A new method to quantify and compare the multiple components of fitness-A study case with kelp niche partition by divergent microstage adaptations to Temperature

Point 1 Management of crops, commercialized or protected species, plagues or life-cycle evolution are subjects requiring comparisons among different demographic strategies. The simpler methods fail in relating changes in vital rates with changes in population viability whereas more complex methods lack accuracy by neglecting interactions among vital rates. Point 2 The difference between the fitness (evaluated by the population growth rate.) of two alternative demographies is decomposed into the contributions of the differences between the pair-wised vital rates and their interactions. This is achieved through a full Taylor expansion (i.e. remainder = 0) of the demographic model. The significance of each term is determined by permutation tests under the null hypothesis that all demographies come from the same pool. Point 3 An example is given with periodic demographic matrices of the microscopic haploid phase of two kelp cryptic species observed to partition their niche occupation along the Chilean coast. The method provided clear and synthetic results showing conditional differentiation of reproduction is an important driver for their differences in fitness along the latitudinal temperature gradient. But it also demonstrated that interactions among vital rates cannot be neglected as they compose a significant part of the differences between demographies. Point 4 This method allows researchers to access the effects of multiple effective changes in a life-cycle from only two experiments. Evolutionists can determine with confidence the effective causes for changes in fitness whereas population managers can determine best strategies from simpler experimental designs.CONICYT-FRENCH EMBASSADY Ph.D. gran

Living on a trophic subsidy: Algal quality drives an upper-shore herbivore’s consumption, preference and absorption but not growth rates

Indexación: Scopus.The transfer of seaweeds from subtidal bottoms to nearby intertidal rocky shores is a common but often overlooked phenomenon. Freshly detached seaweeds often represent critical trophic subsidies for herbivores living in upper-shore rocky intertidal areas, such as the marine snail Diloma nigerrima. This species relies on three species of seaweeds for food and displays feeding strategies to deal with a resource that is scarce and at times unpredictable. This study focused on the nutritional quality of freshly detached algae (Durvillaea antarctica, Lessonia spicata and Lessonia trabeculata) and measured Diloma nigerrima’s algal consumption rates in trials with and without choice. Absorption efficiency and growth of individual snails fed on each alga were also measured. Durvillaea antarctica had the highest nutritional quality and was the most consumed algae in both single and multiple-choice trials. Absorption efficiency was also highest for D. antarctica but growth rates of snails fed with this species were similar to those fed with the other algae. Combined, these results suggest that D. nigerrima has the ability to discriminate among seaweeds based on their nutritional quality. A potential increase in oxygen uptake when D. nigerrima is consuming the preferred food item is also proposed as a plausible hypothesis to explain the mismatch between snails’ preference and growth rate. These results aim to guide further studies on trophic subsidies and their role in coastal systems. © 2018 Quintanilla-Ahumada et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.https://journals.plos.org/plosone/article?id=10.1371/journal.pone.019612

Species-speciWc defense strategies of vegetative versus reproductive blades of the PaciWc kelps Lessonia nigrescens and Macrocystis integrifolia

Chemical defense is assumed to be costly and therefore algae should allocate defense investments in a way to reduce costs and optimize their overall fitness. Thus, lifetime expectation of particular tissues and their contribution to the fitness of the alga may affect defense allocation. Two brown algae common to the SE Pacific coasts, Lessonia nigrescens Bory and Macrocystis integrifolia Bory, feature important ontogenetic differences in the development of reproductive structures; in L. nigrescens blade tissues pass from a vegetative stage to a reproductive stage, while in M. integrifolia reproductive and vegetative functions are spatially separated on different blades. We hypothesized that vegetative blades of L. nigrescens with important future functions are more (or equally) defended than reproductive blades, whereas in M. integrifolia defense should be mainly allocated to reproductive blades (sporophylls), which are considered to make a higher contribution to fitness. Herein, within-plant variation in susceptibility of reproductive and vegetative tissues to herbivory and in allocation of phlorotannins (phenolics) and N-compounds was compared. The results show that phlorotannin and N-concentrations were higher in reproductive blade tissues for both investigated algae. However, preferences by amphipod grazers (Parhyalella penai) for either tissue type differed between the two algal species. Fresh reproductive tissue of L. nigrescens was more consumed than vegetative tissue, while the reverse was found in M. integrifolia, thus confirming the original hypothesis. This suggests that future fitness function might indeed be a useful predictor of anti-herbivore defense in large, perennial kelps. Results from feeding assays with artificial pellets that were made with air-dried material and extract-treated Ulva powder indicated that defenses in live algae are probably not based on chemicals that can be extracted or remain intact after air-drying and grinding up algal tissues. Instead, anti-herbivore defense against amphipod mesograzers seems to depend on structural traits of living algae

Translating Ecological Integrity terms into operational language to inform societies

It is crucial that societies are informed on the risks of impoverished ecosystem health for their well-being. For this purpose, Ecological Integrity (EI) is a useful concept that seeks to capture the complex nature of ecosystems and their interaction with social welfare. But the challenge remains to measure EI and translate scientific terminology into operational language to inform society. We propose an approach that simplifies marine ecosystem complexity by applying scientific knowledge to identify which components reflect the state or state change of ecosystems. It follows a bottom-up structure that identifies, based on expert knowledge, biological components related with past and present changing conditions. It is structured in 5 stages that interact in an adaptive way: stage 1, in situ observations suggest changes could be happening; stage 2 explores available data that represent EI; stage 3, experts' workshops target the identification of the minimum set of variables needed to define EI, or the risk of losing EI; an optative stage 4, where deviance from EI, or risk of deviance, is statistically assessed; stage 5, findings are communicated to society. We demonstrate the framework effectiveness in three case studies, including a data poor situation, an area where lack of reference sites hampers the identification of historical changes, and an area where diffuse sources of stress make it difficult to identify simple relationships with of ecological responses. The future challenge is to operationalize the approach and trigger desirable society actions to strengthen a social-nature link.Comment: Submitted to Journal of Environmental Management 13 April 2018; Received in revised form by the journal 3 September 2018; Accepted 10 September 201

Despliegue aéreo y sonidos mecánicos en el Sobrepuesto Andino (Lessonia oreas), con comentarios sobre la estructura básica de los despliegues aéreos de los Fluvicolinae

Describimos el despliegue aéreo de Lessonia oreas. El despliegue aéreo posee tres partes: notas en percha tsi, vuelo diagonal con notas tic y giro y descenso con matraqueo de alas trrrrrrrrrr y nota psie. El matraqueo de alas parece ser un sonido fuerte de naturaleza mecánica previamente desconocido en la especie pero consistente con su posición filogenética en el clado Lessonia-Knipolegus-Hymenops. Los despliegues en vuelo están ampliamente distribuidos en los tiránidos. Los despliegues más conspicuos ocurren en los Fluvicolinae, especialmente en Fluvicolini y Xolmini. Los despliegues de algunas Knipolegus (al menos striaticeps, aterrimus y hudsoni) y Lessonia (al menos oreas) parecen compartir sonidos vocales y mecánicos homólogos (notas en percha; notas en vuelo; descenso con sonido mecánico y nota vocal tajante). La inferencia de pérdidas de despliegues en algunas Knipolegus en trabajos previos puede ser al menos en parte un artefacto de muestreo. Si Lessonia es hermano de Knipolegus+Hymenops, los despliegues en vuelo con sonidos mecánicos serían la condición ancestral del grupo. Homologías comportamentales profundas en los Xolmini son sugeridas por observaciones en la Monjita Castaña (Neoxolmis rubetra) y el reemplazo de sonidos mecánicos por la elevación y congelamiento ritualizados de alas en el despliegue de la Dormilona Chica (Muscisaxicola maculirostris). La porción subapical del vexilo interno de las primarias octava y novena es más cóncava en L. oreas que en L. rufa, y el perfil de la pluma es levemente más cóncavo en el primero y levemente recto o apenas cóncavo en el último. Estas diferencias sugieren que estos taxa difieren en sus despliegues en vuelo y potenciales sonidos mecánicos y son por lo tanto correctamente considerados especies distintas.We describe the display flight of the Andean Negrito (Lessonia oreas). The display flight consists of three parts: perched tsi notes, diagonal flight with tic notes, and turn and descent with trrrrrrrrrr wing-whirr and psie note. The wing-whirr appears to be a loud mechanical sound heretofore unknown in the species but consistent with the species’ phylogenetic position in the Lessonia-Knipolegus-Hymenops clade. Flight displays are widespread in the tyrant flycatchers. The most conspicuous displays occur in the Fluvicolinae, especially in Fluvicolini and Xolmini. The display flights of some Knipolegus (at least striaticeps, aterrimus and hudsoni) and Lessonia (at least oreas) appear to share homologous vocal and mechanical sounds (perched notes; flight notes; descent with mechanical sound and sharp vocal note). The inferred loss of display in some Knipolegus species in previous works may partly be a sampling artifact. If Lessonia is sister to Knipolegus+Hymenops, flight displays with mechanical sounds would be the ancestral condition for the group. Deep behavioral homologies in the Xolmini are suggested by observations on the Rusty-backed Monjita (Neoxolmis rubetra) and replacement of mechanical sounds by ritualized elevation and freezing of wings in the display of the Spot-billed Ground-tyrant (Muscisaxicola maculirostris). The sub-apical portion of inner vanes of the eighth and ninth primaries are more concave in the Andean Negrito than in the Austral Negrito (L. rufa) and feather profile is slightly concave in the former and slightly straight or convex in the latter. These differences suggest that these taxa differ in flight displays and potentially in mechanical sounds and are thus correctly considered as different speciesFil: Areta, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Bio y Geociencias del Noroeste Argentino; ArgentinaFil: Miller, Edward H.. Memorial University. Biology Department; Canad

The distribution of marine algae

Thesis (M.A.)--Boston Universit

Las macroalgas marinas bentónicas de la Argentina

Las algas que proliferan en el fondo marino se denominan macroalgas marinas bentónicas y se clasifican en tres grandes grupos: las rojas (Rhodophyta), las de color pardo (Phaeophyta o Phucophyta) y las verdes (Chlorophyta). Cuando las plantas forman grandes poblaciones -como los bosques de Macrocystis pyrifera o las praderas de Lessonia nigrescens o Durvillaea antarctica - se las puede observar aun en los momentos de marea alta. Este artículo de divulgación científica incluye información sobre las características morfológicas, las provincias fitogeográficas, la distribución geográfica, y la biodiversidad existente en las principales macroalgas de la Argentina (océano Atlántico sudoccidental), así como otras lecturas sugeridas sobre la temática

General features of the ecology and biogeography of Tasmanian subtidal rocky shore communities

A number of subtidal benthic assemblages of plants and animals which commonly occur around the Tasmanian coast are described. These assemblages are incorporated into a general scheme which relates subtidal zonation patterns to wave exposure and depth. The existence of a cool-temperate marine biogeographic province (the Maugean), centred in southern, western and eastern Tasmanian waters, is reaffirmed. The biota of the northern Tasmanian coast is considered similar to that of the Victorian coast and includes a large component of Flindersian (Southern Australian) species. A number of Peronian (New South Wales) species reach the Tasmanian east coast. Most of these animals probably drift to Tasmania as pelagic larvae in southward flowing currents, and may even travel further afield to New Zealand, but have difficulty surviving to maturity and spawning. Many Maugean plant and animal species also occur in New Zealand

Metales pesados: aspectos ecológicos y tecnológico-alimentarios

Se realizó un estudio tendiente a determinar el contenido de algunos metales pesados en material biológico empleado habitualmente como indicador de contaminación ambiental. incluyéndose ciertos alimentos de consumo humano v animal. Muestras. de especies marinas fueron obtenidas del área costera de la V Región de Chile y productos derivados de ellas se recolectaron de industrias y establecimientos de alimentos ubicados en las regiones l. V, VIII y Región Metropolitana de Chile. Muestras de especies vegetales se recolectaron de campos de cultivos y establecimientos de alimentos localizados en la Región Metropolitana. Los análisis se efectuaron por los métodos del dietilditiocarbamato de plata en piridina. fluorescencia de rayos X (FRX) y especrrofotometría de absorción atómica. Los resultados obtenidos muestran elevados niveles de arsénico en algas (7.6 mglkg. base húmeda), cadmio y plomo en peces marinos. especialmente en el esqueleto de jurel (0.25 mglkg y 2.26 mglkg. sobre bases húmedas respectivamente). Igualmente se destaca el alto contenido de mercurio en harina y aceite de pescado (0,7 mglkg, base húmeda) y plomo en lechuga (3.5 mglkg. base húmeda). Estos resultados muestran que existe contaminación ambiental debido a metales pesados y se sabe que esos contenidos implican daño en la salud humana y animal