Sexual vs. asexual reproduction in an ecosystem engineer: the massive coral Montastraea annularis

Long-lived sedentary organisms with a massive morphology are often assumed to utilize a storage effect whereby the persistence of a small group of adults can maintain the population when sexual recruitment fails. However, employing storage effects could prove catastrophic if, under changing climatic conditions, the time period between favourable conditions becomes so prolonged that the population cannot be sustained solely be sexual recruitment. When a species has multiple reproductive options, a rapidly changing environment may favour alternative asexual means of propagation. Here, we revisit the importance of asexual dispersal in a massive coral subject to severe climate-induced disturbance. Montastraea annularis is a major framework-builder of Caribbean coral reefs but its survival is threatened by the increasing cover of macroalgae that prevents settlement of coral larvae. To estimate levels of asexual recruitment within populations of M. annularis , samples from three sites in Honduras were genotyped using four, polymorphic microsatellite loci. A total of 114 unique genets were identified with 8% consisting of two or more colonies and an exceptionally large genet at the third site comprising 14 colonies. At least 70% of multicolony genets observed were formed by physical breakage, consistent with storm damage. Our results reveal that long-lived massive corals can propagate using asexual methods even though sexual strategies predominate

Parasitismo por Cryptosporidium sp. em crianças com diarréia aguda Cryptosporidium sp. in children with acute diarrhea

No período de agosto de 1987 a julho de 1990, examinaram-se, na Seção de Enteroparasitoses do Instituto Adolfo Lutz, 241 amostras de fezes de crianças, com idade variável entre 1 e 48 meses, que apresentavam episódio agudo de diarréia e foram atendidas no Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Quarenta e duas (17,43%) amostras revelaram a presença de Cryptosporidium sp. após coloração por fucsina-carbólica. O achado de oocistos de Cryptosporidium sp. foi mais freqüente no período compreendido pelos meses de março a maio. Os autores discutem as associações entre Cryptosporidium sp. e outros agentes diarréicos.<br>During the period from August 1987 to July 1990, 241 fecal samples collected from 1 to 48 months old children with acute diarrhea and examined in the Child's Institute of Hospital das Clínicas of Faculdade de Medicina da Universidade de São Paulo, were submitted to parasitological tests in the Enteroparasitosis Section of the Instituto Adolfo Lutz. Fourty two (17.43%) fecal samples showed Cryptosporidium sp. oocysts by carbol-fucsin stain. Parasitism by Cryptosporidium sp. was more frequent during the period comprised from March to May, in the studied three years. The authors discussed the Cryptosporidium sp. in association with other agents