus delphis and Balaenoptera edeni were associated with upwelling events that occur along the region, affecting the isotopic values of their main prey. Juvenile M. novaeangliae had higher δ13C and δ15N than the adults, which may indicate feeding in areas with different isoscapes and consumption of pelagic schooling fish with relatively higher trophic levels than krill. This study provides preliminary information that are useful to understand the habitat use and coexistence of cetacean species occurring in south-eastern Brazil.


2008 ◽  
Vol 88 (6) ◽  
pp. 1199-1205 ◽  
Author(s):  
L.V. de Oliveira ◽  
E.L.A. Monteiro-Filho

Individual identification using Hi8 video images was tested on the population of estuarine dolphins, Sotalia guianensis that inhabit the Cananéia estuary, south-eastern Brazil. Between June 2001 and August 2002, 25 different dolphins were identified by nicks on the dorsal fin (80%) and by the association of cuts and scratches on the dorsal fin and the body's dorsal region (20%). The existent marks were used to create an identification key to ease the matching between dolphins. The animals were present on 100% of the sampled days, and some of them were repeatedly registered at the same sector in the area, suggesting that although they occupy an extensive area, they use it in an intended way. When compared to researches that used photographs to identify cetaceans, the video images showed some loss of information, nevertheless the analysis could be done without impairment of results, therefore this method proved to be efficient.


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