Reproductive biology of two species ofHyalellaSmith, 1874 (Crustacea: Amphipoda: Hyalellidae) from southern Brazil

Ecological aspects of natural populations of Hyalella pampeana (Crustacea, Amphipoda, Hyalellidae) from the Natural Reserve Island of Martín García (Río de La Plata, Argentina)

“…Males of H. pampeana were larger than females. This difference in size between sexes has been reported in other Hyalella species, such as H. pleoacuta, H. castroi (Castiglioni and Bond-Buckup 2008a), H. bonariensis (Castiglioni et al 2016), H. longistila (Bastos-Pereira and Bueno 2016), H. georginae and H. gauchensis (Ozga and Castiglioni 2017). According to low (1978), crustacean growth is similar between sexes until reproductive maturity.…”

“…Ovigerous females of H. pampeana were collected in most of the months, indicating that reproduction is continuous in this species throughout the year, in agreement with data reported by lopretto (1983) in ponds of the province of Buenos Aires, Argentina. Continuous reproduction has been reported in other Hyalella species that inhabit natural populations in tropical and subtropical temperature regimes (edwards and Cowell 1992, Castiglioni and Bond-Buckup 2009, Bastos-Pereira and Bueno 2016, Ozga and Castiglioni 2017, Torres et al 2015, Castiglioni et al 2016). According to Sainte-Marie (1991), gammaridean populations exhibit reproductive patterns that can be associated with latitude.…”

“…Reduction in fecundity and size of amphipods during summer months could be attributed to a metabolic effect. Higher temperatures result in higher costs for females in metabolic maintenance, which could result in a lower amount of energy invested in the production of eggs during warmer months (Nelson 1980, Ward 1986 (Ozga and Castiglioni 2017).…”

“…South American ecological studies on the genus are mainly focused on the sympatric species Hyalella castroi gonzález, Bond-Buckup and Araujo 2006 and Hyalella pleoacuta gonzález, Bond-Buckup and Araujo 2006 from Brazil (Castiglioni and Bond-Buckup 2008a, b, 2009, garcía-Schroeder and Araujo 2009. Other population studies concentrate on Hyalella longistila Faxon 1876 (Bastos-Pereira and Bueno 2016) and Hyalella bonariensis Bond-Buckup, Araujo and Santos 2008 (Castiglioni et al 2016), whereas important aspects of the reproductive biology have been recently studied in Hyalella carstica Bueno 2012 (Torres et al 2015), Hyalella georginae Streck et al 2017 andHyalella gauchensis Streck et al 2017 (Ozga and Castiglioni 2017). In Argentina, the biology and ecology of the Hyalella species are poorly known aspects.…”

Population structure of two freshwater amphipods (Crustacea: Peracarida: Hyalellidae) from southern Brazil

“…In the last few years, understanding of American's Hyalella has risen with an increasing number of taxonomic publications, indicating that there is still a large number of species unknown to science (González and Watling, 2002a, 2002b, 2003a, 2003bBaldinger, 2004;Pereira, 2004;González et al, 2006;Cardoso et al, 2011;Bueno et al, 2013;Rodrigues et al, 2014;Cardoso et al, 2014;Colla and César, 2015). In Brazil, most studies of Hyalella concern new species descriptions (Bastos- Pereira and Bueno, 2013;Bueno et al, 2013;Cardoso et al, 2014;Bueno et al, 2014;Streck et al, 2017), however, knowledge on their life cycles, population biology e reproductive biology are limited by the studies of Castiglioni and Bond-Buckup (2008a) (Hyalella castroi González, Bond-Buckup andAraujo, 2006 andHyalella pleoacuta González, Bond-Buckup andAraujo, 2006), Castiglioni et al (2016) (Hyalella bonariensis Bond-Buckup, Araujo and Santos, 2008) and Ozga and Castiglioni (2017) Streck and Castiglioni, 2017). Most of the remaining studies published on population, reproductive, systematic, and taxonomic aspects of Hyalella species were performed with the North American species H. azteca (Cooper, 1965;Wellborn, 1994;Grosso and Peralta, 1999;Wellborn et al, 2005).…”