Abstract:Recebido em 20/12/2011. Aceito em 4/07/2012
RESUMO(Morfologia e distribuição de duas diatomáceas (Bacillariophyta) epizóicas no Brasil). As diatomáceas epizóicas em copépodos Pseudohimantidium pacificum e Falcula hyalina foram investigadas em microscopias óptica e eletrônica de varredura, com base em amostras coletadas em diferentes ambientes marinhos da costa brasileira. Pseudohimantidium pacificum é reportada pela primeira vez no Oceano Atlântico Sul Ocidental, ampliando significativamente sua faixa de distr… Show more
“…Although no quantitative analysis was performed, some diatom taxa were dominant such as Tabularia affinis (Kützing) Snoeijs, 1992, Licmophora spp., H. coffaeiformis, and A. helenensis, comprising about 50% of the total diatom composition in the majority of analysed amphipod individuals. While some diatoms are known to be specialised epizoic on planktonic copepods [27], only a few studies have dealt with the growth of diatoms on benthic invertebrates. Usually diatoms of the genera Navicula, Amphora, and Cocconeis are known to occur on several species of cnidarians [28], sponges [29], and gastropods [30,31].…”
Epibiotic associations can result in co-introductions of non-indigenous species, which may affect ecosystems in several ways. In fouling communities of three estuaries in southern Brazil, a number of amphipods was found to harbour a dense coverage of epibionts. Three different species, the two globally widespread caprellids Caprella equilibra and Paracaprella pusilla, as well as the ischyrocerid Jassa valida, had been colonised by diatoms. Further scanning electron microscope analyses assigned these diatoms to 14 different species that had previously been reported from benthic habitats. This is one of the scarce records of diatoms attached to amphipods. The occurrence of the diatom Amphora helenensis represents the first report for Brazilian waters as well as the second record for the whole SW Atlantic Ocean. As some diatoms were associated with common fouling amphipods, a possible regional spread aided by these crustaceans seems likely. Possible effects of this amphipod-diatom association on the animals and their implications for the underlying ecosystems of this remain to be elucidated.
“…Although no quantitative analysis was performed, some diatom taxa were dominant such as Tabularia affinis (Kützing) Snoeijs, 1992, Licmophora spp., H. coffaeiformis, and A. helenensis, comprising about 50% of the total diatom composition in the majority of analysed amphipod individuals. While some diatoms are known to be specialised epizoic on planktonic copepods [27], only a few studies have dealt with the growth of diatoms on benthic invertebrates. Usually diatoms of the genera Navicula, Amphora, and Cocconeis are known to occur on several species of cnidarians [28], sponges [29], and gastropods [30,31].…”
Epibiotic associations can result in co-introductions of non-indigenous species, which may affect ecosystems in several ways. In fouling communities of three estuaries in southern Brazil, a number of amphipods was found to harbour a dense coverage of epibionts. Three different species, the two globally widespread caprellids Caprella equilibra and Paracaprella pusilla, as well as the ischyrocerid Jassa valida, had been colonised by diatoms. Further scanning electron microscope analyses assigned these diatoms to 14 different species that had previously been reported from benthic habitats. This is one of the scarce records of diatoms attached to amphipods. The occurrence of the diatom Amphora helenensis represents the first report for Brazilian waters as well as the second record for the whole SW Atlantic Ocean. As some diatoms were associated with common fouling amphipods, a possible regional spread aided by these crustaceans seems likely. Possible effects of this amphipod-diatom association on the animals and their implications for the underlying ecosystems of this remain to be elucidated.
“…Ecology: the species was only found attached on the exoskeleton of marine copepods by Takano (1983), Kimor et al (1992) and Skovgaard & Saiz (2006). Fernandes & Calixto-Feres (2012) analysed epizoic diatoms on several species of copepods and they only found Pseudohimantidium pacificum Hustedt & Krasske in Krasske (1941: 272) on Euterpina acutifrons from Paranaguá Bay, Paraná State, Brazil.…”
Sceptronema orientale was found epizoic on the harpacticoid copepod Euterpina acutifrons (Dana) collected from several locations along Bahía Anegada, Province of Buenos Aires, Argentina. Material was examined with light and scanning electron microscopy and new data about the morphology of the chloroplast and ultrastructural details of the girdle, valves, apical slit fields and rimoportulae pattern were obtained. Based on this new knowledge the descriptions of the species and of the monotypic genus Sceptronema are emended. Considering that in the protologue three pictures were designated as iconotype, the material from Ría del Jabalí is chosen as an epitype to serve as the interpretative type of Sceptronema orientale. A comparison with the morphologically similar genera Licmophora and Gato was conducted and the inclusion of Sceptronema in the Family Licmophoraceae, Order Licmophorales is proposed.
“…However, occurrences of microalga epibiosis on copepods were mostly documented with particular focus on epibiont morphology, phylogeny, and distribution (Carman and Dobbs, 1997;Fernandes and Calixto-Feres, 2012;Li et al, 2014;Gómez et al, 2018;Nayak et al, 2021). The impacts of algal epibiosis on copepod reproduction were rarely investigated as yet.…”
We evaluated here the effects of the epibiotic diatom Tabularia sp. on the productivity of the calanoid copepod Acartia tonsa (Dana) for assessing their risk on copepod intensive aquaculture industry for the provision of live feed. In the first experiment, uninfested and intensively infested females were cultivated individually for the assessment of egg production. Intensively infested females appeared to have a significantly lower egg production (5.0–9.0 eggs/female/d) than uninfested females (22.0–26.0 eggs/female/d) during 5 consecutive days. In the second experiment, effects of culture densities on diatom epibiosis were investigated in 9 L cultures at three different densities (200, 400, and 600 ind. L–1). Another culture at higher volume (250 L) and lowest density (200 ind. L–1) was also carried out to test the effect of culture volume on diatom epibiosis. The infestation rate (%), infestation intensity (ratio of surface diatom coverage levels, classified as levels 0–3) and daily egg harvest rate (number of harvested eggs per day per liter) were evaluated among the four culture populations. The copepods had higher infestation rate (53.69–60.14%) and intensity rate (high ratios at level 2 and 3) when the densities were increased from 200 ind./L to 400 and 600 ind./L. Although egg harvest increased with increasing culture density, it seemed that the diatom-infested A. tonsa population reach a saturated egg production when the density was higher than 400 ind./L. Nevertheless, the differences of culture volumes (250 and 9 L) appeared to be not to have any effect when the copepods were cultivated at the same density (200 ind./L). This study reveals for the first time that the epibiosis of the diatom Tabularia sp. reduces the individual egg production, and egg harvest rate in high-density culture of the copepod A. tonsa. Our findings implicate that diatom epibiosis should be avoid in copepod intensive culture systems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.