Unravelling the identity of Pandora species (Bivalvia: Pandoridae) from Southern South America

Four species of Pandora have been reported from southern South America: P. cistula Gould, 1850, P. braziliensis G. B. Sowerby II, 1874, P. diffissa Mabille & Rochebrune, 1889 and P. patagonica (Dall, 1915). The group has received little taxonomic attention in this area, resulting in arbitrary and wrong usage of these names, for which several contradictory synonymies have been proposed. This study provides the first revision of Pandora species living in southern South America, including photographs of the type material and descriptions of shells, gross anatomy and living animals. Out of the four species previously mentioned, P. braziliensis is here regarded as valid, including P. patagonica and P. diffissa as synonyms. The fourth species, P. cistula, remains known only from its type specimen. In addition, a new species, P. brevirostris, is described from the shallow waters of Argentina.Fil: Güller, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Zelaya, Diego Gabriel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentin

The smallest marine bivalves from the end of the world (Tierra del Fuego, Isla de Los Estados and Burdwood Bank)

Small molluscs are known to be particularly abundant towards the poles. Although recent studies on sub-Antarctic waters of the southernmost tip of South America have begun to show a highly diversified small-sized fauna, micromolluscs have not yet received sufficient attention. Recently, samplings targeting the smallest molluscan benthic fauna have been conducted in the sub-Antarctic waters of South America, providing material of three new minute species occurring in The End of the World (Tierra del Fuego, Isla de los Estados and Burdwood Bank). The present study describes Pachykellya fuegiensis n.sp. (Neoleptonidae), Benthocardiella ituartei n.sp. and Benthocardiella finisterra n.sp. (Condylocardiidae). These are not only the smallest bivalves currently known from the area, but are also smaller than any other species thus far known from the adjacent Antarctic waters, and are included among the smallest species of their respective genera. To confirm generic placement, the type species of Pachykellya (P. edwardsi F.B. Bernard 1897) and Benthocardiella (B. pusilla Powell 1930) are studied for the first time with scanning electron microscopy. This study allows to amend the previous descriptions of hinge teeth number, morphology and arrangement for these genera. Based on these new findings, Pachykellya and Benthocardiella are here reported for the first time in South America.Fil: Güller, Marina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zelaya, Diego Gabriel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The families carditidae and condylocardiidae in the magellan and Perú-Chile provinces (bivalvia: Carditoidea)

Based on the study of available types and extant collections, this paper provides a systematic revision of the living species of Carditoidea occurring in the Magellan and Perú-Chile Provinces. Out of the 19 nominal species reported for the area, eight species are recognized as valid: Cyclocardia compressa, C. spurca, C. thouarsii, C. velutina, Carditella naviformis,C. semen, C. tegulata and Carditopsis flabellum. Other eight nominal species are regarded as synonyms: Cardita magellanica of Cyclocardia velutina; Carditella pallida of C. tegulata; Cardita australis and Actinobolus philippi of Carditella naviformis; Cardium pygmaeum of Carditella semen; Cardita paeteliana of Cyclocardia spurca; Carditella pallida duodecimcostata of Carditopsis flabellum; and Cardita congelascens of Cyclocardia thouarsii. Furthermore, Cardita malvinae and Cardium parvulum are nomina dubia, and the occurrence of Carditella exulata in Magellanic waters is doubtful.Fil: Güller, Marina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Zelaya, Diego Gabriel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A new species of Mysella from Patagonia (Bivalvia: Galeommatoidea)

The poorly known diversity of the genus Mysella in the southwestern Atlantic is improved with the description of a new species from San Julian Bay, Santa Cruz Province, Argentina. Mysella patagona new species is characterized by the relative large, strikingly subquadrate, slightly inequilateral and flat shell; a cleft hinge plate, with two widely diverging teeth in the right valve, and a cylindrical internal ligament located in a deep ligamental pit. From the anatomical point of view, M. patagona new species is characterized by the presence of inner and outer demibranchs, with very few interlamellar junctions. The marked subquadrate shell outline easily distinguishes M. patagona from any other Mysella species currently known from the Magellan Region.Fil: Ituarte, Cristian Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Martin, Juan Pablo. Universidad Nacional de la Patagonia Austral. Unidad Académica San Julián; ArgentinaFil: Zelaya, Diego Gabriel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The genus Cyamiocardium Soot-Ryen, 1951 (Bivalvia: Cyamiidae) in sub-Antarctic and Antarctic waters

For more than 50 years the genus Cyamiocardium was regarded as represented by three species: Cyamiocardium denticulatum (with Cyamiocardium rotundatum as a synonym), Cyamiocardium dahli, and Cyamiocardium crassilabrum. However, in the last years, the latter was removed from Cyamiocardium, alternatively being placed into Perrierina. All these species were mainly based on the general shell morphology of a reduced number of specimens, with scarce (or no) information on their anatomy and reproductive traits. The present study provides the first systematic revision of the species of Cyamiocardium occurring in sub-Antarctic and Antarctic waters. For that, an extant source of material was available; and several characters not studied (in detail) before, such as prodissoconch morphology and microsculpture, gross anatomy, and reproductive characteristics, were investigated. As part of this study, the identity of C. denticulatum (the type species of the genus) and that of C. dahli are clarified. In addition, C. rotundatum is revalidated as a full species, and C. crassilabrum is transferred again to Cyamiocardium. Furthermore, three new species were detected and are described herein: Cyamiocardium chuanisinense new species, Cyamiocardium namuncurense new species, and Cyamiocardium yeskumaala new species. The new information arising from this study is used to redefine the genus Cyamiocardium, and to re-analyze the similarities/differences of this genus with other cyamiids.Fil: Urcola, Matías R.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Zelaya, Diego Gabriel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentin

Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia)

This contribution provides the first integrative study of Cyamioidea, a group of bivalves largely neglected in the past.By combining information obtained from shell morphology, gross anatomy, histology, reproductive biology and DNAsequencing, the distinctive characters of Cyamioidea are determined, and the taxa belonging to this superfamily are revised. Gaimardioidea, previously considered as a distinct superfamily, is reduced to family level (Gaimardiidae),which, along with Cyamiidae, are assigned to Cyamioidea. All studied cyamioideans share a common reproductive character: the presence of a true follicular epithelium surrounding each developing oocyte, which persists afterspawning, surrounding the developing embryos and participating in their anchorage to the gill filaments. Several morphological and anatomical characters support the distinction of Gaimardiidae and Cyamiidae. Based on thatinformation, the placement of Gaimardia and Kidderia in Gaimardiidae, and that of Cyamiocardium, Cyamiomactra, Cyamium, Heteromactra, Pseudokelly, Ptychocardia and Reloncavia in Cyamiidae, is confirmed. Jukesena, historicallyplaced in Veneroidea, is here allocated to Cyamiidae. Neoleptonidae, previously also attributed to Cyamioidea, are reallocated to Veneroidea.Fil: Zelaya, Diego Gabriel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Güller, Marina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ituarte, Cristian Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Crepipatella dilatata (Lamarck, 1822) (Calyptraeidae): an example of reproductive variability among gastropods

Fil: Zelaya, Diego Gabriel. División Zoología Invertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Pechenik, Jan A.. Biology Department. Tufts University. Medford; USAFil: Gallardo, Carlos S.. Instituto de Zoología. Universidad Austral de Chile. Valdivia; Chil

Crepipatella dilatata (Lamarck, 1822) (Calyptraeidae): An example of reproductive variability among gastropods

Reproductive characteristics of a species are often defined from a small number of individuals collected from a single location at one particular time. However, this study reveals that the South American gastropod Crepipatella dilatata (Lamarck, 1822) shows an unusually high level of intraspecific variability in some key reproductive characteristics: the number of egg capsules brooded per female, the size of the egg capsules, the number of eggs per capsule and the sizes and size distributions of the uncleaved eggs. Larger females were more fecund than smaller ones, not because they produced more egg capsules, but because they produced capsules of significantly larger size. Such variability was evident not only when considering different populations, but also within a single population sampled in different years, as well as among specimens collected during a single sampling event. Thus our data emphasize the importance of obtaining information from numerous specimens per locality as well as from specimens from different localities and in different years when describing the reproductive characteristics of any particular taxon.Facultad de Ciencias Naturales y Muse

Crepipatella dilatata (Lamarck, 1822) (Calyptraeidae): An example of reproductive variability among gastropods

Reproductive characteristics of a species are often defined from a small number of individuals collected from a single location at one particular time. However, this study reveals that the South American gastropod Crepipatella dilatata (Lamarck, 1822) shows an unusually high level of intraspecific variability in some key reproductive characteristics: the number of egg capsules brooded per female, the size of the egg capsules, the number of eggs per capsule and the sizes and size distributions of the uncleaved eggs. Larger females were more fecund than smaller ones, not because they produced more egg capsules, but because they produced capsules of significantly larger size. Such variability was evident not only when considering different populations, but also within a single population sampled in different years, as well as among specimens collected during a single sampling event. Thus our data emphasize the importance of obtaining information from numerous specimens per locality as well as from specimens from different localities and in different years when describing the reproductive characteristics of any particular taxon.Facultad de Ciencias Naturales y Muse

A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world