Crecimiento alométrico y disminución de la capacidad de regeneración de la aleta pectoral en Polypterus senegalus terrestrizados

Background: Polypterus condense unique characteristics that astonished and confused naturalists since 1802 when Geoffroy St. Hilaire first described and named this fish. Polypterus was seen in that epoch as primitive amphibians or a link between fishes and amphibians. Polypteriformes have the ability to regenerate its pectoral fins with the accuracy only seen in urodel amphibians and have the capacity to breathe air using paired lungs. Goals: We aimed to evaluate how forced land-living condition (i.e., terrestrialization) could affect pectoral girdle bones shape and pectoral fin regeneration in Polypterus senegalus. Methods: Polypterus were reared in semi-terrestrial conditions for nine months and iterative amputations of pectoral fins were performed every two months. The bone elements of the shoulder girdle and pectoral fins were measured and compared between terrestrialized organisms and controls. Results: Terrestrialization produces notable morphological alterations, including general reduced body growth and big eyes, serial amputations under this condition decreases the number of radial bones of pectoral fins. Conclusions: We propose allometry and heterochrony as reliable concepts to explain the modifications generated by terrestrialization. Also, we suggest that anatomical alterations in early tetrapod ancestors were an unavoidable consequence of the influence of environment on general metabolic processes associated with growth.Antecedentes: Polypterus condensa características únicas que sorprendieron y confundieron a los naturalistas desde que Geoffroy St. Hilaire lo describiera y nombrara por primera vez en 1802. En esa época Polypterus fue visto como un anfibio primitivo o como el eslabón entre peces y anfibios. Los Polypteriformes tienen la capacidad de regenerar las aletas pectorales con la precisión que solo se ve en los anfibios urodelos y tienen la capacidad de poder respirar aire utilizando un par de pulmones. Objetivos: Fue evaluar cómo una condición forzada de vida en tierra pudiera afectar a los huesos de la cintura escapular y la regeneración de la aleta pectoral de Polypterus senegalus. Métodos: Los Polypterus fueron mantenidos en condiciones semi-terrestres durante nueve meses y se realizaron amputaciones iterativas de las aletas pectorales cada dos meses. Los elementos óseos de la cintura escapular y aletas pectorales fueron medidos y comparados entre organismos terrestrizados y controles. Resultados: La terrestrización produce alteraciones morfológicas notables, que incluyen reducción del tamaño corporal general y ojos más grandes, las amputaciones seriales en esta condición provocaron que el número de huesos radiales de las aletas pectorales se redujera. Conclusiónes: Proponemos que los conceptos alometría y heterocronía pueden explicar las modificaciones generadas por la terrestrización. Así mismo, sugerimos que las alteraciones anatómicas en los ancestros de los tetrápodos fueron una consecuencia inevitable de la influencia del medio ambiente sobre los procesos metabólicos generales asociados con el crecimiento

First record of Placozoa from the Gulf of Mexico

Placozoa is a phylum with only one species:Trichoplax adhaerens (F. E. Schulze, 1883); recent genetic studies suggest, however,that several haplotypes inhabit tropical and subtropical waters around the world. Placozoans have been found usually close to littoral zones where mangrove forests occur. Goals. To provide the second record of this species from the coasts of Mexico and describe a new filament structure observed in the upper epithelium. Methods. Photographic images were taken of Placozoans found in glass slides introduced in marine aquariums. Some specimens were collected and stained with Mito Tracker, DAPI and Lyso Tracker fluorescent dyes according to the manufacturer instructions. Results. Puerto Morelos in the Mexican Caribbean Sea and Florida in the Atlantic coast are the closest places to the Gulf of Mexico were Placozoans have been recorded. We report here the first record of Trichoplax adhaerens in the Gulf of Mexico. The organisms were found in sea water aquariums built with materials, water, and invertebrates obtained from the Tuxpan reef (21.016667 N, 97.186389 W), an emerged platform that belongs to the Lobos-Tuxpan Reef System. Conclusions. This finding is the first record of Trichoplax for the coasts of the western Gulf of Mexico and includes the description of a filament structure in the upper epithelium not reported before

Lista actualizada y nuevos registros de babosas marinas (Gastropoda: Heterobranchia) en el Sistema Arrecifal Lobos-Tuxpan, México

Background: In the Lobos-Tuxpan Reef System Protected Natural Area (LTRS), Mexico, the presence of sea slugs has been documented in several scientific investigations, but the information is limited, scattered and out of date. Goals: To elaborate an updated list of species with new field data and the compilation of species previously reported in the literature for LTRS. Methods: Samplings were carried out in the Lobos reef (during November 2014 and 2017), Enmedio reef (September 2016, April 2017, June 2018, July and November 2019) and the Tuxpan reef (June and October 2016, and April 2017). The list of species was complemented with records of species previously reported for LTRS. Results: The updated list comprises up to 27 species of sea slugs. The most representative groups are: Order Cephalaspidea with nine species, Aplysiida with seven species and Superorder Sacoglossa with seven species. The distribution of Cyerce habanensis and Elysia cornigera extends to the north of Veracruz and Lobiger souverbii constitutes a new record for the Southwestern Gulf of Mexico Reef Corridor. Conclusions: Our study favorably increases the knowledge of sea slugs for the LTRS. This information could support strategies of conservation and protection for the management plans of this protect natural area.Antecedentes: En el Área Natural Protegida Sistema Arrecifal Lobos-Tuxpan (SALT), México, la presencia de babosas marinas se ha documentado en varias investigaciones científicas, pero la información es limitada, se encuentra dispersa y desactualizada. Objetivo: elaborar una lista actualizada de las especies con base en la adición de nuevos datos de campo y de la compilación de especies reportadas previamente en la literatura para el SALT. Métodos: Se realizaron muestreos en el arrecife Lobos (durante noviembre 2014 y 2017), arrecife Enmedio (septiembre 2016, abril 2017, junio 2018, julio y noviembre 2019) y en el arrecife Tuxpan (junio y octubre 2016, y abril 2017). El listado de especies se complementó con registros de especies reportadas previamente para el SALT. Resultados: La lista actualizada comprende 27 especies de babosas marinas. Los grupos más representativos son: orden Cephalaspidea con nueve especies, Aplysiida con siete especies y Superorden Sacoglossa con siete especies. Se extiende la distribución de Cyerce habanensis y Elysia cornigera para el norte de Veracruz y Lobiger souverbii constituye nuevo registro para el Corredor Arrecifal del Suroeste del Golfo de México. Conclusiones: La presente investigación incrementa favorablemente el conocimiento de las babosas marinas para el SALT. Esta información puede apoyar las estrategias de conservación y protección para el plan de manejo de esta área natural protegida

Genetic diversity, phylogenetic position, and co-phylogenetic relationships of Karyolysus, a common blood parasite of lizards in the Western Mediterranean

The genus Karyolysus was originally proposed to accommodate blood parasites of lacertid lizards in Western Europe. However, recent phylogenetic analyses suggested an inconclusive taxonomic position of these parasites of the order Adeleorina based on the available genetic information. Inconsistencies between molecular phylogeny, morphology, and/or life cycles can reflect lack of enough genetic information of the target group. We therefore surveyed 28 localities and collected blood samples from 828 lizards of 23 species including lacertids, skinks, and geckoes in the western Mediterranean, North Africa, and Macaronesia, where species of Karyolysus and other adeleorine parasites have been described. We combined molecular and microscopic methods to analyze the samples, including those from the host type species and the type locality of Karyolysus bicapsulatus. The phylogenetic relationship of these parasites was analyzed based on the 18S rRNA gene and the co-phylogenetic relationship with their vertebrate hosts was reconstructed. We molecularly detected adeleorine parasites in 37.9% of the blood samples and found 22 new parasite haplotypes. A phylogenetic reconstruction with 132 sequences indicated that 20 of the newly detected haplotypes clustered in a well-supported clade with another 18 sequences that included Karyolysus galloti and Karyolysus lacazei. Morphological evidence also supported that K. bicapsulatus clustered in this monophyletic clade. These results supported the taxonomic validity of the genus. In addition, we found some parasite haplotypes that infected different lizard host genera with ancient diverging histories, which suggested that Karyolysus is less host-specific than other blood parasites of lizards in the region. A co-phylogenetic analysis supported this interpretation because no significant co-speciation signal was shown between Karyolysus and lizard hosts

Potencial regenerativo de la estrella de mar Linckia guildinguii

Asteroidea is a class of Phylum Echinodermata with great capacity for body regeneration. The genera Linckia are among the species with higher capacity to regenerate and, in contrast to most sea stars, can reproduce asexually from arm fragments without portions of the central disc. In this article, we characterized the regeneration of Linckia guildinguii at a morphological and histological level and aimed to understand its regenerative potential. We performed experiments with arm fragments of different size and shape. A star will regenerate anew in 32 days by morphallactic regeneration. We note that sea stars regenerated de novo are again able to regenerate a new sea star. The ease with which this deuterostomatous organism can be maintained in a confined state made L. guildinguii a suitable animal to study the regenerative phenomenon and the processes associated with the establishment of body axes.Los Asteroideos son una clase del filo Echinodermata que presenta una amplia capacidad de regeneración corporal. Entre las especies con mayor capacidad de regeneración están las del género Linckia, que pueden reproducirse asexualmente a partir de fragmentos del brazo sin requerir de una porción del disco central, como ocurre con la mayoría de las estrellas de mar. En el presente trabajo caracterizamos a nivel morfológico e histológico el proceso de regeneración de los brazos de Linckia guildinguii e hicimos experimentos con fragmentos de diferentes longitudes y geometrías. Determinamos que la formación de una nueva estrella tarda aproximadamente 32 días, que los pequeños brazos de estas estrellas a su vez son capaces de regenerar una nueva estrella y que la regeneración es de tipo morfaláctica. Por la facilidad para mantener a este organismo deuterostomado en cautiverio y por su amplio potencial regenerativo, consideramos que es un buen modelo para estudiar el fenómeno de la regeneración y entender procesos asociados al establecimiento de los ejes corporales

Inequalities in catastrophic health expenditures in conflict-affected areas and the Colombian peace agreement : an oaxaca-blinder change decomposition analysis

Abstract Background The present study analyzes inequalities in catastrophic health expenditures in conflict-affected regions of Meta, Colombia and socioeconomic factors contributing to the existence and changes in catastrophic expenditures before and after the sign of Colombian Peace Agreement with FARC-EP guerilla group in 2016. Methods The study uses the results of the survey Conflicto, Paz y Salud (CONPAS) conducted in 1309 households of Meta, Colombia, a territory historically impacted by armed conflict, for the years 2014 and 2018. We define catastrophic expenditures as health expenditures above 20% of the capacity to pay of a household. We disaggregate the changes in inequalities in catastrophic expenditures through the Oaxaca-Blinder change decomposition method. Results The incidence of catastrophic expenditures slightly increased between 2014 to 2018, from 29.3 to 30.7%. Inequalities in catastrophic expenditures, measured through concentration indexes (CI), also increased from 2014 (CI: -0.152) to 2018 (CI: -0.232). Results show that differences in catastrophic expenditures between socioeconomic groups are mostly attributed to an increased influence of specific sociodemographic variables such as living in rural zones, being a middle-aged person, living in conflict-affected territories, or presenting any type of mental and physical disability. Conclusions Conflict-deescalation and the peace agreement may have facilitated lower-income groups to have access to health services, especially in territories highly impacted by conflict. This, consequently, may have led to higher levels of out-of-pocket expenditures and, therefore, to higher chances of experiencing catastrophic expenditures for lower-income groups in comparison to higher-income groups. Therefore, results indicate the importance of designing policies that guarantee access to health services for people in conflict -affected regions but also, that minimize health care inequalities in out-of-pocket payments that may arouse between people at different socioeconomic groups

A light of hope? Inequalities in mental health before and after the peace agreement in Colombia : a decomposition analysis

Background The present study seeks to evaluate the change in mental health inequalities in the department of Meta after the signing of Colombia’s Peace Agreement in 2016 with the FARC guerrilla group. Using a validated survey instrument composed of 20 questions (‘SRQ-20’), we measure changes in mental health inequalities from 2014, before the signing of the agreement, to 2018, after the signing. We then decompose the changes in inequalities to establish which socioeconomic factors explain differences in mental health inequalities over time. Methods Our study uses information from the Conflicto, Salud y Paz (CONPAS) survey conducted in the department of Meta, Colombia, in 1309 households in 2018, with retrospective information for 2014. To measure inequalities, we calculate the concentration indices for both years. Through the Oaxaca change decomposition method, we disaggregate changes in mental health inequalities into its underlying factors. This method allows us to explain the relationship between changes in mental health inequalities and changes in inequalities in several sociodemographic factors. It also identifies the extent to which these factors help explain the changes in mental health inequalities. Results Mental health inequalities in Meta were reduced almost by half from 2014 to 2018. In 2018, the population at the lower and middle socioeconomic levels had fewer chances of experiencing mental health disorders in comparison to 2014. The reduction in mental health differences is mostly attributed to reductions in the influence of certain sociodemographic variables, such as residence in rural zones and conflict-affected territories, working in the informal sector, or experiencing internal displacement. However, even though mental health inequalities have diminished, overall mental health outcomes have worsened in these years. Conclusions The reduction in the contribution of conflict-related variables for explaining mental health inequalities could mean that the negative consequences of conflict on mental health have started to diminish in the short run after the peace agreement. Nevertheless, conflict and the presence of other socioeconomic inequalities still contribute to persistent adverse mental health outcomes in the overall population. Thus, public policy should be oriented towards improving mental health care services in these territories, given the post-accord context

Population Analysis of The Snapper Lutjanus Griseus, Based on The Artisanal Fisheries of The Tamiahua Coast, Veracruz

Artisanal fishery in the Gulf of Mexico is mainly undertaken for subsistence and is, thus, of great socioeconomic importance, with Lutjanidae one of the most important families caught in the region. However, there is scarce fisheries knowledge in the Gulf of Mexico and, in light of pressure from the fishing community, research into the population dynamics of these species is of vital importance for the management or conservation of coastal resources. This study aims to contribute information for the analysis of the population of Lutjanus griseus (Linnaeus, 1758), a common species on the Tamiahua coast, in the state of Veracruz. Samples and biometric data (weight, sex, total length and maturity) were recorded by the fishing community on this coast. The monthly population structure was constructed using fish size. Data from 987 individuals, the size of which oscillated from 15 to 80 cm, were registered over the course of a year. The sex ratio was 1:1, while the maximum calculated age was 10 years. Von Bertalanffy and Gompertz growth models reported a maximum age and growth of L∞=182.46 K= 0.05 and to = -1.71. The best fit was achieved by means of the Gompertz model, as based on the Akaike criteria and the biological interpretation of the parameters. Reported data and the models used in this study suggest that the minimum catch size should be 40 cm and that the fishery should either cease activities in the months of the reproductive peak or that quotas should be among the fishing cooperatives on the coast of Tamiahua

Estudio anatómico y morfológico de las células de Hofbauer por medio de impregnaciones argénticas / Anatomical and morphological study of Hofbauer cells by means of impregnation argenticas

Las células de Hofbauer se describieron por primera vez en 1847. Estudios posteriores ayudaron a que se supiera más de dichas células, denominadas “células errantes” y posteriormente células de Hofbauer.La función de las células de Hofbauer, consideradas macrófagas, ha sido discutida ampliamente; según algunos autores su actividad es endocrina e inmunológica, de transportación de substancias nutritivas y función fagocitaria. El presente estudio pretende identificar y describir la morfología de las células de Hofbauer por medio de impregnaciones argénticas específicas para macrófagos, para lo cual fueron utilizadas cinco placentas de primer trimestre, una de segundo trimestre y cinco a término, así como una técnica alternativa de impregnación argéntica para macrófagos.Se halló la llamada célula típica de Hofbauer, de forma esférica u ovoide, grande (20 µm a 30 µm), con apariencia macrófaga e impregnación argéntica para macrófagos. Fueron pocas las células con inclusiones en el citoplasma y su actividad fagocitaria fue mínima ya que se utilizaron únicamente placentas provenientes de embarazos normales.Las células de Hofbauer presentaron una apariencia de macrófago y además tomaron la impregnación argéntica para macrófagos