The distribution and conservation status of coral reefs along the northern section of the archipelago of Bocas del Toro are evaluated (ca. 120 km), and the structure of 18 reefs around the islands of Bastimentos, Solarte, Carenero and Colón is described. Reef habitats located on the seaward side (exposed) of the islands exhibited the lowest coral cover (8%) and coral diversity, while leeward reefs (protected) showed the highest living coral cover (32%) and diversity. Macroalgae coverage was similar in both habitats but high (50%) if compared with other continental reefs described in the Ensenada Grande of Almirante Bay (4%). A total of 54 coral species was recorded, representing a 35% increase from previous studies for the region and 88% of the total species described for Panama. The diversity of reefs, reef organisms and habitats in the archipelago was greater outside the national park of Isla Bastimentos, the only marine protected area in western Panama. Some recommendations are provided for an integrated management of marine-terrestrial natural resources in the region, in particular, a complete change on the existing limits of the protected area and the creation of new reserves.
Se presenta la distribución de arrecifes coralinos a lo largo de la costa de las islas de Bastimentos, Solarte, Carenero y Colón (ca. 120 km), Provincia de Bocas del Toro, Panamá. Se describe la estructura de 18 arrecifes coralinos, los cuales representan la diversidad de hábitats y condiciones hidrológicas y orográficas de la zona costera del archipiélago. Los arrecifes encontrados en hábitats a barlovento de las islas (expuestos), son menos diversos en corales y presentan una cobertura de coral vivo baja (8%), mientras que los arrecifes de hábitats protegidos (sotavento), son los de mayor diversidad y cobertura de corales (32%). Las macroalgas presentaron un patrón similar de cobertura con promedio de 50%, alta si se le compara con arrecifes descritos para la Ensenada Grande de Almirante (4%), al sur del archipiélago. Se registra un aumento del 35% en el número de especies de corales para Bocas del Toro; el total de especies conocidas para la región es de 54, lo cual representa el 88% del total de la diversidad para Panamá. Se encontró que los arrecifes del Parque Nacional Marino Isla Bastimentos no representan la variedad de hábitats, diversidad de especies y abundancia que están presentes en otras localidades fuera de los límites del área protegida. Se señalan recomendaciones para el manejo integral de los recursos naturales marinos y terrestres del archipiélago de Bocas del Toro, donde se proponen variantes a los límites existentes del área protegida y la creación de nuevas categorías de protección (reservas biológicas), entre otros.
Production and biomass of Chione cancellata, an abundant species in Thalassia testudinum sea beds, were studied from March, 1984 to May, 1985 in Guaracayal, Cariaco Gulf, Venezuela. The population distribution ranges were stable. Many individuals were 20-30 mm long (80%) and recruitment was low. The mean density was 45.54 ind m-2 with a mean standing dry weight biomass of 7.37 g m-2, both changed significantly with time. Growth rates in marked bivalves of different size classes was maximum in the period between 14-X-1984 and 10-V-1985. A production of 17.34 g m-2 year-1 was obtained using a method designed to study populations with continuous reproduction and indistinguishable age classes. The greatest production values were obtained for cockles 20 to 30 mm in length. Highest production was between 28-II-1985 and 27-IV-1985. The annual turnover rate (P/B) was 2.65 year-1.
La producción y la biomasa de Chione cancellata un bivalvo abundante en praderas de Thalassia testudinum se estudió desde marzo, 1984 hasta mayo, 1985 en Guaracayal, localidad de la costa sur del Golfo de Cariaco, Venezuela. La población está integrada principalmente por individuos entre 20 y 30 mm de longitud (80%), la cual presentó un bajo reclutamiento. La densidad promedio (45.54 ind m-2) y la biomasa promedio en peso seco de (7.37 g m -2) presentaron variaciones significativas entre los muestreos. Las tasas de crecimiento en individuos marcados en diferentes clases de tallas fueron más altas durante el período comprendido entre el 14-X-1984 al 10-V-1985. Utilizando un método para poblaciones con reproducción continua y clases de edades no separables se obtuvo una producción total de 17.34 g m-2 año-¹ durante el período de estudio. Los máximos valores fueron aportados por los bivalvos entre 20 y 30 mm de longitud y la mayor producción ocurrió entre el 28-II al 27-IV-1985. La tasa anual de renovación (P/B) se estimó en 2.65 año -1 .
A total of 37 specimens of the freshwater crab Pseudothelphusa belliana were collected from four new localities in the state of Michoacan. Morphometric variation, specially carapace width ( <IMG SRC="http:/img/fbpe/rbt/v46n4/equis_promedio.JPG" WIDTH=19 HEIGHT=16> = 48.7, S.D. <IMG SRC="http:/img/fbpe/rbt/v46n4/equis_promedio.JPG" WIDTH=19 HEIGHT=16 > or = 3.3 for Chucutitán versus <IMG SRC="http:/img/fbpe/rbt/v46n4/quis_promedio.JPG" WIDTH=19 HEIGHT=16> = 33.5, S.D. = 9.1 for the rest of specimens), shape of chela, coloration in vivo, and differences on gonopods of two geographically separate populations, suggest two subspecies or a cryptospecies complex. Diagnosis, habitat and distributional data are also included.
Un total de 37 ejemplares del cangrejo dulceacuícola, Pseudothelphusa belliana fueron recolectados en cuatro nuevas localidades del estado de Michoacán. La variación morfométrica, sobre todo la anchura de caparazón (<IMG SRC="http:/img/fbpe/rbt/v46n4/equis_promedio.JPG" WIDTH=19 HEIGHT=16> = 48.7, D.E. <IMG SRC="http:/img/fbpe/rbt/v46n4/http:/img/fbpe/rbt/v46n4/equis_promedio.JPG" WIDTH=19 HEIGHT=16 > o = 3.3 para Chucutitán versus <IMG SRC="http:/img/fbpe/rbt/v46n4/equis_promedio.JPG" WIDTH=19 HEIGHT=16> = 33.5, D.E.<IMG SRC="http:/img/fbpe/rbt/v46n4/equis_promedio.JPG" WIDTH=19 HEIGHT=16> = 9.1 para el resto de los ejemplares), la forma de la quela, la coloración y las diferencias en los gonópodos de dos poblaciones separadas geográficamente, sugieren probablemente que se trate de dos subespecies o un complejo de criptoespecies. Una diagnosis, datos de hábitat y de distribución geográfica son incluidos.
Age and growth of Oreochromis niloticus from Lagoon of Coatetelco, Morelos State, Mexico were studied from January through December, 1993. Scales of 318 specimens were collected. Modal length at capture was 10.5-11.5 cm standard length. Scales rings were formed during December. Back-calculated lengths-at-age showed no significant differences by sex. Four check marks were recorded. According to the growth curve parameters for population, the fish grow at a low rate (k=0.07) until they achieve a size (L*) of 29.19 cm. Length-frequency analysis (Bhattacharya's Gaussian component determination procedure) do not differ significantly (t-student, p<0.05), from the scale reading.
Se realizaron estudios de enero a diciembre de 1993 para conocer la edad y crecimiento de Oreochromis niloticus obtenida de las capturas comerciales de la laguna de Coatetelco, Morelos, Mexico. Se colectaron escamas de 318 peces. La moda de longitud patrón que se obtuvo en la captura fue de 10.5-11.5 cm. Se encontró que la formación de los anillos se realiza en Diciembre. Asimismo, no se detectaron diferencias significativas entre las hembras y los machos para las longitudes retrocalculadas para cada edad. En las escamas se registraron cuatro marcas. Se encontró que de acuerdo a los parametros de la ecuación de crecimiento, los peces tienen baja tasa de crecimiento (k=0.07) y alcanzan un tamaño adecuado (L* =29.19 cm). Los resultados obtenidos por medio del análisis de distribución de frecuencias no difieren significativamente (t-student, p<0.05) de los obtenidos por medio de la lectura de la estructura ósea (escamas).
Diet and food preference of Caprodon longimanus were studied at Alejandro Selkirk Island, Chile. The fishes (N=55) were collected in November and December 1996 using long line and the sizes ranged from 176-286 mm in SL. This grouper is a pelagic opportunistic zooplanktivorous predator. Thalia sp. (Tunicata:Salpida) was the most frequent and abundant prey accounting for 93.3% occurrence based on 1655 individuals. A total of 17 genera of crustaceans as well as pteropods, chaetognaths and polychaete worms were found in the stomach contents. A total of 14.3% of all stomachs were empty.
La dieta y preferencia alimentaria de Caprodon longimanus fue estudiada a partir de 55 especímenes capturados en la Isla Alejando Selkirk, Chile entre Noviembre y Diciembre de 1996. Los ejemplares fueron capturados utilizando línea de profundidad. El intervalo de tallas fue 176-286 mm LE. Este serránido es un depredador pelágico zooplactófago oportunista. El componente alimentario más abundante y frecuente fue Thalia sp. (Tunicata:Salpida), con un total de 1655 individuos y 93.3% de frecuencia de ocurrencia. Se identificaron crustáceos (17 géneros), pterópodos, quetognatos y poliquetos. El 14.3% de los estómagos estaba vacío.
Histological characteristics and gametogenesis have received little attention in endemic Mexican fish, thus they are little understood. In this study, the histology of the testis of charal Chirostoma jordani, and ultrastructure of gamete cells through fotonic and electron microscopy are described. Sixty male fish were collected in Corrales, Hidalgo state, México, 70 km NW México city. Charal testis are paired, and added to the dorsolateral wall of abdomen. They are covered by a mesorquium, which has small black pigmentation spots. Testes are tubular, and spermatogonia are restricted to the distal part of tubules, basically in the cortical region. Cell sizes were measured: spermatogonia (8 + 0.7 µm), primary spermatocytes (6.2 + 0.3 µm), secondary spermatocytes (4.4 + 0.1 µm), spermatids (2.5 + 0.2 µm) and spermatozoa (15.4 + 0.3 µm). Sertoli cells surround gamete cells; together they form cysts which have approximately the same degree of development. All the testes have gamete cells simultaneously, and Leydig cells are easy to see in the central part of the testis.
We analysed the fish assemblage in the "Mergulhão" stream (southern Brazil) with underwater observations for habitat use, considering water depth, current velocity, bottom type, shadow from vegetation cover, distance of stream-edge, and vertical position. Stomach contents or foregut content samples of the most abundant species were collected from 26 species (10 families). The fish assemblage occupied the bottom stream. The similarity analysis of spatial occupation of species grouped four habitat use guilds: A) "lambaris" (Astyanax sp. and Deuterodon langei), Characidium spp. (C. lanei and C. pterostictum) and Rineloricaria kronei used the bottom in deep sites and waters with middle current; B) Pimelodella pappenheimi and Corydoras barbatus used the bottom in sites with lower current; C) Mimagoniates microlepis used the surface of the water column; and D) Phalloceros caudimaculatus used shallow sites and waters without current. Species with few records were analysed descriptively. Diet similarity suggested seven trophic guilds: Microglanis sp. and Pimelodella pappenheimi: omnivorous/carnivorous guild; Corydoras barbatus: omnivorous/insectivorous guild; Characidium lanei: aquatic insectivorous guild, mainly aquatic insects; Mimagoniates microlepis: terrestrial insectivorous guild, mainly terrestrial insects; Deuterodon langei and Astyanax sp.: omnivorous/herbivorous guild; Rineloricaria kronei, Kronichthys subteres, Schizolecis guntheri, Hisonotus leucofrenatus and Pseudotothyris obtusa: herbivorous guild; and Phalloceros caudimaculatus: algivorous guild. When the guilds were similar, the species were generalists in diet and in habitat use.
An orchid florula of Parque Nacional Manuel Antonio, Costa Rica, is provided on the basis of collections made in 91 plots within the park and field observations carried out in the neighbouring areas; 39 species belonging to 25 genera are recorded. Orchid species are described and a key to the species for field identification, based on vegetative features, is provided. Analytical drawings are provided for 35 of the taxa considered. Ecological notes and estimate of frequency for each species within the Park are given. A new orchid species, Lockhartia pandurata, is described and illustrated.
The family Droseraceae is reported for the first time from Costa Rica represented by Drosera capillaris Poiret. The species grows in vernal pools of hyperhumid savannahs of the Parque Nacional Amistad, Puntarenas Province. The population was small, of some 30 individuals that reduce dipterans to empty exoskeletons in 82 hr. Glandular secretion in higher when humidity is high and light is low. To date, the nearest locality reported for this species was Mexico.
Erythrina species are widely distributed in Costa Rica and known popularly as "poró". In this study, two species were selected, Erythrina poeppigiana and Erythrina steyermarkii. Seed extracts were prepared in phosphate-buffered saline. The presence of lectins in the extracts was verified by hemagglutinating effect over suspensions of human erythrocytes. A selective hemagglutinating effect on erythrocytes of several mammal species, goat, horse and rabbit red cells was tested; only the latter were agglutinated by E. steyermarkii. The hemagglutinating effect of both lectins was inhibited with the following carbohydrates: D-galactose, N-acetyl galactosamine, D-lactose and D-raffinose. The lectin from E. steyermarkii was also inhibited with L-rhamnose. Both lectins were isolated with gel filtration and affinity chromatography using lactose as ligand. Fractions that proved positive were tested with the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Gel filtration and SDS-PAGE showed that these lectins have an apparent molecular mass of 50kDa, and are formed by two subunits of approximately 25 kDa. E. poeppigiana had no mitogenic effect, but the extract of E. steyermarkii had a mitogenic effect on human mononuclear cells isolated from peripheral blood. The stability of the lectins was tested at different temperature and pH ranges (4 to 100 °C) and at pH 2 to 12. Both were stable at a pH range from 2 to 10, and at temperatures from 40 to 70 °C.
Las diferentes especies de Erythrina se encuentran ampliamente distribuidas en Costa Rica y se las conoce popularmente con el nombre de "poró". En el presente estudio, se seleccionaron dos especies: Erythrina poeppigiana y Erythrina steyermarkii. Se prepararon extractos de las semillas en solución tampón salina de fosfatos y se verificó la presencia de lectinas en ellos mediante la técnica de hemaglutinación, utilizando eritrocitos humanos. Se trató de demostrar un efecto selectivo de la hemaglutinación empleando eritrocitos de varias especies de mamíferos, específicamente de carnero, caballo y conejo. Solo los eritrocitos de conejo fueron aglutinados con la lectina de E. steyermarkii. El efecto hemaglutinante de las dos lectinas fue inhibido con los siguientes carbohidratos: D-galactosa, N-D-acetil galactosamina, D-lactosa y D-rafinosa. La lectina de E. steyermarkii también fue inhibida con L-rhamnosa. Las dos lectinas fueron aisladas por filtración en gel y cromatografìa de afinidad, usando lactosa como ligando. Las fracciones que resultaron positivas se analizaron mediante la técnica de electroforesis en gel de poliacrilamida y duodecil sulfato de sodio (SDS-PAGE). Con la filtración en gel y el SDS-PAGE, se comprobó que las dos lectinas tienen una masa molecular aparente de 50 kDa y que están formadas por dos subunidades de 25 kDa, aproximadamente. Se buscó un efecto mitogénico en las dos lectinas y se encontró que sólo E. steyermarkii lo manifestaba sobre células mononucleares humanas aisladas de sangre periférica. Se determinó la estabilidad de las lectinas en diferentes ámbitos de temperatura (4 a 100 °C) y de pH (2 a 12 ). Las dos lectinas se mantuvieron estables en un rango de temperatura de 40 a 70 °C y en un pH de 2 a 10.
This paper describes the wood anatomy of Acacia gaumeri Blake, Diphysa carthagenensis Jacq., Gliricidia sepium (Jacq.) Steud., Leucaena glauca (L.) Benth., Senna racemosa (Mill) Irwin & Barneby, Murraya paniculata L.Mant., Maytenus guatemalensis Lundell, and Pimenta dioica (L.) Merr. These species are aesthetically attractive as well as hard, highly durable and resistant to insects and locally are widely used in posts, fences, sleepers and rural buildings. Samples were collected from the rainforest in Quintana Roo, Mexico. One tree for each species was collected, and macroscopic and microscopic characteristics were described and measured in wood samples, permanent slides and macerated material. Woods have diffuse porosity, simple perforation plates, alternate and opposite vessel pits and small rays. Crystals are absent only in Acacia gaumeri and Senna racemosa. Axial parenchyma aliform paratracheal, banded types and libriform fibres were common. Differences were found in rays, pore arrangement, presence of fibrotracheids, vascular tracheids and tyloses.
Se estudió la anatomía de la madera de ocho especies procedentes de asociaciones secundarias de las selvas alta y mediana subperennifolia del estado de Quintana Roo: Acacia gaumeri, Diphysa carthagenensis Gliricidia sepium, Leucaena glauca, Senna racemosa, Murraya paniculata, Maytenus guatemalensis, y Pimenta dioica, de acuerdo con la metodología establecida. Son especies de interés por su distribución, abundancia en el estado, y por los usos que tradicionalmente les han dado los campesinos mayas en postería, cercas, construcción rural durmintes, tablones y leña, debido a las cualidades de dureza y resistencia a la humedad y a los insectos. Las especies presentan porosidad difusa, los vasos con puntuaciones areoladas opuestas y alternas, la placa perforada es simple; el parénquima axial se presenta aliforme y en bandas; con cristales en todas las especies a excepción de Acacia gaumeri y Senna racemosa. Los rayos son bajos finos y numerosos; las fibras son de tipo libriforme. Las diferencias encontradas son: el arreglo de los poros, tipo de parénquima axial y radial, la presencia de fibrotraqueidas y traqueidas vasculares y tílides.
A comparison was made of the gametophytic development of Phlebodium araneosum, P. pseudoaureum and P. decumanum. Spores were collected from several Mexican localities ranging in altitude from 30 to 2300 m and sown on agar with mineral salts. Similarities in germination type and prothallial development were observed. Adult gametophytes are cordate-spathulate to cordate-reniform; gametangia are of the tipical type of the common leptosporangiate ferns. All three species share similar morphogenetic features of the gametophytes, and these do not lend additional characteristics to support the distinction of Phlebodium from Polypodium, Microgramma and Niphidium, as regard the sexual phase.
Una comparación del desarrollo del gametofito de Phlebodium araneosum, P. pseudoaureum y P. decumanum fue hecha. Las esporas fueron sembradas en agar con sales minerales. Similitudes en el tipo de germinación y desarrollo protálico fueron observadas. Los gametofitos adultos fueron cordiforme-espatulados a cordiforme-reniformes; los gametangios son del tipo común de los helechos leptosporangiados. Las tres especies muestran caracteristicas morfogenéticas del gametofito similares y no a aden características adicionales que apoyen la distinción entre Phlebodium, Polypodium, Microgramma y Niphidium, por lo que se refiere a la fase sexual.
Most Costa Rican forests have been intensively studied in recent years. One exception is the transition zone from lowland wet forest to the high elevation Quercus forest belt at the pacific slopes of the Cordillera de Talamanca. An inventory of secondary forest composition, structure and diversity was done on a specific slope (1150- 2300-m elevation) in the conservation and development project Amisconde. Thirteen plots of 500 m² were evenly spread along an elevation gradient. Specimens were collected of all woody individuals ( 3 cm DBH), dried, placed in a herbarium of morphospecies and afterwards identified. In total 90 genera within 49 families were found. The vegetation was separated in three forest types using TWINSPAN classification. Forest types were elevation based. Elevation and forest age showed (overall) no correlation with diversity using ANOVA, with the single exception of a positive correlation of the number of genera and elevation. This was opposite to the negative correlations mostly found on elevation gradients. The main factors for this positive correlation were the level of recent disturbance and the distance to primary forest, in combination with forest age.
Six new species in the genus Exobasidium are described: E. aequatorianum n. sp., parasitic on Vaccinium crenatum (Don) Sleumer from Ecuador where it is widely distributed; E. arctostaphyli Harkn., found on Arctostaphylos arbutoides (Lindl.) Hemsl., and on Comarostaphylos costaricensis Small in Costa Rica is redescribed; E. jamaicense n. sp., on Lyonia jamaicensis (Swartz) D.Don from Jamaica and possibly throughout the Caribbean range of the host genus; E. disterigmicola n.sp., on Disterigma humboldtii (Kl.) Nied., from the Talamanca Range, Costa Rica and possibly, throughout the range of its host, E. sphyrospermii n. sp.,on Sphyrospermum cordifolium Bentham in Costa Rica, E. poasanum n. sp., on Cavendishia bracteata (R. & P. ex J. St.-Hil.) Hoer., from the Poás massif in Costa Rica. Exobasidium escalloniae Gómez & Kisimova, described from Costa Rica, is now known to occur in Ecuador on the same host, Escallonia myrtilloides L.f. Exobasidium vaccinii (Fkl.) Wor. is here reported from Vaccinium floribundum H.B.K. from various Ecuadorean localities, and E. pernettyae n. sp. is described as a parasite of Pernettya prostrata (Cav.) DC in Costa Rica. With the exception of Escallonia, of saxifragaceous affinities, all hosts belong in the Ericaceae. Exobasidium arctostaphyli is a first record for the neotropical region. With the exception of E. jamaicense, not seen in the wild by us, all others have been found associated with small slugs (Mollusca: Limacidae) which are suspected to be one of the vectors of the parasite. Some biogeographical considerations are presented. The Cryptobasidiaceae Clinoconidium bullatum Syd., not collected since first described in 1925, and Clinoconidium farinosum (P. Henn.) Pat., are both parasites of Lauraceae, Cinnamomum sp. and Ocotea monteverdensis Burger, respectively, and were found in the Monteverde Reserve, Costa Rica. Drepanoconis larviformis (Speg.) Speg. is reported as a parasite of Aiouea costaricensis (Mez) Kosterm. from the cloud forests of San Gerardo de Dota, Costa Rica. Clinoconidium farinosum and Drepanoconis larviformis constitute new records for Central America.
Se describen seis nuevas especies (Exobasidiales, Exobasidiaceae): Exobasidium aequatorianum parásito de Vaccinium crenatum (Don) Sleumer en los Andes ecuatorianos; Exobasidium jamaicense como parásito de Lyonia jamaicensis (Sw.)D.Don de Jamaica, Exobasidium disterigmicola como parásito de Disterigma huboldtii (Klz.) Nied., de Costa Rica y que forma distrofias del tipo escoba de bruja, Exobasidium sphyrospermii de Costa Rica, como parásito de Sphyrospermum cordifolium Bentham, Exobasidium poasanum, de Costa Rica y que forma gigantescas pseudoagallas en hojas y yemas de Cavendishia bracteata (R. & P. ex St.-Hil.) Hoer., Exobasidium pernettyae, de Costa Rica y parásito foliar de Pernettya prostrata (Cav.) DC. Es muy posible que esas especies de parásitos se extiendan en todo el ámbito geografico de las plantas que parasitan, como lo demuestra el hallazgo de Exobasidium escalloniae Gómez & Kisimova, descrito de Costa Rica, en Escallonia myrtilloides var. patens, en Ecuador de donde tambien se registra Exobasidium vaccinii (Fkl.) Wor. Como parásito de las especies costarricenses de Arctostaphylos y Comarostaphylos, se registra, describe e lustra la especie Exobasidium arctostaphyli Hark., descrita de la coasta occidental de los E.E.U.U. lo que constituye un nuevo registro neotropical. La exploración en búsqueda de criptobasidiáceas eleva el número de Cryptobasidiales registrados en Costa Rica a tres: Clinoconidium bullatum Sydow, originalmente descrito de las inmediaciones de Grecia, Alajuela, ahora se conoce también de Monteverde, Puntarenas, como parásito de Cinnamomum spp., Clinoconidium farinosum (P.Henn.) Pat., de la misma localidad y como parásito de Ocotea monteverdensis Burger. En la Cordillera de Talamanca, se localizó una población de Aiouea costaricensis (Mez) Kosterm., con numerosas agallas foliares y caulinares causadas por Drepanoconis larviformis (Speg.) Speg. Con excepción de C. bullatum, todos son nuevos registros centroamericanos.
The floral biology, the pollination biology and the mating system were studied in two native and three introduced species of an arboretum in Venezuela. All the species presented thin, long, tubular corollas; predominantly red. The antheses were diurnal (between 04:00 and 11:00 hr). Nectar production was high, except for Salvia coccinea (Lamiaceae) (native). Nicotiana glauca (Solanaceae) (native) and Erythrina mitis (Fabaceae) (introduced) shared their hummingbird pollinators, Chlorostilbon mellisugus and Amazilia tobaci (Apodiformes, Throchilidae). S. coccinea was pollinated by Heliconius erato (Lepidoptera). Kalanchöe pinnata and K. daigremontiana (Crassulaceae) (exotic) did not receive any visits. All the species were hermaphrodite. K. daigremontiana and K. pinnata were obligate outcrossers, and S. coccinea N. glauca and E. mitis were partialy outcrossers and non-autogamus. The species presented high total biomass allocation, compared to other polination systems. The reproductive biomass allocation were allways smaller than the attraction and vegetative biomass allocation. The male biomass allocation were greater than the female biomass allocation in N. glauca, S. coccinea and E. mitis; and smaller in K. daigremontiana and K. pinnata. The introduced species did not seem to affect the reproductive efficiencies of the native species during our observation period. The lowest reproductive efficiencies in introduced species resulted as a consequence of the absence of their natural pollinators.
La biología floral, biología de polinización y sistema de apareamiento fueron estudiados en dos especies nativas y tres especies introducidas presentes en un fragmento de bosque caducifolio secundario en Venezuela. Todas las especies estudiadas presentaron corolas tubulares, largas y estrechas; predominando los colores rojos. La antesis de todas las especies fue diurna, entre las 04:00 y las 11:00. La producción de néctar fue alta, excepto para Salvia coccinea (Lamiaceae) (nativa). Nicotiana glauca (Solanaceae) (nativa) y Erythrina mitis (Fabaceae) (introducida) compartían sus polinizadores Chlorostilbon mellisugus y Amazilia tobaci (Apodiformes, Throchilidae). S. coccinea recibió visitas legítimas de Heliconius erato (Lepidóptera). Kalanchöe daigremontiana y K. pinnata (Crassulaceae) (exóticas) no recibieron ninguna visita legítima. Todas las especies fueron hermafroditas. K. daigremontiana y K. pinnata resultaron xenógamas obligadas; mientras S. coccinea, N. glauca y E. mitis resultaron parcialmente autocompatibles no autógamas. Las cinco especies mostraron una alta a-signación de biomasa total con respecto a otros sistemas de polinización. La a-signación de biomasa reproductiva fue siempre menor a las asignaciones de biomasa de atracción y de biomasa vegetativa floral. La asignación de biomasa masculina fue mayor que la femenina para N. glauca, S. coccinea y E. mitis, y menor para K. daigremontiana y K. pinnata. Las especies introducidas no parecen afectar notoriamente las eficiencias reproductivas de las especies nativas. Las eficiencias reproductivas de las especies nativas fueron superiores a las de las especies introducidas. Las eficiencias reproductivas de las especies introducidas resultaron bajas, debido a que se encuentran afectadas por la ausencia de sus polinizadores naturales.
The effect of several saline solutions (as given by six salts) and salt stress (as given by 0.1 - 2m sodium chloride solutions) on the germination of seeds of six selected tropical forest tree species was investigated. Saline solutions (0.2m) of the six salts used had highly significant effects on seed germination in most of the tree species. Sodium sulphate (Na2So4) permitted germination in the seeds of Ceiba pentandra and Tectona grandis presoaked in its 0.2m solution for 36 and 48h respectively. The Zinc sulphate (ZnSO4) solution enhanced the germination of seeds of Terminalia ivorensis and Terminalia superba. Solution of Potassium per Manganate favoured the germination of seeds of T. grandis, T. ivorensis and T. superba. In general, increase in molar concentration of NaCl adversely affected the germination rate of seeds. Sees of the two Terminalia species could withstand NaCl salt stress. Seeds of T. grandis have high ability to withstand salt stress comparatively.
Se estudió el crecimiento de Vaccinium consanguineum Klotzsch en la Cordillera de Talamanca, Costa Rica, cinco años después del incendio de 1992 , usando 50 plantas en cada uno de dos lugares. Las laturas medias fueron 72.6 + 24.6 cm en Asunción y 75.2 + 17.6 cm en Zacatales, mientras que las medias antes del incendio diferían en 30 cm. Esta diferencia puede explicarse por diferencias en condiciones climáticas locales.
White rats were inoculated with 10(6) trypomastigotes of Trypanosoma lewisi, simultaneously or two days before and after inoculation with 10(5) oocysts of T. gondii. A greater number of cysts was found in the brain of the animals having concomitant inoculations, as compared with rats inoculated with either one of the two parasites. An apparent immunosuppressive effect is likely. Since both organisms can be found in rat, it is possible that infections with T. lewisi, could make this rodent another intermediate host for Toxoplasma infections.
A ntibody dynamics (IgG and IgM) against Babesia bigemina was studied on 41 under 15 days of age from three ranches (R1, R2 and R3) in Yucatan, Mexico. Blood samples were collected every 30 days, for eight months. Sera were tested by the indirect fluorescent antibody method to detect IgG and IgM. Overall IgM seroprevalence during the calves first eight months of life was 17.1% without relation to age. Overall IgG seroprevalence was 66.8%, increasing with age. Seroprevalence in R1, R2 and R3 were 87.5%, 77.1% and 31.8% respectively. Ranches 1 and 2 were in enzootic stability. In Yucatan, the modification of management factors in ranches with enzootic instability, could increase the risk of clinical babesiosis. Cattle mobilization from ranches with enzootic instability must be strictly controlled.
Se estudió la dinámica de anticuerpos (IgG e IgM) contra Babesia bigemina en becerros explotados en condiciones del trópico mexicano. Se monitorearon 41 becerros menores de 15 días de edad de tres ranchos del estado de Yucatán, México ( R1, R2 y R3). Los becerros fueron muestreados cada 30 días edurante un período de 8 meses, para la obtención de 369 sueros. Los sueros fueron evaluados mediante la técnica de inmunofluorescencia indirecta para la detección de anticuerpos de la clase IgG e IgM contra Babesia bigemina. La seroprevalencia general de IgM en los primeros 8 meses de edad de los becerros fue de 17.1%, no presentándose un comportamiento definido con relación a la edad. La seroprevalencia general de IgG fue de 66.8%, incrementándose con relación a la edad. La seroprevalencia para los animales del R1, R2 y R3 fue de 87.5%, 77.1% y 31.8% respectivamente. El R1 y R2 se ubicaron en una situación de estabilidad enzoótica y R3 en inestabilidad enzoótica. Se concluye que en el estado de Yucatán, Mexico, la modificación de factores de manejo en los ranchos con inestabilidad enzoótica, podría favorecer la presentación de brotes clínicos de babesiosis. Se pone de manifiesto la importancia de controlar la movilización de animales de ranchos con inestabilidad enzoótica a ranchos con establidad enzoótica.
The influence of wing length on mate preference was examined in natural populations of the Neotropical guava fruit fly, Anastrepha striata Schiner, at two locations in Costa Rica. Based on evidence that the fungi are transmitted during mating, site-specific infection by Laboulbeniales fungi on the body surface was used to assess mating history. Males and females that carried fungi on the legs and/or on the ventral part of the thorax (males), and on both sides of the notum and/or the dorsal base of the abdomen (females), had significantly longer wings than males and females without fungi. This suggests that individuals of both sexes with longer wings (i.e. larger individuals) enjoy higher mating success. Fungus infection is more frequent in the wet than in the seasonally dry forest, possibly because hosts are available year-round in the wet forest.
Se estudió poblaciones naturales de la mosca frutera Anastrepha striata Schiner, en dos lugares de Costa Rica. Los hongos Laboulbeniales se transmiten en éstas durante la cópula. Hembras y machos con hongos en las patas y/o parte ventral del tórax (machos), y en ambos lados del noto y/o base dorsal del abdomen (hembras), tenían alas significativamente más largas que los individuos no parasitados. Esto sugiere que los individuos más grandes logran más apareamientos.
We evaluated the effect of interspecific competition between M. minense and C. flavipes larvae on survival in both species and on the growth of M. minense. Interspecific competition was evaluated by the inoculation of M. minense larvae (1 or 2 per host larvae: D. sacharalis) 1 to 5 days before or 3 to 8 days after the inoculation of C. flavipes eggs (one inoculation = 45 - 50 eggs). All experiments were done with ten replicas. We found a significant effect of interspecific competition on larval and pupal survival in both parasitoids and body weight in M. minense. M. minense dominated over C. flavipes, except when M. minense was inoculated 5 or more days after C. flavipes.
Evaluamos el efecto de la competencia interespecífica entre larvas de M. minense y C. flavipes en la supervivencia de la progenie de ambas especies y en el crecimiento de M. minense. La competencia interespecífica fue evaluada mediante la inoculación de larvas de M. minense (1 o 2 por larva del hospedador: D. saccharalis) 1 a 5 días antes o 3 a 8 días después de la inoculación de huevos de C. flavipes (una inoculación = 45 a 50 huevos). Se hicieron diez repeticiones de todos los experimentos. Encontramos un efecto significativo de competencia en la supervivencia larval y pupal en ambas especies parasitoides y en el peso corporal de M. minense. M. minense predominó sobre C. flavipes, excepto cuando M. minense fue inoculado 5 o mas días después de C. flavipes.
The nest pedicel of a social sphecid wasp Microstigmus nr. thripoctenus plays an important role in protecting the brood against ant predators, as inferred from data on artificial nests. A pair of artificial nests with or without pedicels was suspended from the undersides of leaves (Carludovica palmata) for 30 min to assess rates of discovery and removal of food (tuna bait) by ants (N = 36 pairs). Three-hundred and forty-three individuals of five ant species removed food at a higher frequency from nests without pedicels (83.3% of 36 nests) than for nests with pedicels (11.1% of 36 nests).
La suspensión pedicelar en la arquitectura del nido de la avispa social Microstigmus nr. thripoctenus juega un importante papel en la protección de las crías contra los depredadores, especialmente hormigas, basado de estudios con nidos artificiales. Debajo de las hojas de Carludovica palmata un nido artificial con pedicelo y otro sin pedicelo fueron suspendidos por 30 min para determinar la frecuencia de descubrimiento y eliminación de un cebo (atún) (N = 36 pares). El porcentaje de depredación fue menor (11.1%) en los nidos con pedicelo que en nidos sin pedicelo (83.3%). Se observaron 343 individuos de cinco especies de hormigas atacando los nidos artificiales.
The fibrinogenolytic activity of Lachesis muta stenophyrs venom was studied. Wistar rats catheterized at carotid artery and jugular vein were inoculated with crude venom or enzyme and changes in arterial pressure, cardiac frequency and electrocardiogram were monitored. The enzyme induced a greater fibrinogen reduction than the crude venom without any cardiovascular or histological alteration. In vitro crude venom coagulated blood whereas the enzyme reduced fibrinogen in 23%. Results suggest the potential use of the fibrinogenolytic enzyme as antithrombotic agent.
Se estudió la actividad fibrinolítica del veneno Lachesis muta stenophyrs y de su enzima fibrinogenolítica. Ratas Wistar cateterizadas en la arteria carótida y vena yugular fueron inoculadas con el veneno crudo o la enzima. Se monitoreó los cambios en la presión arterial, frecuencia cardíaca y electrocardiograma. La enzima indujo una mayor reducción del fibrinógeno que el veneno crudo sin causar alteraciones cardiovasculares o histológicas. In vitro el veneno crudo coaguló la sangre mientras que la enzima redujo el fibrinógeno en un 23%. Los resultados sugieren el uso potencial de la enzima fibrinogenolítica como agente antitrombótico.
Fall reproduction is a common pattern in viviparous lizards from Mexican mountains. The reproductive pattern of Sceloporus palaciosi is seasonal but asynchronous between sexes. Males show testicular development in May and June whereas females ovulate in October. We suggest that the same environmental stimulous to reproduction occur twice a year, but the internal system determines the response of both sexes to different seasons, and fall stimulation allows early sexual maturity in females.
La riqueza avifaunística en los manglares es relativamente alta contrastando con su pobre diversidad florística. Durante 18 meses (julio 1986 a diciembre 1987) visité por ocho dias cada dos semanas un área de manglar de 200 hectáreas en Chomes, noroeste de Costa Rica. En estas visitas cuantifiqué la actividad reproductiva de las especies residentes de este manglar. El 55% de las 69 aves terrestres residentes se reproducen en el manglar. Probablemente el número de especies así como el número de individuos que se reproducen en este ecosistema se ha incrementado con la destrucción de los bosques originales que cubrían las tierras circundantes. La destrucción de los bosques aledaños así como la del mismo manglar, incrementa el riesgo de extinción local de aquellas especies que utilizan este ecosistema como su hábitat primario, incluyendo a Amazilia boucardi, una especie endémica a los manglares de Costa Rica y cuyo límite norte de distribución es precisamente Chomes.
A lower mastodont molar was found in Nacaome river, Nicoya, Guanacaste, Costa Rica. It is a Pleistocene specimen of Cuvieronius hyodon. C. hyodon and Haplomastodon waringi, mountain and savanna mastodonts respectively, have been found in the same place. This evidence and the dental morphology suggest that they were seasonaly simpatric species with different alimentary niches. Probably H. haringi fed on savanna or prairie plants (very ligneous with high silica concentration, e.g. Cyperaceae ) whereas C. hyodon consumed softer plants (the enamel is less damaged).
We compared characteristics of a population of nine-banded armadillos (Dasypus novemcinctus) studied in the southern United States with a population found in the Atlantic coastal rainforest of Brazil. Adult armadillos in Brazil weighed less than those in the U.S., but when weight was accounted for, did not differ in other measures of body size. However, juveniles in the U.S. were proportionately bigger than those in Brazil. Armadillos in Brazil were less abundant (numbers sighted per h of observation) and were active later at night than those in the U.S. Adult sex-ratios were male-biased in both populations. Finally, there was no significant difference in the incidence of littermate associations observed in the two populations, but groups of juveniles (which included non-littermates) were observed more frequently in the U.S. Many of these differences may be due to the fact that armadillos are hunted extensively in Brazil but not in the United States.
Eight white-tailed deer were released in La Emilia farm, Guanacaste, Costa Rica, during November 1987 and March 1988. Four females were from an insular population (San Lucas Island, ISL) and had been raised in captivity up to 9 months of age when they were liberated. The remaining four were adults, three females and one male from Palo Verde National Park (PV). All deer were marked with radio telemetry collars and followed for a 13-month period. The four deer from ISL were also observed directly for 8 months. The home range and habitat use of each group was determined and compared. The average daily home range was 18.3 ha for the ISL group and 18.4 ha for the PV group; the differences between these values were not significant (Analysis of Variance, ANOVA, P .05). The home ranges of the two groups were not significantly different between seasons; however the ISL group did show a significant difference between the two seasons (ANOVA, P< .05). The ISL group used eight habitat types of the 14 available, while the PV group utilized 11 habitat types; differences were found in the habitat preferences between the two groups (X² P< .001). Habitat utilization was significantly different between the two groups in both the dry season and the wet season (X², P< .001). The most utilized habitats (confidence intervals of Bonferroni) of the ISL group were grazing land, forest plantations (Pithecelobium saman), cultivated land (sorghum and fruits), and riparian vegetation. The PV group used habitats with certain forest cover, chaparral, jaraguales and guacimales (Guazuma ulmifolia).
Se liberaron ocho venados cola blanca (Odocoileus virginianus) en finca La Emilia, Guanacaste, Costa Rica entre noviembre de 1987 y 1988; cuatro hembras juveniles de una población insular (Isla San Lucas, ISL) fueron criadas en cautiverio y liberadas a los nueve meses de edad. Los restantes fueron adultos: tres hembras y un macho procedentes del Parque Nacional Palo Verde (PV). Todos los venados fueron marcados con collares radiotransmisores y monitoreados por 13 meses. La observación visual se uso por ocho meses para los venados de la ISL. Se determinó el ámbito de hogar (AH) y utilización del hábitat de los venados liberados. El AH promedio diario fue de 18.2 ha para el grupo de ISL y 18.5 para los venados de PV; no se encontraron diferencias entre los AH entre grupos (Análisis de Varianza ANDEVA, P .05). Los AH estacionales no presentaron diferencias significativas; sin embargo, el grupo ISL sí mostró diferencias entre las dos estaciones (ANDEVA, P< .05). El grupo de ISL utilizó ocho tipos de hábitats, de los 14 disponibles y, el grupo de PV 11. Los dos grupos de venados utilizaron los hábitats de manera diferencial (X², P< .001). La utilización de hábitat fue diferente entre los grupos durante la época seca y durante la estación húmeda (X², P< .001). Los hábitat seleccionados (Intervalos de Confianza de Bonferroni) por los venados de ISL fueron plantaciones forestales (Pithecelobium saman), cultivos agrícolas (sorgo y frutales), área urbana, vegetación riparia y pastizales; para el grupo de PV fueron guacimales (Guazuma ulmifolia), charrales, áreas con cobertura boscosa y jaraguales.