Hill K.M.,Virginia Institute of Marine Science |
Hill K.M.,College of Charleston |
Stokes N.A.,Virginia Institute of Marine Science |
Webb S.C.,Cawthron Institute |
And 6 more authors.
Diseases of Aquatic Organisms | Year: 2014
The genus Bonamia (Haplosporidia) includes economically significant oyster parasites. Described species were thought to have fairly circumscribed host and geographic ranges: B. ostreae infecting Ostrea edulis in Europe and North America, B. Exitiosa infecting O. chilensis in New Zealand, and B. roughleyi infecting Saccostrea glomerata in Australia. The discovery of B. Exitiosa-like parasites in new locations and the observation of a novel species, B. perspora, in noncommercial O. stentina altered this perception and prompted our wider evaluation of the global diversity of Bonamia parasites. Samples of 13 oyster species from 21 locations were screened for Bonamia spp by PCR, and small subunit and internal transcribed spacer regions of Bonamia sp ribosomal DNA were sequenced from PCR-positive individuals. Infections were confirmed histologically. Phylogenetic analyses using parsimony and Bayesian methods revealed one species, B. Exitiosa, to be widely distributed, infecting 7 oyster species from Australia, New Zealand, Argentina, eastern and western USA, and Tunisia. More limited host and geographic distributions of B. ostreae and B. perspora were confirmed, but nothing genetically identifiable as B. roughleyi was found in Australia or elsewhere. Newly discovered diversity included a Bonamia sp in Dendostrea sandvicensis from Hawaii, USA, that is basal to the other Bonamia species and a Bonamia sp in O. edulis from Tomales Bay, California, USA, that is closely related to both B. Exitiosa and the previously observed Bonamia sp from O. chilensis in Chile. © Inter-Research 2014.
Gonzalez Carman V.,CONICET |
Alvarez K.C.,Fundacion Mundo Marino PRICTMA |
Prosdocimi L.,University of Buenos Aires |
Inchaurraga M.C.,Asociacion Cooperadora Reserva Natural Bahia Blanca |
And 9 more authors.
Marine Biology Research | Year: 2011
Three out of the five threatened species of sea turtle occurring in the SW Atlantic Ocean are regularly found in the coastal waters of Argentina: green (Chelonia mydas), loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) turtles. From 1995 to 2008, fishery and beach surveys were carried out along 2800 km coastline and reports from the public were gathered. Incidental capture in artisanal fisheries and strandings suggest that an important concentration of these species occurs in the estuarine, highly productive areas of Samborombón Bay (35°30'S-36°30'S) and El Rincon (39°S-41°S), although green and loggerhead turtles were also recorded as far south as northern Patagonian waters (42°35'S-64°17'W). Depending on the species, different age classes use these temperate areas probably as foraging grounds: small juvenile green turtles, juvenile to adult loggerheads and adult leatherbacks. All three species are mainly captured in small-scale, gillnet fisheries. This information provides an essential background to conduct further studies and propose mitigation plans to reduce sea turtle mortality in Argentina. Global conservation strategies will also benefit from including temperate environments of the SW Atlantic Ocean as regular habitats in the life history of threatened turtles. © 2011 Taylor & Francis.
Garibotti I.A.,Instituto Argentino Of Nivologla |
Ferrario M.E.,National University of La Plata |
Ferrario M.E.,CONICET |
Almandoz G.O.,National University of La Plata |
And 2 more authors.
Diatom Research | Year: 2011
Seasonal variations in the composition and carbon biomass of diatoms and other phytoplankton groups were analyzed over two years, from December 1996 to January 1999, at a fixed station in Anegada Bay, within the El Rincón estuarine system (38-41 °S). Phytoplankton communities characterizing the different seasons were identified by classification and detrended correspondence analyses. Diatom communities were highly speciose, with 117 species recorded during the two-year study. Three diatom species are new records for the Argentinean Sea (i.e., Minidiscus trioculatus (FJ.R. Taylor) Hasle, M. decoratus Chrétiennot-Dinet & Quiroga and Thalassiosira tealata Takáno). Phytoplankton taxonomie composition and carbon biomass showed a strong seasonality, with two carbon (C) biomass maxima occurring in summer and winter (maximum concentration: 193 μ.g CL -1). Summer blooms were mainly dominated by tychoplanktonic diatom species (Paralia sulcata (Ehrenberg) Cleve, Rhaphoneis amphiceros (Ehrenberg) Ehrenberg and Delphineis surirella (Ehrenberg) Andrews), probably resuspended from the sediments, and by the pelagic diatom T. hendeyi Hasle & Fryxell. The winter phytoplankton community was characterized by a high number of diatom species and a high carbon biomass of diatom resting spores. The occurrence of the winter bloom seems to be closely associated with the inoculation of the water column by diatom resting spores. Maximum diatom carbon biomass corresponded to periods of increased freshwater inflow, whereas seasonal variations in diatom taxonomie composition may be explained by the life-cycle strategies of the species. The taxonomie composition and temporal succession of phytoplankton communities in Anegada Bay are comparable with previous studies in Blanca Bay, suggesting relatively uniform phytoplankton seasonality over shoals in the El Rincón estuarine system. © 2011 The International Society for Diatom Research.
Perier M.R.,Institute Biologia Marina Y Pesquera Alte Storni |
Perier M.R.,National University of Comahue |
Estalles M.,Institute Biologia Marina Y Pesquera Alte Storni |
Estalles M.,CONICET |
And 7 more authors.
Revista del Museo Argentino de Ciencias Naturales, Nueva Serie | Year: 2011
The San Matías Gulf (SMG; 41°- 42° S; 64°- 65° W) is the largest gulf in Northern Patagonia, Argentina. Up to date, the chondrichthyan fauna of this area has not been reported. Therefore, the aim of this work is to provide a list with species presence and biological characteristics of the chondrichthyans recorded in SMG during the last 30 years. A total of 13 sharks distributed in 11 families, 19 skates and rays distributed in six families, and one holocephalan have been so far recorded in SMG. From the zoogeographical point of view, this chondrichthyan fauna is a mixed assemblage of species typically found in the Argentinean and Magellanean Provinces. The holocephalan Callorhinchus callorynchus is the most landed chondricthyan of the local fishery. With it, five sharks and seven skates are also exploited.
Kroeck M.A.,Institute Biologia Marina Y Pesquera Alte Storni
Diseases of Aquatic Organisms | Year: 2010
Haplosporidian microcells belonging to the genus Bonamia parasitise various species of oysters around the world. In Argentina, Bonamia sp. was the causative agent of mass mortality among Ostrea puelchana cultured in San Antonio Bay (San Matías Gulf), and it was detected in natural beds inside San Matías Gulf. In order to describe the gross and histopathological signs caused by Bonamia sp. in O. puelchana, cultured and wild oysters were sampled and analysed by traditional techniques including heart imprints and histology. Cells of Bonamia sp. were observed in connective tissue, free or within haemocytes, in gills and around the digestive gland, stomach, intestine and gonad. Gross signs, histopathological alterations in O. puelchana, and Bonamia sp. cytological morphology resemble those reported for B. exitiosa. However, I propose to treat the Argentinean species as B. exitiosa-like until more molecular and ultrastructural studies are conducted to determine the correct taxonomy. © Inter-Research 2010.
Estalles M.,Institute Biologia Marina Y Pesquera Alte Storni |
Estalles M.,CONICET |
Coller N.M.,Institute Biologia Marina Y Pesquera Alte Storni |
Coller N.M.,National University of Comahue |
And 4 more authors.
Neotropical Ichthyology | Year: 2011
The Electric ray Discopyge tschudii is distributed in the Southwest Atlantic from southern Brazil to southern Argentina and in the Southeast Pacific from Peru to southern Chile. The main threat to this species is fishing. Discopyge tschudii is noncommercial and individuals caught are discarded on board. The present study analyzes the distribution and the morphological and reproductive characteristics of this ray in San Matías Gulf (SMG), Argentina. A total of 1087 individuals were analyzed. The species presented an aggregate distribution, with the main concentrations in the northern and eastern areas of SMG, at depths below 100 m. Males ranged from 9 to 43 cm and females from 11 to 38 cm. The species presented sexual dimorphism. Males were larger and heavier than females and also matured at larger sizes. Size at 50% of maturity was estimated at 30 cm for males and 21 cm for females. A total of 199 embryos were sampled and the proportion of sexes showed no significant differences from the expected 1:1. The number of embryos per female varied from 1 to 12. The most frequent values were 2 and 5. Length at birth was estimated at 82.17 ± 3.87 mm. Based on our findings, we hypothesize that the electric ray D. tschudii completes its reproductive cycle in SMG. © 2011 Sociedade Brasileira de Ictiologia.