Sexual maturity and egg production in an unexploited population of the red squat lobster Pleuroncodes monodon (Decapoda, Galatheidae) from Central America

Hermit crabs are soft-abdomen decapods. They depend upon gastropod shells for protection, with the latter influencing growth rate, mortality and reproduction. The present work aims to provide information about the biology and reproduction of Pagurus brevidactylus in a conservation area in Brazilian southeastern littoral. The material was sampled through active searching by SCUBA diving and refuge traps. We analyzed population structure, fecundity, reproductive output (RO), reproductive periodicity and shell utilization for P. brevidactylus. In total, 54 males, 18 nonovigerous females, 34 ovigerous females and 10 juveniles were sampled. The females had a fecundity of 69.5 ± 65 eggs, which was lower than that compared to other populations from different localities. The RO ranged from 1.48% to 63.04%, with a mean of 26.75 ± 18.23%. There was a positive relationship between egg number and female size. The animals had continuous reproduction, but they reached smaller maximum sizes when compared with other populations. The shell occupation pattern was also different from other localities, the shells of Phrontis alba being the most occupied; this shell has a smaller size when compared to others that P. brevidactylus occupies in other localities. Therefore, P. alba could have had limited the growth and reproduction of P. brevidactylus.

Section: Discussionsupporting

confidence: 57%

Shell occupation as a limiting factor forPagurus brevidactylus(Stimpson, 1859) in the Marine State Park of Laje de Santos, Brazil

Silva

Galli

Stanski

et al. 2018

“…Analysis of covariance (ANCOVA) was applied to determine the embryo loss and embryo volume increase during the developmental stage using the number of embryos vs. CL (co-variable = stage of embryonic development) and embryo volume vs. embryonic development (co-variable = female weight), respectively (Hernáez & Wehrtmann 2011;da Silva et al 2016). Linear regressions were tested to observe the relationship between females (CL and female weight) and embryo features (embryo number and brood mass weight) (Anger & Moreira 1998;Terossi et al 2010).…”

Section: Discussionmentioning

confidence: 99%

“…Females and embryo mass were dried at 60 °C for 24 h and weighed using a Shimadzu® Aux 220 analytical balance (precision 0.0001 g) to calculate the RO, which is defined as the energy invested in reproduction (Hernáez & Wehrtmann 2011). RO was determined only in females carrying recently produced embryos (Stage I).…”

Section: Ro and Brood Mass Volumementioning

confidence: 99%

Fecundity and reproductive output of the caridean shrimp Periclimenes paivai associated with scyphozoan jellyfish

Moraes

Wolf

Gonçalves

et al. 2017

Periclimenes paivai is notable for its symbiotic lifestyle with jellyfish. The objective of this study was to investigate the fecundity and reproductive output of females, and specifically to determine whether females protected in their host have a greater reproductive success than other shrimp species. All anatomical parts of the medusae were analyzed and the P. paivai individuals were separated. Among 83 females analyzed, 65 presented embryos in the first developmental stage, and 18 were in the final stage of development. The mean fecundity was 229.08 ± 120.04 in initial-stage embryos and 191 ± 114.76 in final-stage embryos. We observed a positive relationship between the embryo number and the female size; however, the embryo number was not related to the embryonic stage, which indicates that females did not lose their embryos during the incubation period. The weight of brood mass during production is closely related to the female weight according to the results of linear regression, as fecundity increased with female size. In its symbiosis, P. paivai can increase the amount of energy used to produce embryos (mean reproductive output = 10.38%) and can elevate the reproductive success.

“…We used only females that contained embryos in stage 1 for fecundity and reproductive output analyses, because crustaceans tend to lose eggs during their incubation (Bueno & Shimizu 2008;Hernáez & Wehrtmann 2011).…”

Section: Reproductive Output and Fecunditymentioning

confidence: 99%

“…A covariance analysis (ANCOVA) was applied to the number of eggs vs. CL (using embryonic development stage as a co-variable), to estimate potential egg loss during the incubation period (Hernáez & Wehrtmann 2011).…”

Section: Reproductive Period and Functional Maturitymentioning

confidence: 99%

Reproduction, growth and longevity of the endemic South American crabAegla marginata(Decapoda: Anomura: Aeglidae)

Silva

Wolf

Castilho

2016

Reproduction, growth and longevity of Aegla marginata sampled with traps in Intervales State Park (Brazil) from October 2013 to December 2014 are described. Male and female carapace lengths (CL) ranged in size from 5.50 to 20.00 mm and 5.20 to 19.67 mm, respectively. Functional sexual maturity was determined at a CL of 9.28 mm. The main reproductive period occurred during colder seasons (autumn and winter, March-August). Egg number varied between 40 and 146 (mean ± SD; 95 ± 31.5), with an average reproductive output of 10.8% of the female weight, a value close to that found in other anomurans, enough to guarantee the success of this species during embryonic development. Fecundity increased with animal size (ANCOVA, p < 0.05), which allows an animal to produce more eggs, maximising reproductive efficiency, according to its size. Sex ratio was skewed towards males (Chi-Square, p < 0.05), especially during the reproductive period, in which females tended to exhibit cryptic behaviour when incubating eggs. The number of females and males was similar in the months before reproduction, suggesting that females were more active looking for food to store energy for the next reproductive period, and/or were looking for mates. The longevities of 2.43 (males) and 2.49 (females) years (Von Bertalanffy method) corroborate other studies that estimated a longevity of 2 to 3.3 years for Aegla spp. We conclude that A. marginata has seasonal reproduction and recruitment. All the information gathered here should be useful to future studies with other populations of A. marginata outside protected areas.