Amphibian parasites of the Order Dermocystida (Ichthyosporea) are widespread pathogens known mainly from Europe and North America, which cause primarily a disease of skin and subcutaneous tissue in their hosts. The taxonomy of these organisms has been problematic given their conserved morphology, similar clinical disease and pathology. Currently recognized taxa belong to the three closely related genera, Amphibiocystidium, Amphibiothecum, and Rhinosporidium, whereas species of Dermocystidium and Sphaerothecum destruens include fish parasites. Here, we review the taxonomy of Dermocystida based on a molecular phylogenetic analysis, principally of amphibian parasites, including DNA sequences obtained from amphibian hosts collected in the central-eastern region of South America. A new taxonomic arrangement is proposed, which includes the designation of type material for Dermocystidium pusula, synonymization of Amphibiothecum with Dermocystidium, and the restriction of Amphibiocystidium to its type species A. ranae. We also review the taxonomic status of Dermosporidium hylarum until the present work included in the synonymy of the human and animal pathogen R. seeberi, and considered herein as a valid taxon, however. In addition, a new species of Sphaerothecum parasitic to amphibians is described, being the first record of this genus in the southern hemisphere and in an amphibian host.

Melanophryniscus orejasmirandai is a species of toad known only from two localities in southern Uruguay. This toad isthe southernmost suggested taxon of the M. tumifrons group, whose species are characterized by a glandular frontal swell-ing on the snout. The study of the type series of M. orejasmirandai and of M. pachyrhynus, along with observations madeon many specimens of both species suggested a close relationship between them. The analysis of the variation of snout-vent length, coloration pattern, relative size of the frontal swelling, and presence/absence of the metatarsal gland showedthat characters previously used to separate both species resulted of no diagnostic value. Further comparison of the externalmorphology, osteological characters, and partial sequences of the cytochrome b gene indicated that M. orejasmirandai isa junior synonym of M. pachyrhynus. Melanophryniscus pachyrhynus is characterized by a reticulated orange ventral pat-tern which is shared only with M. peritus, from which it differs by its smaller size. The ornamentation of the nasal bonesunderlying the frontal swelling in M. pachyrhynus seems to be characteristic of the M. tumifrons group. An updated distribution map of M. pachyrhynus and some new localities are also provided.

The cultivation of genetically modified (GM) Bt maize (Zea mays L.) events MON810 and Bt11 is permitted in Uruguay. Local regulations specify that 10% of the crop should be a non-GM cultivar as refuge area for biodiversity, and the distance from other non-GM maize crops should be more than 250 m in order to avoid crosspollination. However, the degree of cross-fertilization between maize crops in Uruguay is unknown. The level of adventitious presence of GM material in non-GM crops is a relevant issue for organic farming, in situ conservation of genetic resources and seed production. In the research reported here, the occurrence and frequency of cross-fertilization between commercial GM and non-GM maize crops in Uruguay was assessed. The methodology comprised field sampling and detection using DAS-ELISA and PCR. Five field-pair cases where GM maize crops were grown near non-GM maize crops were identified. These cases had the potential to cross-fertilize considering the distance between crops and the similarity of the sowing dates. Adventitious presence of GM material in the offspring of non-GM crops was found in three of the five cases. Adventitious presence of event MON810 or Bt11 in non-GM maize, which were distinguished using specific primers, matched the events in the putative sources of transgenic pollen. Percentages of transgenic seedlings in the offspring of the non-GM crops were estimated as 0.56%, 0.83% and 0.13% for three sampling sites with distances of respectively 40, 100 and 330 m from the GM crops. This is a first indication that adventitious presence of transgenes in non-GM maize crops will occur in Uruguay if isolation by distance and/or time is not provided. These findings contribute to the evaluation of the applicability of the "regulated coexistence policy" in Uruguay.

In this paper we examine a new distance-based method for identifying and characterizing possible interactions between biological structures and objects, with respect to the initial developmental stages of Echinococcus granulosus . By adopting the surface of the foramen as the distance reference, several interesting results have been identified, including the fact that the cell nuclei tend to be organized with respect to the foramen surface as well as the stability of the spatial distribution of these nuclei along the development stages.

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We describe the external morphology, buccal cavity, chondrocranium, hyobranchial skeleton and musculature of the tadpole of R. achavali, along with its karyotype. Tadpoles were found in a permanent streamlet, showing schooling behavior. External larval morphology seems to be much conserved in Rhinella, not helping in the characterization of the proposed species groups. Buccal cavity morphology confirms the distinctiveness of the R. veraguensis group with respect to other known Rhinella. Musculoskeletal characters show most features shared with other Bufonidae, except for some typical of the basal genus Melanophryniscus.Karyotype is composed of 22 biarmed chromosomes, with secondary constrictions in pair 7, like the other species in the R. marina group.

The freshwater cnidarian Craspedacusta sowerbii Lankester 1880, has invaded lakes and ponds as well as artificial water bodies throughout the world. The first record in Uruguay corresponding to the jellyfish was made in 1961 in two artificial fountains, with no mention of the polyp form. Although local reports of other related polyp species have been made, information on the benthic form of C. sowerbii is lacking. Here we report the finding of live frustules, solitary individuals, medusae and colonies from a natural lagoon in August 2010, allowing us to observe the morphology and behavior of the polyp stage in captivity. In addition, molecular identification and remarks on the potencial path of introduction are presented. This is the first record in Uruguay of both polyp and medusa stages of C. sowerbii in a natural water body, Del Medio Lagoon (Dpto. de Florida), Uruguay.Keywords: Craspedacusta sowerbii, freshwater jellyfish, 16S RNA, polyp stage, Uruguay. Primeiro registro de

Molecular techniques could aid earthworm species identification, especially when morphological characters are not taxonomically informative, or difficult to discern. No previous study has investigated molecular-based methods for earthworm taxonomy in Uruguay. The present study aimed to make a first approach using DNA barcoding as a tool to smoothen the way towards determining the earthworm richness in Uruguay. This study was based on an earthworm collection, identified both by morphological characters and molecular techniques, from samplings from different agricultural soils in Montevideo and Paysandú, Uruguay. Adult individuals were identified by external morphology following available descriptions of regional earthworms. From each morphological group a representative sample was selected for genomic DNA extraction, mitochondrial COI region amplification and sequencing. Sequences obtained were subject to BLAST searches and compared to sequences available in GenBank. Eight out of 11 sequenced exotic species were fully identified and matched morphological characters and molecular information; two were less consistent, with lower sequence similarity percentage; and one could not be fully identified due to lack of close related sequences in GenBank. While most exotic species had representative sequences annotated in GenBank, this was only the case for one native species, highlighting the need to develop this important area at a regional level. This study could kick-start an innovative research program, since there are limited records of earthworm samplings in Uruguay and no identification of species by DNA sequences from national studies.