The brooded larva of Ostrea chilensis is not an obligate lecithotroph, as has often been supposed, because it removes particles from the mantle cavity of the parent oyster. The ingestion of exogenous particles by the larva becomes apparent when the shell length of the veliger is approximately 290 µm, the same stage at which the velar ciliature is also visible for the first time. Experiments using red plastic marker particles showed that gut retention time in brooding oysters was significantly greater (10 to 11 h) than in non-brooding oysters (8 h), providing a mechanism for more efficient use of the ingested food. Although there was no significant difference in gut retention time between oysters brooding early and late larval stages, the late brooders eliminated most of the faeces earlier than the early brooders. Experiments using 14 C-labelled algae demonstrated a shorter gut retention time in the larva (6 h) than in the non-brooding adult (10 h). Faeces from larvae contained relatively more chlorophyll a and less phaeopigment than faeces from brooding adults. The data suggest that the digestive system of the larva is much less efficient than that of the adult. Following the introduction of larvae previously fed 14 C-labelled algae into the pallial cavity of the brooding parent, the radiolabel was detected in the faeces of the adult, suggesting that the parent may ingest faeces produced by the larvae. The increase in gut retention time by the adult during the brooding period and the ingestion of larval faeces compensate for the high energy costs associated with the brooding process.

Morphology of mouthparts and feeding habits of Leptonema and Smicridea (Trichoptera: Hydropsychidae) from Gaira river, Sierra Nevada de Santa Marta, Colombia. The genera Leptonema and Smicridea belong to the family Hidropsychidae and constitute one of the most important groups in the nutrient dynamics in the tropical aquatic ecosystems, which diversity of microhabitats is exploited by their larvae. However, there is lack of information concerning the detailed and comparative descriptions of mouthparts between these two genera, and their possible relation with their diet. The aim of this paper was to describe the morphology of the mouthparts and the feeding habits of both genera, in the middle basin of the Gaira River (Sierra Nevada de Santa Marta, Colombia). The samples were collected on a monthly basis, with a surber net, between October and December of 2014, and May of 2015. A total of 15 larvae per genus were taken and the Blue Zen Software was used to determine the morphometric measurements of the cephalic pieces. Measurements were taken on photographs obtained from an AxioCam ERc5s camera adapted to a Nikon SMZ 745T stereoscope. To describe the mouthparts a M205A microscope-stereoscope Leica was used. The dietary habits of 15 individuals in total were evaluated by means of the analysis of stomach contents. A discriminant analysis of Hotelling was applied to the morphometric measurements. There were significant differences in head area (HA), head width (HW3), head length (HL2) and left mandible length (LML). In the morphological descriptions were found differences in: head, labrum and submentum. Dietaries profiles were performed to the stomach contents for both genera and the items with highest percentage for Leptonema was MOPG and MOPF with 38 % and 32 %, respectively, and for Smicridea MOPF (38 %) and MOPG (34 %) with significant differences (F = 8.8298, p < 0.05). This study indicated that the evaluated individuals consume a wide variety of resources and the difference of the diet of both genera can be related to the detected morphological differences. Rev. Biol. Trop. 65 (4): 1231-1244. Epub 2017 December 01.

Diversas especies de mariposas han demostrado sensibilidad a transformaciones de ecosistemas debido a sus asociaciones de alimentación con plantas, razón que ha permitido proponerlas como bioindicadores del estado del hábitat. El objetivo del presente estudio fue evaluar las relaciones entre la fenología reproductiva del bosque seco tropical y la estructura de mariposas diurnas en cinco sitios del departamento del Atlántico-Colombia. En cada sitio las mariposas fueron capturadas con redes entomológicas y con trampas Van Someren-Rydon cebadas con una mezcla de frutas en descomposición. Simultáneamente, se estimó la fructificación y la floración aplicando el método de cuantificación de la cobertura que ocupó cada fenofase. Se registraron 261 mariposas, distribuidas en 28 especies, siendo la más abundante Hamadryas amphichloe con 89 individuos aportando con más del 30 % de la abundancia total. La fenología en 89 individuos de 19 especies de plantas estuvo caracterizada por cuatro fenofases: brotes de frutos, frutos verdes, frutos maduros y flores abiertas. Se observó que la riqueza de mariposas abundantes y dominantes se correlacionaron positivamente con brotes de frutos (p < 0,05). Adicionalmente, con el Análisis de Correspondencia Canónica se determinó que las mayores abundancias de mariposas como Hermeuptychia hermes, Callicore pitheas, Hamadryas feronia y H. amphichloe se relacionaron principalmente con altas proporciones de las fenofases frutos maduros y flor; mientras que Historis acheronta, Hypna clytemnestra y Myscelia leucocyana, mostraron una relación negativa con las dos fenofases mencionadas. Para las mariposas no frugívoras como Agraulis vanillae, Junonia evarete e Isapis agyrtus, se relacionaron principalmente con las mayores proporciones de la fenofase flores abiertas. Los resultados evidencian la posibilidad de una respuesta sincrónica (por ejemplo, coincidencia de eclosiones de mariposas con eventos de floración), por parte de ciertas mariposas a la disponibilidad de algunos recursos, como los frutos en los hábitats estudiados.