Mesophotic Coral Ecosystems in the Eastern Tropical Pacific: The current state of knowledge and the spatial variability of their depth boundaries.

In the Eastern Tropical Pacific (ETP), Mesophotic Coral Ecosystems (MCEs) are limited by oceanographic conditions and are thought to be mostly absent. However, considering the currently discussed more flexible approach to define mesophotic boundaries, based on light availability, we performed a systematic search to assess their current state of knowledge. Using MODIS-Aqua satellite data (Kd490), we calculated the mesophotic boundaries in the ETP, based on optical depths, and performed a bibliographic search of studies carried out at those depths, including those present in turbid waters with KdPAR values up to 0.2 m-1. Seventy-seven papers on MCEs research were compiled in this review, recording a total of 138 species. The studies focus almost exclusively on taxonomy, ecosystem function, and reviews, indicating the need for future research regarding aspects, such as structuring environmental variables, molecular ecology, and natural resource management. Furthermore, remote sensing data show that there exists a high spatial variability of water transparency in the ETP, resulting in significant differences in KdPAR between oceanic and continental locations, mostly related to the occurrence of seasonal upwelling in the latter. Based on KdPAR, we estimated the mesophotic depth boundaries (z10%, z1%, z0.1%) for specific locations within the ETP and found that MCEs can potentially occur as shallow as 13-15 m in coastal regions. Also, we compared the calculated boundaries with the respective deepest records of light-dependent corals. With one exception, the presence of the corals was restricted to the upper mesophotic subzone (z10%-z1%), which agrees with reports for other regions, showing that light availability is one of the main drivers for the bathymetric distribution of MCEs and can be used as a first approach to identify their potential presence, though other local factors (e.g., geomorphology, temperature, internal waves) should also be considered, as they can cause shifts in depth limits.

Análisis reproductivo en hembras de Iguana iguana criadas en cautiverio en Oaxaca, México / Reproductive analysis of Iguana iguana females raised in captivity in Oaxaca, Mexico

With the objective to evalúate the reproductive stage in green iguana (Iguana iguana) females maintained in captivity in Oaxaca, Mexico, a total of 137 females were used during six years. Iguanas were fed with concentrate, frijolillo plants (Desmodium infortum) and tulip flower (Tulipa gesneriana). The females were identified and housed in cages of 30 m² and were observed. Reproductive activities such as proestrus, estrus and pregnancy were daily recorded. In the stage of hatching, variables were measured in eggs that were incubated in styrofoam boxes with relative humidity of 65 to 85% and temperature between 28 to 34°C, and the newborn were measured after hatching. Results were analyzed with descriptive statistics and canonical correlation analysis using the Statistical Analysis System. At the beginning of the reproductive season the females weighed 975.9 ± 405 g and measured 27.9 ± 3.4 cm snout-vent length, with a relative clutch mass of 36.3 ± 7.1%, clutch size of 23.5 eggs, hatching success of 64.8%, and newborn weight of 12.5 ± 2.3 g. The periods of proestrus, estrus, and pregnancy were 85, 36.2 y 59.7 days, respectively. The females weight at the beginning of the reproductive stage, snout-vent length and total were correlated (canonical correlation r = 0.69, r = 0.64 and r = 0.64, respectively) with the number and weight of newborn, indicating the importance of female management before the breeding season.

Con el fin de evaluar la etapa reproductiva en hembras de iguana verde (Iguana iguana) mantenidas en cautiverio, en Oaxaca, México, se utilizaron 137 hembras, durante seis años. Se ofreció alimento concentrado, plantas de frijolillo (Desmodium infortum) y flor de tulipán (Tulipa gesneriana). Las hembras fueron identificadas y alojadas en jaulas de 30 m²; se observaron y registraron las actividades reproductivas de proestro, estro y gestación. En la etapa de eclosión, se midieron las variables de los huevos y se incubaron en cajas de unicel con humedad relativa de 65% a 85% y temperatura de 28° a 34°C; las crías se midieron después de la eclosión. Para el análisis de resultados se utilizó estadística descriptiva y análisis de correlación canónica con el paquete estadístico SAS. En el inicio del periodo reproductivo, las hembras pesaron 975.9 ± 405 g y midieron de longitud hocico-cloaca 27.9 ± 3.4 cm, la masa relativa de nidada fue de 36.3 ± 7.1%, con tamaño de 23.5 huevos, de los cuales eclosionaron 64.8%; las crías pesaron 12.5 ± 2.3 g. La duración de proestro, estro y gestación fue de 85, 36.2 y 59.7 días, respectivamente. El peso de las hembras al inicio de la etapa reproductiva, la longitud hocico-cloaca y el total se correlacionaron canónicamente (r = 0.69, r = 0.64 y r = 0.64) con el número y peso de las crías eclosionadas, lo que indica la importancia del manejo de las hembras antes del periodo reproductivo.