Macrobrachium amazonicum (Heller, ). AphiaID. (urn:lsid: :taxname). Classification. Biota; Animalia. Pupil of a Macrobrachium amazonicum (freshwater shrimp). Alex H. Griman. Affiliation: Alex Kawazaki Photography São Paulo, Brazil. Technique. Macrobrachium amazonicum — Overview. Amazon River Media. Image of Macrobrachium amazonicum. Macrobrachium amazonicum Unreviewed.
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This raises doubts whether allopatric, ecologically diverse populations belong to the same species. Aquaculture and Research, vol.
Table 1 provides a detailed description of each group. In summary, our data show biologically relevant differences in life-history traits of shrimps from the Pantanal compared to M. The prawns were sexed and identified by the presence or absence of the appendix masculina on the second pair of pleopods Valenti, Acta Limnologica Brasiliensia, vol. Additionally, here we compare the sizes and male morphotypes of M. University of Oklahoma Press.
This analysis was conducted as an exploratory tool to search for any evidence of groups’ separation and reduce the number of variables. However, cheliped length was always greater in GC2. It was reported that freshwater individuals differ from estuarine individuals in a few essential reproductive characteristics. Only males were used in the analysis. Different biological characteristics were found between the populations studied.
Reproductive and morphometric macrbrachium of Macrobrachium amazonicum Decapoda: All measurements were based in the method of Kuris et al. There is strong human disturbance here, caused by an excessive external supply of nutrients, such as fish food pelletsviscera of caught fish and corn, to attract fish for sport fishing.
WoRMS – World Register of Marine Species – Macrobrachium amazonicum (Heller, )
Revista Brasileira de Zoologia, vol. This also occurs with size of morphological sexual maturity, estimated with relative growth at 4.
According to this author, in these inland populations, female downstream amazoncium or a passive larval export to estuarine waters must be considered as biologically impossible, which raises the question if coastal, estuarine, and hololimnetic inland populations assigned to M. Individual fecundity was determined from the total egg counting, using a stereoscopic microscope. However it is clearly not characteristic of the studied population here, which presents large male morphotypes with strongly developed chelipeds.
In this species, sexually mature males can have different morphotypes, which have different sizes, morphology, physiology and behavior. In this work, the maximum number of larvae observed per macgobrachium for females kept in laboratory was 2, Among the ovigerous M. We would also like to extend thanks to Dr.
The mean angle and standard deviation were then calculated for each group. GC1 and GC1 vs. However, this estimative is not available in the works of Santos et al.
Thus, the passage from one morphotype to another in a natural environment could occur through a single molt. Results Carapace length ranged from 4. This method distributes the data into groups of numbers previously established by an iterative process that minimizes the variance within groups and maximizes the variance among them.
According to these authors, changes in cheliped size, color and spination necessarily cause deep modifications to the intraspecific interactions and in the male’s interaction with the environment. wmazonicum
They remain small, cryptic, and highly mobile Bauer, The following dimensions were measured with a digital caliper 0. To determine fertility, ovigerous M. Similarly to observed in the present comparison, Mashiko suggested the presence of separate populations of Macrobrachium nipponense De Haan within the same river. The relative growth was analyzed based on the change in growth patterns of certain body parts in relation to amazoniccum independent variable CL.
These inland populations do not depend on brackish water to complete the larval maazonicum, in contrast of what occurs in coastal populations Guest, Four samples were taken during the morning, in each month, from January through April 16 samples. Additionally, the spination pattern of the chelipeds among the four morphotypes of our specimens was quite different, similar to demonstrated by Moraes-Riodades and Valenti Because of this, there is some discussion about the taxonomic status of coastal and continental populations Moraes-Valenti and Valenti, Each male specimen was mavrobrachium with amazonicm to seven body dimensions as follows: This study records, for the first time, the occurrence of all four male morphotypes in a population of Macrobrachium amazonicum from a continental environment, with an entirely freshwater life cycle.
Palaemonidae from the Pantanal, Brazil, suggests initial speciation.