Consulta: subjectFacets:"Echinoderm"
Registros recuperados: 5
Data/hora: 02/06/2024 06:40:04

Large-scale genetic patchiness among NE Atlantic populations of the brittle star Ophiothrix fragilis
Provedor de dados: 5
Autores: Muths, D.; Jollivet, D.; Gentil, F.; Davoult, D.
The brittle star Ophiothrix fragilis (Abilgaard, 1789) constitutes a heterogeneous morphological group that can be subdivided into 4 varieties. The species is also characterized by high demographic variability. The present study explores the possibility of genetic patchiness arising due to admixture of varieties or recruitment heterogeneity. We sequenced a portion of the mitochondrial cytochrome oxidase subunit I (mtCOI) gene and genotyped 7 allozymes from 21 populations of the 2 most common varieties. While mtCOI analyses showed that all the varieties grouped together with virtually no divergence among them (&lt; 1%), a clear divergence (18.6%) was evident between the northern Atlantic populations and individuals collected in the Mediterranean and along...
Tipo: Text
Palavras-chave: Echinoderm; Allozyme; MtCOI; Population dynamics; Ecotypes; Dispersal; Recruitment.
Ano: 2009
URL: https://archimer.ifremer.fr/doc/00301/41247/40439.pdf

Trophic niche of two co-occurring ophiuroid species in impacted coastal systems, derived from fatty acid and stable isotope analyses
Provedor de dados: 5
Autores: Blanchet-aurigny, Aline; Dubois, Stanislas; Quere, Claudie; Guillou, Monique; Pernet, Fabrice.
The trophic niches of 2 common co-occurring ophiuroids, Ophiocomina nigra and Ophiothrix fragilis (Echinodermata, Ophiuroidea), in 2 contrasting coastal systems of Brittany (France) were investigated. We used a combination of fatty acid biomarkers derived from neutral lipids and stable isotopic compositions to explore the contributions of oceanic versus continental inputs to the ophiuroids' diet. We investigated 2 different systems with an inshore versus offshore comparison. We sampled potential food sources and surveyed organisms every 2 mo for 1 yr. Spatio-temporal variations in stable isotopes and fatty acid profiles of the ophiuroids were generally low compared to interspecific differences. Fatty acid markers showed that both ophiuroids relied on...
Tipo: Text
Palavras-chave: Echinoderm; Feeding ecology; Ophiocomina nigra; Ophiothrix fragilis; Trophic markers; Green algae.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00270/38144/36278.pdf

Multi-decadal changes in two co-occurring ophiuroid populations
Provedor de dados: 5
Autores: Blanchet, Aline; Dubois, Stanislas; Hily, Christian; Rochette, Sebastien; Le Goaster, Edouard; Guillou, Monique.
Mixed beds of Ophiocomina nigra and Ophiothrix fragilis (Echinodermata, Ophiuroidea) are usually predominated by O. fragilis and are reported to be stable over time. The Bay of Brest (Brittany, France) is a highly productive ecosystem where both species co-occur in the main central part. Using a geostatistical approach, we tested for changes in O. nigra and O. fragilis density and total biomass patterns between 1987 and 2011. Our results highlighted an increase in O. nigra population size and the induction of a spatial shift of the co-occurring O. fragilis. O. nigra increased similar to 5 times in density and covered almost all the study area, while its density-dependent biomass increased similar to 3 times (22 t km(-2), ash-free dry mass) between 1987 and...
Tipo: Text
Palavras-chave: Echinoderm; Ophiocomina nigra; Ophiothrix fragilis; Food supply; Kriging method; Suspension-feeder.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00090/20136/17782.pdf

Adult acclimation to combined temperature and pH stressors significantly enhances reproductive outcomes compared to short-term exposures
Provedor de dados: 5
Autores: Suckling, Coleen C.; Clark, Melody S.; Richard, Joelle; Morley, Simon A.; Thorne, Michael A. S.; Harper, Elizabeth M.; Peck, Lloyd S.
This study examined the effects of long-term culture under altered conditions on the Antarctic sea urchin, Sterechinus neumayeri.Sterechinus neumayeri was cultured under the combined environmental stressors of lowered pH (-03 and -05 pH units) and increased temperature (+2 degrees C) for 2years. This time-scale covered two full reproductive cycles in this species and analyses included studies on both adult metabolism and larval development. Adults took at least 6-8months to acclimate to the altered conditions, but beyond this, there was no detectable effect of temperature or pH. Animals were spawned after 6 and 17months exposure to altered conditions, with markedly different outcomes. At 6months, the percentage hatching and larval survival rates were...
Tipo: Text
Palavras-chave: CO2; Echinoderm; Gonad maturation; Larval development; Oxygen consumption; Vitellogenesis.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00617/72874/71930.pdf

Inventory of the Echinodermata collection from the Universidade Federal de Alagoas
Provedor de dados: 49
Autores: Miranda,Anderson Luiz Silva; Lima,Maria Lilian de Freitas; Sovierzoski,Hilda Helena; Correia,Monica Dorigo.
Collections and inventories provide important and essential information for understanding the composition and distribution of biodiversity. This contribution presents an inventory of the species held in the Echinodermata collection in the Setor de Comunidades Bentônicas (LABMAR/ICBS), Universidade Federal de Alagoas. The collections were made over a period of more than 20 years, at several localities of coastal Alagoas. This collection now includes 16,201 catalogued individual specimens, with 50 species in the five extant classes Crinoidea, Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea, based on 640 records; the class Ophiuroidea is best represented. The results of this inventory contribute significantly to knowledge of marine benthic diversity...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biodiversity; Echinoderm; Taxonomy; Benthic macroinvertebrate; Brazil.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032012000200014