<b>Experimental study on the efficiency of different types of traps and baits for harvesting <i>Macrobrachium amazonicum</i> (Heller, 1862)

Abstract

Macrobrachium amazonicum is a freshwater prawn endemic to South America with wide distribution in Brazilian Amazon rivers. In estuary and freshwater streams of the Pará State, they are captured with different types of traps locally know matapi. This study evaluated the efficiency of traps of different sizes (large, medium and small) and baits (babassu coconut and fish) for sampling this shrimp. Samplings were conducted with 24 traps with different treatments (trap size and bait). We captured 909 specimens. Higher mean catches were observed in traps baited with babassu coconut. Interactions between babassu coconut bait and medium matapi (BM-M), and fish bait and large matapi (FISH-L) were significant. Carapace length (CL) varied significantly between sites (F = 12.74, p < 0.01). The total maximum length was 13.65 cm. Medium traps baited with babassu coconut were the most successful in the tested combinations, however, there was a clear correlation between size trap and size of shrimp, for both body weight and carapace length.

Population structure, mortality, and recruitment of Macrobrachium amazonicum (Heller, 1862) (Caridea: Palaemonidae) in the eastern Amazon region, Brazil

“…Due to the existence of morphotypes, M. amazonicum populations generally have larger males than females (Silva et al, 2005;Flexa et al, 2005;Bentes et al, 2011). This occurs mainly in populations with marked intraspecific competition, where the sex ratio approaches 1:1 (Bentes et al, 2014). Although in these populations with morphotypes the maximum size occurs in males, the mean size of females is usually larger (Freire et al, 2012;Bentes et al, 2014).…”

“…This occurs mainly in populations with marked intraspecific competition, where the sex ratio approaches 1:1 (Bentes et al, 2014). Although in these populations with morphotypes the maximum size occurs in males, the mean size of females is usually larger (Freire et al, 2012;Bentes et al, 2014). Larger males are uncommon among other palaemonids that do not have Downloaded from https://academic.oup.com/jcb/article-abstract/37/2/131/3089767 by Universidade Estadual Paulista J�lio de Mesquita Filho user on 24 June 2019 morphotypes (Bentes et al, 2011), and the absence of these in M. amazonicum populations is related to the aggregate distribution of the species in marshland environments (Pantaleão et al, 2012), such as those observed at the collection site.…”

“…Macrobrachium amazonicum is extensively exploited in northern and northeastern Brazil (Lucena-Frédou et al, 2010;Lima et al, 2014), where it is overexploited by artisanal fishermen for their own subsistence (Bentes et al, 2014) or for commercial trade (Freire & Bentes, 2008). The ease with which these shrimps are caught in different types of rivers (Odinetz-Collart, 1993), in perennial lakes formed by the dynamics of the rivers in the region (Bentes et al, 2011), and in igarapés (the local name for the sites where these environments merge) (Bentes et al, 2011) has led to a reduction of the fishing stock (Lima et al, 2014).…”

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

“…According to Maciel and Valenti (2009), the occurrence of such morphotypes is related to the local population traits. The morphotypes may mostly occur in populations with intense intraspecific competition and sex ratio close to 1:1 (Bentes et al 2014). The absence of such morphotypes is more common in populations in which individuals show an aggregate distribution, as it occurs in muddy environments (Pantaleão et al 2012), with a great abundance of food and females.…”

“…There are around 20 species registered in Brazil (Mantelatto et al 2016), from which several are among the most economically important ones, such as Macrobrachium carcinus (Linnaeus 1758), Macrobrachium acanthurus (Wiegmann 1836) and Macrobrachium amazonicum (Heller 1862), (Valenti 1985), and the exotic invasive species Macrobrachium rosenbergii (De Man 1879), which was accidentally introduced as a consequence of their cultivation (Iketani et al 2016). Macrobrachium specimens are used as a protein resource by human obtained in nature-fishing activities or shrimp farming (Maciel and Valenti 2009;Bentes et al 2014;Costa et al 2016;Taddei et al 2017a).…”