Cell death and degeneration in the symbiotic dinoflagellates of the coral Stylophora pistillata during bleaching

Rising sea temperatures are increasing the incidences of mass coral bleaching (the dissociation of the coral-algal symbiosis) and coral mortality. In this study, the effects of bleaching (induced by elevated light and temperature) on the condition of symbiotic dinoflagellates (Symbiodinium sp.) within the tissue of the hard coral Stylophora pistillata (Esper) were assessed using a suite of techniques. Bleaching of S. pistillata was accompanied by declines in the maximum potential quantum yield of photosynthesis (F-v/F-m, measured using pulse amplitude modulated [PAM] fluorometry), an increase in the number of Sytox-green-stained algae (indicating compromised algal membrane integrity and cell death), an increase in 2',7'-dichlorodihydrofluroscein diacetate (H(2)DCFDA)stained algae (indicating increased oxidative stress), as well as ultrastructural changes (vacuolisation, losses of chlorophyll, and an increase in accumulation bodies). Algae expelled from S. pistillata exhibited a complete disorganisation of cellular contents; expelled cells contained only amorphous material. In situ samples taken during a natural mass coral bleaching event on the Great Barrier Reef in February 2002 also revealed a high number of Sytox-labelled algae cells in symbio. Dinoflagellate degeneration during bleaching seems to be similar to the changes resulting from senescence-phase cell death in cultured algae. These data support a role for oxidative stress in the mechanism of coral bleaching and highlight the importance of algal degeneration during the bleaching of a reef coral.

Shells of the limpet Patella aspera as habitat for epibionts

World Congress of Malacology, Universidade dos Açores, Ponta Delgada, 21-28 de julho.

Development and characterization of microsattelite Loci for the harvested limpets Patella Candei (D'orbigny, 1839) and Patella Aspera (Röding, 1798) using 454 sequencing

World Congress of Malacology, Ponta Delgada, July 22-28, 2013.

Shells of Patella aspera as 'islands' for epibionts

Copyright © Marine Biological Association of the United Kingdom, 2014.

A new multiplexed microsatellite tool for metapopulation studies in the overexploited endemic limpet Patella aspera (Röding, 1798)

Patellid limpets are ecologically important keystone grazers having a long history of overexploitation in the Macaronesian Archipelagos (NE Atlantic islands), where some species, such as Patella aspera, are under serious risk.[1, 2] Patella aspera is a protandric sequential hermaphrodite species with external fertilization, in which individuals start off as males but may undergo a sex reversal with age.[3] Hence, exploitation tends to focus on the larger females in the population as larger limpets (predominantly females) are selectively removed. Despite conservation legislation in Canaries, Madeira and Azores, limpets are under severe pressure and few individuals survive long enough to become females, a phenomenon that severely restricts the effective population size.[4] New conservation actions for the protection and sustainable use of limpets in Macaronesian Archipelagos are urgently needed and should be based on a multidisciplinary framework based on knowledge of the population dynamics and connectivity of this species.

Desenvolvimento do método de Índice de Qualidade ("QIM-Quality Index Method") para as lapas (Patella candei e Patella aspera) e estudo das suas condições de transporte

Dissertação de Mestrado, Estudos Integrados dos Oceanos, 15 de Março de 2016, Universidade dos Açores.

Trypanosoma nupelianus sp. n. (Protozoa, Kinetoplastida) parasitizing rhinelepis aspera (Osteichthyes, Loricariidae) from Paraná river, Brazil

It is described Trypanosoma nupelianus sp. n. parasitizing Rhinelepis aspera taken from Paraná river (Itaipu reservoir, Brazil). Morphometric characters such as body length, width of the body and nucleus dimensions show that T. nupelianus sp. n. is different from other trypanosomes described for fishes from tropical regions.

[Marssi "Vaikeuksien kautta voittoon" eli "Per aspera ad astra"]

Soitinnus: puhallinorkesteri.