Tuesday, December 20, 2016

Macrolatinos@ Noticias de diciembre

Congresos


XVI Congresso Brasileiro de Limnologia
23 - 27 de Julio 
Rio de Janeiro, Brasil


Simposio sobre urbanización y ecosistemas de río (SUSE)
SUSE4: Making urban stream rehabilitation a co-evolutionary process
Mayo 31 - Junio 3
Carolina del Norte, EEUU




Oportunidades de estudio / trabajo


15 Doctorados en Alemania
Temas diversos
Fecha límite solicitud: 9 de enero de 2017
(Via M. Kuemmerlen)
(Enlace)

Doctorado en Reino Unido
Impacto de eventos climáticos extremos en redes tróficas dulceacuícolas
Fecha límite solicitud:23 de enero de 2017
(Via M. Kuemmerlen)
(Enlaces 1 y 2)

Postdoc en España

River connectivity
Fecha límite: 06 de enero 2017



Publicaciones

Crumiére, A. J., Santos, M. E., Semon, M., Armisen, D.,Moreira, F. F.,& Khila, A. (2016). Diversity in Morphology and Locomotory Behavior is Associated with Niche Expansion in the Semi-aquatic Bugs. Current Biology 26:1-7.
(Enlace)

Martins, T., Moreira, F. F., Mercado, J. & Santiago-Blay, J. A. (2016). Lecto- and Paralectotype Designations and Redescription of Arachnocoris alboannulatus Costa Lima, 1927 (Hemiptera: Heteroptera: Nabidae). Life: The Excitement of Biology 4(3):165-173.
(Via F. Moreira, ppmeiameiameia@gmail.com


Cardona-Rivera, G.A. & A. Ramírez. (2016) Predation of Telebasis vulnerata (Odonata: Coenagrionidae) eggs by detritivorous caddisfly larva, Phylloicus pulchrus (Trichoptera: Calamoceratidae). International Journal of Odonatology 19(4): 253-256.
(Via A. Ramirez, aramirez@ramirezlab.net

Nota - Con mucho gusto compartimos los trabajos que nos hacen llegar a aramirez@ramirezlab.net o a limarie.reyes1@upr.edu (Asunto: Macrolatinos).




Comentario 


Efemerópteros y la fragmentación de la hojarasca
Por:
Tim Moulton y co-autores Claudia Andrade and Vinicius Neres-Lima

Una nota sobre la importancia de los insectos en el procesamiento de la hojarasca, aún cuando no sean fragmentadores según el concepto de grupos funcionales.

There has long been interest in macroinvertebrate shredders – almost perhaps to the degree of obsession amongst stream ecologists. The processes of tearing, masticating, mining and generally converting larger pieces of leaves into small pieces appears to be important in many northern hemisphere and higher latitude streams. Some of the early work in tropical American streams seemed to reveal a lack of shredders, or at least a lack of the classical shredders of temperate streams (Irons et al. 1994). With further work, the picture has become more complex, and there seems to be a variety of conditions of shredder diversity and shredding in different tropical streams (Boyero et al. 2015). Certainly Magnolia Longo found an abundance of shredders in her study at Isla Gorgonia and came up with an unusual and important shredder – cockroaches (Longo and Blanco 2014).


I will not continue on this general theme, but I would like to draw attention to our latest research, which has apparently revealed the shredding activity of a not “classical” shredder group – leptophlebiid ephemeropterans. I mentioned this work at the meeting in Santa Marta (3er Congreso Latinoamericano de Macroinvertebrados de Agua Dulce, marzo de 2016) and Wills Flowers gave me some interesting feedback – that he had been shown Ulmeritoides apparently sclerotizing leaves. Following up on this I found mention of shredding and scraping in Leptophlebiidae, and particularly in the subfamily Atalophlebiinae (Polegatto and Froehlich 2003). See also (Bello and Cabrera 2001).

Here is a brief summary of our work – it should be published soon (Andrade et al. 2016). We researched the effects of shrimps (Macrobrachium and Potimirim ) and insects on leaf processing. We selectively excluded the shrimps and the insects by using electricity at different intensities – low intensity excluded only the shrimps, high intensity excluded the medium and large-sized insects as well as the shrimps. We found, to our surprise, that the low-intensity exclusion had almost 2x the rate of leaf processing compared to the control and the high-intensity. We concluded that this could be caused by a trophic cascade of the shrimps inhibiting the insect shredders. That is, when the shrimps were excluded the insect shredders acted more strongly in processing leaves. 

Our next question was – who were the shredders who were making this difference? This was not obvious from our results. The “classical” trichopteran shredders Triplectides and Phylloicus were quite rare and embarrassingly were more common in the high-intensity electrification – where they were supposed to be excluded. The mining chironomid Stenochironomus was common, but its pattern of abundance did not coincide with the leaf processing. On the other hand, leptophlebiid ephemeropterans were common and almost significantly more abundant in the low-intensity treatment – corresponding with the faster leaf processing. Thus we propose that they were the agents for the faster leaf processing. The principal genera present at the site, Farrodes, Miroculis and Askola are commonly found in leaf litter. They also have a stable-isotope signature which indicates that they assimilate allochthonous material (Neres-Lima et al. 2016).

We find it very interesting that this group apparently causes shredding – it seems to scrape surfaces and perhaps is not so much of a “tearing” shredder, but a scraping shredder. We really need more observations and a more detailed look at the different genera involved. We also find it fascinating that this effect was only revealed when we excluded the shrimp, which apparently cause a very strong trophic cascade – similar to the result we found with periphyton on hard substrate with baetid ephemeropterans and shrimps (Moulton et al. 2015).
We would like to hear from other Latin-American stream ecologists who have had similar experiences – either with leptophlebiids or with other “not-classical” shredders.

Tim Moulton (and co-authors Claudia Andrade and Vinicius Neres-Lima)
moulton.timothy@gmail.com
Rio de Janeiro, December 2016. 


References:

  • Andrade, C. M., V. Neres-Lima, and T. P. Moulton. 2016. Differentiating the roles of shrimps and aquatic insects in leaf processing in a Neotropical stream. Marine and Freshwater Research.
  • Bello, C. L., and M. I. Cabrera. 2001. Alimentación ninfal de Leptophlebiidae (Insecta: Ephemeroptera) en el Caño Paso del Diablo, Venezuela. Revista de Biologia Tropical 49:999-1003.
  • Boyero, L., R. G. Pearson, M. O. Gessner, D. Dudgeon, A. Ramírez, C. M. Yule, M. Callisto, C. M. Pringle, A. C. Encalada, M. Arunachalam, J. Mathooko, J. E. Helson, J. Rincón, A. Bruder, A. Cornejo, A. S. Flecker, C. Mathuriau, C. M´Erimba, J. F. Gonçalves Jr, M. Moretti, and T. Jinggut. 2015. Leaf-litter breakdown in tropical streams: is variability the norm? Freshwater Science 34:759-769.
  • Irons, J. R., M. W. Oswood, R. J. Stout, and C. M. Pringle. 1994. Latitudinal patterns in leaf litter breakdown: is temperature really important? Freshwater Biology 32:401-411.
  • Longo, M., and J. F. Blanco. 2014. Shredders are abundant and species-rich in tropical continental-island low-order streams: Gorgona Island, Tropical Eastern Pacific, Colombia. Int. J. Trop. Biol. 62:85-105.
  • Moulton, T. P., C. Lourenço-Amorim, C. Y. Sasada-Sato, V. Neres-Lima, and E. Zandonà. 2015. Dynamics of algal production and ephemeropteran grazing of periphyton in a tropical stream. International Review of Hydrobiology 100:61-68.
  • Neres-Lima, V., E. F. Brito, F. A. M. Krsulović, A. M. Detweiler, A. E. Hershey, and T. P. Moulton. 2016. High importance of autochthonous basal food source for the food web of a Brazilian tropical stream regardless of shading. International Review of Hydrobiology 101:132-142.
  • Polegatto, C. M., and C. G. Froehlich. 2003. Feeding strategies in Atalophlebiinae (Ephemeroptera: Leptophlebiidae), with considerations on scraping and filtering. Pages 55-61 in E. Gaino, editor. Research update on Ephemeroptera & Plecoptera. Università di Perugia, Perugia.





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