Abstract：
:It is located 650m above sea level along the boundary between the North Caribbean and Pacific slopes, near the Southern end of the volcanic Guanacaste mountain range. In the early 1980s the lake's main outlet was dammed and the outflow was diverted into Arenal Reservoir. Lake Cote was first studied in 1990-1991, and later in 2001, before it was again modified by raising its dam by one meter to use its outflow for hydroelectricity. From 2002 to 2010 it has been monitored twice a year for changes in its limnology. Here I present a summary of its basic characteristics and an analysis of their changes through time. The lake is discontinuous polymictic, and sometimes develops a thermocline at 6m depth that may last for several days as evidenced by the occasional development of an anoxic layer close to the bottom. Since its modification for hydropower production, the surface water temperature has attained higher values than before. Oxygen levels in the lake show periods of hypoxia to anoxia in the hypolimnion, that have become more frequent since modification. Despite its turbid water, the lake has low levels of nutrient concentrations and of chlorophyll a. The trend in these parameters in recent times is a reduction in chlorophyll a and an increase in water transparency, implying a reduction in primary productivity. These changes are discussed in relationship with anthropogenic factors such as the modification of the lake and its management, changes in landscape around the lake and global climate change.
journal_name
Rev Biol Tropjournal_title
Revista de biologia tropicalauthors
Umaña Gsubject
Has Abstractpub_date
2014-06-01 00:00:00pages
567-78issue
2eissn
0034-7744issn
2215-2075journal_volume
62pub_type
杂志文章abstract：:The host plants of Cerambycidae (Coleoptera) in the Province of Espinal (Chaquenian Dominion) and the province of Buenos Aires are mainly exotics, cultivated or naturalized, the last ones growing spontaneously and forming little forests. Forty two species of Cerambycidae are reported using these plants and other nativ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1997-03-01 00:00:00
abstract：:Turbinella angulata and Busycon perversum are two marine gastropods that support the 90% of conch fisheries in the Gulf of Mexico, nevertheless there is no information available to support a management strategy for both species. The aim of this work was to obtain preliminary fishery information to promote management a...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2013-03-01 00:00:00
abstract：:Two types of inclusion bodies were consistently observed under light microscopy in bean (Phaseolus vulgaris) leaf tissue infected with Bean rugose mosaic virus (BRMV), a species of the genus Comovirus, family Comoviridae. One type consisted of vacuolated inclusions found mainly in the cytoplasm of epidermal cells. The...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2000-12-01 00:00:00
abstract：:The structural and ultrastructural features of gonads from endemic Mexican fish have received scarce attention. This study describes the histological and ultrastructural characteristics of oocyte from Chirostoma humboldtianum. The ovary is asynchronic, and as such, most phases of oocyte development are found in the sa...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2008-09-01 00:00:00
abstract：:This paper is the first taxonomic account of the hydroid orders Anthoathecatae and Leptothecatae from the Caribbean and Pacific coast of Costa Rica. All specimens are currently stored at the reference collection of the Museo de Zoología, Escuela de Biología, Universidad de Costa Rica. Sixteen hydroid species are recor...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2002-06-01 00:00:00
abstract：:The Neotropical region exhibits the largest diversity of fish worldwide; however, little is known about the early development of fish species from this region. Therefore, to contribute to this knowledge, this study aimed to morphologically describe the early stages of development (eggs, larvae and juveniles) of S. pap...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v63i1.14121
更新日期：2015-03-01 00:00:00
abstract：:Gastropods are one of the most abundant groups within the Caribbean mangroves, however, little is known about the distribution of particular species at a regional scale. With this aim, we studied the geographic distribution of Littoraria (Littorinopsis) angulifera and Neritina (Vitta) virginea within the Darién Ecoreg...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2012-03-01 00:00:00
abstract：:Structural hemoglobin variants are reviewed for Iberoamerica; specially in Latin America, they reflect racial composition and geographic origin. Latin American genetic composition is a function of ethnic composition in each country (mainly Africans and Spaniards, and the "indians" or native peoples). For this reason t...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1993-12-01 00:00:00
abstract：:A list of the species and taxa of some pelagic animals from a tropical upwelling region, based on collections made off the coast of Costa Rica is presented. The list includes a total of 224 species, 53 genera and 11 subspecific forms in Cnidaria, Annelida, Mollusca, Artropoda (Crustacea), Chaetognatha and Pisces. ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章,评审
doi：
更新日期：1996-08-01 00:00:00
abstract：:The Furnariidae encompasses 293 species and has been recognized as an example of continental adaptive radiation. They inhabit biomes from deserts to humid forests at all strata and show morphological heterogeneity unparalleled among birds at any taxonomic level. Sclerurus is a uniform genus of cryptic, mainly dark bro...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v64i3.21094
更新日期：2016-09-01 00:00:00
abstract：:We studied the composition and seasonal variation of the diet of the capybara (Hydrochaeris hydrochaeris) in the flooded savannas of Caño Limón, Colombia. This was achieved by direct observation of the consumption patterns of these animals. The capybaras only consumed plants, and their diet included 89 species of 22 f...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2003-06-01 00:00:00
abstract：:Egg abundance of Anchoa mitchilli was studied in Laguna de Tamiahua, Veracruz during three annual cycles (84-85, 85-86 and 86-87). Our goal was to detect areas and seasons with high egg abundance and the possible association of such areas and seasons with covariates such as temperature, salinity, transparency, depth, ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2003-06-01 00:00:00
abstract：:The venom of female spiders (Aphonopelma seemanni) induces necrosis of skeletal muscle in mice. This effect was demonstrated by histology and by the increase in the plasma levels of the enzyme creatine kinase (CK). ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1984-06-01 00:00:00
abstract：:Egg clutches of the centrolenid Hyalinobatrachium pulveratum were sampled in four lowland locations of Costa Rica. The ontogenesis of the tadpoles of this species is documented by periodical descriptions of the larval stages. Larvae of H. pulveratum change their shape during development because of the non-equal growth...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v52i1.14912
更新日期：2004-03-01 00:00:00
abstract：:A new species, Cirripathes secchini (Cnidaria: Antipatharia) from the Abrolhos area (Bahia, Brazil) is described and constitutes the first record to this genus from Brazil. Two other species (Antipathes hirta, first record from the Southwestern Atlantic; and Antipathes fernandezi, first record from the Atlantic Ocean)...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2002-09-01 00:00:00
abstract：:Parasites play a crucial role in the ecology of animals. They also appear to be important in mechanisms underlying sexual selection processes. In this article we study the prevalence, effect and potential role in sexual selection of the protozoon Trypanosoma evansi in capybaras, Hydrochoerus hydrochaeris. We collected...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v64i3.20110
更新日期：2017-03-01 00:00:00
abstract：:The arguments presented by Espinoza et al. in their paper "Relationship of genetically modified crops with the environment and health of the Costa Rican human population" published in this journal (Rev. Biol. Trop. 52: 727-732, 2004) are questioned and refuted. The arguments are confronted with evidence offered by sci...
journal_title：Revista de biologia tropical
pub_type： 评论,杂志文章
doi：
更新日期：2007-06-01 00:00:00
abstract：:In Costa Rica, cervical cancer is the second most common female cancer, despite accessibility of screening through the universal health care system. There is little understanding of knowledge levels of the adolescent population on cervical cancer, although this population is the most exposed to risk factors. This stud...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v62i3.14063
更新日期：2014-09-01 00:00:00
abstract：:Neotropical aquatic ecosystems have a rich aquatic flora. In this report, we have listed the aquatic flora of various habitats of the upper Paraná River floodplain by compiling data from literature and records of our own continuous collections conducted during the period 2007-2009. Our main purposes were to assess the...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2011-06-01 00:00:00
abstract：:During the first six months of 1970 we collected 16 lots of the bivalve Anadara tuberculosa from two areas within the Gulf of Nicoya, Costa Rica. These were examined bacteriologically and the coliform levels found in all of them were such that they had to be graded as not satisfactory for human consumption, according ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1977-07-01 00:00:00
abstract：:The reproductive season of tilapia was studied by monthly samplings at Emiliano Zapata dam, Morelos State, Mexico. From February 1999 through February 2000 a sample of 50 fish was taken from the commercial catch (castnet, 6.5 cm of mesh size). The observed sex ratio was 1:1.29 (females:males) (chi(2)=10.26; p<0.05). T...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v53i3-4.14666
更新日期：2005-09-01 00:00:00
abstract：:Basic aspects of the reproductive biology are largely unknown for most tropical tree species, although they are important elements to understand the impacts of anthropogenic activities as logging and forest fragmentation on these populations. In this study, data are presented on leaf and reproductive phenology, fruit ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v57i3.5491
更新日期：2009-09-01 00:00:00
abstract：:Sponges have an important ecological role in coral reef ecosystems. However, when compared to other benthic Phyla, it has been little researched. This research was focused in the variability of the community structure of sponges in three locations at Morrocoy National Park (Cayo Sombrero, Playa Mero and Punta Brava) e...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2013-09-01 00:00:00
abstract：:An in vivo model to study the antimalaric effect of plant extracts is described. White mice (25-30 g body weight) are treated subcutaneously with 0.6 ml of the diluted extract starting seven days before P. berghei infection; treatment continues until death or for 30 days. Simultaneously 0.2 ml of the extract are appli...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1998-03-01 00:00:00
abstract：:A monovalent antivenom was produced by immunizing two horses with venom of the pit viper Bothrops asper (Ophidia: Viperidae). Although development of the immune response against four toxic and enzymatic activities of the venom was similar in both horses during the first two thirds of the immunization schedule, antibod...
journal_title：Revista de biologia tropical
pub_type： 杂志文章,评审
doi：
更新日期：1988-11-01 00:00:00
abstract：:In recent years, the use of new scientific techniques has effectively improved aquaculture production processes. Astaxanthin has various properties in aquaculture and its antioxidant benefits have been closely related to stress resistance; besides, it is an essential factor for growth in many crustaceans and fish. The...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v62i4.13057
更新日期：2014-12-01 00:00:00
abstract：:The land crab Gecarcinus quadratus is an engineering species that controls nutrient cycling in tropical forests. Factors regulating their coastal distribution are not fully understood. We quantified land crab distribution during the dry season at Sirena Field Station in Corcovado National Park, Costa Rica, and found t...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v55i1.6073
更新日期：2007-03-01 00:00:00
abstract：:Bothrops cotiara is a venomous snake sporadically found in the province of Misiones in Argentina, South of Brazil and Paraguay. Data on the clinics of the envenomation produced by its bite and on its venom are scarce. There is no information on the neutralizing capacity of the antivenoms available. In this study, the ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2006-09-01 00:00:00
abstract：:Megalopta Smith, 1853, is a Neotropical genus of nocturnal or crepuscular bees. Two subgenera are recognized with most of its nearly 30 species placed in the nominate subgenus. Species of Megalopta s. str. are more commonly collected than species of Noctoraptor Engel et al. 1997, all presumably parasites of Megalopta ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v58i1.5207
更新日期：2010-03-01 00:00:00
abstract：:Observations about the floral biology and the reproductive system of Macroptilium fraternum were made in two populations in Argentina, with different edaphic conditions, situated at the southern area of distribution of the species. The coexistence of two kind of flowers in the same plant was detected in both populatio...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2003-06-01 00:00:00
