Introduction: Sea urchin gonads (roe or uni) are considered a culinary delicacy worldwide. However, only a few species are considered edible and commercialized. The sea urchin Tripneustes depressus has generated the interest of producers in Baja California Sur, Mexico, due to the quality of its gonads. A biological basis for designing a management strategy is key to consider its commercial exploitation. Objective: To determine the reproductive season of T. depressus through description of the gonad stages and reproductive cycle, and to establish its relationship with environmental factors. Methods: We collected monthly samples (October 2016-September 2017), recording in-situ temperature and photoperiod. We evaluated a sample of 1 055 specimens for demographic characteristics, using total weight (g) and test diameter (cm). We also did a histological analysis of gonads from 178 individuals. Results: Average test diameter was 9.70 ± 0.03 cm (5-12.50 cm). Based on the proportion into the gonad of sexual (gametes) and somatic (nutritive phagocytes) cells, we propose five gonad stages (growing, premature, mature, spawning, and intergametic) for both sexes. There were two times of the year when gonads were heaviest and closely corresponded to the growing stage, coinciding with the highest proportions of nutritive phagocytes. Gonad development (growing and premature stages) peaks in the months with the longest daylight periods, with spawning in the shortest daylight periods. Conclusions: Gonad wet weight and adjusted gonad weight are good indicators of the reproductive season of T. depressus. The lowest gonad wet weights were matched the spawning peak in the shortest daylight period (January and March).

Analizamos las variaciones temporales en el uso de cavidades por la comunidad de aves presente en un área altamente urbanizada de La Habana, durante un año. De las 351 cavidades disponibles en las paredes externas del Convento San Francisco de Asís, 79% (n = 277) fueron usadas durante todo el año por dos especies introducidas (Columba livia, paloma doméstica: 46%, n = 160; Passer domesticus, gorrión doméstico: 4%, n = 16), y entre enero y julio por tres especies nativas (Progne cryptoleuca, golondrina azul cubana: 17%, n = 58; Dives atroviolaceus, totí: ˂ 1%, n = 2; Falco sparverius, cernícalo americano: ˂ 1%, n = 1). Adicionalmente, 10% (n = 36) del total de cavidades fueron usadas por más de una de estas especies y 1% (n = 4) por Apis mellifera (abeja doméstica). Progne cryptoleuca presentó una amplia y mayor variación durante el año, aunque su uso se restringió entre febrero y julio. Desde principios de febrero hasta marzo el uso de cavidades se incrementó, en abril disminuyó (n = 8), pero el valor máximo se observó a mediados de mayo (n = 60). Estas variaciones parecen relacionarse con su estatus migratorio y la conducta asociada a las diferentes etapas del periodo reproductivo, y no por la presencia de C. livia en el área.