/ Laboratório de Biologia e Cultivo de Peixes de Água Doce
Universidade Federal de Santa Catarina
Centro de Ciências Agrárias
Departamento de Aqüicultura
Rodovia SC 406, 3235  Armação
Florianópolis  Santa Catarina
Caixa Postal 476  CEP 88040-900 / Telefones: (48) 389-5216 e 389-5425
Fax: (48) 389-5216
e-mail:

July26st 2011.

Dr. David L. G. Noakes, Environmental Biology of Fishes Editor

Re.:Environmental Biology of Fishesarticle submission

Dear Dr. Noakes:

We are sending thisrevised manuscript entitled “Spatial and temporal variation of the ichthyoplankton in a subtropical river in Brazil” to be considered for publication in the journalEnvironmental Biology of Fishes.

Please contact me if you need any further information.

Thanks for your time and consideration.

Sincerely,

David A. Reynalte-Tataje, Dr.

The revision considers the aspects listed below:

Referee #1:

Comments to reviewer: The statistical analysis is very confusing and the multiple ANOVAs should be combined into a single analysis that separate the effects of the main factors and covariates. I wondered why time of day was not included until I saw that this was analysed in the previous paper. These patterns need to be acknowledged in the analysis and these differences taken into account. Reply: Following the suggestions, a single ANOVA was used, showing the same results. When comparing both approaches we understood that separating the analysis allows a better view and comprehension of the results. In this way, we kept the initial statistical analysis. The aim of this paper is verify the icthyoplankton variation in a year, and not the daily variation, that is already discussed in the paper “Spatial and Temporal variation of the ichthyoplankton in a subtropical region of Brazil”. However, some adjustments were made in the methodology for a better understanding of the aim of this study.

Comments to reviewer: More details of the sampling regime need to be included, such as the dimensions of the net used, it's sampling depth and the spatial position within each site. Some details on river depth and substrate would also be helpful as these could influence the fauna present. Reply: As requested, a better explanation about the sampling method and the characteristics of the sites was made.

Comments to reviewer: There are also scant details on the instruments and methods of sampling of the physical data - where were the samples taken, how did these vary spatially in relation to the plankton sampling etc. Reply: As requested, a better explanation about the used instruments and the sampling method relating to the physical data was made.

Comments to reviewer: The discussion is very local in context and in order for it to be of interest to an international audience, the results need to be compared with those from upper reaches of other rivers from similar latitudes. Reply: The discussion was modified, reducing the local information, and adding studies that apply other river basins.

Comments to reviewer: The size (and age) of larvae should also be presented along with egg sizes as the mesh size is quite large for studies of fish eggs and many eggs could have been lost through the meshes. the size of larvae will also help understand if spawning is local or potentially 10s of km upstream from the sampling sites. How larval size varies temporally will also narrow down the period of peak reproduction. Reply: The point presented by the referee was very relevant and important. A hard work was demanded to carry out this job (classifying the larvae), but it was done. However we consider that classifying the stage of larval development is more relevant than classifying the icthyoplankton according to their size, since, depending on the specie, a certain size can indicate a yolk sack larva or a larva that is almost a juvenile. The use of different stages of larval and embryonic development to determine spawning and nurseries’ areas is an often used tool (Nakatani et al. 2001). The mesh size (500 µm) used in the plankton net prevents the passage of eggs and larvae of any species that inhabit the upper Uruguay river (Reynalte-Tataje e Zaniboni-Filho, 2008). This size of the mesh is commonly used in studies relating to ichthyoplankton at the Plata basin (Nakatani et al. 2001; Bialetzki et al. 2005).

Comments to reviewer: All F-values reported in the results should have the appropriate degrees of freedom and effect interactions appear to have been ignored, whereas previously you report significant interaction effects with the same data. This needs to be rectified. February. Reply: This request was made.

Editor´s Note:

Comments to editor: The major concerns about duplication of publication MUST be addressed. Use of previously published material requires approval of the copyright holder (probably the journal) and acknowledgement in the text that the material has been previously published. Reply: In annex we send a copy of the digital letter from TECPAR (Brazilian Archives of Biology and Technology) indicating that there is no problem about the publication of the article “Spatial and temporal variation of the ichthyoplankton in a subtropical river in Brazil” (View appendix).

REFERENCES

Bialetzki A, Nakatani K, Sanches PV, Baumgartner G, Gomes LC (2005) Larval fish assemblage in the Baía River (Mato Grosso do Sul State, Brazil): temporal and spatial patterns. Environmental Biology of Fishes 73:37-47.

Nakatani K, Agostinho AA, Baumgartner G, Bialetzki A, Sanches PV, Makrakis MC (2001) Ovos e larvas de peixes de água doce: desenvolvimento e manual de identificação. Editora EDUEM, Maringá.

Reynalte-Tataje DA, Zaniboni-Filho E (2008) Biologia e identificação de ovos e larvas de peixes do alto rio Uruguai. Brasil. In: Zaniboni Filho E, Nuñer APO (eds) Reservatório de Itá. Estudos ambientais, desenvolvimento de tecnologias de cultivo e conservação da ictiofauna, Editora UFSC, Florianópolis, pp. 139-154.

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