It is estimated that several million tropical gastropods are exported each year for the marine ornamental trade to become part of a clean‐up crew (those species that have a beneficial function such as controlling nuisance algae) in an aquarium. Collecting non‐tropical species could offset exploitation impacts, reduce shipping costs and increase survival rates due to shorter transport distances. However, these species must be able to survive and function at tropical marine tank temperatures (25 °C). Two species of intertidal temperate top shell (Osilinus lineatus) and (Gibbula umbilicalis) were acclimated to 25 °C, 27 °C and 29 °C and survivorship compared with ambient (UK summer) conditions for 55 days. Virtually all G. umbilicalis died during the experiment in all elevated temperatures. In contrast, O. lineatus had minimal mortality in all treatments except the 29 °C, which reached 46.7% ±3.3 by day 55. Locomotor activity and position in relation to the air/water interface were assessed at 25 °C and ambient conditions. All individuals from both species were active and the mean activity score did not differ between treatments. The majority (63–85%) of the individuals of both species also spent their time either submerged or at the air–water interface and those held at 25 °C spent less time on average out of the water. Nitrocellulose plates impregnated with an algal extract were used to assess grazing of both species at 25 °C compared with ambient temperature. Over 24 h both consumed significant quantities, and no differences in levels were observed between temperatures or species. Together this evidence shows that O. lineatus survives equally well at standard tropical aquarium temperatures and also continues to function as a clean‐up crew. Collection of this and other non‐tropical species may be an important alternative conservation approach to tropical collection if ethical and management issues are addressed. Copyright © 2012 John Wiley & Sons, Ltd.

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Crowding Megoura viciae (Buckton) on bean plants affects both the nymphs and adults. Crowded nymphs show a low mortality, develop more rapidly to produce light adults after a series of synchronized moults: isolated nymphs show a high initial mortality, develop more slowly to heavier adults, the duration of nymphal stages being extremely variable, with no synchronization of moulting. Development is discussed in terms of both weight gain and linear growth rate.Crowding does not affect adult mortality but it does reduce the rate at which nymphs are produced. The significance of these findings in relation to the formation and maintenance of the aphid colony is considered, and possible controlling factors are discussed.

Two Coryphaena hippurus morphotypes (dourado and palombeta) are found along the Brazilian coast and are considered by Rio de Janeiro's fisherman and fishmongers as two different species. Furthermore, these morphotypes are commercialized under different values and suffer different fishing pressure. Therefore, a definition of their taxonomic status is an important economic and biological matter. In order to investigate this problem, allozyme electrophoresis method was undertaken for seventeen loci on 117 individuals of C. hippurus sampled at Cabo Frio/RJ (Brazil). The data indicate homogeneity between the morphotypes gene pools. Nevertheless, differences were found for genetic variation among dourado and palombeta, especially due to alcohol dehydrogenase locus. Natural selection hypothesis is discussed in explaining these findings.Keywords: Alcohol dehydrogenase, Allozyme electrophoresis, Biochemical systematics, Fishery resources, Genetic variation. Dois morfotipos deCoryphaena hippurus (dourado e palombeta) encontrados ao longo da costa brasileira são considerados espécies diferentes por pescadores e mercadores das regiões de desembarque do estado do Rio de Janeiro. Além disso, esses morfotipos são comercializados por valores diferentes e sofrem diferentes pressões de pesca. Desta forma, a definição do status taxonômico desses morfotipos é importante, tanto em termos econômicos quanto biológicos. A fim de investigar esse problema foi utilizado o método de eletroforese de aloenzimas com a amostragem de dezessete loci para 117 indivíduos dos dois morfotipos de C. hippurus obtidos em desembarques pesqueiros na região de Cabo Frio/RJ (Brasil). Os dados indicaram uma homogeneidade entre os conjuntos gênicos dos morfotipos. A despeito disso, diferenças entre os conjuntos gênicos de dourado e palombeta foram encontradas, devido, especialmente, ao locus álcool desidrogenase. A hipótese de seleção natural é discutida como possível explicação para esses resultados. Palavras-chave:Desidrogenase do octanol, Eletroforese de aloenzimas, Recursos pesqueiros, Sistemática bioquímica, Variação gênica.