Dos nuevas especies del género Notropis Rafinesque, 1817 (Actinopterygii, Cyprinidae), de la cuenca del río Lerma, México central

Prior findings suggest the existence of undescribed species among the cyprinids of central Mexico. Within the genus Notropis distributed across central Mexico and adjacent areas sometimes reaching southern basins, two groups have been recognized: a Southern Mexican clade and a central Mexican clade. Within this last clade, Notropis calientis has been defined as a species complex of four small minnows inhabiting upland areas. Here we describe two new species of this complex based on morphometric, meristic and genetic characters. Notropis marhabatiensis sp. nov. was diagnosed according to the following set of characters: 7, rarely 8, branched pelvic fin rays (vs. 8, rarely 7 or 9, in other species of the N. calientis complex) and 9, rarely 8, scales in a transverse series (vs. 10, rarely 9 or 11 in N. grandis & N. calientis); a dark, narrow lateral stripe running from around the pectoral fin to the caudal peduncle origin; and twentysix fixed nucleotide positions in the cytochrome b gene. The diagnosis of Notropis grandis sp. nov. was based on: 6, rarely 7, branched fin rays (vs. 7, rarely 6 or 8, in N. marhabatiensis, N. calientis and N. aulidion and 8, rarely 7 or 9, in N. calbazas and N. amecae), 42, rarely 40-41, or 43-45 scales in a lateral series (vs. 40, rarely 37-39, in N. calabazas; 35- 36, rarely 37-39, or 33-34 in N. amecae; 35, rarely 31-34, or 36 in N. marhabatiensis and N. calientis and 34, rarely 30-33, or35 in N. aulidion) and 11 rarely 10 or 12 gill rakers in the first arch; a dark lateral stripe widening from approximately the pectoral fin origin to the dorsal fin origin, forming a slightly convex segment; adult animals larger (n=30, ? ? =42.6, SD=4.69) relative to N. calientis (n=55, ? ?= 33.3, SD= 3.28) and N. marhabatiensis sp. nov. (n=30, ? ?= 30.5, SD=7.57) (F = 16.87; p < 0.001); and finally 31 fixed nucleotide positions in the mitochondrial gene cytochrome b sequence along with four amino acid changes. Calculated genetic distances between the new species and other species of the complex ranged between ? D GTR = 6.1% to 7.4% for N. marhabatiensis and ? DGTR = 6.3% to 8.1% for N. grandis.Diversos estudios sugieren la existencia de especies no descritas de ciprínidos en el centro de México. Las especies del género Notropis se distribuyen a lo largo del centro de México y regiones adyacentes, algunas especies llegan a cuencas del sur del país. Se han reconocido dos grupos: un clado sureño y uno en la parte central del país. En este último, Notropis calientis fue descrito como un complejo de especies que habita las partes altas de las cuencas donde se distribuyen. Con base en características morfométricas, merísticas y genéticas, se describen dos nuevas especies que emanan del complejo Notropis calientis. Notropis marhabatiensis sp. nov. se diagnostica por presentar: 7, rara vez 8 radios ramificados en la aleta pélvica (vs. 8 rara vez 7 o 9 en las otras especies dentro del complejo N. calientis) y 9 rara vez 8 escamas transversales (vs. 10 rara vez 11 o 9 en N. grandis y N. calientis). Una línea lateral oscura y delgada corre a partir del origen de la aleta pectoral hasta el pedúnculo caudal. Veintiséis posiciones nucleotídicas fijadas en el gen citocromo b. Notropis grandis sp. nov. presenta 6, rara vez 7 radios ramificados en la aleta anal (vs. 7, rara vez 8 o 6 en N. marhabatiensis, N. calientis y N. aulidion y 8, rara vez 7 o 9 en N. calbazas y N. amecae); 42, rara vez 40-41 y 43-45 escamas en una línea lateral (vs. 40 rara vez 37-39 en N. calabazas; 35-36, rara vez 37-39 y 33-34 en N. amecae; 35, rara vez 31-34 y 36 en N. marhabatiensis y N. calientis y 34 rara vez 30-33 y 35 in N. aulidion) y 11, rara vez 10 o 12 branquiespinas en el primer arco branquial. La línea lateral se extiende a partir del origen de la aleta pectoral hasta el origen de la aleta dorsal, con un segmento ligeramente convexo. Los adultos de esta especies son de mayor tamaño (longitud estándar= ? ? = 42.6, SD= 4.69) (vs. N. calientis (n=55, ? ? = 33.3, SD=3.28) y N. marhabatiensis sp. nov. (n=30, ? ? =30.5, SD=7.57) (F = 16.87; p < 0.001)). Presentan treinta y una posiciones nucleotídicas fijadas en la secuencia del gen mitocondrial citocromo b y cuatro cambios aminoacídicos. Las distancias genéticas entre N. marhabatiensis y otras especies del complejo variaron entre ? DGTR = 6.1% a 7.4%. Para N. grandis fueron de ? DGTR = 6.3% a 8.1%

Cambio en la distribución de goodeidos (Osteichthyes: Cyprinodontiformes: Goodeidae) en cuencas hidrológicas del centro de México Changes in the distribution of goodeids (Osteichthyes: Cyprinodontiformes: Goodeidae) in river basins of Central Mexico

La Mesa Central de México cuenta aproximadamente con 100 especies nativas de peces, el 70% son endémicas de la región. Los ecosistemas de esa área geográfica son sobre los que mayor impacto ha tenido la actividad antropogénica. El grupo de peces más representativo es el de los goodeidos que aparentemente han sobrevivido a grandes cambios de calidad de agua y flujo hídrico. Para entender los cambios en la distribución de esta familia, el presente trabajo documenta las desapariciones y extinciones locales de especies de goodeidos y su relación con las diferentes regiones de la Mesa Central. Para conocer su distribución previa, se realizó una búsqueda bibliográfica y en bases de datos de colecciones. Estos registros se compararon con recolectas realizadas entre junio de 1999 y septiembre del 2004 en 287 localidades en 15 estados de la República Mexicana. Se cubrió el 95% de los sitios de recolecta que presentaban registros previos. La comparación entre distribuciones arrojó que en el 68% de estos sitios se registró la desaparición de alguna especie. En 9 de las 18 regiones, las especies previamente registradas redujeron su distribución a la mitad, han desaparecido 5 en más del 50% de su intervalo de distribución y al menos 2 se señalan como extintas. Las especies se clasificaron según su vulnerabilidad y las localidades fueron categorizadas de acuerdo al promedio de desaparición de poblaciones. Se discute el efecto de las extinciones sobre la viabilidad de las especies a largo plazo, y la pertinencia de establecer áreas de conservación para los goodeidos. Las extinciones locales pueden afectar la viabilidad de las especies, y por lo tanto es urgente generar áreas de conservación para los godeidos.The Mexican central plateau hosts around 100 native freshwater fish species, 70% of which are endemic to the region. Freshwater ecosystems in this area are highly impacted by anthropogenic activities. Goodeids are the most representative fish in lakes and rivers in the central plateau. In recent decades, these fishes have suffered from water quality depletion and modification of hydrological regimes, leading to reduction of their original distributions. To understand changes in the distribution of species of this family, we documented local extinctions of its species and its relation with their sensitivity to environmental changes. Previous distribution records for each species were obtained from bibliographical sources and museum collection data. We compared previous distribution with more recent fieldwork data, which was conducted between 1999 and 2004, in 287 localities in 15 states of the country. Fieldwork covered 95% of the localities sampled in previous records. We found local extinction in 68% of the localities surveyed. In 9 of the 18 regions, species distribution was reduced to half of their reported areas. Five species have disappeared in 50% of their original distributional range, and at least 2 species are already extinct. We classified Goodeid species according to their vulnerability and localities were categorized by the quantity of local extinctions. Local extinctions may affect species viability, and it is therefore urgent to generate areas of conservation for goodeids

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)