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1.
Rev. biol. trop ; 62(4): 1273-1284, oct.-dic. 2014.
Artigo em Inglês | LILACS | ID: lil-753689

RESUMO

Genetic material (short DNA fragments) left behind by species in nonliving components of the environment (e.g. soil, sediment, or water) is defined as environmental DNA (eDNA). This DNA has been previously described as particulate DNA and has been used to detect and describe microbial communities in marine sediments since the mid-1980’s and phytoplankton communities in the water column since the early-1990’s. More recently, eDNA has been used to monitor invasive or endangered vertebrate and invertebrate species. While there is a steady increase in the applicability of eDNA as a monitoring tool, a variety of eDNA applications are emerging in fields such as forensics, population and community ecology, and taxonomy. This review provides scientist an understanding of the methods underlying eDNA detection as well as applications, key methodological considerations, and emerging areas of interest for its use in ecology and conservation of freshwater and marine environments. Rev. Biol. Trop. 62 (4): 1273-1284. Epub 2014 December 01.


El material genético que liberan los organismos en los componentes no vivos del ecosistema (aire, suelo, agua y sedimentos) recibe el nombre de ADN ambiental (ADNa) (eDNA, por su nombre en inglés). Este ADN previamente definido como ADN particulado ha sido utilizado desde mediados de la década de los ochenta y principios de los noventas para describir la composición de las comunidades microbianas en sedimentos marinos y de comunidades microbianas y fitoplanctónicas en la columna de agua. Recientemente el ADNa es utilizado principalmente para la detección y monitoreo de especies invasoras y en peligro. No obstante, existen múltiples áreas en las que este método puede ser utilizado como por ejemplo en ciencias forenses, ecología de poblaciones y comunidades, y taxonomía. Esta revisión proporciona información sobre esta nueva herramienta molecular, sus actuales y futuras aplicaciones, historia, principales consideraciones metodológicas y áreas emergentes para su uso en ecología y conservación de ambientes marinos y de agua dulce.


Assuntos
Animais , DNA , Ecossistema , Monitoramento Ambiental/métodos , Água Doce , Água do Mar
2.
Rev. biol. trop ; 56(3): 1209-1223, sep. 2008. ilus, graf, tab
Artigo em Espanhol | LILACS | ID: lil-637859

RESUMO

Observations on the larvae of the tropical marine crab Petrolisthes armatus in the Gulf of Nicoya, Costa Rica. During October and November 1998 (rainy season), and December, February and March 1999 (dry season), larvae distribution of Petrolisthes armatus and associated decapods were sampled in three different sites at the Punta Morales peninsula, Gulf of Nicoya, Costa Rica. A total of 6014 decapod larvae were collected, and 73 belonged to the genus Petrolisthes spp. No significant total larval density differences were found between seasons (p>0.05); but there was a greater density of P. armatus and other decapod larvae (p>0.05) during the dry season. In addition, no significant variations on temperature and oxygen concentration were observed. P. armatus larval abundance was higher during low tide, in contrast with other decapod larvae. Significant differences among sites were found for other decapod larvae, but not for P. armatus. The only parameter that varied significantly between seasons was salinity and results demonstrate that this factor regulates temporal concentration of larvae. Moreover, flow-tide oscillations were the most important spatial factor in larval dynamics. We propose this mechanism: P. armatus liberates larvae during high tide; these larvae leave the coastal area during low tide and return to the rocky intertidal ecosystem during high tide, when they are ready to settle as megalopa (pre-juvenile stage). Parallel laboratory observations showed higher survival rates at lower salinities (15 ups against 35 ups) and that the duration of the period from zoea I to megalopa was, in average, 19 days. Rev. Biol. Trop. 56 (3): 1209-1223. Epub 2008 September 30.


Durante octubre y noviembre de 1998 (estación lluviosa) y diciembre, febrero y marzo de 1999 (estación seca) se muestreó la distribución de la larva de Petrolisthes spp, así como la densidad del total de las larvas de decápodos en superficie y a 3 metros de profundidad. Los muestreos se realizaron en tres sitios de la zona de Punta Morales, Golfo de Nicoya, Costa Rica, por medio de arrastres con una red de plancton de 280 µm. Se recolectaron un total de 6014 larvas de decápodos de las cuales 73 (1.21%) pertenecían al género Petrolisthes spp. No se encontraron diferencias significativas entre estaciones (p > 0.05), sin embargo fue posible observar una mayor densidad tanto de P. armatus como de larvas de decápodos en estación seca. Temporalmente el único parámetro físico-químico que varió significativamente fue la salinidad. En cuanto a la variación espacial no se encontraron diferencias significativas por profundidad, ni para Petrolisthes spp. ni para larvas de decápodos asociados (p > 0.05), a pesar de que la variación de algunos parámetros como la temperatura y el oxígeno si lo fue. Entre mareas se encontraron diferencias significativas para las larvas de Petrolisthes spp., no así para larvas de decápodos. Para la especie estudiada se observó un mayor número de larvas en marea baja. Entre los sitios hubo diferencias significativas para las larvas de decápodos, pero no para Petrolisthes spp.; físico-químicamente estos sitios son muy parecidos y solo difieren en penetración de luz, lo que parece no afectar a la larva de Petrolisthes. spp. Los resultados demuestran que el principal factor que regula la concentración temporal de las larvas es la salinidad, mientras que espacialmente las oscilaciones en el flujo mareal son de mayor importancia. Debido a las diferencias observadas marealmente para la concentración de larvas se propone el siguiente mecanismo: P. armatus libera sus larvas en el máximo de marea, éstas salen hacia fuera de la costa con la marea baja y se reincorporan con la marea alta, cuando están cerca de la fase previa al asentamiento (la megalopa). Adicional a los resultados en el medio natural para esta especie también se estudió en el laboratorio la duración del periodo larval y la supervivencia de las larvas a salinidades extremas utilizándose los valores máximos y mínimos registrados en el medio natural (15 ups y 35 ups). Este ensayo demostró que las larvas presentan un mayor porcentaje de supervivencia en salinidades menores (15 ups) y que la duración del período de desarrollo es de 19 dias.


Assuntos
Animais , Braquiúros/crescimento & desenvolvimento , Braquiúros/classificação , Braquiúros/fisiologia , Costa Rica , Larva/classificação , Larva/crescimento & desenvolvimento , Larva/fisiologia , Densidade Demográfica , Dinâmica Populacional , Estações do Ano , Água do Mar , Clima Tropical
3.
Rev. biol. trop ; 52(4): 897-902, dic. 2004. tab
Artigo em Inglês | LILACS | ID: lil-450782

RESUMO

The composition of the mesozooplanktonic community was studied in the Punta Morales estuary, Gulf of Nicoya,Pacific coast of Costa Rica,during 1997.Oblique plankton hauls were performed during high and low tide using a 280 µm mesh screen net equipped with a flowmeter.The community was characterized by holoplanktonic and meroplanktonic organisms.For the holoplanktonic community,the main groups were copepods (80%)and chaetognaths (16%).The most abundant species were the copepods Acartia lilljeborgii and Paracalanus parvus.A.lilljeborgii is a typical estuarine species that maintains high populations in estuarine systems.Meroplankton was represented mainly by crustacean larvae (66%),and icthyoplankton (18%).The dominance of crustacean larvae and icthyoplankton is an evidence of the ecological importance of the Punta Morales zone


Se estudió la composición de la comunidad mezoplanctónica en Punta Morales,Golfo de Nicoya, Pacífico de Costa Rica,en 1997,arrastrando oblicuamente una red de plancton (280 µm,con flujómetro)durante marea alta y baja.La comunidad estuvo caracterizada por la presencia de organismos holo y meroplanctónicos.Los principales grupos holoplanctónicos fueron copépodos (80%)y quetognatos (16%).Las especies más abundantes fueron los copépodos Acartia lilljeborgii y Paracalanus parvus;A. lilljeborgii es una especie estuarina típica que mantiene altas poblaciones en sistemas estuarinos.El meroplancton estuvo representado principalmente por larvas de crustáceos (66%),e ictioplancton (18%).La dominancia de larvas de crustáceos e ictioplancton evidencian la importancia ecológica de la zona de Punta Morales


Assuntos
Animais , Comportamento Animal/fisiologia , Copépodes/crescimento & desenvolvimento , Ecossistema , Zooplâncton/crescimento & desenvolvimento , Migração Animal , Copépodes/classificação , Costa Rica , Larva/fisiologia , Densidade Demográfica , Dinâmica Populacional , Clima Tropical , Zooplâncton/classificação
4.
Rev. biol. trop ; 49(Supl.2): 97-101, dic. 2001. graf
Artigo em Inglês | LILACS | ID: lil-502403

RESUMO

Population of the porcellanid crab Petrolisthes armatus was studied on a rocky intertidal beach located at the Punta Morales peninsula in the mid upper Gulf of Nicoya estuary, Pacific coast of Costa Rica, from December 1997 to November 1998 (14 dates). Horizontal plankton tows (280 micron mesh net) were also made to verify the presence of P. armatus larvae. Crabs were collected every 3 m along three 18 m long transects, at two sites on the beach, by placing a bottomless bucket fringed with canvas to prevent the organisms from escaping under the rim. A total of 15,382 P. armatus were collected. Only 146 (0.95%) crabs had a carapace length longer than 10 mm, and 8995 (58.5%) were in the size range of 2 to 4.5 mm. The remaining crabs 6241 (40.5%) were in the size range of 4.6 to 10 mm. Male and female P. armatus were represented by 2777 and 3518 individuals respectively, with a sex ratio of 1:1.26. Ovigerous females were found at all dates and included 2937 individuals (83% of females). Plankton tows yielded only 73 larvae of P. armatus (Zoea 1), with a density of 1.2 larvae/m3. No statistically significant seasonal trends in the population of this species were detected. P. armatus appears to reproduce continuously the year around in Punta Morales, and some peaks of abundance were present during the dry and rainy seasons. These trends are similar to trends reported for other crustacean species in the Gulf of Nicoya.


Assuntos
Animais , Masculino , Feminino , Crustáceos/classificação , Costa Rica , Densidade Demográfica , Estações do Ano
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