Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

 In Patagonian coastal areas, intertidal benthic communities are exposed to extreme physical conditions. The interaction between harsh environment and anthropogenic pressure can generate changes in population biology of marine invertebrates, like density and reproduction. The oral brooding sea star Anasterias minuta is a key organism in food chains of Atlantic Patagonian rocky intertidals, hence changes on its population structure can negatively affect shore communities. We studied the population biology of A. minuta and assess the effect of environmental parameters and anthropogenic activities on its population on rocky intertidal shores of San Matías Gulf, Patagonia, Argentina. Seasonal sea surface temperature, pH, salinity, water velocity, desiccation rate, boulders density, and anthropogenic influence (tourists and octopus fishermen) were recorded. In sites with less tourist influence and high refuge, an increase in density was recorded, especially during the summer. Brooding individuals were found in fall and winter, while feeding individuals were observed in all seasons (12 different prey, mainly the molluscs Tegula patagonica and Perumytilus purpuratus). Environmental variables such as boulders density and water velocity were the most important predictor of variation in population structure. Tourism and pH were the most important variables negatively correlated with density. Rev. Biol. Trop. 65(Suppl. 1): S73-S84. Epub 2017 November 01. 

Population parameters of the sea urchin Arbacia dufresnii (Blainville, 1825) from North Patagonian gulfs invaded by kelp Undaria pinnatifida (Harvey) Suringar, 1873. The Asian seaweed Undaria pinnatifida invaded Argentina in 1992 (Golfo Nuevo, Patagonia). Its range has expanded and it has changed the native benthic community. Sea urchins are usually generalist herbivores that have a key role in controlling seaweeds. Arbacia dufresnii is the most abundant sea urchin in the coastal areas of northern Patagonia. The aim of this study was to relate the population parameters of A. dufresnii to the presence of the invasive seaweed. In 2012 we sampled sites with different invasion stages (advanced: Golfo Nuevo, recently invaded: San José Gulf, Punta Tehuelche; no invasion: San José Gulf, Zona 39). Sea urchin density was higher in the invaded sites and varied with the seaweed cycle. In addition, there were variations in the size distribution in the invaded sites. The invasive algae probably affects urchin populations because it is a new source of food that changes environmental structure (it provides microhabitat for new recruits) and affects the native benthic community. Rev. Biol. Trop. 65(Suppl. 1): S101-S112. Epub 2017 November 01. 

The existence of latitudinal marine biodiversity gradients from low to high-southern latitudes is a controversial issue regarding the marine biogeographic division in the Southeastern Pacific. In this region, the Northern Patagonian Icefield is considered a break point for faunistic elements derived from more northern or southern biogeographical realms. However, the division seems to be better defined by distribution patterns and endemism of specific marine taxa. There have been no exhaustive latitudinal benthic inventories compiled along the southern-eastern Pacific Chilean coastline. This study focuses on the spatial distribution variability and relative abundance of the sublittoral echinoderm assemblages and uses them to establish an evaluation of zoogeographic relationship in the Southeastern Pacific and Atlantic Oceans. This is the first time echinoderms have been used for this purpose. A total 3 665 echinoderm specimens were collected in two cruises. Within this organism pool, 29 species were distinguished, belonging to the asteroids (17 species), echinoids (6 species), ophiuroids (4 species) and holothurians (2 species); crinoids were not found. The dominant species were the asteroid Ctenodiscus procurator, the echinoid Pseudechinus magellanicus, the ophiuroid Ophiuroglypha lymani, and the irregular sea urchin Tripylaster philippii. The spatial distribution patterns for the echinoderm clusters along the study area showed only weak geographical trends. Stations belong in three groups: with influence of glacier processes, influence of waters of the open Pacific Ocean, and a third group of stations without any links to specific locations. Rev. Biol. Trop. 65(Suppl. 1): S60-S72. Epub 2017 November 01. 

Irregular echinoids (Order Spatangoida) from the Cretaceous of Mexico. Echinoids are a very important part of the Mesozoic and Cenozoic fossil fauna of Mexico. Among them, spatangoids are widely represented in several Cretaceous fossiliferous outcrops, and have stratigraphical and paleoecological value due to their good preservation of the Cretaceous. The review of order Spatangoida L. Agassiz, 1840 from the Cretaceous in Mexico allowed un update the taxonomy of species and contributed to the study of paleogeographic and stratigraphic distribution. The order Spatangoida is the most diverse in Mexico with three families (Toxasteridae, Hemiasteridae, Micrasteridae), seven genera (Epiaster, Heteraster, Macraster, Washitaster, Hemiaster, Proraster, Micraster) and 21 species. Family Toxasteridae is the most numerous with 54 % of the species reported for the Cretaceous of Mexico. Spatangoids from the Cretaceous of Mexico are found in different localities in Sonora (Cerro de las Conchas), Chihuahua (Cerro de Muleros, Sierra de Juárez, Placer de Guadalupe, Sierras La Ranchera, El Presidio, Sierra Banco de Lucero, Sierra La Encantada, Villa Ahumada), Coahuila (Sierra de Tlahualilo), Nuevo León (Sinclinal de Delgado), San Luis Potosí (Zamachihue), Colima (El Rosario), Puebla (San Juan Raya, Barranca Salitrillo), Guerrero (Cerro de Ahuexotitlán) and Oaxaca (Las Huertas). Rev. Biol. Trop. 65(Suppl. 1): S113-S136. Epub 2017 November 01. 

Richness and distribution of Echinoderms in rocky reefs at Punta Amapala and Los Cobanos, El Salvador. In El Salvador, taxonomic and distribution studies of echinoderms are scarce, and most of them are from Los Cóbanos. This research aims to explore the richness and abundance of echinoderms associated with shallow rocky reefs of El Salvador, as well as their relationship between distribution and abiotic variables. Sampling was carried out in Los Cóbanos and Punta Amapala, on the Pacific coast of El Salvador; between February and April 2016, with three-hour workdays during low tide. The sampling techniques used were wandering dive and three transects of 30m in length. The relationship between species and abiotic variables (temperature, salinity, coast distance and roughness) was identified with canonical correspondence analysis. We report seven species in five orders. The temperature and coast distance are strongly related to the distribution of organisms. Holothuria (Halodeima) kerfersteini and Echinometra vanbrunti are related to high temperature and greater distance from the coast; however, Ophiocoma aethiops, O. alexandri and Ophiothrix rudis are conditioned by low temperature and shorter coast distance. Rev. Biol. Trop. 65(Suppl. 1): S92-S100. Epub 2017 November 01.

The worms Malmgreniella variegata has been found as commensal of Ophionereis reticulata in Florida and Belize.  Here we report the association in Playa Piscina (Arapo Islands), Venezuela. Rev. Biol. Trop. 65(Suppl. 1): S85-S91. Epub 2017 November 01. 

Neogene Argentinean echinoids are important biostratigraphic tools. New specimens of Schizaster iheringi (de Loriol, 1902) from Early Miocene sedimentites (Chenque Formation, Patagonia, Argentina) allowed us to improve its original description, providing for the first time details of the apical disc and the oral side of  test. The species is included into the genus Brisaster: the first unquestionable documented reference to the taxon from the Neogene of Argentina. All previously reported specimens of this species are evaluated, concluding that the stratigraphic range of the genus Brisaster in Patagonia must be restricted to the Early Miocene. Rev. Biol. Trop. 65(Suppl. 1): S137-S146. Epub 2017 November 01.

Taphonomic processes in a Pennsylvanian regional encrinite (Atokano), Sonora, Mexico. Crinoids have an extensive fossil record and were a major component in Paleozoic marine communities; encrinites are common crinoid accumulations where specimens are totally disarticulated from the Ordovician to the Jurassic. In Sonora, Mexico, the crinoid skeleton was altered during diagenesis and replaced by silica. The corrasion was high; the incrustation low and there is evidence of dissolution and compaction. This is a sedimentological type accumulation in a high energy environment of allochthonous organism transported in a debris flow, deposited below the storm wave base in an outer ramp. Our results can be correlated with regional encrinites prevalent in the Pennsylvanian cyclothems of North America. Rev. Biol. Trop. 65(Suppl. 1): S147-S159. Epub 2017 November 01. 

Echinoderms from the Museum of Zoology from the Universidad de Costa Rica. The Museum of Zoology, Universidad de Costa Rica (MZUCR) was founded in 1966 and houses the most complete collection of vertebrates and invertebrates in Costa Rica. The MZUCR currently has 24 collections containing more than five million specimens, and more than 13 000 species. The earliest collections date back to 1960 and include fishes, reptiles, amphibians, polychaetes, crustaceans and echinoderms. For the latter group, the MZUCR has a total of 157 species, in 1 173 lots and 4 316 specimens. These 157 species represent 54% of the total species of echinoderms from Costa Rica. The remaining species are distributed in the following institutions: California Academy of Sciences (CAS) (4.8%), Scripps Oceanographic Institute (SIO) (5.2%), National Echinoderm Collection “Dr. Ma. Elena Caso” from the National Autonomous University of Mexico (ICML-UNAM) (12.7%), the National Museum of Natural History, Smithsonian Institute (USNM) (35.1%), and the Harvard Museum of Comparative Zoology (19.2%). There may be material from Costa Rica in the Natural History Museum of Denmark (NCD) and the Natural History Museum of Los Angeles (LACM), however, there was no access to such collections. There are 9.6% that do not appear in museums, but are reported in the literature. Based on this revision, the taxonomic list of echinoderms for Costa Rica is updated to 293 species, 152 genera, 75 families, 30 orders and 5 classes. The Pacific coast of Costa Rica has 153 species, followed by the Isla del Coco with 134 and the Caribbean coast with 65. Holothuria is the most diverse genus with 25 species. Rev. Biol. Trop. 65(Suppl. 1): S272-S287. Epub 2017 November 01. 

Abstract: Echinoderms from Nicaragua: new records for the Pacific and South Caribbean. There is little information about the echinoderms of Nicaragua. Here we present a list based on bibliographical revisions and collections of specimens made in the last three years. Samplings were made from June 11 to 16, 2016, in 10 locations (two in the Pacific and eight in the Caribbean). In addition, the databases of eight international scientific collections were reviewed. Finally, reports were added from photographic archives of the school of diving Dive Nicaragua and ECOLÓGICA S.A. The list of echinoderms of Nicaragua consists of 193 species distributed in five classes, 112 genera, 58 families and 24 orders. The class with the highest number of species was Asteroidea (57 species), followed by the class Echinoidea (46 species), and the class with the lowest number of species was Crinoidea (10 species). Fifty six new records are added for Nicaragua, 19 of which correspond to the Pacific and 38 to the Caribbean. Rev. Biol. Trop. 65(Suppl. 1): S288-S298. Epub 2017 November 01.