Variations on the larval incubation of Anodontites trapesialis (Unionoida, Mycetopodidae): Synergetic effect of the environmental factors and host availability

Abstract

The unionid Anodontites trapesilais (Lamarck, 1819) like most freshwater mussels is a parasite of fish. So it is trivial to assume that the availability of hosts is an important factor for the maintenance of unionoid populations. What seems obvious is not always so easy to demonstrate. This study proposes to investigate the effects of abiotic and biotic variables related to the incubation of larvae in A. trapesialis. For this, we estimate different biological indexes and try to capture the dimensionality of the fish, along with the temporal variation of environmental variables. From the application of a CCA, it was demonstrated that there was a synchronicity among the factors and variables proposed here, and we infer that the flood pulse acts as a synergistic factor in this process.Keywords: reproduction, freshwater mussels, fishes, host relationship, wetlands. Variações na incubação larval de IntrodutionUnionoida mussels have a complex life cycle. After fertilization, the early stages of development occur in the inner demibranch (Bonetto and Ezcurra, 1962;1965). The planktonic larvae, called glochidium or lasidium, complete their development cycle as temporary parasites of fish (Fryer, 1970, Mansur et al., 1987. Around 27 days after fixation, they complete metamorphosis and unfasten themselves from the fish and become a benthic organism (Bonetto and Ezcurra, 1962;Castellanos and Landoni, 1990).Some limiting factors such as temperature (Bauer, 2000;Strayer, 2008;Oliveira et al. 2010), food availability and parasite-host interaction, influences directly in the reproductive dynamics of these mussels (Haag and Warren-Junior, 1997;Avelar and Mendonça, 1998;Beasley et al., 2000). To know which environmental factors are most important to each one of the reproduction attributes will depend on the combined effect provided by the environment in which these bivalves occur (Galbraith and Vaughn, 2009). Few studies have examined the environmental influences in the reproductive dynamics of the population and information is unknown related to the incubation period, elimination of larvae and parasite-host interaction for neotropical species.Anodontites trapesialis (Lamarck, 1819) (Unionoida, Mycetopodidae) is widely geographically distributed and may represent the highest percentage of benthic biomass in rivers, lakes and flood plains (Colle and Callil, 2012). Although on the national list of endangered species, (Brasil, 2004), this species can be found in abundance in farm ponds and fish farming (Guardia-Felipi and Silva-Souza, 2008) and has been considered a species for cultivation and potential source of protein (Tello-Panduro et al., 2003). However being sedentary and excellent filter feeders it has been used as a sentinel organism (Callil, 2003) for studies of environmental monitoring and an effective biomarker of pesticides (Lopes et al., 1992) and heavy metals like mercury (Callil and Junk 1999, 2000), lead and cadmium (Tomazelli et al., 2003).In order to understand the processes related to the larval developme...

Bivalve distribution in hydrographic regions in South America: historical overview and conservation

“…The species had dispersed further due to fish farming. The lasidia of this species appear not to show specificity with hosts (Callil et al, 2012), facilitating the dispersion in the fish farms, causing damage on fish production (Guardia-Felipi & Silva-Souza, 2008). C. fluminea, which has been reported in South America since the 70s has invaded all the large basins of the continent from Colombia to the North of Patagonia where it became quickly dominant (Santos et al, 2012).…”

Gonad maturity of simping Placuna placenta, Linn 1758 (Bivalve: Placunidae) harvested from Kronjo Coastal, Indonesia

“…Freshwater mussel, resting period star from September dan October, and spawning season once a year (Callil et al, 2012). Ruditapes philippinarum (Bivalvia: Veneridae) in Western Korea earlystage maturity (shell lengths at 50% of sexual maturity (RM50) star from 15.1-20.0 mm and over 65% after 20.00 mm shell length (Chung et al, 2013), .…”

Composição e distribuição de conchas de moluscos límnicos no Parque SESC Baía das Pedras, Pantanal de Poconé, Mato Grosso

“…Assim, os mecanismos que geram diferenças nos padrões de composição das espécies estão ligados à capacidade de dispersão dos indivíduos (Hubbell, 2006). Porém, apesar da baixa capacidade de deslocamento, muitas espécies de moluscos não são limitadas por dispersão, pois existem mecanismos que facilitam a colonização no ambiente aquático, como por exemplo, estágios parasitas de peixes em bivalves Unionoida (Callil et al, 2012).…”