Frequency of sublethal injury in a deepwater ophiuroid, Ophiacantha bidentata, an important component of western Atlantic Lophelia reef communities

The occurrence and relative abundance of tissue (arm) regeneration in the ophiuroid, Ophiacantha bidentata (Retzius), was examined in individuals collected primarily among colonies of the deep-water coral Lophelia pertusa off the southeastern United States. Seven deep-water coral sites (384–756 m), located between Cape Lookout, NC, and Cape Canaveral, FL, were sampled in June 2004 using a manned submersible. The presence of regenerative tissue was evaluated by visual inspection of each individual ophiuroid, and the proportion of regenerating arms per individual was examined relative to size of individual, geographic location, and depth of collection. Ophiacantha bidentata, the dominant brittle star collected, commonly displayed signs of sublethal injury with over 60% of individuals displaying some evidence of regeneration. These levels of regeneration rival those reported for shallow-water ophiuroids. Larger individuals (\u3e6.5 mm disc size) had a higher incidence of regeneration than smaller individuals. Size of individual and percent of regeneration were negatively correlated with depth. Although O. bidentata was significantly less abundant in southern versus northern sites, ophiuroid abundance did not appear to be influenced by amount or density of coral substratum. Presence of dense aggregations of O. bidentata indicates that they are an important component of the invertebrate assemblage associated with deep-water coral habitat especially in the northern part of the study area. Assuming that observed frequencies of injury and subsequent regeneration represent predation events then dense ophiuroid aggregations in deepwater coral habitats represent an important renewable trophic resource within these communities

Structure-function-dynamics relationships in the peculiar Planktothrix PCC7805 OCP1: impact of his-tagging and carotenoid type

The orange carotenoid protein (OCP) is a photoactive protein involved in cyanobacterial photoprotection. Here, we report on the functional, spectral and structural characteristics of the peculiar Planktothrix PCC7805 OCP (Plankto-OCP). We show that this OCP variant is characterized by higher photoactivation and recovery rates, and a stronger energy-quenching activity, compared to other OCPs studied thus far. We characterize the effect of the functionalizing carotenoid and of his-tagging on these reactions, and the time scales on which these modifications affect photoactivation. The presence of a His-tag at the C-terminus has a large influence on photoactivation, thermal recovery and PBS-fluorescence quenching, and likewise for the nature of the carotenoid that additionally affects the yield and characteristics of excited states and the ns-s dynamics of photoactivated OCP. By solving the structures of Plankto-OCP in the ECN- and CAN-functionalized states, each in two closely-related crystal forms, we further unveil the molecular breathing motions that animate Plankto-OCP at the monomer and dimer levels. We finally discuss the structural changes that could explain the peculiar properties of Plankto-OCP. - Complete functional characterization of Synechocystis and Planktothrix OCPs - Hitherto unknown structures of ECN- and CAN-functionalized Planktothrix OC

Catalogue of squat lobsters of the world (Crustacea: Decapoda: Anomura-families Chirostylidae, Galatheidae and Kiwaidae)

220 páginas, 5 figuras, 1 tabla.[EN] This adaptation text reproduces Anexo I of the dissertation “Results”: Sistemática e historia evolutiva de la Familia Galatheidae (Crustacea: Anomura) en el Pacífico Sur, of Patricia Cabezas (2010) http://hdl.handle.net/10261/134771[ES] Este artículo es una adaptación del Anexo I de la tesis doctoral: Sistemática e historia evolutiva de la Familia Galatheidae (Crustacea: Anomura) en el Pacífico Sur, of Patricia Cabezas (2010) http://hdl.handle.net/10261/134771Taxonomic and ecological interest in squat lobsters has grown considerably over the last two decades. A checklist of the 870 current valid species of squat lobsters of the world (families Chirostylidae, Galatheidae and Kiwaidae) is presented. The compilation includes the complete taxonomic synonymy and geographical distribution of each species plus type information (type locality, repository and registration number). The numbers of described species in the world’s major ocean basins are summarised.Peer reviewe

Annotated checklist of decapod crustaceans of Atlantic coastal and continental shelf waters of the United States

Volume: 116Start Page: 96End Page: 15

Estimation du flux de sève du kiwi par bilan de chaleur en conditions semi-contrôlées : note technique

Dans le bilan d'eau du sol d'une savane (végétation éparse) l'exactitude de l'estimation de la transpiration des ligneux est le facteur déterminant la précision d'estimation de l'évapotranspiration réelle totale de la savane. Pour mesurer la transpiration (flux de sève des ligneux) nous avons utilisé la méthode du bilan de chaleur. Nous faisons un rappel théorique de la méthode, décrivons le dispositif de mesure et présentons quelques résultats concernant des individus de kiwi. Les résultats nous permettent d'affirmer que la méthode du bilan de chaleur donne des résultats satisfaisants. L'absence d'étalonnage, le pas de temps, et la souplesse de mise en place (capteurs "sur mesure") sont d'excellents arguments pour que l'on applique cette méthode à l'étude de l'évapotranspiration réelle des savanes. (Résumé d'auteur

Estimation du flux de sève du kiwi par bilan de chaleur en conditions semi-contrôlées : note technique

Dans le bilan d'eau du sol d'une savane (végétation éparse) l'exactitude de l'estimation de la transpiration des ligneux est le facteur déterminant la précision d'estimation de l'évapotranspiration réelle totale de la savane. Pour mesurer la transpiration (flux de sève des ligneux) nous avons utilisé la méthode du bilan de chaleur. Nous faisons un rappel théorique de la méthode, décrivons le dispositif de mesure et présentons quelques résultats concernant des individus de kiwi. Les résultats nous permettent d'affirmer que la méthode du bilan de chaleur donne des résultats satisfaisants. L'absence d'étalonnage, le pas de temps, et la souplesse de mise en place (capteurs "sur mesure") sont d'excellents arguments pour que l'on applique cette méthode à l'étude de l'évapotranspiration réelle des savanes. (Résumé d'auteur