scholarly journals Size distribution and sex ratio between populations of the artisanal harvested land crab Cardisoma guanhumi (Decapoda: Gecarcinidae), with the estimation of relative growth and size at sexual maturity in Puerto Rico

2021 ◽  
Vol 69 (3) ◽  
Author(s):  
Jesús D. Quiñones-Llópiz ◽  
Concepción Rodríguez-Fourquet ◽  
Tomás Luppi ◽  
Nahuel E. Farias
Keyword(s):  
Puerto Rico ◽  
Sex Ratio ◽  
Sexual Maturity ◽  
Goodness Of Fit ◽  
Full Range ◽  
Carapace Width ◽  
Growth Patterns ◽  
Relative Growth ◽  
Land Crab ◽  
Cardisoma Guanhumi

Introduction: Knowledge of growth patterns, sex ratio, and sexual maturity are of importance to exploited populations. The land crab Cardisoma guanhumi is an artisanal and subsistence exploited species in Puerto Rico. However, the growth patterns and sexual maturity of the local populations are not known. Objectives: This study has a double objective: (1) to compare the size and sex structure between populations and (2) to model the relative growth of structures related to reproduction to estimate the average size of morphometric sexual maturity (MSM) for both males and females. Methods: A total of 2 849 specimens were captured from nine dispersed populations on the island between 2001 and 2020. Carapace width (CW) was measured as an estimator of the absolute size of all individuals, together with the propodus length (PL) in males and the abdomen width in females (AW). Differences in length structure between sexes and populations were tested by applying goodness-of-fit tests based on Kernel Density Estimators (KDE). The relative growth pattern was modeled adjusting a spline from which the maximum of its second derivative was calculated as an estimator of the MSM, and bootstrapping was used to generate confidence intervals. Results: Differences were found in size structures, between sexes, and between sites. Our estimates of morphometric sexual maturity resulted in a sexual maturity size for males between 57.9 and 79.0 mm CW, while in females, morphological maturity occurs between 43.8 to 51.5 mm CW. Conclusions: We found inter-population differences in body size that can be attributed to differences in the history of changes of land use and the exploitation biased towards larger individuals, though differences in recruitment should also be considered. Current regulations in Puerto Rico protect female crabs but not to larger male crabs. The regulation establishes that crabs smaller than 64 mm carapace width cannot be captured, leaving immature male crabs over 64 mm CW unprotected. We suggest considering different size limits depending on the sex of the crab. This will allow the full range of sizes where sexual maturity is reached to be protected, increasing the likelihood of the population’s size to increase.

Reproductive biology of the land crab Cardisoma guanhumi (Decapoda: Gecarcinidae) in north-eastern Brazil

2012 ◽  
Vol 93 (3) ◽  
pp. 761-768 ◽  
Author(s):  
Renata Akemi Shinozaki-Mendes ◽  
José Roberto Feitosa Silva ◽  
Jones Santander-Neto ◽  
Fábio Hissa Vieira Hazin
Keyword(s):  
Sexual Maturity ◽  
Histological Analysis ◽  
Carapace Width ◽  
Gonadal Maturation ◽  
Land Crab ◽  
Eastern Brazil ◽  
North Eastern ◽  
Cardisoma Guanhumi ◽  
Maturation Stages ◽  
First Maturity

The reproductive cycle of Cardisoma guanhumi was described from the analysis of seasonal variation of the gonadal maturation stages. The first maturity for both sexes was determined based on three different tests: inflexion point on the curve; relevant character (morphometry); and histological analysis (physiology). In addition, some aspects of sexual dimorphism for the population were studied. A total of 353 individuals caught in north-eastern Brazil between December 2006 and November 2007 were analysed. The sex-ratio was statistically equal (P ≥ 0.05) and the carapace width (CW) of the females ranged from 4.34 to 8.56 cm and of the males from 2.84 to 9.22 cm. Mature females with fully developed gonads begin to appear in the dry season (August) and ovigerous females occurred from November to February, suggesting that spawning occurs mainly during the rainy season. The CW of first sexual maturity for females ranged from 5.87 cm to 6.70 cm and males from 6.22 cm to 7.20 cm. The highest percentage of individuals caught were juveniles, indicating the need for a targeted effort to preserve the species.

scholarly journals Relative growth and sexual maturity of the stone crab Menippe nodifrons Stimpson, 1859 (Brachyura, Xanthoidea) in southeastern Brazil

2007 ◽  
Vol 50 (2) ◽  
pp. 259-267 ◽  
Author(s):  
Giovana Bertini ◽  
Adriane Araújo Braga ◽  
Adilson Fransozo ◽  
Michéle de Oliveira Dias Alves Corrêa ◽  
Fulvio Aurélio de Morais Freire
Keyword(s):  
Sexual Maturity ◽  
Carapace Width ◽  
Southeastern Brazil ◽  
Positive Allometry ◽  
Relative Growth ◽  
Stone Crab

The relative growth and size at onset of morphological sexual maturity of the stone crab Menippe nodifrons were investigated. A total of 399 crabs was captured on Praia Grande and Tenório beaches at Ubatuba. Carapace width (CW) and length, cheliped propodus length and height, abdomen width in females, and gonopod length in males were recorded. In females, the abdominal width showed negative allometry for juveniles and positive allometry for adults; the puberty molt occurred at 31.6 mm CW. In males, the size at onset of morphological sexual maturity was estimated as 29.7 mm CW; the gonopod growth showed positive allometry for juveniles, and an isometric relationship for adults. The gonopod length and the abdominal width were the most appropriate morphometric variables to estimate size at onset of sexual maturity in this stone crab.

Effects of land-use/land-cover changes on land crab,Cardisoma guanhumi, abundance in Puerto Rico

2008 ◽  
Vol 24 (4) ◽  
pp. 417-423 ◽  
Author(s):  
Yogani Govender ◽  
Alberto M. Sabat ◽  
Elvira Cuevas
Keyword(s):  
Land Use ◽  
Puerto Rico ◽  
Land Cover ◽  
Soil Temperature ◽  
Surface Soil ◽  
Negative Relationship ◽  
Land Use Land Cover ◽  
Land Crab ◽  
Cardisoma Guanhumi ◽  
Crab Abundance

AbstractThe land crabCardisoma guanhumipopulations have been on the decline in Puerto Rico for the last three decades. While some studies suggest overexploitation and pesticides as causing the observed population declines, the effect of land-use/land-cover (LULC) changes have not been investigated. In this study we compared the abundance and size ofCardisoma guanhumiin five different LULC types (mangroves, grasslands, forest, urban and industrial), and investigated the relationship between differences in physical microhabitat conditions among the LULC types with crab abundance and size. Although no significant differences in size were found among the different LULC types, crabs were significantly less abundant in grassland sites. Surface soil temperature, depth to groundwater and air temperature were found to vary significantly among the LULC types. Of these, only surface soil temperatures had a significant negative relationship with crab abundance. It appears that high variation in soil temperature and a high groundwater table observed in the grasslands is most detrimental to crabs. Interestingly, during the time when land crab populations declined there was corresponding change of LULC from agriculture to grasslands.Cardisoma guanhumiis resilient to changes in LULC, however, changes that alter their access to groundwater and escape from high soil temperature reduce their habitat.

scholarly journals Long-term monitoring of crab Cardisoma guanhumi (Decapoda: Gecarcinidae) captures in Jobos Bay Estuary, Puerto Rico

2019 ◽  
Vol 67 (4) ◽  
Author(s):  
Yogani Govender
Keyword(s):  
Puerto Rico ◽  
Temporal Dynamics ◽  
Carapace Width ◽  
Management Strategies ◽  
Blue Color ◽  
Anthropogenic Pressures ◽  
The West ◽  
Significant Difference ◽  
Cardisoma Guanhumi ◽  
The Impact

Abstract: The densities of the land crab Cardisoma guanhumi has been dropping for the past decades, as a result numerous management strategies, laws and regulations throughout the tropics have been developed to reduce population declines. The reasons for declines include: overfishing, habitat degradation and loss, and continued capture in Natural Protected Areas (NPA). In Puerto Rico, an admistrative order of 1999, regulates a closed season, prohibits the captures of crabs through the year from NPA and has a legal size for capture (64 mm). The goal of this research was to monitor spatial-temporal dynamics of captures for C. guanhumi after the implementation of the admistrative order. Crabs captured from thirty-one hunters in six communities surrounding the Jobos Bay Estuary (JBE) in south east Puerto Rico was studied over a period of 15 years, 2004 through 2018. The size (carapace width and length), sex and color were documented for 1531 crabs. There was significant difference in crab size through time and space. The smallest crabs with captured in the west of JBE and in the year 2004, while the largest crabs were captured in the west and in 2013. As expected smaller hunting areas had smaller crabs due to higher hunting pressure. Further, there was significant difference in crab color by size, smaller crabs were orange, intermediate size was brown and larger crabs were blue. Color of crab can therefore be used to determine legal limit. From 2009 to 2018 three percent of hunters captured crabs smaller than the legal-size limit. Although there was no significant relationship between climate (temperature, rainfall) and crab size, smaller crabs were captured in 2013-2016 during years of lower rainfall. Also, crab size increase from 2004 until 2013 coincided with mangrove recovery in the JBE. The laws and management strategies in Puerto Rico for the protection of crabs by size and prohibition in NPA, is not enough. Therefore, the impact of climate variability, sea level rise and anthropogenic pressures on crab habitat, therefore, warrants further investigation.

scholarly journals Reproductive biology of the orange mud crab Scylla olivacea (Herbst, 1796) from the Pichavaram mangroves of south-east India

2019 ◽  
Vol 66 (1) ◽  
Author(s):  
C. Viswanathan ◽  
M. Pravinkumar ◽  
T.V. Suresh ◽  
V. Elumalai ◽  
S.M. Raffi
Keyword(s):  
Sex Ratio ◽  
Size Distribution ◽  
Reproductive Biology ◽  
Sexual Maturity ◽  
Carapace Width ◽  
Distribution Analysis ◽  
Mud Crab ◽  
Indian Coast ◽  
Ratio Size ◽  
Commercially Important

The present study was conducted to assess the size distribution, sex ratio, size at first sexual maturity, fecundity and spawning season of the commercially important orange mud crab Scylla olivacea (Herbst, 1796) in Pichavaram mangroves in south-east India. This study is the first contribution to the knowledge of reproductive biology of S. olivacea from the Indian coast. Size distribution analysis in the fishery revealed the irrational exploitation of undersized S. olivacea. The estimated sex ratio deviated from equality, being 1:0.87, revealing a male domination. Size at first sexual maturity was determined to be 87 mm in carapace width (CW) in females. Fecundity ranged from 1.16 to 3.53 million in females of 76 to 135 mm CW. Breeding takes place year-round with a peak in pre-monsoon, indicating that it is a prolific breeder. Results revealed that immature individuals of S. olivacea contributed significantly to the catches and thus an effective management of the resource by framing minimum legal size is crucial so that the females are allowed to spawn at least once prior to capture.

Size at maturity of Liocarcinus depurator (Brachyura: Portunidae): a reproductive and morphometric study

1999 ◽  
Vol 79 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Rámon Muiño ◽  
Luis Fernández ◽  
Eduardo González-Gurriarán ◽  
Juan Freire ◽  
José A. Vilar
Keyword(s):  
Sexual Maturity ◽  
Carapace Width ◽  
Principal Component ◽  
Morphometric Study ◽  
Gonad Maturation ◽  
Body Parts ◽  
Size At Maturity ◽  
Two Phase ◽  
Morphometric Variation ◽  
Relative Growth

Sexual maturity in brachyurans is often associated with an allometric change in the relative growth of the animal. Maturity of Liocarcinus depurator was examined by analysing the monthly percentages of mature females (determined by the stage of gonad maturation and the presence of brood and sperm plugs) by size-class and the relative growth of different body parts: length and width of the carapace, length, height and width of the cheliped propodus; width of the abdominal segments in females and length of the first pleopod in males. Using the reproductive criteria the size at the onset of sexual maturity (carapace width at which 50% females are mature) in females of L. depurator is around 30–34 mm cephalothorax width. Principal component analysis (PCA) showed that the main source of morphometric variation for both sexes was due to heterochelia and allometric changes in growth. Morphometric variables were fitted using different regression techniques to one and two-phase growth models. The length of the first pleopod and the propodus of the right cheliped in males, and width of abdominal segments in females showed two clearly differentiated phases. Estimated maturity size (carapace width) corresponding to 50% mature animals was greater in males than in females. In males, size at the onset of maturity ranged between 31.4 and 35.7 mm, depending on the methods and variables used. The size at the onset of maturity in females ranged between 25.5 and 31.5 mm. In the Ría de Arousa, the size at maturity in females of L. depurator estimated using reproductive criteria is considerably greater than the size found based on morphometric criteria. The size at maturity based on morphometric criteria is greater in males than in females.

Population dynamics of Sesarma rectum (Crustacea: Brachyura: Grapsidae) in the Ariquindá River mangrove, north-east of Brazil

2011 ◽  
Vol 91 (7) ◽  
pp. 1395-1401 ◽  
Author(s):  
Daniela da Silva Castiglioni ◽  
Paloma Joana Albuquerque de Oliveira ◽  
Josivan Soares da Silva ◽  
Petrônio Alves Coelho
Keyword(s):  
Sex Ratio ◽  
Sexual Maturity ◽  
Carapace Width ◽  
Reproductive Activity ◽  
Reproductive Period ◽  
Size Class ◽  
Adult Males ◽  
North East ◽  
Class Frequency ◽  
Autumn And Winter

This study was carried out in order to provide basic information on the population ecology of the crab Sesarma rectum in the Ariquindá River mangrove, Tamandaré, State of Pernambuco, Brazil. The population was analysed with regard to the following aspects, in particular: the size-class frequency distribution of carapace width (CW), mean body size (CW) of males and females, morphological sexual maturity, sex-ratio, reproductive period, and recruitment. Samples were collected monthly from April 2008 through to March 2009; the crabs were collected manually, with a capture effort by one person for 30 minutes, during low tide. The specimens obtained were measured for CW, length of the propodus of males, and abdomen width of females; and the sex and ovigerous condition were noted. Altogether, we obtained 511 specimens (132 juvenile and 137 adult males, and 171 juvenile and 71 adult females, of which 32 were ovigerous). The median CW of males (16.15 mm) was significantly larger than that of females (13.82 mm) (P < 0.05). The size at morphological sexual maturity was 15.73 mm in males and 16.71 mm in females. The sex-ratio for the total of specimens analysed was 1.11:1 (male:female) (P > 0.05). The sex-ratio by size-class showed an anomalous pattern, with a greater abundance of males in the larger size-classes. The reproductive period was continuous and the highest frequency of ovigerous females was recorded in the spring and summer. The major pulse of recruitment occurred during autumn and winter, which is related to greater reproductive activity during the warmer months of the year.

scholarly journals Size at sexual maturity of female crabs Sesarma rectum Randall (Crustacea, Brachyura) and ontogenetic variations in the abdomen relative growth

2005 ◽  
Vol 22 (2) ◽  
pp. 433-437 ◽  
Author(s):  
Maria H. de A. Leme
Keyword(s):  
Sexual Maturity ◽  
Carapace Width ◽  
Analysis Of Covariance ◽  
Northern Coast ◽  
Growth Phases ◽  
Differential Growth ◽  
Relative Growth ◽  
Gonadal Maturity ◽  
Body Sizes ◽  
Size At Sexual Maturity

The aim of the present study was to ascertain the size at sexual maturity in females of the crab Sesarma rectum Randall, 1840 by comparing gonadal maturity to morphologic maturity (using abdomen-width data). The relative growth of the abdomen was analysed for all growth phases (for each 3-mm carapace width size class), and the slopes of the separate allometric relationships were compared through analysis of covariance (ANCOVA) from log e-transformed data to detect changes in the level of allometry during ontogeny. The physiological size at maturity (gonadal criteria) was determined through a logistic curve, indicating the size at which 50% of females presented mature gonads (M50 = 17.4 mm CW). The highest allometric levels occurred in growth phases 2 and 3 (body sizes ranging from 15 to 21 mm CW), indicating faster growth of the abdomen during those phases. Phases 1 (< 15 mm CW) and 4 and 5 (size classes above 21 mm CW) showed isometric growth. In the study area, a mangrove on the northern coast of the state of São Paulo, Brazil, individuals of S. rectum began to reach sexual maturity from 15 mm CW onward, when the slopes of the relationship of abdomen width to carapace width became positively allometric, indicating a differential growth rate. A gradual decrease in the slope, tending to isometry, occurred during ontogeny, as the animals became larger (older).

scholarly journals Morphological variability in populations of the fiddler crab Leptuca uruguayensis (Nobili, 1901) (Crustacea, Decapoda, Ocypodidae) from South America

2017 ◽  
Vol 65 (3) ◽  
pp. 373-381 ◽  
Author(s):  
Setuko Masunari ◽  
Salise Brandt Martins ◽  
Murilo Zanetti Marochi ◽  
Wilson Sebastián Serra ◽  
Fabrizio Scarabino
Keyword(s):  
Posterior Margin ◽  
Sexual Maturity ◽  
Growth Analysis ◽  
Fiddler Crab ◽  
Carapace Width ◽  
Morphological Variability ◽  
Centroid Size ◽  
Relative Growth ◽  
Abiotic Variables ◽  
Major Cheliped

Abstract A comparative study on size and shape of Leptuca uruguayensis was carried out between populations from Garças River, Brazil (BP), and Solís Grande River, Uruguay (UP). The size of the onset of sexual maturity was also estimated for UP. A total of 36 crabs BP and 387 crabs UP were analyzed. In the relative growth analysis, carapace width (CW) for both sexes, major cheliped length (LMC) for males and abdomen width (AW) for females were measured. The centroid size of carapace (1.40±0.19 cm BP and 1.88±0.30 cm UP) and cheliped (1.16±0.22 cm BP and 1.58±0.45 cm UP) differed significantly (p<0.001). The shape also differed significantly (p<0.001), having UP wider carapace than BP, rostrum projected forward and posterior margin positioned more anteriorly; the cheliped of UP was also wider than BP. In UP, males' CW ranged 4.28-19.5 mm and females' 2.53-16.3 mm CW; males' LMC ranged 1.79-31.60 mm and females' AW, 0.80-8.53 mm. The onset of sexual maturity of UP was estimated in 12.20 mm CW for males and 7.81 mm for females. These differences are likely related to abiotic variables acting distinctly in the two localities.

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