Cross-basin and cross-taxa patterns of marine community tropicalization and deborealization in warming European seas.

Ocean warming and acidification, decreases in dissolved oxygen concentrations, and changes in primary production are causing an unprecedented global redistribution of marine life. The identification of underlying ecological processes underpinning marine species turnover, particularly the prevalence of increases of warm-water species or declines of cold-water species, has been recently debated in the context of ocean warming. Here, we track changes in the mean thermal affinity of marine communities across European seas by calculating the Community Temperature Index for 65 biodiversity time series collected over four decades and containing 1,817 species from different communities (zooplankton, coastal benthos, pelagic and demersal invertebrates and fish). We show that most communities and sites have clearly responded to ongoing ocean warming via abundance increases of warm-water species (tropicalization, 54%) and decreases of cold-water species (deborealization, 18%). Tropicalization dominated Atlantic sites compared to semi-enclosed basins such as the Mediterranean and Baltic Seas, probably due to physical barrier constraints to connectivity and species colonization. Semi-enclosed basins appeared to be particularly vulnerable to ocean warming, experiencing the fastest rates of warming and biodiversity loss through deborealization.

Same species, different population dynamics: Spatio-temporal differences of Undaria pinnatifida (Ochrophyta, Phaeophyceae) in the intertidal of North Patagonia, Argentina.

Population dynamics can be influenced by physical and biological factors, particularly in stressful environments. Introduced species usually have great physiological plasticity, resulting in populations with different traits. Undaria pinnatifida, a macroalga originally described from northeast Asia, was introduced in Northern Patagonia, Argentina (San Matías Gulf) around 2010. To describe the spatio-temporal variability in population structure and morphometry of U. pinnatifida, we conducted monthly field samplings for 2 years at the intertidal area of two contrasting sites in the San Matías Gulf. Individuals of U. pinnatifida were classified by developmental stage, and their morpho-gravimetric variables were measured. In both intertidal sites juveniles were found in higher proportion during austral autumn and grew and matured during the autumn-winter months (from May onwards), and individuals senesced during early austral summer (December and January). Conversely, density and biomass were largely different between sites, and individuals showed slight morphological variability between sites. Environmental (e.g., nutrient concentration, available substrate) and biological factors (e.g., facilitation, competition) may explain the observed differences. Since there is not a macroalga with U. pinnatifida morphometrical characteristics in the intertidal environments of San Matías Gulf, studying this recent introduction gives us a better understanding of its potential ecological effects.

Loxoscelismo cutáneo predominantemente edematoso: a propósito de un caso / Cutaneous loxoscelism mainly edematous: a case report

In Chile, loxoscelism is caused by the bite of the Loxosceles laeta spider. The clinical presentation has two different forms: cutaneous loxoscelism (CL) and vicero-cutaneous loxoscelism, which is less frequent. Cutaneous loxoscelism includes an uncommon clinical variation (4%), called CL with edematous predominance (CLEP). We present a 5-year-old patient with sudden pain and edema on his right eyelid associated with fever, which progressed rapidly involving the right hemifacial area, frontal region, and left eyelid. Angioedema and pre-orbital cellulitis were discarded and CLEP was suspect. Cutaneous loxoscelism with an edematous predominance is self-limited, benign and with little or no necrotic injury due to the edema, which dilutes the toxin-induced enzymatic process causing necrosis. As in the reported cases it usually responds well to medical treatment and does not cause visceral involvement.

El loxoscelismo en Chile es un cuadro producido por la mordedura de la araña Loxosceles laeta. Las formas de presentación son: loxoscelismo cutáneo (LC) y loxoscelismo cutáneo-visceral (LCV), el último menos frecuente. Dentro del LC existe una variante poco común (4%) conocida como loxoscelismo cutáneo predominantemente edematoso (LCPE). Nuestro caso es un paciente de 5 años que consultó por cuadro de inicio súbito de dolor y edema palpebral derecho, asociado a fiebre el cual evolucionó con rápida progresión extendiéndose en la hemicara derecha, región frontal y párpado izquierdo. Se descartó un angioedema y una celulitis periorbitaria, sospechándose un LCPE. Se manejó con hidrocortisona y clorfenamina. El LCPE es un cuadro benigno, autolimitado, en que no está presente la lesión necrótica o ésta es insignificante. Predomina el edema, el cual abortaría la necrosis al diluir el proceso enzimático producido por el veneno. Tiene buena respuesta al tratamiento médico, con ausencia de compromiso visceral.