Revista de Biología Tropical

Conserving biological diversity in the tropics: the role of private nature reserves in Costa Rica

**Biología floral de Passiflora foetida (Passifloraceae)**

A reproductive experiment shows that Passiflora foetida is autocompatible. Observations of floral characteristics and visitors during anthesis, plus the analysis of pollen allowed identification of floral syndrome (melittophily) and functions for each visitor. Anthesis occurs from 6 to 11 AM. Three floral phases were identified: 1) stigmas above anthers, 2) stigmas at anther level, 3) stigmas above anthers; radii, petals and sepals become incurved. The stigmas are receptive during the whole anthesis. The concentration of sugars in nectar is 34 %. The predominant color in the visible spectrum is white. The stamens and the gynoecium contrast against the limen and androgynophore in the UV spectrum, maybe a nectar guide. Three species of hymenopterans are the most frequent and constant visitors: Ptiloglossa tarsata (Colletidae) always contact the anthers and the stigmas while sucking nectar, carry a high percentage of P. foetida pollen and visit flowers in phases 1 and 2; they can be considered the main pollinators. Pseudaugochloropsis sp. (Halictidae) rarely contact anthers and stigmas while puncturing the limen to access nectar, and visit flowers in phases 2 and 3; they are nectar robbers that rarely pollinate. Augochlorella sp. (Halictidae) collect pollen without touching the stigmas and visit flowers in phases 2 and 3; they are pollen thieves.

Un experimento reproductivo muestra que Passiflora foetida es autocompatible. Observaciones de las características florales y de los visitantes durante la antesis, más el análisis del polen transportado, permitieron identificar el síndrome floral (melitofilia) y las funciones de cada visitante. La antesis ocurre desde las 6 hasta las 11 hs. Se identificaron 3 fases florales: 1) estigmas por encima de las anteras, 2) estigmas a la altura de las anteras, 3) estigmas por encima de las anteras; los radii, los pétalos y los sépalos se incurvan. Los estigmas están receptivos durante toda la antesis. La concentración de azúcares del néctar es 34 %. El color predominante en el espectro visible es el blanco. En el espectro UV, los estambres y el gineceo contrastan con el limen y el androginóforo; pueden ser una guía de néctar. Tres especies de himenópteros fueron los visitantes más frecuentes y constantes: Ptiloglossa tarsata (Colletidae) siempre contactan las anteras y los estigmas cuando liban, transportan un alto porcentaje de polen de P. foetida y visitan flores en fase 1 y 2; pueden ser considerados los principales polinizadores. Pseudaugochloropsis sp. (Halictidae) raramente contactan las anteras o los estigmas cuando perforan el limen para acceder al néctar y visitan flores en fase 2 y 3; son ladrones de néctar que raramente polinizan. Augochlorella sp. (Halictidae) recolectan polen sin tocar los estigmas y visitan flores en fase 2 y 3; son hurtadores de polen.

**Actividad gastrointestinal del extracto acuoso bruto de Quassia amara (Simarubaceae)**

The gastrointestinal activity of an aqueous extract of the dry wood of Quassia amara was investigated using animal models. Oral administration of the extract to mice produces an increase of gastrointestinal transit at doses of 500 and 1000 mg/kg. The antiulcerogenic activity was measured inducing ulcers on Sprague-Dowly rats with indomethacin or ethanol and by the induction of stress. The experimental group was treated orally with the extract, using doses of 250, 500 and 1000 mg/kg before inducing the ulcers. Animals treated orally with 0.5 ml of water and ranitidine (50 mg/kg) were used as controls. All the animals treated with the extract at doses of 500 and 1000 mg/kg showed important protection against ulcer generation. Piloric ligation was used to stablish the activity on total acidity, peptic activity, non-protein sulfhydryl groups, and mucus production. Animals treated with 1000 mg/kg showed a reduction on acidity and peptic activity. No activity was detected on mucus production and non-protein sulfhydryl groups at these dosis but with 1500 mg/kg they showed an increase non-protein sulfhydryl groups producction.

En este estudio se ha investigado el efecto del extracto acuoso bruto de Q. amara a nivel gastrointestinal utilizando varios modelos experimentales en animales. Los resultados muestran que este extracto a dosis de 500 y 1000 mg/kg produce un aumento del tránsito gastrointestinal y que es capaz de inhibir las lesiones inducidas por la indometacina, el alcohol y el estrés. Los animales tratados con dosis de 1000 mg/kg mostraron disminución de la acidez de los contenidos estomacales y de la actividad péptica y un incremento en la cantidad del moco protector de la mucosa.

Presencia de micorrizas en orquídeas de un jardín botánico neotropical

Mycorrhizal occurrence was tested in roots of 24 terrestrial and epiphytic orchid species growing at the Lankester Botanical Gardens (Cartago, Costa Rica). Standard staining and light microscopy were used to search for pelotons. Roots in contact with the substrate harbor extensive mycorrhyzal fungi. There may be a wide distribution and density of the fungal flora in the secondary forests of the site, this could explain the high natural regeneration of orchids on the garden.

**Biomass-diversity relations of epiphytic bryophytes on small Quercus copeyensis stems in a Costa Rican montane cloud forest**

Se muestreó briófitas epífitas sobre tallos pequeños de Quercus copeyensis Müll. en un bosque montano nuboso maduro (Talamanca, Costa Rica). Se muetreó a 0.8-1.8 m en cinco tallos (d.a.p. 1.8 -2.8 cm, hallándose 22 especies de musgos y 22 de hepáticas). La biomasa de briófitas ("briomasa") se correlacionó con la frecuencia, contribuyendo los musgos 54-99% . Un 14% de las especies contribuyó casi el 90% de la briomasa, sobresaliendo Pilotrichella flexilis (Hedw.) Ångstr., Rigodium sp. 1, Porotrichodendron superbum (Taylor) Broth., Prionodon densus (Hedw.) Müll. Hal., Neckera chilensis Schimp. ex Mont. y Plagiochila guilleminiana Nees & Mont. Estas especies podrían jugar un papel importante en la regulación del flujo de agua.

In vitro organogenesis in Albizia guachapele, Cedrella odorata and Swietenia macrophylla (Fabaceae, Meliaceae)

Regeneration of adventitious buds was achieved from hypocotyl explants of Albizia guachapele (Guayaquil) and Cedrella odorata (Spanish cedar), and from epicotyl explants from Swietenia macrophylla (Honduran Mahogany). Seeds were obtained from CATIE's Latin American Forest Seed Bank and germinated under aseptic conditions. Four explants were cultured in each Petri dish on half strength modified Murashige and Skoog basal medium, and five concentrations of BA (benzyladenine) were studied; A. guachapele and S. macrophylla responded positively to the presence of BA in the culture medium. Otherwise, Cedrella odorata required media supplemented with citokinin and auxin combinations to induce adventitious buds.

**Cryptobiota associated to dead Acropora palmata (Scleractinia: Acroporidae) coral, Isla Grande, Colombian Caribbean**

Cryptobiota of dead fragments of five branches in live position and five fallen pieces of the coral Acropora palmata each one of approximate 1dm3, covered by filamentous algae were extracted from the north reef crest of Isla Grande (Colombian Caribbean), in April 1991. There were three groups of organisms according to size and position (on and within the coral): 1) mobile epibenthos, mainly microcrustaceans that live among the filamentous algae 2) boring microcryptobiota, located in the layer between the epilithic organisms and the coral skeleton itself and, 3) perforating macrocryptobionts that bore and penetrate the coral skeleton. Polychaetes, sipuncu-lids, mollusks and crustaceans were most abundant in the last group. There were no differences in macrocryptobiont composition between standing dead branches and fallen fragments. There was a large variation in total biomass and type and density of macro-cryptobionts, possibly associated to stochastic factors such as placement and thickness of branches and small scale variations in recruitment

La criptobiota de diez fragmentos coralinos muertos de Acropora palmata, de 10 dm3 cada uno, cubiertos de algas filamentosas, se colectó en abril de 1991en la cresta arrecifal de Isla Grande (Caribe colombiano). Se halló tres grupos: 1) móviles epibentónicos asociados a las algas filamentosas y conformados principalmente por microcrustáceos; 2) microcriptobiontes perforantes, ubicados en la capa intermedia entre los organismos epilíticos y el esqueleto del coral y 3) macrocriptobiontes que perforan todo el cuerpo del esqueleto coralino (principalmente poliquetos, sipuncúlidos, moluscos y crustáceos). No se encontraron diferencias en la composición de los macrocriptobiontes que habitan los corales en posición de vida y los fragmentos caidos sobre el fondo. Se presentó una amplia variación en biomasa total, tipo y densidad de macrocriptobiontes, posiblemente asociada a factores estocásticos tales como la ubicación y grosor de las ramas, y variaciones del reclutamiento a pequeña escala.

Superficial sediments and their relation to polychaete families in a subtropical embayment, Mexico

The soft bottoms in front of Mazatlan Bay and "Isla de la Piedra" Peninsula were studied to produce maps (depth, grain size and organic matter content in sediments). Sixty samples were obtained with a 30 x 30 van Veen grab (4-21 m depth) and polychaetewere extracted from 21 subsamples. Grain size ranged from -1.05 phi (gravel) to 3.81 phi (very fine sand), with fine sand predominating. Organic matter content in sediment was 0.91-3.06 % (most values = 1-2 %). Thirty polychaete families (905 individuals/m2 in mean) were found, and Cirratulidae, Spionidae, Onuphidae, and Pilargiidae were dominant. Pearson's correlation of grain size, organic matter and depth proved significant (p<0.01; p<0.02), confirming the observed relationships of distribution patterns in the area. A Principal Component Analysis showed the association of several families to depth (Factor 1), to grain size (Factor 2), and to organic matter (Factor 3). Nevertheless, the distribution of polychaete families in the area may be governed by the combination of the three abiotic variables. Results indicated that abiotic and biotic variables have not changed considerably since 1980

Se realizó una caracterización de los fondos blandos de la bahía de Mazatlán y de la Península "Isla de la Piedra" a través de mapas de profundidad, tamaño de grano y materia orgánica en sedimentos. Se recolectaron 60 muestras entre 4 y 21 m de profundidad con una draga van Veen de 30 x 30 cm. De estas 60 muestras, se recolectó sedimento en 21 localidades para el estudio de las familias de poliquetos. El tamaño de grano de los sedimentos osciló entre 1.82 phi (arena mediana) y 3.81 phi (arena muy fina), dominando la arena fina. El contenido de materia orgánica varió entre 0.91 y 3.06 %, siendo los valores comprendidos entre 1 y 2 %, los más frecuentes. En total se recolectaron 30 familias de poliquetos (905 individuos/m2 en promedio), de las cuales Cirratulidae, Spionidae, Onuphidae y Pilargiidae resultaron dominantes. Los valores de correlación de Pearson entre el tamaño de grano, la materia orgánica y la profundidad resultaron significativos (p<0.01; p<0.02), lo que confirma las relaciones observadas en los patrones de distribución a lo largo del área de estudio. El análisis de componentes principales mostró la asociación de varias familias con la profundidad (factor 1), con el tamaño de grano (factor 2) y con la materia orgánica (factor 3). Sin embargo, se sugiere que la distribución de las familias de poliquetos en el área de estudio está gobernada por la combinación de las 3 variables abióticas. Los resultados obtenidos aquí indican que las variables abiótica y bióticas no han cambiado considerablemente desde 1980.

Composición química de la fauna de acompañamiento del camarón de Veracruz (Golfo de México)

Chemical composition and energy content of the shrimp by-catch used for human and livestock consumption were studied in Alvarado, Veracruz (Gulf of Mexico). Five on-board samplings were done between September 1994 and March 1995 on shrimp ships off Veracruz. The samples were frozen on board for laboratory analysis of the edible portion, they included 16 families and 22 species of fishes and 1 mollusc (squid). After moisture, the crude protein was the most abundant chemical fraction (14.3 and 19.6%); carbohydrates were numerically variable in all groups (2.1 to 7.4%); ether extract (lipids) was less abundant but variable (0.5 to 3.8%), ashes were 0.10 to 0.24%. Crude energy was less variable numerically (4.5 to 5.2 kcal/g); 12 species are used as animal feed and only Pristipomoides aquilonaris was reported as exclusively used for this purpose: chemical composition was similar in species used for human and for livestock consumption; Anchoa hepsetus, Synodus foetens, Cynoscion arenarius, Upeneus parvus and Trichiurus lepturus are recomended for human consumption, specially for low economic level areas of Gulf of Mexico.

La composición química aproximada y la energía de las especies acompañantes del camarón utilizadas para consumo humano y animal se estudió en Alvarado, Vereacruz (Golfo de México). Cinco muestreos se realizaron entre septiembre de 1994 y marzo de 1995 en barcos camaroneros. Las muestras se congelaron a bordo para los análisis de laboratorio de la porción comestible. Los resultados indicaron 16 familias, 22 especies de peces y 1 molusco (calamar). Después de la humedad, la fracción química más abundante fue la proteína cruda con valores entre 14.3 y 19.6%. Los hidratos de carbono fueron desde 2.1 a 7.4%. El extracto etéreo (lípidos) fue menos abundante pero variable numéricamente (0.5 a 3.8%), las cenizas se cuantificaron entre 0.10 y 0.24%. La energía presentó la menor variación numérica (4.5 a 5.2 kcal/g). 12 especies son empleadas como alimento animal y solo Pristipomoides aquilonaris se reportó como de uso exclusivo para este propósito; la composición química fue similar a la de las especies de consumo humano. Anchoa hepsetus, Synodus foetens, Cynoscion arenarius, Upeneus parvus y Trichiurus lepturus, se recomiendan para alimentación humana, especialmento por su bajo costo en la costa del Golfo de México.

**Distribución, abundancia y reproducción de Opisthonema oglinum (Pisces: Clupeidae) en la plataforma continental del sur del Golfo de México**

At present the ecological understanding and evaluation of tropical demersal fish communities have their bases on studies about the biology and ecology of dominant species. The Campeche Sound, in the southern Gulf of Mexico, has more than 300 species in the demersal fish community and 30 are dominants. Among these species, Opisthonema oglinum is dominant by its frequency, distribution and abundance. This work determined the pattern of abundance and distribution of O. oglinum, and its reproduction, maturity and recruitment. Fish were collected with a shrimp trawl net during six oceanographic cruises in the Campeche Sound. The cruises correspond with the three characteristic seasons in the area: rainy, "nortes", and dry season. A total of 813 individuals with sizes between 56 and 205 mm of total length were collected; they weighted 30 211.5 g. O. oglinum is a typical pelagic-neritic species, and is estuarine dependent. This species occurs in the inner shelf waters of the Campeche Sound, less than 36 m deep and mainly in areas influenced by coastal discharges. It also occurs in the Terminos Lagoon (southern Campeche Sound) and occasionally in the riverine systems that drain into the lagoon. The highest biomass and density are on depths lesser than 20 m, in June and August-October. The high density of juveniles mainly determines the higher biomass. Maturity can start at a total length of 126 mm, but the size of first maturity is 135 mm of total length. Reproduction occurs from May to October with two evident peaks during May and August in depths greater than 18 m. The juveniles are found in the shelf and inside of the Terminos Lagoon. Recruitment is from June to October (rainy season). The visceral and gonadic indices showed that the greatest alimentary activity is from June to August and in November. The condition factor is lowest in June, where the recruitment is highest, and highest in November, after spawning.

Se analizan diversos aspectos de la biología y ecología de Opisthonema oglinum con base en 813 individuos obtenidos en seis cruceros oceanográficos. Esta especie dependiente estuarina, se distribuye en la Sonda de Campeche entre los 12 y 36 m. Las hembras tienen una talla de primera madurez de 135 mm de LT. Se reproduce desde mayo a octubre, con dos máximos en mayo y agosto, a profundidades mayores de 18 m. Los juveniles se encuentran en la plataforma y dentro de la Laguna de Términos. El reclutamiento se presenta en junio y octubre. Las máximas abundancias se presentan alrededor de las isobatas de 12 y 36 m, y en nortes en el área carbonatada.

Peces de la plataforma continental de Michoacán y sus relaciones regionales en el Pacífico mexicano

The ichthyofauna from the continental shelf of Michoacan (Mexico) was surveyed from June 1987 through June 1992 to produce a checklist of 257 species. The sample size and collection representativeness were validated by fitting a logistic model for the accumulative number of species (St=298.86(1-e-0.122t)). In agreement with this model, 85% of the maximum forecast for cumulative species that can be caught under the same sampling conditions (298), have been identified. A probable scenario for the regional species inter-relationships was obtained with a multivariate analysis that includes 1180 species (rows) belonging to 16 checklists (columns) of the northwestern Pacific Ocean ichthyofauna. From the analysis, the species composition on the Pacific shelf of Michoacan seems to be influenced by conditions similar to those of northern areas (lower Gulf of California) and not only by the physiography of the narrow coastal shelf of Michoacan.

Como resultado de 18 campañas de muestreo llevadas a cabo desde junio de 1987 a junio de 1992 en la plataforma continental de Michoacán (México), se presenta un listado sistemático que incluye a 257 especies de peces. Se determinó la representatividad de la muestra a nivel regional ajustando el número acumulativo de especies a una curva de tipo logístico. El resultado señala que se cuenta con mas del 85% del total de especies que teóricamente podrían capturarse en la región (298) en las mismas condiciones de muestreo. A partir de una matriz que incluye 1180 especies (renglones) correspondientes a 16 listados (columnas) elaborados por diversos autores para el Pacifico nor-oriental, se establecen las probables relaciones regionales por medio de un análisis jerárquico de clasificación. Se concluye que las condiciones ambientales con influencia en la boca del Golfo de California coadyuvan a determinar la riqueza de especies marinas en la plataforma continental de Michoacán.

Composición y distribución de la ictiofauna en la Laguna del Mar Muerto, Pacifico mexicano

Fish composition was sampled in Mar Muerto Lagoon (Mexico) between 1991 and 1993. A total of 27 971 fish with a weight of 120.9 kg were collected. The total sample consists of 29 families, 45 genera and 66 species. The highest number of species is in the area with strong marine influence (near Tonala Inlet), abundant coastal vegetation and fluvial discharge. The lowest number of species is in the inner part of the lagoon, which is hipersaline in the dry season and of low salinity in the rainy season. The species with broad distribution are Diapterus peruvianus, Lile stolifera, Anchoa lucida, Anchoa mundeola, Mugil curema, Atherinella guatemalensis and Anchovia macrolepidota.

La Laguna del Mar Muerto, Oaxaca-Chiapas fue muestreada entre 1991 y 1993 con el objetivo de caracterizar la ictiofauna en cuanto a su composición y abundancia. Se colectaron un total de 27 971 peces que aportaron 120.9 kg. La ictiofauna de la región está caracterizada por 29 familias, 45 géneros y 66 especies. El mayor número de especies se presenta en la parte sureste de la laguna (cerca de la Boca de Tonalá), área con mayor influencia marina, abundante vegetación costera y mayor descarga fluvial. El menor número de especies se presenta en la parte más interna de la laguna, caracterizada por hipersalinidad en la época de secas y baja salinidad en la época de lluvias. Las especies que presentan amplia distribución son Diapterus peruvianus, Lile stolifera, Anchoa lucida, Anchoa mundeola, Mugil curema, Atherinella guatemalensis y Anchovia macrolepidota.

Species composition, abundance and distribution of zooplankton in a tropical eutrophic lake: Lake Catemaco, México

From April 1992 to May 1993, zooplankton samples were collected monthly by means of horizontal tows in nine sites of the lake. Prior to the towing, temperature of surface water, transparency (Secchi), pH and dissolved oxygen were evaluated. A total of 31 zooplankton forms, including 14 species of rotifers, three copepods, five cladocerans and one ostracod, as well as protozoans (mainly vorticellids and ciliates), were detected. Rotifers were the dominant organisms, mainly Brachionus havanaensis (27.6 ind l-¹), B. angularis (6.9 ind l-¹), Keratella cochlearis (4.9 ind l-¹), Conochilus unicornis (10.8 ind l-¹) and C. dossuarius (3.1 ind l-¹). Within crustaceans, higher densities were shown by larvae (nauplii and copepodites) of calanoid (16.8 ind l-¹) and cyclopoid (15.6 ind l-¹) copepods, as well as Arctodiaptomus dorsalis (2 ind l-¹), Mesocyclops edax (0.5 ind l-¹), and the cladocerans Bosmina longirostris (1.6 ind l-¹) and Diaphanosoma brachyurum (0.5 ind l-¹). Densities were low, probably because of a high predation pressure imposed by fishes. A gradual increase in total zooplankton density related with a progressive diminution of transparency was observed throughout the sampling period. Zooplankton densities in the stations located at the central part of the lake were higher when compared with those at a more peripheral position. Time variation in rotifer's relative abundance was directly related to temperature fluctuations. The low density and diversity values, the small size of the zooplankters, the presence of an important number of indicator species, and the calanoid copepods: other planktonic crustaceans low ratio, are all indicators of eutrophy. Evidences suggest that the eutrophication process of Lake Catemaco is still progressing rapidly.

Entre abril de 1992 y mayo de 1993, se realizaron mensualmente recolectas subsuperficiales de zooplancton, con red, en nueve localidades del lago, en donde también se determinaron la temperatura superficial, la visibilidad del disco de Secchi, el pH y la concentración de oxígeno disuelto. Entre las 31 formas de plancton detectadas en las distintas submuestras se registraron 14 especies de rotíferos, tres de copépodos, cinco de cladóceros y un ostrácodo, además de protozoarios, principalmente vorticélidos y ciliados. Los rotíferos fueron los organismos más abundantes; Brachionus havanaensis fue la especie dominante, seguida por Conochilus unicornis, Brachionus angularis, Keratella cochlearis y Conochilus dossuarius. Entre los copépodos destacaron Arctodiaptomus dorsalis y Mesocyclops edax, además de sus nauplios y copepoditos, y entre los cladóceros Diaphanosoma brachyurum, Bosmina longirostris, y Bosminopsis sp. Las densidades observadas en los grupos dominantes del zooplancton fueron bajas; sin embargo, a lo largo del período de estudio se observó un incremento paulatino en la densidad zooplantónica total, relacionado con una disminución progresiva de la visibilidad del disco de Secchi. Las densidades más altas se detectaron en los sitios más alejados de la costa. Las variaciones estacionales en la abundancia relativa de los rotíferos estuvieron estrechamente relacionadas con las fluctuaciones de la temperatura. Los bajos valores de densidad y diversidad, el pequeño tamaño de los zooplancters, la presencia de un importante número de especies indicadoras y la baja razón copepodos calanoides: otros crustáceos planctónicos, son todos indicadores de condiciones eutróficas. Además, existen evidencias de que el proceso de eutrofización del lago está avanzando aceleradamente.

**Spatial distribution, territoriality and sound production by tropical cryptic butterflies (Hamadryas, Lepidoptera: Nymphalidae): implications for the "industrial melanism" debate**

Neotropical butterflies of the genus Hamadryas, noted by the emission of sound, spend much time perching on trees and are believed to be cryptically patterned and colored with respect to tree trunks and branches they use as perching sites, but the subject had not been studied previously. This paper describes spatial distribution, territoriality and sound production in five species, under natural conditions: Hamadryas amphinome (Lucas, 1853), H. februa (Godart, 1824), H. feronia (Fruhstorfer, 1916), H. glauconome (Bates, 1864) and H. guatemalena (Bates, 1864). Tree characteristics and use by butterflies were recorded under natural conditions in open habitats (grassland thinly covered with trees) in Costa Rica and Panama, avoiding the problems that affected previous natural selection studies in Biston betularia (the "industrial melanism" moth). Males perched on the trees and used them as courting territories. The butterflies perched more often on some individual trees, and did not use others. The general tree bark ("background") color tended to match wing coloration, while presence of food, position of trees along flight routes, tree size, bark texture, and lichen cover were not associated with the frequency of perching on the trees. Most individuals that perched in the study sites were males. Species differed in perching height and populations of H. februa perched at the same heights in both countries; H. feronia moves to higher perches near day's end. The relative use of branches and trunks is not related to the time of day but reflects the typical perching height of each species. The northern side of trees is less used and cardinal side distribution is independent of time of day. Perches exposed to direct sunlight are less used in hot days. All species perch with the head downwards. Perching males frequently fly towards other Hamadryas as well as towards tethered cardboard models. Trees with experimentally removed males were taken by newcomers 32 times more often than trees with resident males. Each marked H. feronia male was seen perching on 1-4 trees daily, without difference between seasons, and each tree used had a minimum daily mean of 1.5 perching butterflies. Most H. feronia interactions occur from 13:00 through 15:00 hours and are more frequent in the rainy season. At night males share perches. Sound emission was studied by using non-destructive experimental methods (N=858) and with a scanning electron microscope. Both sexes emit sound and the sound apparatus, located in the forewing, is percussive, not stridulatory. At the end of the upward wingstroke, the wings are clapped and modified r-m1-2 veins meet at a speed of approximately 1420 mm/s, producing the characteristic clicks. Wingbeat frequency of free-flying individuals is 20-29 Hz. There is some wing deformation during movement. Clicks last a mean of 1.38 ms with mean intervals of 43.74 ms and the component frequencies concentrate around 2.4 kHz, matching Hamadryas hearing capacity and being appropriate for the acoustic conditions of habitat. The swollen Sc vein is present exclusively in Hamadryas; has a serpentine structure inside and probably acts as resonance box. Growth of the sound apparatus may be checked by its effect on flight capacity, physiological costs and ecological reasons. All Hamadryas have a membrane, shaped as an elongated cupola, in the costal cell, that acts as ear. A second and smaller ear has four chambers and may detect predatory bats when the insects are perching at night. Field observations showed that Hamadryas spp. emit audible clicks when approached by potential predators, to defend territories from other Hamadryas and in at least one species also during courtship. Severe wing damage, common in wild Hamadryas almost never affects the section with the sound mechanism. A review of the literature shows that more than 50 species of lepidopterans (11 families) emit sound audible to humans and suggests that sound mechanisms evolved several times. In general, lepidopteran sound is used basically as a warning to predators and for intraspecific communication.

Las Hamadryas son mariposas neotropicales que emiten sonido y pasan mucho tiempo posadas en árboles, donde son crípticas. Se estudió cinco especies en Costa Rica y Panama. Cada especie tiene una altura característica para posarse. Se posaron menos del lado sur de los árboles y evitaron las partes soleadas en días calurosos. Los machos dejaron su percha para volar hacia otras Hamadryas y hacia "mariposas" de cartón. Cuando se retiró los machos de los árboles éstos fueron tomados con mucha mayor frecuencia por otros machos. La mayoría de las interacciones aéreas de H. feronia se dieron entre las 13:00 y las 15:00 h y fueron más frecuentes en la estación lluviosa. De noche, los machos compartían los árboles. El sonido característico del grupo es producido por venas modificadas en las alas delanteras.

Diversity and distribution of small terrestrial rodents along a disturbance gradient in montane Costa Rica

A total of 389 rodent captures in five unequally disturbed habitats in a Costa Rican montane cloud forest corresponded to 185 individuals (seven species, two families). Species richness was similar for all habitats, averaging 4-5 species/habitat. Population density and capture frequency were higher in moderately disturbed habitats; Peromyscus mexicanus and Scotinomys xerampelinus were four to five times more common than other murids. These species represented 79.4 % of all captures and 73.5 % of all captured individuals. Heteromyid species were rarely trapped. The importance of disturbance-mediated within-habitat microenvironmental heterogeneity for terrestrial small-sized rodent populations is stressed.

Se estudió la distribución y diversidad de roedores terrestres en cinco hábitats perturbados en un área de bosque montano nuboso en Costa Rica. Un total de 389 capturas correspondió a 185 individuos (siete especies en 2 familias). La riqueza de especies resultó muy similar para todos los hábitats, con 4-5 especies/hábitat. La densidad de población y la frecuencia de captura fueron más altas en hábitats con niveles intermedios de perturbación; Peromyscus mexicanus y Scotinomys xerampelinus fueron cuatro a cinco veces más comunes que otras especies de Muridae. Estas representaron el 79.4 % de todas las capturas y el 73.5 % de todos los individuos. Se capturo pocos Heteromyidae.

**Especies de Eimeria (Eucoccidida: Eimeriidae) en la rata de milpa Sigmodon hispidus de Costa Rica**

Cotton rats (Sigmodon hispidus) were collected from Ojo de Agua, Alajuela (N=74) and Cañas, Guanacaste (N=29). Feces had 31 E. sigmodontis, nine E. tuskegeensis, eight E. roperi, three E. webbae and two Eimeria sp. This is the first report of these coccidian parasites for Costa Rica.

Los equinodermos (Echinodermata) del arrecife de Cabo Pulmo, Pacífico de México

A systematic list of the echinoderms from Cabo Pulmo reef, Pacific coast of México (23.5° N), is presented. Data were obtained from field surveys (1986 to 1993), and complemented with literature searches. A total of 38 species have been reported at Cabo Pulmo, but only 25 of them were actually observed in the reef during our visits. This finding suggests that community structure and composition have changed in important ways since 1943, date of the first reports of echinoderms for the locality.

Este trabajo presenta una lista sistemática de los equinodermos del arrecife de Cabo Pulmo, México. Los datos fueron obtenidos de revisiones de literatura y labores de campo llevadas a cabo entre los años de 1986 a 1993. Un total de 38 especies han sido registradas para Cabo Pulmo, pero sólo 25 de ellas fueron observadas directamente en el campo durante nuestras visitas, lo que sugiere que la estructura y composición de la comunidad han cambiado de forma importante desde 1943, fecha de los primeros registros de equinodermos para la localidad.

Theletrum lamothei sp. nov. (Digenea), parasite of Echidna nocturna from Cuajiniquil, Guanacaste, and other digenes of marine fishes from Costa Rica

A new species of Theletrum is described from the intestine of two palenose morays, Echidna nocturna, collected in Cuajiniquil, Guanacaste Province, Costa Rica. The new species differs from the type species, T. fustiforme Linton, 1910 by having a subspherical pars prostatica, a subspherical seminal vesicle extending anteriorly to the anterior border of the acetabulum, by the presence of a poorly developed hermaphroditic sac, and by having a larger body size. We also report eight additional species of digeneans parasitizing marine fishes in several localities along the Atlantic and Pacific coast of Costa Rica: Bianium simonei, Didymozoinae (metacercariae), Ectenurus virgulus, Hypocreadium myohelicatum, Lecithochirium microstomum, Pseudolecithaster sp., Stephanostomum casum, and Tergestia laticollis. In addition, we present an updated list of helminth parasites of marine fish from Costa Rica and discuss the importance of including parasites as an integral part of biodiversity inventories.

Se describe una especie nueva de digéneo del género Theletrum, parásito del intestino de una "morena pecosa", Echidna nocturna, recolectada en Playa Cuajiniquil, Provincia de Guanacaste, Costa Rica. La nueva especie es diferente de T. fustiforme Linton, 1910, la especie tipo, por presentar una pars prostatica subesférica, una vesícula seminal subesférica que se extiende hasta el borde anterior del acetábulo, por la presencia de un saco hermafrodita y por una mayor longitud del cuerpo. También se registran ocho especies adicionales de digéneos parásitos de peces marinos en varias localidades de las costas del Atlántico y del Pacífico de Costa Rica. Por último, presentamos una lista actualizada de los helmintos parásitos de peces marinos y dulceacuícolas de Costa Rica y discutimos la importancia de incluir a los parásitos como una parte integral de las investigaciones sobre biodiversidad.

Relaciones filogenéticas entre las especies del género Cynoscionicola (Monogenea: Microcotylidae)

Phylogenetic analysis of seven nominal species of the genus Cynoscionicola Price 1962 based on 18 characteres and 31 character states, produced two equally parsimonious cladograms, with a consistency index of 0.85 and 35 steps. Different tree topologies depends on the position of the members that inhabit scianids in the Pacific Coast, with respect to the ones that inhabit Cynoscion in the Atlantic. Monophyly of Cynoscionicola is supported by three unambiguos synapomorphies: genital atrium formed by four atrial pouches, genital atrium presenting spines of different size and shape, and shape of spines in anterior chamber of atrial pouch. Using phylogenetic analysis as a template, we analyzed host relationships, and biogeographic distribution for members of Cynoscionicola, and we propose an origin for both, hosts and monogeans, in the Atlantic, with an early dispersal route along the Atlantic Coast, and a speciation event (vicariance) determined by the isolation of a population of Cynoscion when the Ithsmus of Panama arose in the Pliocen, combined with a host switching event to other members of the Scianidae.

En este trabajo se presenta un análisis filogenético para siete especies nominales del género Cynoscionicola Price 1962, el cual esta basado en 18 caracteres y 31 estados de carácter. El análisis produjo dos cladogramas igualmente parsimoniosos con un índice de coherencia de 0.85 y 35 pasos. Las diferentes topologías de los cladogramas dependen de la posición de los miembros que habitan en Scíanidos de la costa del Pacífico, con respecto a aquellas que habitan en Cynoscion en la costa del Atlántico. La monofilia de Cynoscionicola es apoyada por tres sinapomorfías no ambigüas: atrio genital formado por cuatro bolsas atriales, atrio genital armado con espinas de distinta forma y tamaño y forma de las espinas anteriores del atrio genital. Usando el análisis filogenético como un "templado", analizamos las relaciones con el hospedero y la distribución geográfica de los miembros de Cynoscionicola, proponemos un origen para ambos, hospederos y monogéneos, en el Atlántico, con una ruta de dispersión temprana a lo largo de la costa del Atlántico, un evento de especiación por vicarianza, determinado por el aislamiento de una población de Cynoscion cuando surgió el Istmo de Panamá en el Plioceno, en combinación con un evento de colonización a otros miembros de la familia Scianidae.

Life history of the terrestrial snail Ovachlamys fulgens (Stylommatophora: Helicarionidae) under laboratory conditions

Aspects of the biology of Ovachlamys fulgens (Gude 1900) were studied under laboratory conditions in Costa Rica for 16 months. The lifespan of this snail in captivity was about nine months (N= 22) and it could lay viable eggs without mating (N= 40). Oviposition began 42 days after eclosion, when shell diameter averaged 5.12 mm (N= 24). Clutches had about three eggs each (N= 252). One clutch was laid daily over periods of one to four days, with intervals of one to two days (N= 252). Age, shell diameter and clutch size were positively correlated (N= 1097) as were shell diameter of adult, egg diameter and shell diameter of the offspring (N= 136). Oviposition took place between crevices of the soil and in the leaf litter. Eggs had a soft egg shell and were laid semi-hydrated; they hydrated by absorbing water from the surroundings (N= 21). This strategy may be the evolutionary compromise between a mechanical limitation (small body size) and the advantage of producing bigger eggs with a larger amount of nutritive substances. At room temperature (mean = 21°C) egg eclosion took place in 14 days (N= 67) and in 11 days at 28 °C (N= 32). Egg shell dissolution was not uniform (N= 107), it began in a local area, that usually was the side on which it rested (N= 46). The fact that eggs with and without an embryo (N= 5) underwent the same process of egg shell's calcium dissolution suggested a chemical mechanism. Embryos did not induce the process, but accelerated it. Egg viability was decreased by the tannins of the surrounding leaf litter (N= 50). Juveniles could feed on leaves of Persea americana (Lauraceae) (N= 299).

Durante 16 meses se estudió en laboratorio la biología básica de Ovachlamys fulgens en Costa Rica. Esta especie se reprodujo sin copular (N= 40) y su longevidad fue de nueve meses (N= 22). La oviposición inició a los 42 días de haber eclosionado y con 5.12 mm de diámetro de concha (N= 24). Los huevos fueron depositados en camadas diarias de alrededor de tres huevos (N= 252). Existe una correlación positiva entre la edad y el diámetro de la concha del progenitor y el tamaño de la camada (N= 1097), y entre el diámetro de los huevos y el de la concha de adultos y neonatos (N= 136). Los huevos de cáscara suave son depositados semi-deshidratados y se hidratan absorbiendo agua del entorno (N= 21). Esta estrategia puede ser el resultado evolutivo entre una limitación mecánica (pequeño tamaño corporal) y la ventaja de producir huevos más grandes con más sustancias nutritivas. Los huevos tardan 14 días en eclosionar a 21°C (N= 67). La disolución de la cáscara del huevo no es uniforme (N= 107), sino que comienza en un área específica, que normalmente es en la que reposa (N=46). El hecho de que huevos sin embrión (N= 5) pasen por el mismo proceso de disolusión de la cáscara sugiere que éste es de carácter químico. El embrión no induce el proceso, pero si lo acelera. Los taninos de la hojarasca que rodea los huevos reduce su viabilidad (N= 50).

Reestablecimiento de los géneros Frankliniella, Exophtalmothrips y Bolbothrips (Thysanoptera: Thripidae)

Four new species are described in Frankliniella genus Frankliniella marinae sp. n., moundi sp. n., sandovalensis sp. n. and orlandoi sp. n. The later synonyms of Frankliniella (Exophtalmothrips and Bolbothrips) are discussed upon phylogenetical criteria, these criteria support the redescription of these genera because they are independent evolutionary lineages. The three genera are redescribed and resurrected Exophtalmothrips and Bolbothrips following the actual phylogenetics of the generic group. The genus Exophtalmothrips was a little genus with only three species, some studies on Mexico fauna, and the analysis of the species of Frankliniella from Costa Rica described in the last years increase the number of species for this genus. Bolbothrips is considered a monospecific genus with the single species aztecus misidentified as Frankliniella aztecus by some writers.

Una visión filogenética de Frankliniella (Thysanoptera: Thripidae)

The phylogeny of the species groups of Frankliniella and the position of Exophtalmothirps and Bolbothrips are discussed with reference to recent literature and analysis with the cladistic software PAUP 3.0 in its heuristic option, the matrix has 24 taxa and 25 characteristics for each; 1) the intonsa group is not a well defined taxon and may include groups of species, but there are no good morphological traits for its recognition, 2) the pulchella and cephalica groups are consistent monophyletic groups of species, 3) the minuta group is monophyletic with a few morphological constraints, 4) Exophtalmothrips and Bolbothrips seem to be segregated, and not synonymous of Frankliniella.

New species of Scolytodes (Coleoptera: Scolytidae) from Costa Rica and Panamá

Seven species of Scolytodes (tribe Ctenophorini) are described as new to science: S. concavus and S. circumsetosus (from Ficus branches, La Selva), S. montanus (Monteverde), S. nudifrons (Las Cruces near San Vito), and S. triangulus (fogging sample, La Selva), all from Costa Rica, and S. ungulatus (Cerro Punta) and S. punctifrons (from Astronium graveolens, Canal Zone), both from Panama. New distributional and host plant data are given for the following species: S. amoenus (Ficus branch, La Selva, and the first record south of Mexico), S. immanis (Cerro de La Muerte), S. impressus (Xylopia branch, Peninsula de Osa), S. ochromae (Ochroma branch, La Selva), S. piceus (fogging sample, La Selva, the first low altitude record), and S. swieteniae (fogging sample, La Selva and Braulio Carrillo, the first exact locality data), all from Costa Rica, and S. nanellus (Barro Colorado Island) from Panama.

Dos especies nuevas de hormigas de la tribu Attini de Costa Rica y México: Mycetosoritis vinsoni y Mycocepurus curvispinosus (Hymenoptera: Formicidae)

I describe Mycetosoritis vinsoni from Loma Barbudal, Guanacaste Prov., Costa Rica, based on a holotype worker. It is most closely related to M. hartmanni, but can be easily separated as the hairs on the scapes are curved and appressed (straight and semierect in M. hartmanni), the median pronotal denticles are absent (present and well developed in M. hartmanni) and the petiolar teeth are poorly developed (well developed in M. hartmanni). Mycocepurus curvispinosus is described based on five workers from Costa Rica, Guanacaste Prov., Loma Barbudal and Mexico, Chiapas, 24 km southeast of Cintalpa. It can be easily recognized as the propodeal spines are thickened and bent upwards, and the mid pronotal denticles are absent. These two characters separate this new species from all others in the genus.

Se describe Mycetosoritis vinsoni de Loma Barbudal, Guanacaste Prov. de Costa Rica, con base en el obrera holotipo. Es similar a M. hartmanni, pero se puede diferenciar gracias a que los pelos de los escapos son curvos y oprimidos (derechos y erectos en M. hartmanni), los dentículos de la mitad del pronoto están ausentes (presentes y bien desarrollados en M. hartmanni), y los dientes del peciolo son poco diferenciados (bien desarrollados en M. hartmanni). Mycocepurus curvispinosus es descrito con base en cinco obreras de Costa Rica, Guanacaste Prov., Loma Barbudal y de México, Chiapas, 24 km suroeste de Cintalpa. Se puede separar Mycocepurus curvispinosus fácilmente porque las espinas principales del propodeo son curvadas hacia arriba y gruesas, y los dientecillos de la mitad del pronoto están ausentes. Estas dos características separan esta nueva especie del resto de las especies en el género.

Macrobenthic invertebrates as food for a penaeid shrimp pond farm in Brazil

El macrobentos de estanques de cultivo de Penaeus subitilis y Penaeus schmitti se estudió en la costa nordeste de Brasil durante 12 semanas. El poliqueto Laeonereis culveri (2 433 ind/0.1m2) y el anfípodo Grandidierella bonnieroides (2 726 ind/0.1m2) fueron intensamente depredados por los peneidos. Ningún individuo de G. bonnieroides sobrevivió más de seis semanas: en el tiempo restante L. culveri, que también puede reclutarse en el periodo, fue el principal recurso natural alimenticio disponible.

Morfología externa del desarrollo larvario de Hemicaranx amblyrhynchus (Pisces: Carangidae) del sur del Golfo de México

Larval development of Hemicaranx amblyrhynchus is described from wild specimens (standard length SL: 1.8-16.4 mm) caught in the southern Gulf of Mexico (N=25). A serrated occipital crest was present only in specimens smaller than 5.73 mm SL and a supraocular crest with a small spine in those between 4 and 5 mm. As in all larval carangids, the angle preopercle spine was conspicuous since the first stages. Supracleithral and posttemporal spines were present during flexion stage, and then disappeared in transformation stage. Body depth is moderate, increasing with development. The dorsal and anal fins start to be evident in the 2.65 mm NL specimen; total number of spines and soft rays are almost complete around 9.0 mm SL. The pelvic bud was observed in the 3.16 mm LP specimens. From the early stages, the larvae are very pigmented and could be recognized by a pigmentation blotch on the tip of nose, which is conformed by palatine melanophores among others. Larvae of H. amblyrhynchus occurred scarcely in the area; they were essentially recorded on the inner shelf, in surface waters, not deeper than 30 m. The present paper is the first larval record for the species in the southern Gulf of México.

Se describe el desarrollo larvario de Hemicaranx amblyrhynchus con especímenes capturados en el sur del Golfo de México. Los ejemplares presentaron tallas desde 1.87 mm hasta 16.43 mm. Los ejemplares más pequeños presentan una cresta supraoccipital aserrada que se distingue todavía en el espécimen de 5.7 mm de LP y desaparece en los de talla superior. El cuerpo es moderadamente alto en la preflexión y aumenta ligeramente durante el desarrollo. Las aletas dorsal y anal son visibles a partir del espécimen de 2.65 mm de LN; el número de espinas y radios está casi completo alrededor de los 9.0 mm LP. Las larvas de H. amblyrhynchus pueden reconocerse por una mancha de pigmentos en la punta del hocico, que está conformada, entre otros, por melanóforos en el palatino.

Gymnothorax phalarus, a new eastern Pacific moray eel (Pisces: Muraenidae)

Gymnothorax phalarus is described from 23 individuals taken in trawl and dredge collections made on the Pacific coast of Costa Rica. The new species is nearly always syntopic with a similar species, Gymnothorax equatorialis. The new moray is distinguished by its white-spotted pattern, uniserial, slightly serrated teeth in adults, four infraorbital pores and mean vertebral formula of 6-58-140. Of the total of 21 valid species of morays recorded from the Pacific coast of Costa Rica, only the new species and G. equatorialis form part of the trawl fishery as the remainder are almost entirely restricted to nearshore rocky habitats. The known range of G. phalarus is from Baja California to Peru.

Gymnothorax phalarus se describe con base en 23 individuos de colecciones hechas por redes de arrastre y dragas en la costa Pacífica de Costa Rica. La especie nueva es casi siempre sintópica con la especie similar, Gymnothorax equatorialis. La nueva morena se distingue por su patrón de puntos blancos, dientes ligeramente aserrados y uniseriales en adultos, cuatro poros infraorbitales y MVF (Fórmula de Vértebras) de 6-58-140. México a Perú.

Eggs and hatchlings of the Mexican salamander Pseudoeurycea cephalica (Caudata: Plethodontidae)

Eggs and hatchlings of Pseudoeurycea c. cephalica from Parque Nacional Lagunas de Zempoala, Morelos, Mexico are described for the first time. The eggs are similar to eggs of P. cephalica manni and P. belli in being unstranded. Egg capsules resemble P. nigromaculata and P. juarezi in having two gelatinous envelopes. The embryos have extensively webbed hands and feet with a continuous reduction in webbing during embryogenesis, supporting the hypothesis that webbing of the feet is a paedomorphic character. The hatchlings are uniform grayish-black dorsally and slightly paler ventrally. They are robust with broad heads and short tails and lack both vomerine and maxillary teeth. Lack of dentition has previously been found in juveniles of P. belli.

Se describe por primera vez huevos y recién nacidos de Pseudoeurycea cephalica cephalica procedentes del Parque Nacional Lagunas de Zempoala, Morelos, México. Los huevos se paracen a los de P. cephalica manni y P. belli en que no están unidos entre sí por ningún cordón. Se parecen en cuanto a constitución a los de P. nigromaculata y P. juarezi en tener dos capas gelatinosas. Los embriones tienen los pies y manos palmeados, produciéndose una reducción de la superficie palmeada a lo largo de la embriogénesis, lo cual confirma que el palmeado de pies y manos es un carácter pedomórfico. Los recién nacidos son de color gris negruzco, uniforme dorsalmente y de color más claro ventralmente. Son robustos, con cabeza ancha, cola corta y carecen de dientes tanto vomerinos como maxilares. Esta falta de dentición ya fue encontrada anteriormente en juveniles de P. belli.

Redescription and validation of Bothriechis supraciliaris (Serpentes: Viperidae)

The populations of pit vipers from South West CostaRica, have traditionally been identified as Bothriechis schlegelii(Berthold). However, in 1954 E. H. Taylor described one specimen fromthe area as a new subspecies, B. schlegelii supraciliaris. Wermanreturned supraciliaris to synonymy with schlegelii four decadeslater. However, morphometric and color pattern in a SW Costa Ricapopulation (25 specimens) differ from those of specimens (N=57) fromother parts of Costa Rica and from descriptions a South Americanspecimens. Here the epithet Bothriechis schlegelii supraciliarisTaylor 1954, is reestablished as a valid taxon and elevated tospecific rank as B. supraciliaris stat.nov. It is closely related toB. schlegelii from which it differs by its color patterns based on auniform ground color with polymorphic dorsal designs and its lowercounts of ventral and caudal scales.

Las poblaciones de toboba de pestañas o bocaracá delsuroeste de Costa Rica han sido denominadas tradicionalmente Bothriechis schlegelii supraciliaris Taylor 1954. Sin embargo, lamorfometría y el patrón de coloración sugierenque es una especie aparte, que aquí se propone como Bothriechis supraciliaris stat.nov.