10 documents found, page 1 of 1
A long photoperiod following a short one, and low temperature, stimulate gameto...
Marquet, Nathalie; Canario, AdelinoTemperature and photoperiod are critical regulators of reproduction. However, few studies have evaluated experimentally their specific effects on gametogenesis in sea cucumbers. We tested the effect on gametogenesis of combinations of photoperiod and temperature: "accelerated" (long days following short days; a 12 degrees C deep in temperature), "constant" (constant short photoperiod; constant Spring/Summer tem...
Anatomy of the olfactory system and potential role for chemical communication i...
Modesto, Teresa; Gregório, Beatriz Neves; Marcelino, Gonçalo; Marquet, Nathalie; Costa, Rita; Guerreiro, Pedro Miguel; Velez, Zélia; Hubbard, PeterThe current study investigated the structure and function of the olfactory system of the Lusitanian toadfish, Halobatrachus didactylus, using histology and electrophysiology (electro-olfactogram [EOG]), respectively. The olfactory system consists of a digitated anterior peduncle, of unknown function, containing the inhalant nostril. This then leads to a U-shaped olfactory chamber with the olfactory epithelium-i...
A new subfamily of ionotropic glutamate receptors unique to the echinoderms wit...
Sania, Rubaiyat E.; Cardoso, João; Louro, Bruno; Marquet, Nathalie; Canario, AdelinoChemosensation is a critical signalling process in animals and especially important in sea cucumbers, a group of ecologically and economically important marine echinoderms (class Holothuroidea), which lack audio and visual organs and rely on chemical sensing for survival, feeding and reproduction. The ionotropic receptors are a recently identified family of chemosensory receptors in insects and other protostome...
Holothurians have a reduced GPCR and odorant receptor-like repertoire compared ...
Marquet, Nathalie; Cardoso, João CR; Louro, Bruno; Fernandes, Stefan; Silva, Sandra; Canario, AdelinoSea cucumbers lack vision and rely on chemical sensing to reproduce and survive. However, how they recognize and respond to environmental cues remains unknown. Possible candidates are the odorant receptors (ORs), a diverse family of G protein-coupled receptors (GPCRs) involved in olfaction. The present study aimed at characterizing the chemosensory GPCRs in sea cucumbers. At least 246 distinct GPCRs, of which c...
Localization and distribution of nitric oxide synthase and other neuronal marke...
Marquet, Nathalie; Canario, Adelino; Power, DeborahThe organization of the nervous system of the holothurian podia-the tentacles, papillae, and tube feet-is still poorly understood, which limits the development of functional studies. Knowledge of nitric oxide (NO) signaling in sea cucumbers is nonexistent, although it is known to play an important role in many essential biological functions, including neurotransmission, throughout the animal kingdom. The object...
Biogeographical patterns of endolithic infestation in an invasive and an indige...
Ndhlovu, Aldwin; McQuaid, Christopher D.; Nicastro, Katy; Marquet, Nathalie; Gektidis, Marcos; Monaco, Cristián J.; Zardi, GerardoBy altering the phenotypic properties of their hosts, endolithic parasites can modulate the engineering processes of marine ecosystem engineers. Here, we assessed the biogeographical patterns of species assemblages, prevalence and impact of endolithic parasitism in two mussel species that act as important ecosystem engineers in the southern African intertidal habitat, Perna perna and Mytilus galloprovincialis. ...
Chemicals released by male sea cucumber mediate aggregation and spawning behavi...
Marquet, Nathalie; Hubbard, Peter; da Silva, Jose P.; Afonso, João; Canario, Adelino V. M.The importance of chemical communication in reproduction has been demonstrated in many marine broadcast spawners. However, little is known about the use of chemical communication by echinoderms, the nature of the compounds involved and their mechanism(s) of action. Here, the hypothesis that the sea cucumber Holothuria arguinensis uses chemical communication for aggregation and spawning was tested. Water conditi...
Sea cucumbers, Holothuria arguinensis and H-mammata, from the southern Iberian ...
Marquet, Nathalie; Conand, Chantal; Power, Deborah; Canario, Adelino; Gonzalez-Wanguemert, MercedesNew fisheries in the western Mediterranean and north eastern Atlantic target the sea cucumbers Holothuria arguinensis and H. mammata; however, lack of biological information hinders management decisions. Here, the reproductive biology of populations the two species was investigated in the southern Iberian Peninsula. Different populations located along a narrow latitudinal range displayed the same general reprod...
Comparison of phototrophic shell-degrading endoliths in invasive and native pop...
Marquet, Nathalie; Nicastro, Katy R; Gektidis, M.; McQuaid, C. D.; Pearson, G. A.; Serrão, Ester; I Zardi, GerardoThe intertidal mussel Mytilus galloprovincialis is a successful invader worldwide. Since its accidental introduction onto the South African west coast in the late 1970s, it has become the most successful marine invasive species in South Africa. One possible explanation for this phenomenon is that M. galloprovincialis suffers less from phototrophic shell-degrading endoliths in its invasive than in its native ran...
Caracterização e avaliação dos percursos pedestres da ilha de Santa Maria
Ventura, Maria A.; Queiroz, Rose Emília; Resendes, Roberto; Marquet, Nathalie; Melo, José A.Na Expedição Científica à ilha de Santa Maria realizada entre 12 e 19 de Julho de 2009, foram caracterizados e avaliados os 3 trilhos pedestres classificados da ilha: Entre a Serra e o Mar - PRC3 SMA, Santo Espírito e a Maia - PR4 SMA e Pico Alto e Anjos - PR2 SMA. Do levantamento efectuado ressaltaram aspectos importantes, tais como: os trilhos encontram-se no geral bem preservados, ainda que existam situações...