Feeding habits of a large endangered skate from the south-west Atlantic: the spotback skate, Atlantoraja castelnaui

2012 ◽  
Vol 63 (2) ◽  
pp. 180 ◽  
Author(s):  
Santiago A. Barbini ◽  
Luis O. Lucifora
Keyword(s):  
Body Size ◽  
Prey Size ◽  
Feeding Habits ◽  
Warm Season ◽  
Cold Season ◽  
The South ◽  
The North ◽  
South West ◽  
Multiple Hypothesis ◽  
Modelling Approach

Elasmobranch predation has important effects on marine ecosystems. Identifying the main correlates of the feeding habits of skates is of paramount importance for determining their ecological role. We tested the hypotheses that the diet of the spotback skate, Atlantoraja castelnaui, off Uruguay and northern Argentina, changes with increasing body size, between seasons and regions and that prey size increased with predator’s size using a multiple-hypothesis modelling approach. A. castelnaui preyed mainly on teleosts, followed by cephalopods, elasmobranchs and decapods. Small individuals of A. castelnaui consumed decapods and large individuals ate elasmobranchs and cephalopods. The consumption of teleosts was constant along the ontogeny but differed between seasons; more demersal-benthic teleosts were consumed in the cold season, whereas more benthic teleosts were eaten in the warm season. Also, A. castelnaui consumed more cephalopods in the warm season than in the cold season. Benthic teleosts were consumed more in the south region, whereas decapods were eaten more in the north region. A. castelnaui is able to consume larger teleosts as it grows. We conclude that A. castelnaui is a versatile, mainly piscivorous, consumer that shifts its diet with increasing body size and in response to seasonal and regional changes in prey abundance or distribution.

scholarly journals Diet composition and feeding habits of the eyespot skate, Atlantoraja cyclophora (Elasmobranchii: Arhynchobatidae), off Uruguay and northern Argentina

2016 ◽  
Vol 14 (3) ◽  
Author(s):  
Santiago A. Barbini ◽  
Luis O. Lucifora
Keyword(s):  
Body Size ◽  
Diet Composition ◽  
Prey Size ◽  
Prey Availability ◽  
Feeding Habits ◽  
Warm Season ◽  
Cold Season ◽  
The North ◽  
Multiple Hypothesis ◽  
Modelling Approach

ABSTRACT The eyespot skate, Atlantoraja cyclophora, is an endemic species from the southwestern Atlantic, occurring from Rio de Janeiro, Brazil, to northern Patagonia, Argentina. The feeding habits of this species, from off Uruguay and north Argentina, were evaluated using a multiple hypothesis modelling approach. In general, the diet was composed mainly of decapod crustaceans, followed by teleost fishes. Molluscs, mysidaceans, amphipods, isopods, lancelets and elasmobranchs were consumed in lower proportion. The consumption of shrimps drecreased with increasing body size of A. cyclophora. On the other hand, the consumption of teleosts increased with body size. Mature individuals preyed more heavily on crabs than immature individuals. Teleosts were consumed more in the south region (34º - 38ºS) and crabs in the north region (38º - 41ºS). Shrimps were eaten more in the warm season than in the cold season. Prey size increased with increasing body size of A. cyclophora , but large individuals also consumed small teleosts and crabs. Atlantoraja cyclophora has demersal-benthic feeding habits, shifts its diet with increasing body size and in response to seasonal and regional changes in prey availability and distribution.

Feeding habits of the Rio skate, Rioraja agassizi (Chondrichthyes: Rajidae), from off Uruguay and north Argentina

2010 ◽  
Vol 91 (6) ◽  
pp. 1175-1184 ◽  
Author(s):  
Santiago A. Barbini ◽  
Luis O. Lucifora
Keyword(s):  
Body Size ◽  
Linear Models ◽  
Feeding Habits ◽  
Warm Season ◽  
Cold Season ◽  
Maturity Stage ◽  
Ontogenetic Diet Shifts ◽  
Multiple Hypothesis ◽  
Diet Shifts ◽  
Modelling Approach

The feeding habits of the Rio skate, Rioraja agassizi, from off Uruguay and north Argentina were evaluated using a multiple-hypothesis modelling approach. Relationships between number of preys and sex, maturity stage, body size, season and region were assessed by building generalized linear models. Rioraja agassizi fed mainly upon crustaceans (shrimps, crabs and amphipods) and teleosts, but also upon isopods, cumaceans, lancelets and polychaetes. Ontogenetic diet shifts were found: small R. agassizi consumed amphipods, cumaceans and isopods and large individuals on shrimps, crabs and teleosts. The consumption of crustaceans (amphipods, shrimps, crabs, isopods and cumaceans) was higher in the northern (34°–38°S) than in the southern area (38°–41°S). Rioraja agassizi consumed more teleosts in the cold season and preyed more on lancelets in the warm season. Prey size increased with increasing body size of R. agassizi, but large individuals also consumed small prey. Ontogenetic shifts may be related to body size rather than other life-history traits. Rioraja agassizi adapts its feeding habits in response to regional and seasonal changes.

Feeding ecology of the apron rayDiscopyge tschudii(Elasmobranchii, Narcinidae) in San Jorge Gulf, Patagonia, Argentina

2015 ◽  
Vol 96 (5) ◽  
pp. 1093-1099 ◽  
Author(s):  
M. Cecilia Spath ◽  
Gabriela Delpiani ◽  
Daniel E. Figueroa
Keyword(s):  
Body Size ◽  
Feeding Habits ◽  
Marine Ecosystem ◽  
Warm Season ◽  
Cold Season ◽  
Maturity Stage ◽  
Multiple Hypothesis ◽  
Discopyge Tschudii ◽  
Modelling Approach

The study of the feeding habits of elasmobranch populations should help to elucidate the ecological role of these fishes in the marine ecosystem. Feeding habits of the apron ray,Discopyge tschudiifrom San Jorge Gulf were investigated. An evaluation of whether the diet ofD. tschudiichanges with body size, seasons, maturity stage and sex was performed using a multiple-hypothesis modelling approach.Discopyge tschudiipreyed mainly on polychaetes. The consumption of polychaetes was higher in males. Also, amphipods and siphons of clams were preyed more heavily in the cold season andMunida gregariain the warm season. Stomatopods were consumed more with increasing body size. All prey categories were independent of maturity stage. We concluded thatD. tschudiiis a benthic feeder.

Feeding habits of the apron ray,Discopyge tschudii(Elasmobranchii: Narcinidae), from off Uruguay and northern Argentina

2012 ◽  
Vol 93 (2) ◽  
pp. 291-297 ◽  
Author(s):  
M. Cecilia Spath ◽  
Santiago A. Barbini ◽  
Daniel E. Figueroa
Keyword(s):  
Body Size ◽  
Seasonal Changes ◽  
Feeding Habits ◽  
Cold Season ◽  
Relative Importance ◽  
Multiple Hypothesis ◽  
Index Of Relative Importance ◽  
Discopyge Tschudii ◽  
Modelling Approach

The feeding habits of the apron ray,Discopyge tschudii, were investigated, off Uruguay and northern Argentina, and we tested the hypothesis that the diet changes with increasing body size, between sexes and seasons using a multiple-hypothesis modelling approach.Discopyge tschudiipreys mainly on polychaetes (88.77% index of relative importance (IRI)) followed by siphons of the clamAmiantis purpurata(8.13% IRI) and amphipods (3.08% IRI). Ontogenetic, sexual and seasonal changes were found. Larger individuals ofD. tschudiiconsumed buried polychaetes more often. The consumption of errant polychaetes was higher in males and in the cold season. Also, amphipods were preyed on more heavily by females and the number of siphons ofA. purpurataconsumed was higher in the cold season.

scholarly journals Feeding habits of the cockfish, Callorhinchus callorynchus (Holocephali: Callorhinchidae) from off northern Argentina

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Jorge M. Roman ◽  
Melisa A. Chierichetti ◽  
Santiago A. Barbini ◽  
Lorena B. Scenna
Keyword(s):  
Body Size ◽  
Trophic Level ◽  
Coastal Waters ◽  
Diet Composition ◽  
Feeding Habits ◽  
Prey Abundance ◽  
Multiple Hypothesis ◽  
Species Shift ◽  
Brachyuran Crabs ◽  
Modelling Approach

ABSTRACT The feeding habits of Callorhinchus callorynchus were investigated in coastal waters off northern Argentina. The effect of body size, seasons and regions was evaluated on female diet composition using a multiple-hypothesis modelling approach. Callorhinchus callorynchus fed mainly on bivalves (55.61% PSIRI), followed by brachyuran crabs (10.62% PSIRI) and isopods (10.13% PSIRI). Callorhinchus callorynchus females showed changes in the diet composition with increasing body size and also between seasons and regions. Further, this species is able to consume larger bivalves as it grows. Trophic level was 3.15, characterizing it as a secondary consumer. We conclude that C. callorynchus showed a behavior of crushing hard prey, mainly on bivalves, brachyuran, gastropods and anomuran crabs. Females of this species shift their diet with increasing body size and in response to seasonal and regional changes in prey abundance or distribution.

The Metamorphosed Limestones and Associated Contaminated Igneous Rocks of the Carlingford District, Co. Louth

1932 ◽  
Vol 69 (5) ◽  
pp. 209-233 ◽  
Author(s):  
G. D. Osborne
Keyword(s):  
Igneous Rocks ◽  
The South ◽  
Ordnance Survey ◽  
Igneous Complex ◽  
North East ◽  
The North ◽  
South West ◽  
Carboniferous Limestone ◽  
Contamination Effects

THE Carlingford-Barnave district falls within the boundaries of Sheet 71 of the Ordnance Survey of Ireland, and forms part of a broad promontory lying between Carlingford Lough on the north-east and Dundalk Bay on the south-west. The greater part of this promontory is made up of an igneous complex of Tertiary age which has invaded the Silurian slates and quartzites and the Carboniferous Limestone Series. This complex has not yet been investigated in detail, but for the purposes of the present paper certain references to it are necessary, and these are made below. The prevalence of hybrid-relations and contamination-effects between the basic and acid igneous rocks of the region is a very marked feature, and because of this it has been difficult at times to decide which types have been responsible for the various stages of the metamorphism.

scholarly journals The Results of a Chemical, Microscopical and Bacteriological Examination of Samples of London Milks

1907 ◽  
Vol 7 (1) ◽  
pp. 22-31 ◽  
Author(s):  
R. Tanner Hewlett ◽  
George S. Barton
Keyword(s):  
Bacteriological Examination ◽  
Milk Supply ◽  
The South ◽  
The West ◽  
The North ◽  
South West ◽  
Pure Milk

In view of the importance of a pure milk supply, we considered that it might be of interest to examine chemically, microscopically, and bacteriologically, a number of specimens of milk coming into the Metropolis for which purpose we decided to select samples from the various counties, the milk of which is consigned to London. We found that milk so consigned comes from about twenty-six counties extending from Derby in the North, to Hampshire and Devonshire in the South and South-West, and from Hereford in the West, to Norfolk in the East.

Part VI. The Cyclopean Terrace Building and the Deposit of Pottery beneath It

1954 ◽  
Vol 49 ◽  
pp. 267-291
Author(s):  
Elizabeth B. Wace
Keyword(s):  
Contour Line ◽  
The South ◽  
Main Road ◽  
North West ◽  
North East ◽  
The North ◽  
South West

The Cyclopean Terrace Building lies to the north-west of the Lion Gate on the northern end of the Panagia Ridge and faces almost due west across the valley of the Kephissos and modern main road from Corinth to Argos. It lies just below the 200 m. contour line, and one terrace below the houses excavated in 1950–51 by Dr. Papadimitriou and Mr. Petsas to the east at the same end of the ridge. The area contains a complex of buildings, both successive and contemporary, and in view of the discovery of structures both to the south-west and, by the Greek Archaeological Service, to the north-east it is likely that this whole slope was covered by a portion of the outer town of Mycenae. This report will deal only with the structure to which the name Cyclopean Terrace Building was originally given, the so-called ‘North Megaron’, supported by the heavy main terrace wall.The excavation of this structure was begun in 1923. The main terrace wall was cleared and two L.H. IIIC burials discovered in the top of the fill in the south room. In 1950 it was decided to attempt to clear this building entirely in an endeavour to find out its date and purpose. The clearing was not, however, substantially completed until the close of the 1953 excavation season, and this report presents the available evidence for the date as determined by the pottery found beneath the building; the purpose is still a matter for study, though various tentative conclusions can be put forward.

scholarly journals Late antique necropolis in Davidovac-Crkviste

Starinar ◽  
2013 ◽  
pp. 269-286
Author(s):  
Perica Spehar ◽  
Natasa Miladinovic-Radmilovic ◽  
Sonja Stamenkovic
Keyword(s):  
Bronze Age ◽  
Late Antiquity ◽  
Late Antique ◽  
The South ◽  
The North ◽  
South West ◽  
North Eastern ◽  
Constantius Ii ◽  
Small Finds ◽  
Roman Province

In 2012, in the village Davidovac situated in south Serbia, 9.5 km south-west from Vranje, archaeological investigations were conducted on the site Crkviste. The remains of the smaller bronze-age settlement were discovered, above which a late antique horizon was later formed. Apart from modest remains of a bronze-age house and pits, a late antique necropolis was also excavated, of which two vaulted tombs and nine graves were inspected during this campaign. During the excavation of the northern sector of the site Davidovac-Crkviste the north-eastern periphery of the necropolis is detected. Graves 1-3, 5 and 6 are situated on the north?eastern borderline of necropolis, while the position of the tombs and the remaining four graves (4, 7-9) in their vicinity point that the necropolis was further spreading to the west and to the south?west, occupying the mount on which the church of St. George and modern graveyard are situated nowadays. All graves are oriented in the direction SW-NE, with the deviance between 3? and 17?, in four cases toward the south and in seven cases toward the north, while the largest part of those deviations is between 3? and 8?. Few small finds from the layer above the graves can in some way enable the determination of their dating. Those are two roman coins, one from the reign of emperor Valens (364-378), as well as the fibula of the type Viminacium-Novae which is chronologically tied to a longer period from the middle of the 5th to the middle of the 6th century, although there are some geographically close analogies dated to the end of the 4th or the beginning of the 5th century. Analogies for the tombs from Davidovac can be found on numerous sites, like in Sirmium as well as in Macvanska Mitrovica, where they are dated to the 4th-5th century. Similar situation was detected in Viminacium, former capital of the roman province of Upper Moesia. In ancient Naissus, on the site of Jagodin Mala, simple rectangular tombs were distributed in rows, while the complex painted tombs with Christian motifs were also found and dated by the coins to the period from the 4th to the 6th century. Also, in Kolovrat near Prijepolje simple vaulted tombs with walled dromos were excavated. During the excavations on the nearby site Davidovac-Gradiste, 39 graves of type Mala Kopasnica-Sase dated to the 2nd-3rd century were found, as well as 67 cist graves, which were dated by the coins of Constantius II, jewellery and buckles to the second half of the 4th or the first half of the 5th century. Based on all above mentioned it can be concluded that during the period from the 2nd to the 6th century in this area existed a roman and late antique settlement and several necropolises, formed along an important ancient road Via militaris, traced at the length of over 130 m in the direction NE-SW. Data gained with the anthropological analyses of 10 skeletons from the site Davidovac-Crkviste don't give enough information for a conclusion about the paleo-demographical structure of the population that lived here during late antiquity. Important results about the paleo-pathological changes, which do not occur often on archaeological sites, as well as the clearer picture about this population in total, will be acquired after the osteological material from the site Davidovac-Gradiste is statistically analysed.

scholarly journals Volcanic centres between Frigg Fjord and Midtkap, eastern North Greenland

1981 ◽  
Vol 106 ◽  
pp. 69-75
Author(s):  
I Parsons
Keyword(s):  
Fault Zone ◽  
Fold Belt ◽  
The South ◽  
The North ◽  
Rock Types ◽  
South West ◽  
North Greenland

A series of smal! volcanic centres cut Ordovician turbidites of Formation A in the southem part of Johannes V. Jensen Land between Midtkap and Frigg Fjord (Map 2). Their general location and main rock types were described by Soper et al. (1980) and their nomenclature is adopted here for fig. 22 with the addition of the small pipe B2. A further small intrusion, south-west of Frigg Fjord, was described by Pedersen (1980). The centres lie 5-10 km south of, and parallel to, the important Harder Fjord fault zone (fig. 22) which traverses the southern part of the North Greenland fold belt and shows substantial downthrow to the south (Higgins et al., this report).

Sign in / Sign up

Export Citation Format

Share Document