A new species of Buenoa Kirkaldy (Hemiptera, Heteroptera, Notonectidae) from Rio de Janeiro, Brazil

Members of Buenoa are restricted to the Western Hemisphere, with the greatest diversity of species in South America. There are about 50 described species and approximately 20 of them have been reported from Brazil. Buenoa pseudomutabilis Barbosa, Ribeiro and Nessimian, sp. nov. is described here from Maricá, Rio de Janeiro State. This species resembles B. mutabilis Truxal, 1953 because males have a stridulatory area on inner surface of forefemur, forefemur narrowed at apex, with length more than three times its width at apex, and rostral prong longer than third rostral segment. Males of B. pseudomutabilis sp. nov. can be readily recognized by the presence of 21 to 25 teeth in the stridulatory comb of foretibia, whereas in B. mutabilis the stridulatory comb of foretibia consists of approximately 33 to 38 teeth. Males of B. pseudomutabilis sp. nov. bear one nodule on each ventral laterotergite 1 of abdomen. A key to male species of Buenoa occurring in Rio de Janeiro State, including the new species, is provided.

Spermatogenesis of riffle bugs, Rhagovelia whitei and Rhagovelia sp (Veliidae), and backswimmers Martarega sp (Notonectidae).

We examined the course of spermatogenesis and the meiotic chromosome complements in aquatic species of true bugs, Heteroptera. The chromosome complement of the Veliidae species was 2n = 39 (38A + X0) and 23 (22A + X0) in Rhagovelia whitei and Rhagovelia sp, respectively, and in the species of the Notonectidae (Martarega sp) it was 26 (22A + 2m + XY); all collected from the region of São José do Rio Preto, SP, Brazil. An impressive characteristic of the first analysis was the size of the cells belonging to Martarega sp, which were six times larger than the same cells in Pentatomidae and twice as large as the cells in aquatic Heteroptera (Gerridae). Regarding spermatogenesis, all the species analyzed showed the same pattern: holocentric chromosomes and elongated spermatids with the chromatin distributed evenly along the head. The family Veliidae showed several bodies impregnated with silver nitrate at prophase, while the family Notonectidae displayed only one. The cells of Notonectidae also showed an evident and round body until the end of prophase I and in the family Veliidae the silver-impregnated bodies were disorganized, where the only region visualized was possibly that of the NOR. In metaphase, silver-stained regions were found at the periphery of all chromosomes in Veliidae and at the periphery of some chromosomes in Notonectidae. The spermatids of Veliidae showed a less silver-impregnated vesicle, while Notonectidae showed silver staining only in part of the nuclear membrane. Therefore, families of Heteroptera have some differences and features that can help identify and classify these species.

Relacionamento filogenético entre espécies pertencentes às famílias Belostomatidae, Gelastocoridae, Gerridae, Notonectidae, Veliidae (Hemiptera: Heteroptera) e Cercopidae (Hemiptera:Auchenorrhyncha)

Pós-graduação em Genética - IBILCE

Spermatogenesis of riffle bugs, Rhagovelia whitei and Rhagovelia sp (Veliidae), and backswimmers Martarega sp (Notonectidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cytogenetics Analysis and Testis Morphology of Aquatic Species of the Families Belostomatidae, Gelastocoridae, Gerridae, Notonectidae, and Veliidae (Heteroptera)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Spermatogenesis and nucleolar behavior in males of aquatic Heteroptera

Aspects of spermatogenesis and nucleolar behavior were analyzed in Brachymetra albinerva, Cylindrostethus palmaris, Halobatopsis platensis, Limnogonus aduncus (Gerridae), Martarega sp (Notonectidae), Rhagovelia whitei, and Rhagovelia sp (Veliidae). The testicles are rounded (Veliidae), elongated (Gerridae) or spiral (Notonectidae) and have a transparent membrane covering them. The complement chromosome was 2n = 23 (22A + X0, L. aduncus and Rhagovelia sp), 25 (24A + X0, B. albinerva and H. platensis), 26 (22A + 2m + XY, Martarega sp), 29 (28A + X0, C. palmaris), or 39 (38A + X0, R. whitei) chromosomes, and the only species with a different sex chromosome system was Martarega sp, which showed an XY system and m-chromosomes. The meiotic behavior of all species was similar: holocentric chromosomes and heteropyknotic material at prophase, interstitial and/or terminal chiasmata, and first reductional division for the autosomes and the reverse for the sex chromosomes. The only difference observed was related to the very large size of Martarega sp cells in all stages of spermatogenesis. With regard to nucleolar behavior, the species did not show differences, except for Martarega sp with larger nucleoli than the other species. The only species in which it was clearly possible to identify the nucleolar organizer region was L. aduncus, in the region of a terminal autosome. It was also confirmed that the telomeric associations do not occur at random. In the other species, specific staining was very discrete, and the nucleolar organizer region location was not at all evident.

Espermatogênese e comportamento nucleolar em machos de Heteoptera aquáticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Macroinvertebrate abundance and proportion of trait categories in river biotopes across England and Wales

There is a long tradition of river monitoring using macroinvertebrate communities to assess environmental quality in Europe. A promising alternative is the use of species life-history traits. Both methods, however, have relied on the time-consuming identification of taxa. River biotopes, 1-100 m**2 'habitats' with associated species assemblages, have long been seen as a useful and meaningful way of linking the ecology of macroinvertebrates and river hydro-morphology and can be used to assess hydro-morphological degradation in rivers. Taxonomic differences, however, between different rivers had prevented a general test of this concept until now. The species trait approach may overcome this obstacle across broad geographical areas, using biotopes as the hydro-morphological units which have characteristic species trait assemblages. We collected macroinvertebrate data from 512 discrete patches, comprising 13 river biotopes, from seven rivers in England and Wales. The aim was to test whether river biotopes were better predictors of macroinvertebrate trait profiles than taxonomic composition (genera, families, orders) in rivers, independently of the phylogenetic effects and catchment scale characteristics (i.e. hydrology, geography and land cover). We also tested whether species richness and diversity were better related to biotopes than to rivers. River biotopes explained 40% of the variance in macroinvertebrate trait profiles across the rivers, largely independently of catchment characteristics. There was a strong phylogenetic signature, however. River biotopes were about 50% better at predicting macroinvertebrate trait profiles than taxonomic composition across rivers, no matter which taxonomic resolution was used. River biotopes were better than river identity at explaining the variability in taxonomic richness and diversity (40% and <=10%, respectively). Detailed trait-biotope associations agreed with independent a priori predictions relating trait categories to near river bed flows. Hence, species traits provided a much needed mechanistic understanding and predictive ability across a broad geographical area. We show that integration of the multiple biological trait approach with river biotopes at the interface between ecology and hydro-morphology provides a wealth of new information and potential applications for river science and management.