Population dynamics of the crabHepatus pudibundus(Herbst, 1785) (Decapoda, Aethridae) on the southern coast of São Paulo state, Brazil

Abstract

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.

Assessing the factors driving the changes in the spatio‐temporal distribution of Hepatus pudibundus (Decapoda, Brachyura) over a 20‐year interval in a region under the influence of El Niño (ENSO)

“…(2014) in Ubatuba and by Miazaki et al. (2019) in the region of Cananéia have shown that H. pudibundus recruitment occurs in the winter. Altogether, these and previous results indicate that this is the recruitment pattern along the coast of São Paulo, and that it increases the reproductive success and leads to a high adaptive value (fitness) in this region.…”

“…The higher abundance of adult females compared to adult males in the two periods can be explained by sex-specific dispersal, migration, mortality, and growth rates, corroborating with Jesse and Stotz (2002) and Miazaki et al (2019). Females naturally prefer sheltered areas or strategic locations to avoid conflict, increase protection against predators, and favor egg release (Mantelatto, 2000).…”

Unveiling the dynamics of the spider crab Libinia ferreirae, through reproductive and population characteristics on the south-eastern coast of Brazil

“…Sexual dimorphism with larger males than females seems to be a common pattern for crustaceans, including brachyurans and crayfishes (Miazaki et al ., 2019; Sousa et al ., 2019; Bernardo et al ., 2020; Hamasaki et al ., 2020). According to Hartnoll (1969), males are larger because they tend to protect pre- and post-moulting females with the copulatory embrace, representing an adaptation to ensure reproductive success.…”

“…When analysing L. emarginata and other Majoidea as Chionoecetes opilio and Maja squinado (Herbst, 1788), it has been found that OFs can also copulate, since their gonads are already developed and they can store new sperm masses, with females being able to spawn up to four times in a row (Hinsch, 1968; Elner & Beninger, 1995; González-Gurriarán et al ., 1998). The same pattern was found in Cananéia for this species (Gonçalves et al ., 2017), with continuous reproduction being a common feature of tropical and subtropical marine brachyurans such as: L. spinosa (Braga et al ., 2007), Persephona mediterranea (Herbst, 1794) (Bertini et al ., 2010 b ), C. ornatus (Andrade et al ., 2014), Arenaeus cribarius (Lamarck, 1818) (Silva et al ., 2018) and H. pudibundus (Miazaki et al ., 2019).…”

Individual growth and mortality of Rhithropanopeus harrisii (Decapoda: Panopeidae) in the estuarine region of Patos Lagoon, Southern Brazil

“…Thereafter, a pooled VBGF was estimated. Maximum longevity (T max ) was calculated by the inverted von Bertalanffy equation, using 99 % of the asymptotic size as recommended by D'Incao and Fonseca 2000, and recently supported by investigations on brachyurans (Miazaki et al, 2019;Gonçalves et al, 2020). Average maximum longevity was estimated by 95 % of the largest animals (Taylor, 1965).…”