Search results for "Ostracod"
showing 8 items of 58 documents
Asociaciones de Ostrácodos del Mioceno Temprano—Medio de Loma Negra (Bardenas Reales de Navarra, Cuenca del Ebro): Evolución Paleoambiental de un Med…
2014
LOWER-MIDDLE MIOCENE OSTRACOD ASSEMBLAGES OF LOMA NEGRA (BARDENAS REALES DE NAVARRA, EBRO BASIN): PALAEOENVIRONMENTAL EVOLUTION OF A LACUSTRINE SYSTEM. The palaeoenvironmental evolution of the Loma Negra section (Bardenas Reales de Navarra, Ebro Basin) during the lower-middle Miocene, is studied for the first time. The paleoen- vironmental interpretation is based on the recovered ostracod assemblages and the sedimentology. The lower part of this section is composed by red, yellow and grey mudstones, and with Paralimnocythere sp. as the most abundant ostracod taxon. The lithological features and the fau- nistic assemblage allows the interpretation of a paleoenvironment with the development o…
Revision of Recent and fossil Mixtacandona Klie 1938 (Ostracoda, Candonidae) from Italy, with description of a new species
2017
Although studies on ostracods dwelling in inland subterranean habitats of Italy have increased in the last decades, highlighting a considerable taxonomic diversity, available information is still far from sufficient to understand phylogenetic and biogeographic relationships. Mixtacandona Klie 1938 is one of the most common and diverse genera of ostracods in subterranean waters. Of the 20 living recognized species in the genus, all stygobiontic and restricted to the Palearctic Region, four are known for the Italian peninsula and Sardinia, one of which exclusively as fossil. Several other Recent and fossil taxa attributable to Mixtacandona, but identified at supraspecific level, have been rep…
Ecologia de comunitats d´invertebrats aquàtics de la Península Ibèrica, amb especial rellevància als Ostracoda
2015
L’ecologia dels invertebrats d’aigües continentals pot abordar-se mitjançant distints enfocaments. En aquesta tesi, que presenta dos parts diferenciades, incidim inicialment en el paper que juga la interrelació de comunitats planctòniques i bentòniques amb el medi, que en comunitats somes (com moltes de les estudiades) es troben habitualment mesclades a la columna d’aigua. En un primer treball es va estudiar com varien estacionalment les comunitats d’invertebrats aquàtics de dos llacunes de muntanya properes (4,5 km) amb climatologia similar però distint hidroperiode (Llacuna de Bezas, semi-permanent i Llacuna de Rubiales, una bassa temporal, ambdues a Terol). A Bezas s’observà un canvi en …
Pyriproxyfen, a juvenoid hormone analog, does not induce male production in parthenogenetic lineages of Eucypris virens (Crustacea: Ostracoda)
2007
Analogs of juvenoid hormones are increasingly recommended for controlling insect pests in agriculture. One of these analogs, pyriproxyfen, was found to be very potent in inducing male production in Daphnia under laboratory conditions, even after acute exposure. Other studies also demonstrated a major role of juvenoid hormones for the sex determination in arthropods that have sex chromosomes. We exposed parthenogenetic lineages of the freshwater ostracod Eucypris virens to a wide range of pyriproxyfen concentrations, and compared mortality and fecundity between treated and control animals. Animals exposed to the highest concentrations of pyriproxyfen (3-30 nM) experienced a higher mortality …
Distribution of recent ostracods in inland waters of Sicily (Southern Italy)
2006
From 2003 to 2005, freshwater ostracods were sampled in 67 water bodies of mainland Sicily (Provinces of Agrigento, Caltanisetta, Catania, Enna, Palermo, Messina, Ragusa, Siracusa and Trapani) located from sea level up to 1300 m a.s.l. This survey took into account streams, springs, wells, but especially temporary and ephemeral habitats (e.g., flooded meadows, temporary ponds). The aim of this research was to give the first comprehensive picture of the regional ostracod fauna and establish relationships between the distribution of ostracod species and some habitat features. Altogether, 21 ostracod taxa belonging to five families (Candonidae, Ilyocyprididae, Cyprididae, Notodromadidae, and L…
Experimental test on the use of MS-222 for ostracod anaesthesia: concentration, immersion period and recovery time
2010
Anaesthesia of animals may be useful for different purposes, particularly for veterinary reasons or in experimental research, for manipulation or treatment of immobilized but alive animals. Its use in crustaceans is not uncommon, but it has never been described for Ostracoda. We provide brief and preliminary guidelines on the use of the tricaine mesylate (MS-222) on the widespread freshwater ostracod Eucypris virens and we show that this compound is an effective anaesthetic used as a bath treatment at minimum concentrations of 500 mg L-1. This value is considerably higher than that recommended for other aquatic animals like fish. Recovery time, ranging from 5 to 15 minutes, is mostly determ…
Mecanismes estructuradors de les metacomunitats d'ostracodes d'aigües continentals
2016
Un dels objectius principals de l'estudi de les metacomunitats és entendre els patrons de distribució de grups d'espècies i els mecanismes ecològics que condicionen aquestos patrons. Recentment, els estudis sobre metacomunitats han estat centrats en determinar la importància relativa de l'ordenació d'espècies (i.e. l'efecte filtrador de l'ambient) i la dispersió (i.e. els efectes espacials) com a mecanismes estructuradors de les metacomunitats. En aquesta tesi hem analitzat el paper d'aquestos mecanismes estructuradors sobre diferents metacomunitats d'ostracodes i altres invertebrats en tres sistemes aquàtics diferents situats a l'est de la Península Ibèrica: llacunes temporals, basses de r…
Late Quaternary marine ostracods of the Basque Basin (S Bay of Biscay): taxonomy and distribution
2018
Late Quaternary taxonomy and ecologic and age distributions of ostracods from the Basque Basin (S Bay of Biscay) are described. More than forty-four thousands ostracod specimens have been obtained from one hundred surface samples and core samples from six cores located in shelf and upper bathyal depths and other infrabathyal core as comparative deep reference. A total of 155 species have been taxonomically described, belonging to 67 genera. Most characteristic species (123) have been SEM figured, and ecologic-geographic distributions and ages have been provided for all species. The resulting database will be a useful help for palaeoceanographic and palaeoclimatologic studies of the region.