Morphometric differences between two exotic invasive freshwater caridean species (genus Macrobrachium)

Abstract

The prawns Macrobrachium amazonicum and Macrobrachium jelskii, have been introduced in the southeastern Brazilian region. Thus, it becomes necessary knowing the reproductive aspects of these invasive species. This study aimed to analyze the relative growth and to estimate the morphological sexual maturity of the freshwater prawn species M. amazonicum and M. jelskii. We collected monthly samples from January through December 2010 in th Rio Grande riverbank. Prawns were measured to their cephalothorax length (CL), length of the pleura of the second abdominal somite in females (PL) and length of the appendix masculina (AML). We analyzed 2937 specimens of M. amazonicum (628 males and 2,309 females) and 2167 specimens of M. jelskii (504 males and 1663 females). We observed different allometric patterns in the relative growth of the AML and PL (both more accentuated in M. amazonicum) between the species. The present results indicate that these species adopt different reproductive strategies, possibly representing adaptations that may have facilitate their establishment in the Rio Grande riverbank. When comparing our results to the ones obtained in previous studies, we observed that the reproductive traits of both species indicate a marked phenotypic plasticity.

Non-Native Decapods in South America: Risk Assessment and Potential Impacts

“…The presence of this species in coastal and estuarine regions within the Atlantic Forest domain, which includes several biological reserves, PAs, RPPN and Integral Protection Areas, raises concerns about its spread in South America. Although some authors consider M. jelskii an invasive species, the lack of studies demonstrating impacts makes this statement questionable [25,107,108].…”

Does fecundity of Macrobrachium amazonicum (Heller, 1862) change between upstream and downstream a dam? A case study in Água Vermelha Reservoir, Brazil

“…Due to rapid reproduction, this prawn has quickly spread throughout several dams (Paiva & Campos 1995). In the state of Minas Gerais, M. amazonicum has been recorded in dams by Silva et al (2017), Silva et al (2018), Costa e Silva et al (2019), Paschoal et al (2019) and Rodrigues et al (2020).…”

Population structure of Macrobrachium amazonicum (Heller, 1862) (Decapoda: Palaemonidae) in Miranda Hydroelectric Plant Reservoir, Araguari river, Minas Gerais, Brazil

“…The poor knowledge about the natural biology of Brazilian inland populations of M. amazonicum can be one of the reasons of this little explored market. It is endemic in South America and distributed in the main river basins of the continent, like the Amazon River in the state of Pará and Paraná River in the states of Minas Gerais, São Paulo and Goiás (Vergamini et al, 2011;Pileggi et al, 2013;Pantaleão et al, 2014;Silva et al 2017;Silva et al, 2018).…”