Energetics and development modes of Asteroidea (Echinodermata) from the Southwestern Atlantic Ocean including Burdwood Bank/MPA Namuncurá

Reproduction is a highly expensive process that during gonadal development requires an important supply of nutrients. The allocation of energy can vary throughout the reproductive cycle, between sexes and development modes. During research cruise aboard the RV Puerto Deseado in April 2016, we collected fifteen species of sea stars from the southernmost region of Argentina. The main purposes of the present study were threefold: first, to revise and report novel information on the reproductive strategies and energetic density (ED) of body components from the asteroids of the southwestern Atlantic Ocean including Burdwood Bank/ MPA Namuncurá; second, to compare the ED of these body components across species with contrasting reproductive strategies; third, to provide a tool to estimate the ED from dry mass of organs of the sea star species examined. Ovaries of Diplopteraster verrucosus (a brooder with a nidamental chamber) revealed a significantly greater ED than did the testes (29.81 ± 1.38 and 17.76 ± 1.59, respectively). In Glabraster antarctica (a broadcaster with yolky eggs and facultative planktotrophic larvae), the gonads had EDs of 25.78 ± 3.16 and 19.21 ± 0.52 (females and males, respectively). While in Peribolaster folliculatus (a broadcaster with eggs with low yolk content and inferred planktotrophic larvae) there was no significant difference in the ED values between sexes (females: 22.79 ± 1.10 and males: 20.46 ± 1.05). For the pyloric caeca, ED values did not reveal any difference between sexes, although in P. folliculatus, the ED was significantly higher than that for D. verrucosus and G. antarctica (25.90 ± 1.00, 23.03 ± 0.34, and 22.66 ± 0.65, respectively). The body wall had higher ED values in D. verrucosus and P. folliculatus than that for all the sea star species analyzed (46.48 ± 1.63, 51.17 ± 1.34, respectively). Higher ED values in the ovaries could be related to the nutrition of offspring, while differences found in the body wall may reflect the skeletal structure of this body component. This research provides basic information for understanding the differences on energetic allocation when contrasting development modes are considered.Fil: Fraysse, Cintia Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Pérez, Analía F.. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Calcagno, Javier Ángel. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Boy, Claudia Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

An alternative method to freeze and transport biological tisue blocks for microscop

Se describe un método simple y económico para congelar material biológico destinado a la obtención de cortes histológicos en crióstato. Se propone la utilización de CO2 para producir una mezcla refrigerante en reemplazo del nitrógeno líquido como criogénico. Esta mezcla (compuesta por hielo seco y acetona) enfría el isopentano utilizado como medio de congelación hasta -76ºC y lo mantiene por aproximadamente una hora y media permitiendo la congelación de más de 20 bloques de tejido. La calidad de las secciones obtenidas en crióstato es similar a aquellas obtenidas mediante la utilización de nitrógeno líquido. Este método resulta especialmente práctico durante los muestreos a bordo de embarcaciones y/o en sitios alejados de los centros urbanos.A cheap and simple method for freezing raw biological material destined to obtain histological sections through a cryostat is described. We propose the utilization of solid CO2 (dry ice) to make a cooling mixture, instead of liquid nitrogen. The temperature of the refrigerating mixture (composed by acetone and dry ice) reaches isopentane to -76ºC which is maintained for ~1.5h allowing the freezing of more than 20 tissue blocks. The quality of cryostat sections obtained is similar to the ones obtained by using liquid nitrogen. This method is particularly suitable during sampling on board, and/or far away from urban centers.Fil: Calvo, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Morriconi, Elba Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Boy, Claudia Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Sub-Antarctic streams break the rules: functional feeding groups along watershed gradients with and without urban impact

The River Continuum Concept (RCC) has been widely used to understand the relationship between abiotic conditions, basal resources and aquatic communities, including longitudinal patterns of benthic macroinvertebrate functional feeding groups (FFG). However, the RCC has been quested for southern hemisphere temperate streams, and we asked whether it applies to sub-Antarctic streams in southern Patagonia. We studied FFG assemblages in Fuegian stream gradients with urbanization and reference conditions (?type?). We assessed physicochemical characteristics and basal resources in 6 streams (54°50' S, 68° W). We measured FFG abundance with 4-5 benthic samples using a Surber net (450 um mesh) in each watershed?s upper, mid and lower reaches (N = 85). We conducted ANOVAs and perMANOVAs to evaluate differences due to stream type and reach on the proportion of each FFG and overall FFG assemblage, respectively. Urban streams had lower canopy cover, dissolved oxygen, and substrate size and higher temperature and nutrient concentration, compared to Reference streams. The overall assemblage differed among stream reaches and type. While RCC hypothesized higher proportion of shredders in headwaters, scraper in mid-, and collector-filterers in lower-waters, In Reference reaches, shredders were more abundant in midstream, and no differences were found for the other FFGs between reaches In Urban streams, collectors-gatherers were more abundant downstream; scrapers increased towards midstream, decreasing downstream, and collector-filterers had the greatest abundance upstream. Moreover, shredders were more abundant in Urban streams, and collector-filterers in Ref streams. FFG distribution in Fuegian streams differed from the expectations of the RCC, which relies on gradients in basal resources. This might be due to extreme upstream conditions (e.g., low temperature and nutrient concentrations). Moreover, although collector-gatherers had similar proportion comparing downstream areas between RCC and Urban streams, it might be consequence of the availability of resources (RCC) and their tolerance to urban conditions (unexpected in RCC).Fil: Tagliaferro, Marina Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Anderson, Christopher Brian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Boy, Claudia Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaV Congreso Latinoamericano de Macroinvertebrados y Ecosistemas AcuáticosPanamáInstituto Conmemorativo Gorgas de Estudios de la SaludUniversidad de PanamáComité de Biomonitoreo de la Red Analítica de Latino América y el Carib

Pathology in skeletons of Peale's dolphin Lagenorhynchus australis from southern South America

Peale's dolphin Lagenorhynchus australis is frequently seen off the coast of southern South America, where it feeds among coastal kelp beds and occasionally strands. We searched for macroscopic evidence of skeletal lesions in 78 specimens of Peale's dolphin from 2 museum collections, which contain almost all of the species' skeletons known in collections worldwide. Thirtytwo specimens (41%) had some type of osteological abnormalities. In 21 cases (66%), congenital deformations were the most predominant abnormality found. Acquired lesions included (1) induced trauma: abnormal curvature (n = 5 specimens) and fractures (n = 2); (2) infectious diseases: spondylo-osteomyelitis (n = 3); and (3) degenerative diseases: exostoses (n = 8) and spondylosis deformans (n = 4). It is noteworthy that all of these animals died incidentally in gillnet entanglement and were presumably healthy at the time of death. The effect that different osseous lesions may have on an animal's quality of life may depend on the area of the spine affected and the number of vertebrae involved.Fil: San Martín, Analía Anahí. Museo Acatushún de Aves y Mamíferos Marinos Australes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Macnie, Silvina V.. Museo Acatushún de Aves y Mamíferos Marinos Australes; ArgentinaFil: Prosser Goodall, Rae Natalie. Museo Acatushún de Aves y Mamíferos Marinos Australes; ArgentinaFil: Boy, Claudia Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Subdivisión funcional de la columna vertebral en cuatro delfines sudamericanos

Subdivisión funcional de la columna vertebral en cuatro delfines sudamericanos. La descripción e interpretación funcional de la variación morfológica en la columna de delfines pueden facilitarse mediante el reconocimiento de unidades estructurales a lo largo de toda la estructura de la columna. Esta información ofrece pistas importantes sobre la proporción de la columna involucrada en la oscilación y el desplazamiento de la aleta caudal, y cómo el estilo de natación puede variar entre las especies. Por lo tanto, la caracterización morfológica y la subdivisión funcional de la columna vertebral son de fundamental importancia para obtener información sobre el comportamiento locomotor de las especies de cetáceos que habitan ambientes diferentes. Se empleó morfometría tradicional para establecer la subdivisión funcional de la columna vertebral del delfín de la tonina overa (Cephalorhynchus commersonii), una especie costera, y el delfín oscuro (Lagenorhynchus obscurus), una especie de plataforma, realizando una primera caracterización morfológica de sus columnas vertebrales. Estas especies están estrechamente relacionadas y, en algunos casos, son parcialmente simpátricas. También comparamos los resultados obtenidos con información previamente reportada por Marchesi et al. (2017) para el delfín austral (Lagenorhynchus australis), una especie costera, y el delfín cruzado (Lagenorhynchus cruciger), una especie oceánica. Estos resultados apoyan nuestra hipótesis de que las especies costeras tienen rasgos morfológicos asociados con mayor flexibilidad, mientras que las especies oceánicas y de plataforma tienen características asociadas con una mayor estabilidad en una mayor proporción de su columna.Description and functional interpretation of morphological variation in the dolphin column can be facilitated by recognizing structural units. This information offers important clues to the proportion of the column involved in the oscillation and displacement of the flukes, and how swimming style can vary among species. Thus, the morphological characterization and functional subdivision of the vertebral column is of key importance to gain insights into the locomotor performance of cetacean species occurring in different environments. We employed traditional morphometrics to establish the functional subdivision of the vertebral column of Commerson’s dolphin (Cephalorhynchus commersonii), a coastal species, and the dusky dolphin (Lagenorhynchus obscurus), a shelf species. These species are closely related, and some of them are partially sympatric. We also compared the obtained results against information previously reported by Marchesi et al (2017) on Peale’s dolphin (Lagenorhynchus australis), a coastal species, and the hourglass dolphin (Lagenorhynchus cruciger), an oceanic species. These results bring further support to our hypothesis that coastal species have morphological traits associated with higher flexibility, whilst platform and oceanic species have features associated with higher stability in a greater proportion of their column.Fil: Marchesi, María Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Mora, Matías Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Boy, Claudia C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: González-José, Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Ciencias Sociales y Humanas; ArgentinaFil: Prosser Goodall, Rae Natalie. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Museo Acatushún de Aves y Mamíferos Marinos Australes; Argentin

New Insights into the Distribution, Physiology and Life Histories of South American Galaxiid Fishes, and Potential Threats to this Unique Fauna

South American galaxiids occupy both Patagonia and the ichthyogeographic Chilean Province, encompassing glacial Andean deep lakes, shallow plateau lakes, reservoirs, short Pacific rivers and long Atlantic rivers. The total fish fauna includes 29 species, comprising Neotropical fishes (siluriforms and characids), galaxiids, percichthyids, atherinopsids and mugilids, two lamprey species, and several exotic fishes (salmonids, Gambusia spp. and common carp). The family Galaxiidae shares a common ancestry with the Gondwanan temperate fish fauna, played a major role in the post-glacial colonization of Andean lakes and streams, and contributes key species to the food webs. Galaxiid species occupy an enormous latitudinal gradient, show a wide variety of life history patterns and are the southernmost native freshwater fishes of the world. Knowledge of South American galaxiids has improved notably, but new challenges arise due to climate change, biological invasions, damming, aquaculture and contamination. In this changing environment, the future of South American galaxiids should be carefully considered as a legacy of the old Gondwana and a unique attribute of the freshwaters of southern South America.Fil: Cussac, Victor Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; ArgentinaFil: Barrantes, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Boy, Claudia Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Górski, Konrad. Universidad Austral de Chile; ChileFil: Habit, Evelyn. Universidad de Concepción; ChileFil: Lattuca, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Rojo, Javier Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

First Insights Into the Growth and Population Structure of Cottoperca trigloides (Perciformes, Bovichtidae) From the Southwestern Atlantic Ocean

The aim of this work was to describe the growth of Cottoperca trigloides, a notothenioid species with a non-Antarctic distribution, and to test the existence of different nursery areas and fish stocks through changes in the otolith elemental composition. Fish were collected during spring 2009 over the Patagonia continental shelf, including the Marine Protected Area Namuncurá/Burdwood Bank, in the southwestern Atlantic Ocean. The age and growth analyses were performed by counting marks in sagittae, assuming an annual periodicity of their deposition, and identified 8-year classes (0+ to 7+). Given the size range of the fish, length-at-age data were fitted to the Gompertz growth model TLt = 55.45 [exp ((exp) –0.32 (t – 1.89))], explaining more than 95% of the growth pattern. Moreover, the chemical composition of otolith core and edge areas was analyzed by laser ablation inductively coupled plasma mass spectrometry. The canonical analysis of principal coordinates successfully allocated 72.92% of the fish for the core and 91.67% for the edge area of the otolith, in three groups corresponding to “northern Patagonia shelf,” “southern Patagonia shelf,” and “Marine Protected Area Namuncurá/Burdwood Bank” areas, suggesting a high segregation among them over the Patagonian shelf. Thus, otolith elemental composition has proven to be an efficient approach to identify different nursery areas and stocks for the species. The present results provide new information on the growth and the population structure of C. trigloides, from a geographical area where information on this issue is still scarce, constituting an essential tool to develop conservation principles for the species.Fil: Lattuca, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Llompart, Facundo Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; ArgentinaFil: Avigliano, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; ArgentinaFil: Renzi, Marta. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: De Leva, Ileana. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Boy, Claudia Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Vanella, Fabián Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Barrantes, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Fernandez, Daniel Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; ArgentinaFil: Queiroz de Albuquerque, Cristiano. Universidade Federal Rural Do Semi Arido.; Brasi

Prey selection and energy values of main food items of the torrent duck (Merganetta armata) in Northwestern Patagonia, Argentina

The Torrent Duck (Merganetta armata) is one of four species of waterfowl that live in fast flowing rivers. Torrent Ducks feed on benthic invertebrates in mountain rivers from Venezuela to Argentina. Prey selection by Torrent Ducks was investigated by comparing the proportion of prey taxa in their feces with the proportion available in river benthos. Feces and benthos were sampled during spring and autumn at sites with different precipitation levels in northwestern Argentine Patagonia. Energy values of the most important prey items were evaluated and the results adjusted for the amount of chitin body proportions. The average energy value of each individual prey item was 3.60 J in Gripopterygidae, 5.88 J in Simuliidae, 11.48 J in Atalophlebiinae and 12.25 J in Smicridea spp. These four invertebrate taxa represented approximately 80% of Torrent Duck diet. Prey availability and energy value alone could not explain the total Torrent Duck diet, and it was necessary to consider other factors such as aspects of prey natural history and their distribution in the benthos. Most consumed items were filter-feeding species (Simuliidae and Smicridea spp.) that inhabited rock surfaces that were more accessible to Torrent Ducks. Gripopterygidae and Atalophlebiinae were less accessible as they inhabit in the lower part of rocks. Diet information can be used to assess the availability of the most important prey items of Torrent Ducks in different rivers, and thus to estimate an important feature of habitat quality.Fil: Cerón, Geardo Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Departamento de Zoología; ArgentinaFil: Boy, Claudia Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Campaña binacional Argentina Chile. Canal Beagle 2019 (Código de campaña VA11/19): Datos discretos de densidad energética de fracciones del plancton

Los datos discretos de densidad energética del microplancton, microzooplancton y mesozooplancton corresponden a la campaña denominada "Canal Beagle 2019. Campaña binacional Argentina-Chile", código INIDEP VA-11/19 realizada entre el 9 y 15 de noviembre en el área compartida del Canal Beagle. El objetivo central de la campaña fue realizar un estudio interdisciplinario en el Canal Beagle y en la zona sudeste de la Isla de Tierra del Fuego, dentro de un marco de colaboración bilateral entre instituciones argentinas (CADIC e INIDEP) y chilenas (UACh, UMAG, UdeC, coordinados por el Centro IDEAL). Se seleccionaron tres áreas con características contrastantes: las zonas oeste y este del Paso Mackinlay, y la zona sudeste de la Isla de Tierra del Fuego. En dicha campaña se obtuvo información que permitirá estudiar los efectos de la acidificación y la hipoxia sobre la "Bomba Biológica" de carbono y sobre distintos niveles de las tramas tróficas en el Canal Beagle, con énfasis en especies de importancia ecológica y/o comercial. Se realizaron mediciones continuas de presión parcial de CO2 (pCO2), salinidad, temperatura y fluorescencia subsuperficiales, mediciones de corrientes con ADCP e hidroacústica. Asimismo, se ejecutaron perfilados verticales de columna de agua CTD y toma de muestras de agua con roseta. Por último, se realizaron dos estaciones fijas para medición de variables cada 6 horas durante un período de 48 horas por estación. En dichas estaciones fijas se realizó muestreos de organismos planctónicos con redes de apertura y cierre múltiple, redes para fitoplancton, redes bongo, FRRF y muestras de sedimento con snapper. Al comienzo de la campaña se instaló una trampa de sedimentos, la cual fue recuperada al concluir la misma. Por último, se realizó un fondeo de un perfilador de corrientes. La campaña se cumplimentó exitosamente permitiendo concretar el 100 % de los objetivos propuestos.Fil: Boy, Claudia Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Bruno, Daniel Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Life-history traits in the southernmost landlocked population of the fish Galaxias maculatus

Studying life-history traits is critical to understanding the intraspecific variation among fish populations. In this research, we investigated the age, growth, and sexual maturity of Galaxias maculatus population from Laguna Negra (LN), the southernmost landlocked population of the species, and compared the results obtained with those obtained before for the diadromous population from Arroyo Negro (AN), 1.8 km away from LN. We read otolith growth bands to estimate age structure and calculated the gonadosomatic index to estimate sexual maturity. We found five age classes (0 + to 4 +) in LN; the maximum age was 4.5 years, the maximum documented age for the species, exceeding in 1 year the maximum age found previously for the AN population. Age class 2 + was the most represented throughout the year, and the greater age and length-at-age ratio observed in this landlocked population suggest a slower growth rate than that of AN. We hypothesize that landlocked individuals reach their first sexual maturity 1 year later than their diadromous counterparts. The protracted reproductive season detected in this landlocked population (9 months) may be related to the high size variability within age classes, where some individuals might maximize growth while others might maximize first sexual maturity. Our results suggest higher energetic costs for these basic biological activities in landlocked than diadromous populations from Tierra del Fuego, Argentina. Further studies are necessary to understand the trade-off between growth and sexual maturation in sub-Antarctic G. maculatus populations.Fil: Rojo, Javier Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Boy, Claudia Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin