ABSTRACT
Resumen Los lagos tropicales de alta montaña presentan condiciones ambientales únicas donde los quironómidos tienen un papel importante en el funcionamiento del ecosistema. Las características de estos ambientes podrían favorecer el solapamiento de dietas y por ende una alta competencia interespecífica. En este estudio se describen los hábitos alimentarios de géneros de quironómidos, se identifica si los hábitos alimenticios son especializados o generalistas y se analiza el solapamiento en la dieta de los géneros. Entre abril y mayo de 2016 se colectaron larvas de Chironomidae de cuatro lagos del páramo de Chingaza. Se evaluó la dieta de larvas, mediante el análisis de contenido estomacal. Se ubicó cada género en gremios tróficos (carnívoro, detritívoro y alguívoro) y se estimó el solapamiento de las dietas entre los géneros mediante el índice de Pianka. Se colectó un total de 1 003 individuos y se identificaron nueve géneros. Las larvas consumieron principalmente materia orgánica particulada fina (MOPF), algas, fragmentos de macrófitas, macroinvertebrados y tejido animal. La MOPF fue la fuente principal de alimento de detritívoros. El análisis de dietas mostró una alta afinidad de cada género con un único gremio trófico y la mayor parte de los géneros son generalistas en el uso de recursos. En todos los lagos se observaron valores altos de solapamiento en la dieta entre los géneros y los gremios tróficos, principalmente entre los detritívoros. Los resultados sugieren que las larvas de Chironomidae presentan hábitos tróficos bien diferenciados, ocurriendo un moderado solapamiento de dietas entre géneros de detritívoros y carnívoros.
Abstract Tropical high mountain lakes show unique environmental conditions where chironomids play an important role in ecosystem functioning. The characteristics of these environments could favor diet overlap and therefore a high interspecific competition. This study described the dietary habits of chironomid genera, identified whether the dietary habits were specialized or generalist, and analyzed the diet overlap in the genera. Chironomidae larvae were collected from four lakes of the Chingaza paramo during the dry season, between April and May of 2 016. The feeding habits of larvae were evaluated by analyzing gut contents following standard methods. Each genus was assigned to trophic guilds (carnivore, detritivore and algivore) and the diet overlap was estimated using the Pianka's index. A total of 1 003 individuals were collected and nine genera were identified. Larvae consumed mainly fine particulate organic matter (FPOM), algae, macrophyte fragments, macroinvertebrates, and animal tissues. FPOM was the main feeding resource of detritivores. The analysis of diets showed a high affinity of each genus for a single trophic guild and most of the genera were generalist in the use of resources. For all lakes, high levels of diet overlap were observed among genera and trophic guilds, mainly among detritivores. Our results suggested that Chironomidae larvae of these lakes presented well differentiated trophic habits, and showed a moderate diet overlap within detritivores and carnivores. Rev. Biol. Trop. 66(1): 136-148. Epub 2018 March 01.
ABSTRACT
Some Pontomyia Edwards, 1926 larvae were sampled associated with algae and sediment at Atol das Rocas, Rio Grande do Norte, Brazil. This is the first record of the genus from South Atlantic Ocean.
Larvas de Pontomyia Edwards, 1926 foram coletadas associadas a algas e sedimento no Atol das Rocas, Rio Grande do Norte, Brasil. Este é o primeiro registro do gênero para o Atlântico Sul.
Subject(s)
Chironomidae , Coasts , Diptera/classification , Ecosystem/analysis , Ecosystem/classification , Insecta , Larva/classificationABSTRACT
Quatro larvas foram coletadas em água retida pelo fungo Aquascypha hydrophora (Berk.) Reid (Fungi: Stereaceae) fixo em troncos de árvores eretas, na Reserva Florestal Adolpho Ducke, Amazonas, Brasil. Das larvas coletadas, apenas um exemplar desenvolveu até a fase adulta, sendo identificado como Polypedilum (Tripodura) amataura Bidawid-Kafka, 1996. Esta é a primeira descrição para uma forma imatura deste gênero, e também o primeiro registro em micotelmata.
Four larvae were collected in water with the fungus Aquascyphahydrophora (Berk.) Reid (Fungi: Stereaceae), fixed in tree trunks found in the Adolpho Ducke Forest Reserve, Amazonas, Brazil. Only one specimem reached the adult phase, which was identified as Polypedilum (Tripodura) amataura Bidawid-Kafka, 1996. This is the first description of an immature form of this genus, and also the first registered in mycotelmata.