Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Más filtros










Intervalo de año de publicación
1.
PLoS One ; 18(3): e0281545, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36893164

RESUMEN

Long considered on the margins, far from the major cultural traditions, the Sechura Desert is situated at the crossroads between the cultures of southern Ecuador and those of the northern Peruvian coast and preserves a large number of varied archaeological sites. Despite this evidence, little is known about the societies that inhabited this region during the Holocene. Exposed to natural hazards, including El Niño events, and to major climatic changes, they were able to adapt and exploit the scarce resources that this extreme environment offered them. Because of this rich history, we have been conducting archaeological research in this region since 2012 in order to clarify the dynamics of human occupation and their links with climate oscillations and environmental changes. This paper present the results of a multidisciplinary study of Huaca Grande, a mound located on Nunura Bay, 300 m from the Pacific Ocean. The nature of the human occupations at Huaca Grande was varied, and several adjustments occurred over time. The subsistence economy was based mainly on local marine resources and a continual use of terrestrial vegetal resources. However, a major change occurred in the more recent occupations, with the apparition of non-local resources (maize and cotton) indicating that Huaca Grande was connected to trade networks. The results show two main phases of occupation separated by a long abandonment (mid-5th century CE to mid-7th century CE and mid-13th century to mid-15th century CE). The occupation of the site appears to have been influenced by changes in the local climate and by extreme El Niño events. Our results highlight the great adaptability of these human groups over the span of a millennium and their capacity to react to the climatic changes and hazards that characterise this region.


Asunto(s)
Bahías , Cambio Climático , Humanos , Perú , Océano Pacífico , Ecuador
2.
Mar Pollut Bull ; 176: 113411, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35217416

RESUMEN

Studies integrating trophic ecology, physiological condition and accumulation of heavy metals in top predators, such as swordfish, are needed to better understand the links between them and the risk to humans associated with consumption of these fish. This research focuses on the swordfish of the Catalan Sea and follows a multi method approach that considers their diet, their liver lipid content, and mercury accumulation in their bodies as well as in their prey. The aim is to highlight the links between trophic ecology, physiology (fish condition), and eco-toxicology. Results indicate that poor condition of swordfish based on size and the levels of lipid in the liver, and the high Hg levels accumulated to the trophic web (particularly from cephalopods) may indicate potential unfavourable feeding and reproduction conditions for swordfish in the NW Mediterranean and this warrants further investigation.


Asunto(s)
Mercurio , Perciformes , Contaminantes Químicos del Agua , Animales , Bioacumulación , Peces , Mercurio/análisis , Alimentos Marinos/análisis , Contaminantes Químicos del Agua/análisis
4.
Zootaxa ; 5194(4): 497-518, 2022 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-37045318

RESUMEN

The taxonomic status of the keeled back mullets (Teleostei: Mugilidae) has been reinvestigated. Two nominal mugilid species having keeled backs from East Asia: Mugil lauvergnii Eydoux & Souleyet, 1850 and Mugil affinis Günther, 1861 have been re-evaluated through examination of the holotypes and fresh specimens. Comparison of morpho-meristic characters of the holotypes shows that both species are identical. Phylogenetic analysis based on mitochondrial cytochrome c oxidase 1 (CO1) confirmed morphological data by highlighting presence of a single clade from East Asia. Mugil lauvergnii (=Planiliza lauvergnii) is thus the sole keeled back mullet from East Asia and a senior synonym of Mugil affinis (=Planiliza affinis). The taxonomic status of two other keeled back mullets, Planiliza carinata and P. klunzingeri, is also contentious due to their similar morphology. Meristic and morphometric variation as well as sequence divergence between the two species are limited but phylogenetic analyses delineate well-supported clades consistent with biogeography and currently accepted taxonomy. Planiliza carinata and P. klunzingeri share a recent common ancestor in a Maximum Likelihood tree, with separate distribution ranges while P. lauvergnii formed a paraphyletic lineage. Based on present findings, we suggest maintenance of the taxonomic distinction of P. klunzingeri and P. carinata and discuss its evolutionary significance.


Asunto(s)
Smegmamorpha , Animales , Filogenia , Peces/genética , Evolución Biológica , Mitocondrias
5.
Sci Total Environ ; 793: 148544, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34182448

RESUMEN

Nitrogen (N) and water are crucial in crop production but increasingly scarce environmental resources. Reducing their inputs can affect the whole plant-arthropod community including biocontrol agents. In a multitrophic system, we studied the interaction of the bottom-up effects of moderately reduced N concentration and/or water supply as well as the top-down effects of pests of different feeding guilds on plant nutritional quality (N and carbon concentration), direct defense (alkaloids and phenolics), and indirect defense (plant volatile organic compounds); on herbivore performance and host quality (N and carbon) to parasitoids and the latter's performance. Studied organisms were tomato plants, the sap feeders Macrosiphum euphorbiae and Bemisia tabaci, the leaf chewers Tuta absoluta and Spodoptera littoralis, and the parasitic wasps Aphelinus abdominalis and Necremnus tutae. Resource limitation affected plant quality, triggering bottom-up effects on herbivore and parasitoid performance, except for T. absoluta and N. tutae. Feeding guild had a major influence: bottom-up effects were stronger on sap feeders; N effects were stronger on sap feeders while water effects were stronger with leaf chewers (S. littoralis). Top-down effects of leaf chewer herbivory partly attenuated bottom-up effects and partly suppressed plant defenses. Bottom-up effects weakened when cascading up trophic levels. In summary, the interaction between plants, pests, and beneficial insects was modulated by abiotic factors, affecting insect performance. Simultaneous abiotic and biotic impact shaped plant biochemistry depending on the feeding guild: the biotic top-down effect of leaf chewer herbivory attenuated the bottom-up effects of plant nutrition and hence dominated the plant biochemical profile whereas in sap feeder infested leaves, it corresponded to the abiotic impact. This study highlights the plant's finely tuned regulatory system facilitating response prioritization. It offers perspectives on how smart manipulation of plant nutrient solutions might save resources while maintaining efficient biocontrol in crop production.


Asunto(s)
Áfidos , Solanum lycopersicum , Avispas , Animales , Herbivoria , Spodoptera
7.
Neotrop. ichthyol ; 18(3): e190106, 2020. tab, graf, mapas, ilus
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1135398

RESUMEN

Lutjanus argentiventris presents a large intertropical distribution within the Eastern Pacific, which is as important to fisheries now as it was in the pre-Hispanic period. The purpose of this article is to present an allometric model that enables the size and weight of L. argentiventris to be predicted, using the isolated bones found in archaeological and paleontological contexts or the stomach contents of ichthyophagous species. A modern collection of L. argentiventris from Ecuador was used, composed of 37 individuals covering a wide range of sizes and weights. The total length (TL), standard length (SL), and total fresh weight (W) of each individual was gathered. The TL of the sample ranged between 210 and 760 mm, the SL between 164 and 627 mm and the W ranged between 123 and 6550 g. The most frequent bones (15) and otoliths were chosen and 39 measurements were taken. The total length-weight relationship was W = 6E-06 TL3.1513 with R 2 = 0.997. In general, it was observed that the relationships between the TL and the bone measurements had a strong correlation (R² > 0.95). The allometric model will be useful not only for archaeologists but also for biologists working on historical ecology.(AU)


Lutjanus argentiventris presenta una distribución intertropical en el Pacífico Oriental, siendo una especie importante desde épocas prehispánicas hasta la actualidad. El propósito de este artículo es presentar un modelo alométrico que prediga la talla y el peso de L. argentiventris, usando restos óseos aislados encontrados en contextos arqueológicos y paleontológicos. Se empleó una colección de 37 individuos con tallas y pesos variados, provenientes del Ecuador. La longitud total (LT), la longitud estándar (LE) y el peso (P) de cada individuo fueron recolectados. La LT varió entre 210 y 760 mm, la LE entre 164 y 627 mm y el P entre 123 y 6550 g. Se escogieron los huesos más frecuentes (15) y los otolitos para realizar 39 mediciones. La relación de la longitud total y el peso fue P = 6E-06 TL3,1513 con un valor de R 2 = 0,997. En términos generales se observa que las relaciones entre la LT y las medidas de los huesos presentan una correlación fuerte (R² > 0,95). El modelo alométrico presentado puede utilizarse para predecir el tamaño y el peso, no sólo de L. argentiventris, sino también de sus congéneres, y será útil para arqueólogos y biólogos interesados en ecología histórica.(AU)


Asunto(s)
Animales , Pesos y Medidas , Perciformes , Membrana Otolítica
8.
Zookeys ; 861: 119-128, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31333329

RESUMEN

The new monocle bream Scolopsislacrima sp. nov. is described from a single specimen (213.6 mm standard length) collected from Grande-Terre Island, New Caledonia. The new species closely resembles S.meridiana, both species having the upper part of the pectoral-fin base with reddish blotch when fresh, two bands across the top of the snout, a dorsal scaled area on the head reaching anteriorly to between the anterior margin of the eye and anterior nostril, a similar number of lateral-line scales, and absence of a small antrorse spine below the eye. However, S.lacrima sp. nov. is distinguished from S.meridiana by having diagonal lines on the body absent (vs. 18-20 diagonal lines in the latter), a dark longitudinal band below the lateral line (vs. longitudinal lines absent), the caudal fin central area not patterned (vs. with several dark horizontal lines), a narrower body and shallower caudal peduncle.

9.
PLoS One ; 14(5): e0214638, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31091235

RESUMEN

Recent evidence suggests the existence of Pre-Hispanic fisheries in savanna areas of the Amazon basin. How these fisheries may have functioned is still poorly known. Although many studies have drawn attention to how Pre-Hispanic inhabitants of these savannas managed to deal with excess water, little attention has been paid to understanding how large and permanent populations were sustained during long periods of drought. In the Llanos de Mojos, one of the largest savannas in South America, the landscape is greatly affected by the impacts of annual, seasonal flooding and inundations, alternating with a dry period that can last 4-6 months. The fishing practices in this area were studied on the basis of analysis of more than 17,000 fish remains recovered at Loma Salvatierra, a monumental mound located in an interfluvial area 50 km from the Mamoré River and occupied between 500 and 1400 AD. In Loma Salvatierra, a network of circular walled ponds connected to a system of canals has been identified, raising questions about a possible use of these structures for fishing. The exceptional conservation of the bone material has enabled precise taxonomic identification of more than 35 taxa, the richest fish spectrum thus far documented in the Mojos region. The dominant fish, swamp-eels (Synbranchus spp.), armored catfishes (Hoplosternum spp.), lungfish (Lepidosiren paradoxa), and tiger-fish (Hoplias malabaricus) are characteristic of shallow and stagnant waters. Our work documents the first zooarchaeological evidence of a dryland, interfluvial fishing system in the Bolivian Amazon that incorporates distinct species and fishing practices, demonstrating that these regions contain year round resources. Research is taking its first steps toward understanding landscape modifications, fish environments, and specific cultural technologies employed on this and other lowland neotropical savannas that differ from those for fishing in open waters and rivers.


Asunto(s)
Arqueología , Explotaciones Pesqueras/historia , Animales , Bolivia , Huesos/anatomía & histología , Peces/clasificación , Historia Antigua , Ríos
10.
Sci Rep ; 8(1): 5998, 2018 04 16.
Artículo en Inglés | MEDLINE | ID: mdl-29662075

RESUMEN

Archaeology provides few examples of large-scale fisheries at the frontier between catching and farming of fish. We analysed the spatial organization of earthen embankments to infer the functioning of a landscape-level pre-Columbian Amazonian fishery that was based on capture of out-migrating fish after reproduction in seasonal floodplains. Long earthen weirs cross floodplains. We showed that weirs bear successive V-shaped features (termed 'Vs' for the sake of brevity) pointing downstream for outflowing water and that ponds are associated with Vs, the V often forming the pond's downstream wall. How Vs channelled fish into ponds cannot be explained simply by hydraulics, because Vs surprisingly lack fishways, where, in other weirs, traps capture fish borne by current flowing through these gaps. We suggest that when water was still high enough to flow over the weir, out-migrating bottom-hugging fish followed current downstream into Vs. Finding deeper, slower-moving water, they remained. Receding water further concentrated fish in ponds. The pond served as the trap, and this function shaped pond design. Weir-fishing and pond-fishing are both practiced in African floodplains today. In combining the two, this pre-Columbian system appears unique in the world.


Asunto(s)
Explotaciones Pesqueras/historia , Animales , Arqueología/historia , Bolivia , Conservación de los Recursos Naturales , Ecosistema , Historia Medieval , Estanques
11.
Pest Manag Sci ; 74(3): 516-522, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28967203

RESUMEN

BACKGROUND: Bottom-up and top-down forces are major components of biological control against pests in an agro-ecosystem. Understanding the multi-trophic interactions between plants and secondary consumers would help optimize pest control strategies. We manipulated nitrogen and/or water inputs to tomato plants (Solanum lycopersicum) to test whether these manipulations could trigger bottom-up effects on the parasitoid Necremnus tutae via host (Tuta absoluta) and/or non-host (Bemisia tabaci) exposures, and compared the control efficacy of N. tutae on T. absoluta in the presence and absence of B. tabaci. RESULTS: The results showed no cascading effects of plant nitrogen and/or water inputs on N. tutae via either host or non-host exposure. The bottom-up force was mitigated by chewing or sap-feeding insect consumers at the second energy level. By contrast, the top-down force on T. absoluta from parasitoids was enhanced by an additionally provided non-host, which could produce alternative food sources extending N. tutae longevity and enhancing the fitness of its offspring. CONCLUSION: Our results provided evidence for the combination of bottom-up and top-down approaches in tomato integrated pest management programs. © 2017 Society of Chemical Industry.


Asunto(s)
Interacciones Huésped-Parásitos , Nitrógeno/metabolismo , Control Biológico de Vectores , Solanum lycopersicum/metabolismo , Agua/metabolismo , Animales , Hemípteros/fisiología , Herbivoria , Himenópteros/fisiología , Larva/crecimiento & desarrollo , Larva/parasitología , Larva/fisiología , Mariposas Nocturnas/crecimiento & desarrollo , Mariposas Nocturnas/parasitología
12.
Neotrop. ichthyol ; 16(2): [e170164], jun. 2018. tab, ilus, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-948591

RESUMEN

Comparisons of the external morphology and analysis of osteological features of the postcranial and appendicular skeletons of three southwestern Atlantic flatfish species of the genus Paralichthys (P. isosceles, P. orbignyanus and P. patagonicus) were carried out. Bones are described, and detailed morphological, morphometric and meristic characteristics of these flounders are given in order to provide information about the external and internal morphology of three species of Paralichthys occurring in the south-west Atlantic waters that add new information and will help regarding within the framework of a phylogenetic study of the group. Interspecific differences were found in the number of vertebrae and intermuscular bones, as well as in the morphology and morphometry of vertebrae, caudal skeletons, pectoral and pelvic girdle bones. Relationships between bones are discussed and bone characteristics compared with those found in other species of Paralichthys and in other pleuronectiform species. The position of Paralichthys isosceles within Paralichthys is discussed, along with other congeners such as P. triocellatus and P. oblongus.(AU)


Se llevaron a cabo comparaciones de la morfología externa y el análisis de las características osteológicas de los esqueletos postcraneal y apendicular de tres especies de peces planos del Atlántico sudoccidental del género Paralichthys (P. isosceles, P. orbignyanus y P. patagonicus). Se describen los huesos, y se proporcionan características morfológicas, morfométricas y merísticas detalladas de estos lenguados con el fin de aportar información sobre la morfología externa e interna de tres especies de Paralichthys presentes en el Atlántico sudoccidental. Esta nueva información contribuirá al marco de un estudio filogenético del grupo. Se encontraron diferencias interespecíficas en el número de vértebras y huesos intermusculares, así como en la morfología y morfometría de las vértebras, los esqueletos caudales, los huesos de las cinturas pectoral y pélvica. Se discuten las relaciones entre los huesos y las características óseas en comparación con las encontradas en otras especies de Paralichthys y de otros Pleuronectiformes. Se discute la posición de Paralichthys isosceles dentro del género Paralichthys, junto con otros congéneres como P. oblongus y P. triocellatus.(AU)


Asunto(s)
Animales , Osteogénesis/genética , Peces Planos/genética , Peces Planos/anatomía & histología
13.
Ecol Evol ; 7(20): 8329-8337, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-29075452

RESUMEN

Can specialist natural enemies persist in ecosystems when competing with omnivorous natural enemies for their shared prey? The consequences of omnivory have been studied theoretically, but empirical studies are still lacking. Omnivory is nevertheless common in nature and omnivorous predators coexist with specialists in many ecosystems, even when they are intraguild predators. This type of association is also common in agroecosystems in which biological control strategies are used. Our study provides an example of the outcome of such an association in the context of biological control of the invasive pest Tuta absoluta (Lepidoptera) in a tomato agroecosystem. The two natural enemies involved, that is, a specialist (Stenomesius japonicus (Hymenoptera) parasitoid) and an omnivore (Macrolophus pygmaeus (Hemiptera) predator), were able to coexist for 3 months in our experimental cages in the absence of metacommunity mechanisms (i.e., emigration and recolonization), contrary to theoretical expectations. However, they negatively affected each other's population dynamics. We found that spatial resource segregation was not a mechanism that promoted their coexistence. Regarding pest control, the specialist and omnivorous natural enemies were found to exhibit complementary functional traits, leading to the best control when together. Mechanisms that may have promoted the coexistence of the two species as well as consequences with regard to the inoculative biological control program are discussed.

14.
Proc Natl Acad Sci U S A ; 113(52): 14938-14943, 2016 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-27980030

RESUMEN

Erickson [Erickson CL (2000) Nature 408 (6809):190-193] interpreted features in seasonal floodplains in Bolivia's Beni savannas as vestiges of pre-European earthen fish weirs, postulating that they supported a productive, sustainable fishery that warranted cooperation in the construction and maintenance of perennial structures. His inferences were bold, because no close ethnographic analogues were known. A similar present-day Zambian fishery, documented here, appears strikingly convergent. The Zambian fishery supports Erickson's key inferences about the pre-European fishery: It allows sustained high harvest levels; weir construction and operation require cooperation; and weirs are inherited across generations. However, our comparison suggests that the pre-European system may not have entailed intensive management, as Erickson postulated. The Zambian fishery's sustainability is based on exploiting an assemblage dominated by species with life histories combining high fecundity, multiple reproductive cycles, and seasonal use of floodplains. As water rises, adults migrate from permanent watercourses into floodplains, through gaps in weirs, to feed and spawn. Juveniles grow and then migrate back to dry-season refuges as water falls. At that moment fishermen set traps in the gaps, harvesting large numbers of fish, mostly juveniles. In nature, most juveniles die during the first dry season, so that their harvest just before migration has limited impact on future populations, facilitating sustainability and the adoption of a fishery based on inherited perennial structures. South American floodplain fishes with similar life histories were the likely targets of the pre-European fishery. Convergence in floodplain fish strategies in these two regions in turn drove convergence in cultural niche construction.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Explotaciones Pesqueras/historia , Animales , Arqueología/métodos , Bolivia , Ecosistema , Peces , Historia del Siglo XXI , Historia Antigua , Estaciones del Año , Conducta Social , Zambia
15.
PLoS One ; 11(11): e0166610, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27870857

RESUMEN

Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a generalist predatory mirid widely used in augmentative biological control of various insect pests in greenhouse tomato production in Europe, including the invasive tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera, Gelechiidae). However, its biocontrol efficacy often relies on the presence of alternative prey. The present study aimed at evaluating the effect of various prey foods (Ephestia kuehniella eggs, Bemisia tabaci nymphs, Tuta absoluta eggs and Macrosiphum euphorbiae nymphs) on some life history traits of M. pygmaeus. Both nymphal development and adult fertility of M. pygmaeus were significantly affected by prey food type, but not survival. Duration of nymphal stage was higher when M. pygmaeus fed on T. absoluta eggs compared to the other prey. Mean fertility of M. pygmaeus females was greatest when fed with B. tabaci nymphs, and was greater when offered M. euphorbiae aphids and E. kuehniella eggs than when offered T. absoluta eggs. Given the low quality of T. absoluta eggs, the efficacy of M. pygmaeus to control T. absoluta may be limited in the absence of other food sources. Experiments for assessing effectiveness of generalist predators should involve the possible impact of prey preference as well as a possible prey switching.


Asunto(s)
Hemípteros/fisiología , Lepidópteros/fisiología , Control Biológico de Vectores/métodos , Solanum lycopersicum/parasitología , Animales , Femenino , Fertilidad , Rasgos de la Historia de Vida , Solanum lycopersicum/crecimiento & desarrollo , Masculino , Ninfa/crecimiento & desarrollo , Conducta Predatoria
16.
Zootaxa ; 4021(4): 529-40, 2015 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-26624151

RESUMEN

The Indo-West Pacific species, Neomerinthe erostris (Alcock 1896), originally described as Scorpaena erostris, is redescribed as a senior synonym of Scorpaena gibbifrons Fowler 1938, N. rotunda Chen 1981, and N. bathyperimensis Zajonz & Klausewitz 2002. Although the latter three nominal species have been regarded as valid species and N. erostris has not been reported since 1898, examinations of type specimens of the four nominal species revealed that they represent a single species. A lectotype of Scorpaena erostris is herein designated. Neomerinthe erostris is characterized by having a distinct longitudinal ridge on the lateral surface of the maxilla and a strongly rounded dorsal profile of the head.


Asunto(s)
Perciformes/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Tamaño de los Órganos , Perciformes/anatomía & histología , Perciformes/crecimiento & desarrollo , Terminología como Asunto
17.
Ecol Evol ; 5(23): 5468-77, 2015 12.
Artículo en Inglés | MEDLINE | ID: mdl-27069598

RESUMEN

Omnivorous arthropods make dietary choices according to the environment in which they forage, mainly availability/quality of plant and/or prey resources. Such decisions and their subsequent impacts on life-history traits may be affected by the availability of nutrients and water to plants, that is, through bottom-up forces. By setting up arenas for feeding behavior observation as well as glasshouse cages for plant preference assessment, we studied effects of the presence of prey (Lepidoptera eggs) and nitrogen/water availability to host tomato plants on the foraging behavior and life-history traits in the omnivorous predator Macrolophus pygmaeus (Heteroptera: Miridae). In the absence of prey, the predator fed equally on the plants treated with various levels of nitrogen and water. In the presence of prey, however, the feeding rate on plants decreased when the plant received low water input. The feeding rate on prey was positively correlated with feeding rate on plants; that is, prey feeding increased with plant feeding when the plants received high water input. Moreover, plants receiving high water input attracted more M. pygmaeus adults compared with those receiving low water input. For M. pygmaeus fitness, the presence of prey enhanced its fertility and longevity, but the longevity decreased when plants received low compared with high water input. In conclusion, the omnivorous predator may be obliged to feed on plants to obtain water, and plant water status may be a limiting factor for the foraging behavior and fitness of the omnivorous predator.

18.
PLoS One ; 9(2): e88488, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24533093

RESUMEN

The stomach content of 113 individuals of shortfin mako Isurus oxyrinchus was analyzed. Individuals were sampled at landing in Vigo (Spain) and captured by sea-surface long-liners in the vicinity of the Azores Archipelago and between Azores and the Iberian Peninsula, in March and October 2012, and March 2013. Teleosts constituted the dominant item, mainly Atlantic saury Scomberesox saurus (87% of teleost prey). Among them, 94% were deprived of both head and the caudal fin, while the flesh and bones of the body were preserved. The presence of eye's lenses, the number of which was consistent with the number of fish remains, likely rules out the elimination of the heads before ingestion. There is no obvious explanation for this unexpected and unrecorded pattern of digestion.


Asunto(s)
Digestión/fisiología , Contenido Digestivo , Tiburones , Animales , Conducta Alimentaria , Femenino , Peces , Masculino , España
19.
C R Biol ; 336(4): 233-40, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23849726

RESUMEN

Two related perciform fish species of the subfamily Monotaxinae (Sparoidea: Lethrinidae) Gymnocranius superciliosus sp. nov. and Gymnocranius satoi sp. nov. are described from specimens and tissue samples from the Coral Sea and adjacent regions. G. superciliosus sp. nov. is distinct from all other known Gymnocranius spp. by the following combination of characters: body elongated (depth 2.7-3.1 in standard length), caudal fin moderately forked with a subtle middle notch, its lobes slightly convex inside, distinctive blackish eyebrow, snout and cheek with blue speckles, and dorsal, pectoral, anal and caudal fins reddish. G. satoi sp. nov. is the red-finned 'Gymnocranius sp.' depicted in previous taxonomic revisions. While colour patterns are similar between the two species, G. satoi sp. nov. is distinct from G. superciliosus sp. nov. by the ratio of standard length to body depth (2.4-2.5 vs. 2.7-3.1) and by the shape of the caudal fin, which is more shallowly forked, its lobes convex inside and their extremities rounded. The two species are genetically distinct from each other and they are genetically distinct from G. elongatus, G. euanus, G. grandoculis, and G. oblongus sampled from the Coral Sea and adjacent regions.


Asunto(s)
Ojo/anatomía & histología , Dorada/anatomía & histología , Animales , Secuencia de Bases , Color , Citocromos b/genética , ADN/genética , Ecología , Ecosistema , Haplotipos , Océano Pacífico , Población , Dorada/clasificación , Especificidad de la Especie , Terminología como Asunto
20.
Oecologia ; 173(4): 1379-86, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23851986

RESUMEN

Induced defenses mediate interactions between parasites sharing the same host plant, but the outcomes of these interactions are challenging to predict because of spatiotemporal variation in plant responses and differences in defense pathways elicited by herbivores or pathogens. Dissecting these mediating factors necessitates an approach that encompasses a diversity of parasitic feeding styles and tracks interactions over space and time. We tested indirect plant-mediated relationships across three tomato (Solanum lycopersicum) consumers: (1) the fungal pathogen-powdery mildew, Oidium neolycopersici; (2) a sap-feeding insect-silverleaf whitefly, Bemisia tabaci; and (3) a chewing insect-the leaf miner, Tuta absoluta. Further, we evaluated insect/pathogen responses on local vs. systemic leaves and over short (1 day) vs. long (4 days) time scales. Overall, we documented: (1) a bi-directional negative effect between O. neolycopersici and B. tabaci; (2) an asymmetrical negative effect of B. tabaci on T. absoluta; and (3) an asymmetrical positive effect of T. absoluta on O. neolycopersici. Spatiotemporal patterns varied depending on the species pair (e.g., whitefly effects on leaf miner performance were highly localized to the induced leaf, whereas effects on pathogen growth were both local and systemic). These results highlight the context-dependent effects of induced defenses on a diverse community of tomato parasites. Notably, the outcomes correspond to those predicted by phytohormonal theory based on feeding guild differences with key implications for the recent European invasion by T. absoluta.


Asunto(s)
Ascomicetos/fisiología , Resistencia a la Enfermedad/fisiología , Hemípteros/fisiología , Lepidópteros/fisiología , Solanum lycopersicum/fisiología , Animales , Susceptibilidad a Enfermedades/metabolismo , Herbivoria , Interacciones Huésped-Parásitos , Interacciones Huésped-Patógeno , Solanum lycopersicum/microbiología , Solanum lycopersicum/parasitología , Análisis Espacio-Temporal
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...