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Carvalho-Batista A.,Labcam Laboratorio Of Biologia Of Camaroes Marinhos E Of Agua Doce | Castilho A.L.,Institute Biociencias | Fransozo A.,Institute Biociencias | Costa R.C.,Labcam Laboratorio Of Biologia Of Camaroes Marinhos E Of Agua Doce
Crustaceana | Year: 2012

Artemesia longinaris Spence Bate, 1888 is an endemic shrimp of the western South Atlantic. The objective of the present study was to analyse diel variation in the abundance and size of A. longinaris in the Ubatuba region, state of São Paulo, Brazil, during the year 2000. During each season of the year, collections were made during the day and night along 8 transects at depths ranging from 5 to 40 m. The water temperature and salinity was measured during sampling, and sediment samples were taken for the analysis of texture. The shrimp were more abundant at night at all stations and transects, except at a depth of 15 m during the spring (x2, p < 0.05). In the study region A. longinaris conformed to the burying model, in which shrimp are active during the night and only occasionally emerge during the day. However, in periods when juveniles are highly abundant and a decrease in temperature occurs, the shrimp established themselves in shallower areas of the bay (5 to 15 m) where the main sediment was silt and clay, and not in deeper areas (20 to 40 m). In this case, we observed a change in the burying pattern: individuals were active during the day as well as at night. Only in spring it was possible to observe the decrease in average size of individuals collected during the day, due to the peak of juveniles in this season. As a consequence, the sediment type and life cycle of the species appeared to modify the yield of shrimp during the periods analysed. © Koninklijke Brill NV, Leiden, 2012. Source

Pantaleao J.A.F.,Labcam Laboratorio Of Biologia Of Camaroes Marinhos E Of Agua Doce | Hirosec G.L.,Federal University of Sergipe | Costa R.C.,Labcam Laboratorio Of Biologia Of Camaroes Marinhos E Of Agua Doce | Costa R.C.,Sao Paulo State University
Invertebrate Reproduction and Development | Year: 2012

The objective of this study was to estimate the size of morphological sexual maturity based on the study of relative growth, to determine the maximum size of individuals, and to determine if there are different morphotypes of males in a population of Macrobrachium amazonicum with an entirely freshwater life cycle. Collections were made monthly, with the use of a net, from September 2006 through August 2007. In each individual, the following structures were measured: carapace length (CL, in mm), width of the second pleuron (PlL, mm), length of the carpus (CaL, mm), and length of the propodus (PrL, mm). Relative growth was analyzed by observing the change in growth patterns of certain parts of the body in relation to the independent variable CL. The maximum sizes found were 8.5 and 11.4mm CL for males and females, respectively. The morphometric variables: length of the carpus (CL × CaL) for males, and width of the second pleuron (CL × PlL) for females gave the best estimates for the size at maturation, which was 4.26mm CL for males and 5.39mm CL for females. The growth pattern in the different stages and the beginning of differential growth seemed to be closely related to reproductive aspects. No indices were found that separated the males into four different morphotypes, as proposed in the literature for coastal or artificially farmed populations. Only the male morphotype termed translucent claw was found in this population. The different morphological patterns in different regions are probably explained by ecological differences in the environments inhabited by these groups, principally in the availability of nutrients and the salinity in which the larvae develop. © 2012 Taylor & Francis. Source

Pescinelli R.A.,Labcam Laboratorio Of Biologia Of Camaroes Marinhos E Of Agua Doce | Davanso T.M.,Labcam Laboratorio Of Biologia Of Camaroes Marinhos E Of Agua Doce | Da Costa R.C.,Labcam Laboratorio Of Biologia Of Camaroes Marinhos E Of Agua Doce
Invertebrate Reproduction and Development | Year: 2015

Growth in crustaceans is characterized by ontogenetic differentiation during the development of their body structures, so studies on relative growth are widely applied in this group. In this study, the growth pattern of the body structures was verified through the analysis of relative growth, and then, morphological sexual maturity of the mangrove crab Aratus pisonii (H. Milne Edwards, 1837) was estimated. The carapace width (CW), cheliped propodus length (PL), cheliped propodus height (PH), propodus width (PW), abdomen width (AW), and first pleopod length (FPL) of the crabs were measured. The relationships that best showed changes in the allometric coefficient among demographic categories were FPL vs. CW for males and AW vs. CW for females. This study verified the increased size of the cheliped in terms of length, width, and height, which occurred mainly in adult males. This increase reflects the importance of this structure in the reproductive processes of A. pisonii. For females, the increase in abdomen growth reflects their reproductive potential, since it is a structure that provides protection for eggs. © 2015 © 2015 Taylor & Francis. Source

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