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

Zooplankton Variability and Copepod Species Assemblages from a Tropical Coastal Lagoon

Results of monthly zooplankton sampling, carried out from December 1990 to November 1991, are compared from three localities in the Mexican Caribbean. Two stations, Bojórquez, and Cuenca Norte, represent partially enclosed areas of the Nichupté Lagoon System in the northeastern region of the Yucatán Peninsula; a third station was located in adjacent neritic waters. At the neritic station, temperature was lower, salinity was higher, and variations in the two parameters smaller as compared to the two lagoon stations. Zooplankton abundance ranged from 3585.5 org./m3 at the neritic station to 18,742.7 org./m3 at Cuenca Norte. Considering all animals collected, decapod larvae (39%), copepods (28.7%) and ophiopluteus-echinopluteus larvae (22.8%) made the bulk of the catch. A total of 47 copepod species were recorded, of these, 14 were found at Bojórquez, 12 at Cuenca Norte and 42 at the neritic station. Acartia tonsa dominated the copepod population assemblage at Bojórquez (94.4%) and made important contributions at Cuenca Norte (34.5%) and in the neritic station (24.5%). Paracalanus quasimodo was most abundant at Cuenca Norte (40.3%) and contributed 20.9% at the neritic station. It is suggested that both, the high capture of A. tonsa in Bojórquez and the dominance of P. quasimodo at Cuenca Norte, is probably related with two factors: the anthropogenically nutrient-enriched condition of Bojórquez lagoon and the relatively higher breeding frequency of the chaetognath Sagitta hispida in Bojórquez. The highest abundance of zooplankters occurred at the stations within the lagoonal system, and the highest number of copepod species was found at the neritic station, where more stable conditions prevailed

A Survey of the Reef-Related Medusa (Cnidaria) Community in the Western Caribbean Sea

The species composition, distribution, and abundance of medusae collected during a 4-day plankton survey in a reef system of the Mexican Caribbean were studied. Highest mean medusae abundance was observed over the fore-reef zone and in daytime samples. Lowest abundances occurred in the reef lagoon and at dusk. Seventeen species were identified, with Liriope tetraphylla, Aglaura hemistoma, Cubaia aphrodite, and Sarsia prolifera being the most abundant. They belong to a group of medusae dominant along the world\u27s second largest barrier reef. Cluster analysis revealed primary (fore-reef) and secondary (reef lagoon, channel) oceanic groups, showing the strong oceanic influence along and across the reef system. Day-to-day variation in the reef medusan community seemed relatively unimportant. The community structure of the reef medusa fauna appeared to be quite uniform despite the expected migratory behavior of these predators, tidal exchange across the reef, introduction of oceanic species, and time of day. The species composition was most closely related to that of the Campeche Bank and oceanic Caribbean waters. Dominance of oceanic medusae within the reef lagoon was attributed to the narrowness of the continental shelf and the mesoscale hydrological features of the zone

A Survey of the Reef-Related Medusa (Cnidaria) Community in the Western Caribbean Sea

The species composition, distribution, and abundance of medusae collected during a 4-day plankton survey in a reef system of the Mexican Caribbean were studied. Highest mean medusae abundance was observed over the fore-reef zone and in daytime samples. Lowest abundances occurred in the reef lagoon and at dusk. Seventeen species were identified, with Liriope tetraphylla, Aglaura hemistoma, Cubaia aphrodite, and Sarsia prolifera being the most abundant. They belong to a group of medusae dominant along the world\u27s second largest barrier reef. Cluster analysis revealed primary (fore-reef) and secondary (reef lagoon, channel) oceanic groups, showing the strong oceanic influence along and across the reef system. Day-to-day variation in the reef medusan community seemed relatively unimportant. The community structure of the reef medusa fauna appeared to be quite uniform despite the expected migratory behavior of these predators, tidal exchange across the reef, introduction of oceanic species, and time of day. The species composition was most closely related to that of the Campeche Bank and oceanic Caribbean waters. Dominance of oceanic medusae within the reef lagoon was attributed to the narrowness of the continental shelf and the mesoscale hydrological features of the zone

Tree Cover Estimation in Global Drylands from Space Using Deep Learning

We are grateful to Javier Montes for providing help with the Python scripts to access Google Maps’ API.Accurate tree cover mapping is of paramount importance in many fields, from biodiversity conservation to carbon stock estimation, ecohydrology, erosion control, or Earth system modelling. Despite this importance, there is still uncertainty about global forest cover, particularly in drylands. Recently, the Food and Agriculture Organization of the United Nations (FAO) conducted a costly global assessment of dryland forest cover through the visual interpretation of orthoimages using the Collect Earth software, involving hundreds of operators from around the world. Our study proposes a new automatic method for estimating tree cover using artificial intelligence and free orthoimages. Our results show that our tree cover classification model, based on convolutional neural networks (CNN), is 23% more accurate than the manual visual interpretation used by FAO, reaching up to 79% overall accuracy. The smallest differences between the two methods occurred in the driest regions, but disagreement increased with the percentage of tree cover. The application of CNNs could be used to improve and reduce the cost of tree cover maps from the local to the global scale, with broad implications for research and management.S.T., E.G., D.A.-S., and F.H. were supported by the project DeepSCOP-Ayudas Fundación BBVA a Equipos de Investigación Científica en Big Data 2018. E.G. is supported by the European Research Council grant agreement 647038 (BIODESERT). S.T. is supported by the Ramón y Cajal Program of the Spanish Government (RYC-2015-18136). S.T., E.G., and F.H. were supported by the Spanish Ministry of Science under the project TIN2017-89517-P. D.A.-S., E.G., and J.C. received support from project ECOPOTENTIAL, funded by European Union Horizon 2020 Research and Innovation Program, under grant agreement No. 641762, and from European LIFE Project ADAPTAMED LIFE14 CCA/ES/000612. D.A-S, S.T. and E.G. received support from Programa Operativo FEDER-Andalucía 2014-2020 under project DETECTOR A-RNM-256-UGR18. D.A-S. received support from NASA’s Work Program on Group on Earth Observations—Biodiversity Observation Network (GEOBON) under grant 80NSSC18K0446

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

VRK1 (Y213H) homozygous mutant impairs Cajal bodies in a hereditary case of distal motor neuropathy.

Background: Distal motor neuropathies with a genetic origin have a heterogeneous clinical presentation with overlapping features affecting distal nerves and including spinal muscular atrophies and amyotrophic lateral sclerosis. This indicates that their genetic background is heterogeneous. Patient and methods: In this work, we have identified and characterized the genetic and molecular base of a patient with a distal sensorimotor neuropathy of unknown origin. For this study, we performed whole-exome sequencing, molecular modelling, cloning and expression of mutant gene, and biochemical and cell biology analysis of the mutant protein. Results: A novel homozygous recessive mutation in the human VRK1 gene, coding for a chromatin kinase, causing a substitution (c.637T > C; p.Tyr213His) in exon 8, was detected in a patient presenting since childhood a progressive distal sensorimotor neuropathy and spinal muscular atrophy syndrome, with normal intellectual development. Molecular modelling predicted this mutant VRK1 has altered the kinase activation loop by disrupting its interaction with the C-terminal regulatory region. The p.Y213H mutant protein has a reduced kinase activity with different substrates, including histones H3 and H2AX, proteins involved in DNA damage responses, such as p53 and 53BP1, and coilin, the scaffold for Cajal bodies. The mutant VRK1(Y213H) protein is unable to rescue the formation of Cajal bodies assembled on coilin, in the absence of wild-type VRK1. Conclusion: The VRK1(Y213H) mutant protein alters the activation loop, impairs the kinase activity of VRK1 causing a functional insufficiency that impairs the formation of Cajal bodies assembled on coilin, a protein that regulates SMN1 and Cajal body formation.post-print2120 K