The present study investigated the population dynamics of Hepatus pudibundus in the Cananéia region, in southern São Paulo state, Brazil, focusing on population structure, growth parameters, longevity, sex ratio, reproduction and recruitment juvenile period. Sampling was performed monthly at seven stations from July 2012 to June 2014, using a shrimp fishing boat. A total of 1650 specimens were collected: 551 males and 1099 females. The males were larger than females. Reproductive females were captured throughout the study period and juveniles were captured in most months. Both of these demographic categories were positively correlated with temperature. Growth parameters showed differences between sexes: CW∞ = 78.91 mm, k = 0.0066 day−1, t0 = 0.0965 for males and CW∞ = 69.71 mm, k = 0.0053 day−1, t0 = −0.2404 for females. Longevity was estimated at 1.91 and 2.40 years for males and females, respectively. The findings provide a greater understanding of the life cycle in this species. Additionally, since trawl nets are not selective, this study also provides information for better trawl fishery management, addressing not only the target shrimp but also the by-catch species.

Litopenaeus schmitti is one of the most commercially exploited penaeids on the southeastern and southern Atlantic coast of Brazil. Information about juvenile recruitment and growth patterns of individuals is important for management programs. The present study estimated the growth parameters, longevity, and recruitment of L. schmitti in the region of Ubatuba, São Paulo State. The growth parameters of individuals were estimated by the Bertalanffy growth model, and longevity was estimated with the inverted Bertalanffy equation. The growth parameters were, for females and males respectively: CL ∞ = 53.10 mm and 43.23 mm, k = 1.82 year -1 and 2.19 years -1 , t 0 = 1.10 and 0.69. Longevity was calculated to be 2.27 years for females and 2.10 years for males. Juvenile recruitment occurred seasonally from December to April during the first year of sampling and from November to May in the second year. Although the large peak in juveniles seen in March 2007 in the estuarine regions coincided with the closed season, the reopening of the fishery in June may promote the capture of large numbers of newly grown adults who have not yet reproduced.

Xiphopenaeus kroyeri (Heller, 1862) is the third most common species caught by fi shing boats in the state of São Paulo, Brazil and production of this shrimp in the Cananéia region located on the southern coast of this state ranks second in the nation. Th e aim of this study was to investigate the temporal variation of the total biomass and size of X. kroyeri and analyze this variation against environmental factors in order to suggest some information about the best periods to fi sh this species. Samples were caught monthly from four sampling stations in Cananéia between July 2012 and June 2014 using a fi shing boat equipped with ott er-trawl nets. Temperature and salinity were monitored using a multiparameter probe, and sediment samples were also taken using a Van Veen-type gripper for particle size analysis. Th e shrimp were weighed, quantifi ed, and carapace length was measured (mm). In general, the highest total biomass values were recorded when the fi shery was closed in the southeast and south regions, and the highest catch of smaller individuals was also observed during this period. In contrast, in November 2013 the fi shing is permitt ed and high biomass composed of large individuals was observed. Th e monthly biomass showed a positive relationship with sediment texture, because this species prefers very fi ne sediments to burrow as a defense against predators. keY wordsAbundance, closed season, fi shery, Penaeidae, weight. Miazaki et al.2

We estimated the growth parameters of the spider crab, Libinia ferreirae (age, asymptotic size and growth rate) using the von Bertalanffy growth equation model. We obtained nine cohorts for female carapace asymptotic width (CW ∞ ) = 64.32 mm, growth coefficient (day -1 ) (k) = 0.0027 e t 0 = 0.77 days) and seven for males (CW ∞ = 81.93 mm, k= 0.0021 e t 0 = 0.49 days). The longevity for males was higher than that for females, estimated 2,156 days (5.91 years) and 1,706 days (4.68 years), respectively. The growth curves for males and females differed (F = 34.67 e p < 0.001). Males reached gonadal maturity before morphometric maturity and occurred at 8.8 and 16.6 months of life, respectively. Females reach gonad and morphometric maturity synchronously and this was estimated to occur at about 11.42 months of life. These crabs invest a great amount of energy in growth during a brief period of their development until reaching the terminal moult. This growth strategy would bring less wear to the organism and consequently a greater longevity. KeywordsGrowth, von Bertalanffy, puberty moult, age, symbiotic relationship original arTiCle Nauplius, 28: e2020003 CORRESPONDING AUTHOR

The investigation of the temporal dynamics of marine benthonic populations is an important tool to evaluate whether and how they are responding to environmental changes. Here we compared the population biology and reproduction of Hepatus pudibundus in Ubatuba Bay after a 20-year gap. The first samplings were done in September 1995 − August 1996 (hereafter 1ºP), and the second, in September 2016 − August 2017 (hereafter 2ºP). In both periods, five sites were trawled aboard a shrimp fishing boat. We captured 865 crabs in the 1ºP and 4222 in the 2ºP. The mean individual size of each demographic group, the size at the onset of sexual maturity, and the growth rate of females was lower in the 2ºP. The reproductive and recruitment periods were continuous. Our comparable data on population features taken 20-years apart showed adjustments regarding the sizes and abundance of mature individuals of H. pudibundus of Ubatuba Bay, indicating that this species is resilient to the anthropogenic impacts in the region.