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.

Reproductive biology of Hepatus pudibundus (Crustacea: Brachyura), the most abundant crab on the southeastern Brazilian coast

Biologia ◽  
2014 ◽  
Vol 69 (2) ◽  
Author(s):  
Paloma Aparecida de Lima ◽  
Giovana Bertini ◽  
Vivian Fransozo ◽  
Rafael Gregati ◽  
Lissandra Corrêa Fernandes-Góes ◽  
...  
Keyword(s):  
Bottom Water ◽  
Carapace Width ◽  
Sampling Period ◽  
Reproductive Activity ◽  
Gonadal Development ◽  
Reproductive Period ◽  
Brazilian Coast ◽  
Northern Coast ◽  
Adult Males ◽  
Bottom Water Temperature

AbstractThis study analyzed the size at sexual maturity and reproductive period of populations of Hepatus pudibundus in three bays on the northern coast of São Paulo, Brazil. Crabs were collected monthly and the bottom-water temperature was measured at each collection point. The animals were sexed, measured for carapace width (CW), and their gonadal stages were determined. A total of 8,674 specimens were collected (2,435 males and 6,239 females). Adult males showed the highest mean CW; the size at maturity for both sexes was 32.5 mm CW. Reproduction was continuous and peaked in spring and summer, because of the greater availability of plankton food for the larvae. This pattern is typical in tropical and subtropical regions, unlike the seasonal reproduction found in temperate regions. Reproductive activity of females was not significantly correlated with bottom-water temperatures. Immatures and individuals in all stages of gonadal development were found throughout the sampling period and at all depths, probably because the species completes its entire reproductive cycle in that area.

scholarly journals Population biology of the crab Armases angustipes (Crustacea, Decapoda, Sesarmidae) at Brazilian tropical coast

2014 ◽  
Vol 104 (2) ◽  
pp. 150-161 ◽  
Author(s):  
Marina de Sá Leitão C. de Araújo ◽  
Deusinete de O. Tenório ◽  
Daniela da S. Castiglioni
Keyword(s):  
Population Structure ◽  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Population Biology ◽  
Carapace Width ◽  
Reproductive Activity ◽  
Coastal Regions ◽  
Phytoplankton Productivity ◽  
Number Of Individuals ◽  
Tropical Coast

The semi terrestrial crabs are important elements of the fauna of coastal regions. The aim of this study was to analyze the population structure of Armases angustipes (Dana, 1852) at estuaries of the Ariquindá River, considered a non impacted area, and Mamucabas River, considered a few impacted area, on the south coast of state of Pernambuco, Brazil. The species occurred in all months of the year. The number of individuals per month varied, being higher in the months of transition between the seasons. This is probably due to significant seasonal variations of air and burrow temperature and burrow salinity. There was no sexual dimorphism in size of A. angustipes in the mangrove of Ariquindá River, but males were larger than females in the mangrove of Mamucabas River. In both estuaries, the sex ratio did not differ from Mendelian proportion, but showed a deviation for females. The analysis of temporal variation in sex ratio showed significant differences in some months of the year. These variations are due to cyclical events that act distinctly on each sex. In both estuaries, size classes of carapace width were equally represented by both sexes. The ovigerous females of A. angustipes occurred only in some months of the year, especially in summer, in both estuaries. Probably the high phytoplankton productivity observed in summer favors the reproductive activity, since these algae serve as food for the larvae. Specimens of the population of Rio Ariquindá are largest and wider than those of Mamucabas River. This fact, associated with the low abundance of crabs and the lower frequency of ovigerous females observed in Mamucabas River, is an indication that this population may be influenced by the environmental impacts that this estuary has received.

scholarly journals Population structure and reproductive biology of Cichla kelberi (Perciformes, Cichlidae) in Lobo Reservoir, Brazil

2008 ◽  
Vol 6 (2) ◽  
pp. 201-210 ◽  
Author(s):  
Jussara E. de Souza ◽  
Evelise N. Fragoso-Moura ◽  
Nelsy Fenerich-Verani ◽  
Odete Rocha ◽  
José R. Verani
Keyword(s):  
Sex Ratio ◽  
Condition Factor ◽  
Reproductive Activity ◽  
Reproductive Period ◽  
High Fecundity ◽  
Long Period ◽  
Total Length ◽  
Relative Condition Factor ◽  
Central Value ◽  
Large Output

The structure of Cichla kelberi population was characterized regarding the sex ratio, total length composition and some reproductive characteristics. The specimens were collected in two periods, from November 2002 to November 2003 and from December 2004 to May 2006. The sex ratio was significantly different than 1:1. The total length varied from 3.4 to 40.1 cm, with individuals in the shortest length classes occurring throughout the year, but with greater incidence in the warmer periods. Females and males reached similar lengths and there was no difference between the sexes regarding the length-weight relationship. The estimated values of condition factor were near the central value of 1.0 and decreased during the cooler months, coinciding with periods of lower reproductive activity. Individuals with mature or semi-spent gonads occurred from November to April, indicating that Cichla kelberi reproduces for a long period of time. The spawning is partitioned, with an average absolute fecundity of 6072 oocytes (from 5220 to 6908 oocytes). The high relative condition factor values, long reproductive period, large output of fingerlings and high fecundity are biological conditions that indicate the species is well adapted in this reservoir.

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.

Interannual variability of sperm reserves and fecundity of primiparous females of the snow crab (Chionoecetes opilio) in relation to sex ratio

2002 ◽  
Vol 59 (12) ◽  
pp. 1932-1940 ◽  
Author(s):  
Bernard Sainte-Marie ◽  
Jean-Marie Sévigny ◽  
Mireille Carpentier
Keyword(s):  
Sex Ratio ◽  
Carapace Width ◽  
Weight Percent ◽  
Snow Crab ◽  
Adult Males ◽  
Reproductive Condition ◽  
Embryo Production ◽  
Potential Fecundity ◽  
Chionoecetes Opilio ◽  
Female Promiscuity

Demographics of adults and reproductive condition of primiparous (first brood) females of the snow crab (Chionoecetes opilio) were monitored annually from 1994 to 2002 at a fished site to investigate the possibility that sperm supply limits embryo production. Abundance of primipara fluctuated 533-fold because of a recruitment pulse, and this caused a large oscillation in the sex ratio of adult males to primipara. Annual mean of stored ejaculate weight (SL) and potential fecundity index (PF, clutch weight × percent fertilized eggs) adjusted to constant primipara carapace width ranged from 31 to 130 mg by spermatheca and from 1.97 to 3.43 g by clutch, respectively. Annual mean of SL and number of stored sperm (range 3.81 × 106 to 35.00 × 106 sperm by spermatheca) decreased when sex ratio decreased, probably because of a combined reduction of sperm allocation and female promiscuity. Annual mean PF was negatively correlated with abundance of small males, which may reflect egg losses during postoviposition matings. Although sociosexual context has a large impact on reproductive condition of primipara, the possibility that sperm supply limits embryo production could not be confirmed or excluded because of the complexity of snow crab mating behavior.

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.

scholarly journals Disruption of deiodinase type 2 in zebrafish disturbs male and female reproduction

2019 ◽  
Vol 241 (2) ◽  
pp. 111-123 ◽  
Author(s):  
Anne M Houbrechts ◽  
Jolien Van houcke ◽  
Veerle M Darras
Keyword(s):  
Sexual Maturity ◽  
Reproductive Function ◽  
Reproductive Activity ◽  
Reproductive Period ◽  
Biologically Active ◽  
Sex Steroid ◽  
Female Reproduction ◽  
Steroid Production ◽  
Offspring Production

Thyroid hormones are crucial mediators of many aspects of vertebrate life, including reproduction. The key player is the biologically active 3,5,3’-triiodothyronine (T3), whose local bio-availability is strictly regulated by deiodinase enzymes. Deiodinase type 2 (Dio2) is present in many tissues and is the main enzyme for local T3 production. To unravel its role in different physiological processes, we generated a mutant zebrafish line, completely lacking Dio2 activity. Here we focus on the reproductive phenotype studied at the level of offspring production, gametogenesis, functioning of the hypothalamic–pituitary–gonadal axis and sex steroid production. Homozygous Dio2-deficient zebrafish were hypothyroid, displayed a delay in sexual maturity and the duration of their reproductive period was substantially shortened. Fecundity and fertilization were also severely reduced. Gamete counts pointed to a delay in oogenesis at onset of sexual maturity and later on to an accumulation of oocytes in mutant ovaries due to inhibition of ovulation. Analysis of spermatogenesis showed a strongly decreased number of spermatogonia A at onset of sexual maturity. Investigation of the hypothalamic–pituitary–gonadal axis revealed that dysregulation was largely confined to the gonads with significant upregulation of igf3, and a strong decrease in sex steroid production concomitant with alterations in gene expression in steroidogenesis/steroid signaling pathways. Rescue of the phenotype by T3 supplementation starting at 4 weeks resulted in normalization of reproductive activity in both sexes. The combined results show that reproductive function in mutants is severely hampered in both sexes, thereby linking the loss of Dio2 activity and the resulting hypothyroidism to reproductive dysfunction.

scholarly journals Reproductive biology aspects of Alopias pelagicus and A. superciliosus (Lamniformes: Alopiidae) in the Ecuadorian Pacific

2021 ◽  
Vol 19 (4) ◽  
Author(s):  
Jesús Briones-Mendoza ◽  
Pol Carrasco-Puig ◽  
Daniel Toala-Franco
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Sexual Maturity ◽  
Inflection Point ◽  
Maximum Size ◽  
Size Class ◽  
Shark Species ◽  
Thresher Shark

ABSTRACT The reproductive biology of thresher shark species of the Ecuadorian Pacific was analysed based on 1236 specimens of Alopias pelagicus (711 females and 525 males) and 354 of A. superciliosus (164 females and 190 males) landed in “Playita Mía”, from January to December of 2019. The length of A. pelagicus females ranged between 67.2 and 184 cm PCL (precaudal length) and the males between 69.0 and 178.4 cm PCL, A. superciliosus registered a minimum and maximum size of 76.0 and 202.2 cm PCL for females and 94.0 and 204.8 cm PCL for males. The most frequently captured size class for A. pelagicus was 147.2−157.2 cm PCL and for A. superciliosus was 156.0-166.0 cm PCL. The sex ratio (F:M) for A. pelagicus and A. superciliosus was 1.35F:1M and 0.86F:1M respectively. For A. pelagicus males the inflection point of the clasper length adjustment, was 134.2 cm PCL and size at first sexual maturity (L 50 ) was estimated at 136.0 cm PCL. For A. superciliosus males the inflection point of the clasper length adjustment, was 136.8 cm PCL, and the first sexual maturity (L 50 ) was estimated at 138.7 cm PCL.

scholarly journals Population biology of Uca mordax (Smith, 1870) (Crustacea, Decapoda, Ocypodidae) from the southeastern coast of Brazil

2009 ◽  
Vol 31 (73/75) ◽  
Author(s):  
Vivian Fransozo ◽  
Rafael Campanelli Mortari ◽  
Aline Staskowian Benetti
Keyword(s):  
Sex Ratio ◽  
Population Biology ◽  
Sexual Maturity ◽  
Fiddler Crab ◽  
Carapace Width ◽  
Southeastern Coast ◽  
Size Classes ◽  
Median Size ◽  
Size At Sexual Maturity ◽  
Males And Females

The population biology of the fiddler crab Uca mordax (Smith, 1870) was investigated in an estuarinemangrove from the southeastern coast of Brazil. Samplings were monthly performed by 2 collectors for30 min. using the technique of capture per unit effort during low tide periods. The allometric techniquewas used to determine crab size at sexual maturity (males and females). Thus, specimens were classified into juveniles and adults according to their size at sexual maturity for each sex. The specimens weredistributed into size classes. Recruitment was based on the juvenile frequency and the reproduction peakin ovigerous females. The median size of males was 15.9 ± 2.7 mm carapace width (CW) (n = 557) andthat of females, 14.6 ± 2.8 mm CW (n = 528). At sexual maturity, size of crabs was 11.9 mm CW formales and 11.5 mm CW for females. Juveniles were found throughout the year but more frequently inthe winter and autumn. Sex ratio did not differ among seasons, except during the summer (p < 0.05).As regards sex ratio per size class, females predominated in the fi rst size classes. Reproduction peakwas observed in the summer. In short, the population biology of U. mordax was similar to that of mostbroad-front fi ddler crab species.

Ontogenetic and sexual variation in the coloration of the lacertid lizards Iberolacerta monticola and Podarcis bocagei. Do the females prefer the greener males?

2008 ◽  
Vol 58 (2) ◽  
pp. 173-198 ◽  
Author(s):  
Pedro Galán
Keyword(s):  
Field Study ◽  
Sexual Maturity ◽  
Reproductive Period ◽  
Adult Males ◽  
Nw Spain ◽  
Sexual Variation ◽  
Lacertid Lizards ◽  
Deep Green ◽  
Podarcis Bocagei

AbstractChanges in the coloration of the lacertid lizards Iberolacerta monticola and Podarcis bocagei with age in populations from NW Spain are described. The onset of sexual maturity in P. bocagei males involves a change in the ventral (yellow) and dorsal (green) colorations, which is different from immature males (dorsally brownish in color). In I. monticola males, the ventral coloration also changes to a deep green when they reach maturity, while the dorsal coloration remains brownish as in the immature specimens. In this species, the green dorsal coloration is acquired gradually after maturity. Only the oldest individuals have a predominantly green dorsal coloration. The differences between the two species in the time males take to acquire the green dorsal coloration could be related to their different longevity. The coloring is acquired gradually in the most long-lived species (I. monticola). A field study was carried out on the behaviour of adult males of I. monticola during the reproductive period. The males with green dorsal coloration were seen to pair with females significantly more frequently than those with the brownish dorsal color. The increase in the green dorsal coloration (conspicuous) with the size and age of the males of this species would appear to have a clear function as an intersexual or intrasexual signal.

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