scholarly journals Leaf litter as a possible food source for chironomids (Diptera) in Brazilian and Portuguese headwater streams

2007 ◽  
Vol 24 (2) ◽  
pp. 442-448 ◽  
Author(s):  
Marcos Callisto ◽  
José F. Gonçalves Jr ◽  
Manuel A. S. Graça

Our objective was to evaluate the potential use of leaf detritus by chironomid larvae. Field and laboratory experiments were performed using leaves and chironomid species collected in Portugal and Brazil. Laboratory experiments under controlled conditions were done using microbial conditioned senescent leaves of Alnus glutinosa (L.) Gaertn, Neriumoleander L., Protium heptaphilum (Aubl.) March, Protium brasiliense (Spreng) Engl., Myrcia guyanensis(Aubl.) DC and Miconia chartacea Triana. Laboratory experiments were performed using specimens collected from leaf litter in local streams. Whenever possible, after the experiments, chironomids were allowed to emerge as adults and identified. In Portugal the following taxa were identified: Micropsectra apposita (Walker, 1856), Polypedilum albicorne (Meigen, 1838),Eukiefferiella claripennis Lundbeck (1898), Rheocricotopus (Psilocricotopus) atripes Rempel (1937) and Ablabesmyia Johannsen (1905) (Diptera, Chironomidae). Consumption rates ranged from 0.15 ± 0.10 mg (AFDM) of leaf animal-1 day-1 (Micropsectra apposita feeding on Alnus glutinosa) up to 0.85 ± 0.33 mg (AFDM) of leaf animal-1 day-1 (Polypedilum albicorne feeding on Miconia chartacea). In Brazil, the following taxa were identified from leaves: Phaenopsectra sp., Chironomus spp. and Polypedilum sp. and maximum consumption rates reached 0.47 ± 0.28 (AFDM) of leaf mg.animal-1.day-1 (Chironomus Meigen (1803) feeding on Protium heptaphilum). Feeding experiments with laboratory cultured specimens, revealed that some chironomids were unable to feed on decomposing leaves (e.g., C. xanthus Rempel (1939) on P.brasiliensis and M.guyanensis). Our results suggest that some stream chironomids (not typical shredders) can use leaf litter of riparian vegetation as a complementary food source.

2015 ◽  
Vol 66 (8) ◽  
pp. 750 ◽  
Author(s):  
Leandro Bergamino ◽  
Nicole B. Richoux

Feeding by sesarmid crabs on plants represents an important energy pathway within some estuarine ecosystems. We examined the trophic ecology of estuarine sesarmid crabs Sesarma catenata through a series of laboratory feeding-preference experiments. Our experiments considered decomposed and mature leaves of terrestrial riparian trees, marsh plants Chenolea diffusa and Sarcocornia perennis and the marshgrass Spartina maritima as potential food items. S. catenata preferred decomposed leaves of terrestrial riparian trees, followed by decomposed and mature leaves of S. maritima. We suggest that the low carbon:nitrogen (C:N) ratios of S. maritima and high bacterial production associated with decomposed terrestrial leaves may explain the trophic behaviour of S. catenata. The faecal production by S. catenata during these experiments confirmed the preferential assimilation of decomposed material by the crabs. By combining the consumption rates with an estimated density of S. catenata within the local estuary that it inhabits, we suggest that moderate proportions of the leaf material can potentially be consumed by this species (34% of total leaf litter), leaving substantial amounts of unconsumed leaf litter that may represent an important subsidy for adjacent environments. Our results validate previously published trophic data, showing the value of linking feeding experiments with biological tracers to improve food-web models.


Zoosymposia ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 39-53
Author(s):  
MARTA GELLERT ◽  
KATARZYNA KWIATKOWSKA ◽  
JANUSZ MAJECKI

In field and laboratory experiments, we assessed the role of caddisfly larvae in leaf decomposition occurring in headwaters with a focus on the breakdown of alien Quercus rubra leaves. A field experiment was conducted at two sites: in Wolbórka Spring and 150 m downstream. Eight 0.5 x 0.5 m “mats” were constructed. 1m2 of one type of fallen leaves: Quercus robur, Acer pseudoplatanus, Quercus rubra and Alnus glutinosa was placed in each mat. The caddisfly assemblages on the leaf mats consisted of 550 shredder larvae and 394 predatory larvae of Plectrocnemia conspersa. Among the 4 shredder species in both years, the larvae of P. nigricornis dominated on all leaf species at both sites. In the laboratory experiment, ten Vth instar larvae of Potamophylax nigricornis were placed in to each of four square (30 x 30 cm) boxes containing 500 cm2 of Q. robur, A. pseudoplatanus, Q. rubra and A. glutinosa leaves. The length of time of leaf decomposition was measured in the laboratory. The fastest loss of leaf surface was noted with respect to A. glutinosa (in the field as well as in the laboratory). Shredders collected from Q. rubra mats were numerous and the breakdown rate of leaf litter in the field as well as in the laboratory experiments was similar to Q. robur and A. pseudoplatanus. The number of caddis corresponded with the time of decomposition, which in 2014 was 20 days shorter than in 2013.


Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1080 ◽  
Author(s):  
Masoud M. Ardestani ◽  
Vladimír Šustr ◽  
Jan Frouz

The present study was performed to assess the feeding performance of five detritivore species in a microcosm design. The test animals were four millipede species, Telodeinopus aoutii (Demange), Epibolus pulchripes (Gerstäcker), Cylindroiulus caeruleocinctus (Wood), Glomeris hexasticha (Brandt), and one isopod species, Porcellio scaber (Latreille), all feeding on Alnus glutinosa L. leaf litter for five consecutive weeks. At the end of each one-week interval, litter consumption, animal fresh weight, and excrement production were measured. Then, the feeding activity parameters for each species were calculated. Between big-size animal species, higher leaf consumption rates of 12.3–30.9 mg dry weight day−1 individual−1 were calculated for T. aoutii compared to those of 3.72–8.25 mg dry weight day−1 individual−1 for E. pulchripes. However, there was no difference in the consumption rates among small-size animals ranging from 0.46 to 1.65 mg dry weight day−1 individual−1. Excrement production rates followed a similar trend, as the consumption rates and the animals’ body weight remained constant during the experiment. Time was an important factor influencing the feeding activity of the animals, especially for the big-size group. Overall, the average assimilation efficiency of these species varied from 13.7% to 53.3%. The results of the present work will be the first step for understanding the ecological needs of these decomposer species in soil ecosystems.


1995 ◽  
Vol 52 (5) ◽  
pp. 925-935 ◽  
Author(s):  
Edward L. Mills ◽  
Connie Adams ◽  
Robert O'Gorman ◽  
Randall W. Owens ◽  
Edward F. Roseman

The objective of this study was to describe the diet of young-of-the-year and adult alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) in nearshore waters coincident with the colonization of Lake Ontario by Dreissena. Laboratory experiments and field observations indicated that alewife and rainbow smelt consumed dreissenid veligers and that the veligers remained intact and identifiable in the digestive tract for several hours. Dreissenid larvae were found in field-caught alewife and rainbow smelt in August 1992, even though veliger densities were low (<0.1/L). Zooplankton dominated the diet of all fish and veliger larvae were <0.1% of the biomass of prey eaten by these fish. Density of veligers and the distribution of settled dreissenids declined from west to east along the south shore of Lake Ontario. Based on veliger consumption rates we measured and the abundance of veligers and planktivores, we conclude that planktivory by alewife and smelt in the nearshore waters of Lake Ontario did not substantially reduce the number of veligers during 1991–1993. However, our results indicate that if the density of veligers in Lake Ontario decreases, and if planktivores remain abundant, planktivory on veliger populations could be significant.


2013 ◽  
Vol 6 (3) ◽  
pp. 173-177 ◽  
Author(s):  
Rodrigo Aranda

A configuração do habitat é um dos fatores que pode influenciar a distribuição dos organismos. O pantanal por apresentar mosaico natural de formações se enquadra para testar tais afirmações. O presente estudo teve como objetivo avaliar se a distância e o tamanho de capões afetam a composição da comunidade de artrópodes testando a hipótese de que quanto maior e mais próximo o capão da mata ciliar, maior sua diversidade. Foram amostradas seis parcelas de 30 cm² em nove capões onde a serrapilheira e o solo foram coletados, acondicionados em sacos plásticos e posteriormente triados. Houve relação entre a composição da comunidade de artrópodes em relação à distância e o tamanho indicando que o pulso de inundação do último ano afetou de forma significativa a comunidade de artrópodes de solo em capões. O acompanhamento dos processos de recolonização dos capões é sugerido. Capons as Island for Arthropods in Pantanal Abstract. The configuration of habitat is one of the factors that influence the distribution of organisms. The Pantanal by presenting mosaic natural formations fit to test such claims. The present study aimed to evaluate the distance and size of riparian capons affect the community composition of arthropods tested the hypothesis that the higher and closer to the capon of riparian vegetation, the greater its diversity. We sampled six plots of 30 cm² in nine capons where the leaf-litter and soil were collected, placed in plastic bags and later sorted. There was a relationship between the composition of arthropod community in relation to distance and size indicating that the flood pulse of the last year significantly affected the community of soil arthropods in geldings. The monitoring of the processes of recolonization of the capons is suggested.


Nematology ◽  
2020 ◽  
pp. 1-9
Author(s):  
Žiga Laznik ◽  
Ivana Majić ◽  
Stanislav Trdan ◽  
Antoinette P. Malan ◽  
Annika Pieterse ◽  
...  

Summary In the period from August to October 2018, 140 specimens of the Spanish slug, Arion vulgaris, were collected from Podbrezje, Slovenia. Slugs were dissected and examined for the presence of parasitic nematodes within the cadavers. Identification of the nematodes was conducted using morphological and molecular techniques and confirmed the presence of Phasmarhabditis papillosa. This is the first record of P. papillosa from the mollusc host, A. vulgaris. Laboratory experiments aimed at testing the efficacy of P. papillosa against A. vulgaris were conducted using nematodes grown in vivo. Nematodes were applied at concentration rates of 50, 100 and 200 nematodes slug−1, respectively. Three weeks following treatment, the mortality of slugs was confirmed in all treatments (50 nematodes slug−1, 37.4 ± 2.7%; 100 nematodes slug−1, 48.4 ± 2.7%; 200 nematodes slug−1, 50.6 ± 2.7%). However, the pathogenesis of P. papillosa was observed first in the treatments with the lowest nematode dose at 4 days after treatments, while a decrease in the feeding behaviour of slugs was noted first in the treatments with the highest nematode dose. Future opportunities for the potential use of P. papillosa as a biological control agent against slugs are discussed. This is the first report of P. papillosa from Slovenia, and of its virulence against A. vulgaris.


2003 ◽  
Vol 117 (4) ◽  
pp. 601 ◽  
Author(s):  
Kyle Hamish Elliott ◽  
Christina L. Struik ◽  
John E. Elliott

We observed Bald Eagles feeding on Plainfin Midshipman near Crescent Beach, British Columbia, in May and June 2001 and 2002. We quantified consumption rates and eagle numbers during this period, illustrating the potential importance of this food source to breeding eagles. Tide height was the only significant factor influencing consumption rates, likely because this variable reflected the availability of midshipman prey.Nous avons observé les Pygargues à tête blanche alimenter sur les Crapauds à nageoire unie près de Crescent Beach, Colombie-Britannique, en maie et juin 2001 et 2002. Nous avons mesuré les cadences de consommation et les nombres de pygargues pendant cette période, illustrant l’importance potentielle de cette source de nourriture pour les aigles. La taille de marée était le seul facteur significatif influençant les cadences de consommation et les nombres de pygargues pendant la période d’étude, probablement parce que cette variable a reflété la disponibilité des crapauds.


2018 ◽  
Vol 166 ◽  
pp. 73-77
Author(s):  
O. Carrillo-Muro ◽  
R.G. Ramírez-Lozano ◽  
A.S. Castro-Rosales ◽  
P. Hernández-Briano ◽  
M.A. López-Carlos ◽  
...  

2015 ◽  
Vol 105 (9) ◽  
pp. 1191-1197 ◽  
Author(s):  
Miguel A. Redondo ◽  
Johanna Boberg ◽  
Christer H. B. Olsson ◽  
Jonàs Oliva

During the last century, the number of forest pathogen invasions has increased substantially. Environmental variables can play a crucial role in determining the establishment of invasive species. The objective of the present work was to determine the correlation between winter climatic conditions and distribution of two subspecies of the invasive forest pathogen Phytophthora alni: P. alni subspp. alni and uniformis killing black alder (Alnus glutinosa) in southern Sweden. It is known from laboratory experiments that P. alni subsp. alni is more pathogenic than P. alni subsp. uniformis, and that P. alni subsp. alni is sensitive to low temperatures and long frost periods. By studying the distribution of these two subspecies at the northern limit of the host species, we could investigate whether winter conditions can affect the geographical distribution of P. alni subsp. alni spreading northward. Sixteen major river systems of southern Sweden were systematically surveyed and isolations were performed from active cankers. The distribution of the two studied subspecies was highly correlated with winter temperature and duration of periods with heavy frost. While P. alni subsp. uniformis covered the whole range of temperatures of the host, P. alni subsp. alni was recovered in areas subjected to milder winter temperatures and shorter frost periods. Our observations suggest that winter conditions can play an important role in limiting P. alni subsp. alni establishment in cold locations, thus affecting the distribution of the different subspecies of P. alni in boreal regions.


1982 ◽  
Vol 39 (1) ◽  
pp. 203-208 ◽  
Author(s):  
Scott D. Cooper ◽  
Charles R. Goldman

Mysis relicta was fed Epischura nevadensis late instars or Diaptomus tyrrelli males in a series of feeding experiments. Mysis clearance rates were not affected by the time of day mysids were collected, the time of day experiments were conducted, or conditioning of experimental water by predators and prey. Mysis fed as efficiently in the dark as in bright light, and exhibited increasing clearance rates with increasing container size. When Diaptomus males were used as prey Mysis clearance rates were significantly higher at 5 °C than 10 and 15 °C; temperature did not affect clearance rates with Epischura as prey. Mean clearance rates tended to decline with increasing prey density, but the only significant differences were recorded when Epischura was used as prey. Prior acclimation to experimental light and temperature conditions had no effect on the results. When presented with an abundant food supply, freshly collected Mysis fed at initially low rates. Subsequent feeding rate peaks were followed by feeding rate declines to low levels over a 24-h period. Individual Mysis consumption rates remained relatively constant from day to day.Key words: Mysis relicta, predation, copepods, clearance rates, opossum shrimp


Sign in / Sign up

Export Citation Format

Share Document