Seasonal Occurrence of Reef-Related Medusae (Cnidaria) in the Western Caribbean Sea

Seasonal fluctuations in composition and abundance of medusae collected in a reef lagoon of the Mexican Caribbean were analyzed. Plankton samples and hydrological data were taken monthly from January to September 1994 at 2 stations: coastal and near-reef. The highest densities of medusae were recorded in March (17,687 ind/100 m3) and August (2,433 ind/100 m3) at the coastal station. Medusae were less abundant at the nearreef station, but diversity indices were higher in comparison to the coastal station. Twenty-five species (24 hydroidomedusae and 1 scyphomedusa) were identified, with Linuche unguiculata (Swartz, 1788) and Eirene lactea (Mayer, 1900) being the most abundant. Linuche unguiculata was the dominant species, accounting for more than 84% of the total numbers of medusae in the coastal station and over 97% in the near-reef station. The co-occurrence of neritic and oceanic species in the reef-associated community of medusae is probably related to circulation patterns and wind regimes. Dipurena ophiogaster (Haeckel, 1879) and Sarsia eximia (Allman, 1859) were recorded for the first time in the Mexican Caribbean Sea

Variación espacial de la comunidad de medusas (Cnidaria) del sur del Golfo de México, durante el otoño de 1999

The spatial variation of the jellyfish community during fall of 1999 in the southern region of the Gulf of Mexico was analyzed. Plankton material was collected through superficial Bongo-type net tows at 69 sites. Thirty-eight species of jellyfish (35 hydromedusae, two scyphomedusae and one cubomedusa) were found. Liriope tetraphylla was the dominant species, representing 78% of the collected fauna. Other important species due to their abundance were Cunina octonaria, Clytia folleata, Aglaura hemistoma, Solmundella bitentaculata, Pegantha triloba and Octophialucium medium. Six of the identified species are new records for the southern region of the Gulf of Mexico. The distribution of the most abundant species indicated a great concentration of organisms in the shallow waters of Campeche Bank. However, others like Nausithoe punctata and Euphysora gracilis showed their greatest abundances across the stretch continental shelf of the States of Veracruz and Tabasco. The dominant species acted as a community structure stabilizer, but less abundant species better denoted abundance changes in the community in particular oceanographic zones. In this sense, the spatial variation of the community structural components in the autumn season was related to the main oceanographic currents in the continental shelf and food availability.Se analizó la variación espacial de la comunidad de medusas durante el otoño de 1999 en la región sur del Golfo de México. El material planctónico fue recolectado en 69 estaciones mediante arrastres superficiales utilizando una red tipo Bongo. Se determinaron 38 especies de medusas (35 hidromedusas, dos escifomedusas y una cubomedusa). Liriope tetraphylla fue la especie dominante al representar más del 78% de la fauna recolectada. Otras especies importantes por su abundancia fueron: Cunina octonaria, Clytia folleata, Aglaura hemistoma, Solmundella bitentaculata, Pegantha triloba y Octophialucium medium. Seis de las especies determinadas representaron nuevos registros geográficos para la región sur del Golfo de México. La distribución de las especies más abundantes indicó una concentración de organismos en las aguas someras del Banco de Campeche sin embargo, algunas como Nausithoe punctata y Euphysora gracilis, mostraron sus mayores abundancias sobre la estrecha plataforma continental de los estados de Veracruz y Tabasco. La especie dominante actuó como estabilizadora de la estructura de la comunidad aunque las especies de menor abundancia denotaron mejor los cambios de la comunidad en las distintas zonas oceanográficas. En este sentido, la variación espacial de los componentes estructurales de la comunidad durante el otoño, estuvo relacionada con la circulación oceánica imperante sobre la plataforma continental y la disponibilidad de alimento

Further observations on the strobilation of the coronate scyphozoan Linuche unguiculata (thimble jellyfish)

In nature, strobilation of Linuche unguiculata is triggered by an increase in water temperature. However, the results showed that under laboratory conditions, it can be induced when scyphistomae are submitted to a sudden drop of 5 °C

Primer registro de Phialella quadrata y ampliación del límite de distribución de ocho especies de hidromedusas (Hydrozoa) en el Océano Atlántico Occidental

The new records provided here extend the geographic distribution know of nine hydromedusae species collected in the Laguna Madre, Tamaulipas, Mexico. The record of Phialella quadrata is the first one for the Western Atlantic Ocean, while Ectopleura dumortieri is registered for the first time in the Gulf of Mexico and Clytia folleata in the north of the same gulf. The geographic distribution of Bougainvillia superciliaris, Nemopsis bachei, Sarsia tubulosa and Clytia globosa is extended to a lower latitude, while Eirene tenuis and Octophialucium medium increase to a higher latitude.Los nuevos registros que se presentan en este trabajo, amplían la distribución geográfica conocida de nueve especies de hidromedusas, que fueron recolectadas en la Laguna Madre, Tamaulipas, México. La identificación de Phialella quadrata constituye el primer registro para el Océano Atlántico Occidental, mientras que Ectopleura dumortieri lo es para el Golfo de México y Clytia folleata para la región norte del mismo. Se extiende el área geográfica de distribución de Bougainvillia superciliaris, Nemopsis bachei, Sarsia tubulosa y Clytia globosa a menor latitud, mientras que Eirene tenuis y Octophialucium medium a mayor latitud

Medusas (Cnidaria: Hydrozoa) de una zona de afloramiento costero, Bahía Culebra, Pacífico, Costa Rica

Medusae (Cnidaria: Hydrozoa) from a coastal upwelling zone, Culebra Bay, Pacific, Costa Rica. The hydromedusae have an important role in marine trophic webs due to their predatory feeding habits. This is the first study of this group of gelatinous marine zooplankton in a coastal upwelling area of Central America. The composition and abundance variability of hydromedusae were studied during six months in 1999 at four stations in Culebra Bay, Gulf of Papagayo, Pacific coast of Costa Rica (10o37’ N-85o40’ W). A total of 53 species were identified, of which 26 are new records for Costa Rica, 21 are new records for Central America, and eight are new records for the Eastern Tropical Pacific. The more abundant species (more than 30% of the total abundance) were Liriope tetraphylla, Solmundella bitentaculata and Aglaura hemistoma. Six species occurred throughout the sampling period, 10 were present only during the dry season (December-April), and 17 were so during the rainy season (May-November). Significant differences of medusan abundances were found between seasons (dry vs. rainy). Maximum abundance (2.1±4.3ind./m3) was recorded when upwelled deeper water influenced the Bay, as indicated by local higher oxygen concentrations and lower water temperatures. The relatively high species richness of medusae found in Culebra Bay is probably related to factors like the pristine condition of the Bay, the arrival of oceanic species transported by the Equatorial Counter Current (ECC), the eastward shoaling of the Costa Rica Dome, and local currents. Illustrations of the 15 more important species are included to facilitate their identification and foster future work in the region.Las hidromedusas tienen un papel importante en redes tróficas marinas debido a sus hábitos alimenticios depredadores. Este es el primer estudio de este grupo del zooplancton gelatinoso en un area de afloramiento costero en América Central. Durante seis meses de 1999, se estudió la abundancia de hidromedusas en cuatro estaciones en Bahía Culebra, Golfo de Papagayo, costa Pacífica de Costa Rica (10o 37’N-85o40’W). Se identificó un total de 53 especies de las que 26 son registros nuevos para Costa Rica, 21 son registros nuevos para América Central y 8 son nuevos registros para el Pacífico Oriental Tropical. Las especies más abundantes durante el estudio (con más de 30% de la abundancia total) fueron Liriope tetraphylla, Solmundella bitentaculata y Aglaura hemistoma. Seis especies se presentaron en todos los muestreos, 10 especies se presentaron únicamente durante la época seca y 17 se presentaron únicamente durante la época lluviosa. Se mostraron diferencias significativas entre las épocas lluviosa y seca. La máxima abundancia promedio de hidromedusas (2.1±4.3 ind./m3) fue encontrada durante las fechas que se espera el afloramiento costero, indicado por alta concentración de oxígeno y baja temperatura. La rica composición de especies encontrada en Bahía Culebra puede ser el resultado de varios factores, incluyendo la condición prístina de la bahía, el transporte de especies por la Contra Corriente Nor-Ecuatorial (NECC) y los aportes de origen terrestre. Se incluyen ilustraciones de las 15 especies más importantes para facilitar su identificación y promover estudios futuros en la región

Summer composition and distribution of the jellyfish (Cnidaria: Medusozoa) in the shelf area off the central Mexican Pacific

The composition, distribution, and abundance of the jellyfish community of a shelf area of the Mexican tropical Pacific were surveyed during August 1988. Zooplankton samples were collected along transects on the outer and inner sectors of the continental shelf to determine the structure of the jellyfish community and its variation in this area during the rainy season. A total of 23 species were recorded, with Aglaura hemistoma, Solmundella bitentaculata, Liriope tetraphylla, Pelagia noctiluca, and Rhopalonema velatum being the most abundant. The total abundance of medusae and of the most abundant species was statistically independent of depth and distance to the coast. Hence, the total jellyfish abundance of the most abundant species, and Shannon's Diversity index had a uniform distribution in both the inner and the outer shelf; furthermore, neritic-oceanic forms and oceanic species occurred indistinctly over the entire continental shelf. On the outer shelf A. hemistoma and S. bitentaculata were most abundant; the former species, together with L. tetraphylla, weakly characterized the inner shelf jellyfish community. The narrowness of the shelf, the wide distribution of the most abundant forms, and the possible effect of local advective processes from the oceanic zone masked a definite gradient across the shelf. Three species have not been recorded previously in the Mexican Pacific: Amphinema dinema (Péron and Lesueur, 1810), Sarsia coccometra Bigelow, 1909, and Clytia mccradyi (Brooks, 1888). The finding of A. dinema is the first in the Eastern Pacific

Didymozoid Monilicaecum type trematodes in chaetognaths from the Mexican Caribbean Sea Tremátodos didimozoides tipo Monilicaecum en quetognatos del mar caribe mexicano

Analyses of 22,508 holoplanktonic chaetognaths collected at 21 stations were made from four oceanographic campaigns along the coasts of Quintana Roo, Mexico, in 1991 (Caribe I = February; Caribe II = March; Caribe III = May; Caribe IV= August). Unencysted larval didymozoid parasites were identified as belonging to the Monilicaecum type because of the arrangement of the chambers of the heavily twisted intestinal caeca, which occupy nearly the entire body. These larvae were found in the coelom of seven individuals of the chaetognath Flaccisagitta enflata (prevalence = 0.03, mean intensity = 1) and in two of Serratosagitta serratodentata (prevalence = 0.009, mean intensity = 1). The Mexican Caribbean Sea is reported as a new locality for this type of helminth larvae.Se analizan 22,508 quetognatos holoplánticos capturados en 21 estaciones a lo largo de las costas del estado de Quintana Roo, México durante 1991 (Caribe I= febrero; Caribe II= marzo; Caribe III mayo; Caribe IV= agosto). Las formas no enquistadas de los parásitos didimozoides fueron identificadas como tipo Monilicaecum debido al arreglo de las cámaras de los ciegos intestinales fuertemente sinuosas que ocupan casi la totalidad de la cavidad corporal. Las larvas tipo Monilicaecum fueron encontradas en el celoma de siete quetognatos de la especie Flaccisagitta enflata (prevalencia= 0.03; intensidad promedio de parasitismo = 1) y en dos ejemplares de Serratosagitta serratodentata (prevalencia = 0.009, intensidad promedio = 1). El mar caribe mexicano es registrado como una nueva localidad para esta larva de helminto

POPULATION STATUS OF COLLARED Pecari tajacu AND WHITE-LIPPED PECCARIES Tayassu pecari IN THE PERUVIAN AMAZON

The collared peccary (Pecari tajacu) and white-lipped peccary (Tayassu pecari) are very important species as a source of protein and economic income for rural household, and are culturally important in Amazonian Communities. Despite their importance, and due to the scarcity of information on their populations in a large part of the Peruvian Amazon, it is difficult to evaluate the sustainable use as bushmeat and for the export of skins. In this way, this study aims to evaluate populations of P. tajacu and T. pecariin the regions of Loreto and Ucayali by using fixed-width line transects in 33 localities and through interviews to determine the 'cultural consensus' for the abundance of the species in 11 localities. Of a total of 14,220.5 km of 2 linear transects traveled in the study sites, showed that the population density of P. tajacu was 1.24 ind/km 2 being registered in 32 (96.9%) localities, while T. pecarishowed a population density of 1.59 ind/km and was registered in 16 (48.5%) localities. Only the density of P. tajacu was related to the group size. The 162 interviews conducted in 11 communities showed that the population density of P. tajacu was abundant, while the perception of abundance of T. pecari was from frequent to abundant. The population densities of the two species of peccaries were greater in the non-flooded forests than in the flooded forest, and both species showed a positive correlation. According to the study methods used, there were no differences in the population size reported for the two species of peccaries, both inside and outside the natural protected areas. This indicates that areas outside the natural protected areas that contain high population densities are of a great importance for the conservation of peccaries, and contribute to ensuring food security for rural and indigenous communities.El sajino (Pecari tajacu) y la huangana (Tayassu pecari) son especies muy importantes como fuente de proteína y de ingresos económicos a nivel familiar, como elemento cultural y en general del buen vivir de las comunidades nativas. Apesar de su importancia, la escasa información de sus poblaciones en gran parte de la Amazonía peruana dificulta evaluar su uso sostenible como carne de monte o exportación de pieles. De esta forma, este estudio pretende evaluar las poblaciones de P. tajacu y T. pecari en las regiones de Loreto y Ucayali mediante el método de transectos en banda en 33 localidades y mediante el método de consenso cultural en 11 localidades. Los 14,220.5 km recorridos en transectos lineales mostraron que la densidad 2 poblacional de P. tajacu fue de 1.24 ind/km siendo registrado en 32 (96.9%) localidades, mientras que T. 2 pecari mostró una densidad de 1.59 ind/km y fue registrado en 16 (48.5%) localidades. Sólo la densidad de P. tajacu estuvo relacionada con el tamaño de grupo. Las 162 entrevistas realizadas en 11 comunidades mostraron que los cazadores locales percibieron al P. tajacu como abundante y al T. pecari como frecuente o abundante. Las densidades poblacionales de las dos especies de pecaríes fueron mayores en bosques no inundables o de tierra firme que en bosques inundables, presentando ambas especies una correlación positiva. De acuerdo a los métodos de estudio empleados, no hubo diferencias en el tamaño poblacional reportados para ambas especies, tanto dentro como fuera de las áreas naturales protegidas. Esto indica que las zonas fuera de las áreas naturales protegidas contienen altas densidades poblacionales, son de gran importancia para la conservación de los pecaríes y contribuyen a garantizar la seguridad alimentaria de las poblaciones humanas ribereñas y nativas