Population biology and diet of the puffer fish Lagocephalus laevigatus (Tetraodontiformes: Tetraodontidae) in Caraguatatuba Bay, south-eastern Brazil

This study describes the spatio-temporal distribution, population biology, and diet of the puffer fish Lagocephalus laevigatus in Caraguatatuba Bay, south-eastern Brazil. Monthly samples were taken between August 2003 and October 2004 by trawls in two areas, south and north, at depths of 1 to 4 m. The fish were measured and their sex and reproductive stage determined. The abundance of this species was compared between areas and among months, and the items in the diet were identified and quantified. Lagocephalus laevigatus was rare in Caraguatatuba Bay, where only 199 small individuals (4.8 to 15.4 cm) were obtained in the entire study period, suggesting that this species uses the estuary as a nursery. None of the specimens of L. laevigatus captured in Caraguatatuba Bay were sexually mature. Higher densities of L. laevigatus in the bay were recorded in the south area and between October and December 2003, i.e. in the spring, suggesting that spawning may occur from late winter to spring (August through to November). The diet items consumed by L. laevigatus in Caraguatatuba Bay were, as expected from the current literature, crustaceans, mainly amphipods, and fish. However, the most-consumed item was the sea whip Leptogorgia setacea (Cnidaria). This feeding habit may be related to the presence of toxins (tetrodotoxin and saxitoxin) that are frequently found in the skin and viscera of L. laevigatus, which may be sequestered from the sea whip, which possibility still needs to be specifically evaluated.

Esperó de muntanya

DELPHINIUM MONTANUM DC. IN LAM. & DC., FL. FR. 5: 641 (1815) - L'esperó de muntanya(Delphinium montanum, Ranunculaceae) és una espècie perenne, tetraploide, endèmica delsPirineus orientals, restringida a 9 poblacions (3 de les quals no s¿han tornat a trobar recentment) iamenaçada (vulnerable [VU] segons criteris de la UICN de 2001). Tàxon objecte d¿estudi per l¿equipdel BioC des de fa uns 25 anys, des del punt de vista taxonòmic (Blanché, 1991), de biologiareproductiva i diversitat genètica (Bosch, 1999; Simon et al., 2001) i de l¿origen de la tetraploïdia(López-Pujol et al., 2007). Ha format part de diversos projectes de recerca entre els quals destacaConservación de la biodiversidad en zonas sometidas a impacto del sector turístico y fragmentaciónde poblaciones. Bases para la gestión de especies amenazadas, finançat pel Plan Nacional de I+D del Ministeri d'Educació i Ciència.

Esperó de muntanya

DELPHINIUM MONTANUM DC. IN LAM. & DC., FL. FR. 5: 641 (1815) - L'esperó de muntanya(Delphinium montanum, Ranunculaceae) és una espècie perenne, tetraploide, endèmica delsPirineus orientals, restringida a 9 poblacions (3 de les quals no s¿han tornat a trobar recentment) iamenaçada (vulnerable [VU] segons criteris de la UICN de 2001). Tàxon objecte d¿estudi per l¿equipdel BioC des de fa uns 25 anys, des del punt de vista taxonòmic (Blanché, 1991), de biologiareproductiva i diversitat genètica (Bosch, 1999; Simon et al., 2001) i de l¿origen de la tetraploïdia(López-Pujol et al., 2007). Ha format part de diversos projectes de recerca entre els quals destacaConservación de la biodiversidad en zonas sometidas a impacto del sector turístico y fragmentaciónde poblaciones. Bases para la gestión de especies amenazadas, finançat pel Plan Nacional de I+D del Ministeri d'Educació i Ciència.

Icones fucorum : cum characteribus systematicis, synonimis auctorum et descriptionibus novarum specierum = Abbildungen der Tange : mit beygefügten systematischen Kennzeichen, Anführungen der Schriftsteller, und Beschreibungen der neuen Gattungen ... / herausgegeben von Eugenius Johann Christoph Esper.

Mode of access: Internet.

Increased mortality and photoinhibition in the symbiotic dinoflagellates of the Indo-Pacific coral Stylophora pistillata (Esper) after summer bleaching

Coral bleaching (the loss of symbiotic dinoflagellates from reef-building corals) is most frequently caused by high-light and temperature conditions. We exposed the explants of the hermatypic coral Stylophora pistillata to four combinations of light and temperature in late spring and also in late summer. During mid-summer, two NOAA bleaching warnings were issued for Heron Island reef (Southern Great Barrier Reef, Australia) when sea temperature exceeded the NOAA bleaching threshold, and a 'mild' (in terms of the whole coral community) bleaching event occurred, resulting in widespread S. pistillata bleaching and mortality. Symbiotic dinoflagellate biomass decreased by more than half from late spring to late summer (from 2.5x10(6) to 0.8x10(6) dinoflagellates cm(2) coral tissue), and those dinoflagellates that remained after summer became photoinhibited more readily (dark-adapted F (V) : F (M) decreased to (0.3 compared with 0.4 in spring), and died in greater numbers (up to 17% dinoflagellate mortality compared with 5% in the spring) when exposed to artificially elevated light and temperature. Adding exogenous antioxidants (D-mannitol and L-ascorbic acid) to the water surrounding the coral had no clear effect on either photoinhibition or symbiont mortality. These data show that light and temperature stress cause mortality of the dinoflagellate symbionts within the coral, and that susceptibility to light and temperature stress is strongly related to coral condition. Photoinhibitory mechanisms are clearly involved, and will increase through a positive feedback mechanism: symbiont loss promotes further symbiont loss as the light microenvironment becomes progressively harsher.