Colonization and early succession on artificial hard substrata by meiofauna

Abstract

An experiment was undertaken at Farol Island, Brazil, to examine colonization of bare aluminium surfaces by microbes and meiofauna. It was hypothesized that a primary source of meiofaunal colonists was sediment resuspended during upwelling events, two of which occurred during the experiment. Microbial biofilms formed on the experimental substrata within 1 day, and continued to develop throughout the experimental period. Among meiofaunal groups copepods also appeared on the first day, and nematodes on the second. Meiofaunal community structure developed in three main phases: an initial phase of 2 days, characterized by low abundances of copepods; a second phase during the first upwelling period characterized by higher abundances of copepods and also by turbellarians; and a third phase from day 13 onwards characterized by relatively stable abundances of a range of taxa including copepods, cirripedes, nematodes and ostracods. Nematode assemblages also developed in three phases, but with different timings coinciding with upwelling events: an initial phase, from the beginning of the experiment to day 9, characterized by few species and low (or no) abundances; a second phase following the first upwelling characterized by moderate abundances of Chromadorina, Chromadorella, Daptonema and Euchromadora sp. 3; a third phase following the second upwelling period (from day 26 onwards) in which Daptonema disappeared and the assemblage was characterized by moderate to high abundances of Euchromadora (species 1 and 2) and Chromadorella. Although shifts in nematode assemblage structure coincided with upwelling events no evidence was found for sediments being the primary source of colonizers on the aluminium substrata, in contrast to our hypothesis.

Worms without borders: genetic diversity patterns in four Brazilian Ototyphlonemertes species (Nemertea, Hoplonemertea)

“…In this case, even high dispersal rates lead to the establishment of several discrete groups. Some studies have addressed the meiofauna ecological dynamics in Brazil and concluded that mostly abiotic factors like rainfall, grain size, salinity, dissolved oxygen, among others, influence greatly the spatial and temporal distribution and recruitment of interstitial organisms (Somerfield et al 2003;Souza-Santos et al 2003;Fonsêca-Genevois et al 2006;Albuquerque et al 2007). In natural populations, temporal and spatial effects cannot be disentangled and, sometimes, temporal variation enhances effects of spatial variation on distribution of genetic variability, even at a small scale (Bryant 1976;De Wolf et al 1998).…”

Structure and function of nematode communities across the Indian western continental margin and its oxygen minimum zone

“…The genus Acantholaimus increased in relative abundance with increasing depth in many deep-sea areas (Soetaert and Heip, 1995). Moreover, Viscosia viscosia was a good indicator of the shelf because it often inhabits the surface layers of sediment and is apparently capable of floating (Fonsêca-Genevois et al, 2006).…”

Successional trajectory of the fouling community on a tropical upwelling ecosystem in southeast Rio de Janeiro, Brazil

“…The first stage is characterized by biofilm and filamentous algae. Biofilms are composed of organic matter and microorganisms such as bacteria and diatoms and serve as an attractive substrate for colonization filamentous forms (PARK et al, 2011;FONSÊCA-GENEVOIS et al, 2006). The diatoms Nitzschia and Navicula were the main components of Biofilms 1 and 2 and were also identified by DE MESSANO et al (2009) in experimental panels placed at the same site.…”