scholarly journals Importance of biogenic substrates for the stone crab Menippe nodifrons Stimpson, 1859 (Brachyura: Eriphioidea)

2017 ◽  
Vol 41 (3) ◽  
pp. 459-467
Author(s):  
Douglas Fernandes Rodrigues-Alves ◽  
Samara De Paiva Barros-Alves ◽  
Vivian Fransozo ◽  
Giovana Bertini ◽  
Valter José Cobo
Keyword(s):  
Sex Ratio ◽  
Intertidal Zone ◽  
Carapace Width ◽  
Growth Phases ◽  
Stone Crab ◽  
High Prevalence ◽  
Sargassum Cymosum ◽  
Zone Sampling ◽  
Juvenile Development ◽  
Substrate Types

In order to better understand the ecology of the different growth phases of the stone crab, Menippe nodifrons, and provide information for conservation of the natural stocks, this study describes the utilization of different biogenic substrates by this species in the intertidal zone. Sampling was carried out by hand at Ubatuba, State of São Paulo, Brazil. Crabs were captured among rocks or in association with three different biogenic substrates: Phragmatopoma lapidosa, Sargassum cymosum and Schizoporella unicornis. In the laboratory, the substrates were sorted and scanned for specimens of M. nodifrons, which were separated and measured at their maximum carapace width (CW), and classified as juvenile or adult specimens. Sex ratio and size distribution of crabs were analyzed for each of the substrate types. A total of 686 specimens of M. nodifrons were obtained during the sampling, ranging in size between 2.4 and 82.5 mm CW. Different mean sizes were recorded in the different substrates (P < 0.05). The high prevalence of juveniles in the samples suggests that these microhabitats are fundamental for the juvenile development of M. nodifrons, as they provide refuge, protection and probably food for juveniles.

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 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.

scholarly journals Rapid comeback of males: evolution of male-killer suppression in a green lacewing population

2018 ◽  
Vol 285 (1877) ◽  
pp. 20180369 ◽  
Author(s):  
Masayuki Hayashi ◽  
Masashi Nomura ◽  
Daisuke Kageyama
Keyword(s):  
Sex Ratio ◽  
Female Offspring ◽  
Mitochondrial Haplotype ◽  
Green Lacewing ◽  
Haplotype Variation ◽  
Male Killing ◽  
Significant Difference ◽  
High Prevalence ◽  
Laboratory Line ◽  
Male Killer

Evolutionary theory predicts that the spread of cytoplasmic sex ratio distorters leads to the evolution of host nuclear suppressors, although there are extremely few empirical observations of this phenomenon. Here, we demonstrate that a nuclear suppressor of a cytoplasmic male killer has spread rapidly in a population of the green lacewing Mallada desjardinsi . An M. desjardinsi population, which was strongly female-biased in 2011 because of a high prevalence of the male-killing Spiroplasma endosymbiont, had a sex ratio near parity in 2016, despite a consistent Spiroplasma prevalence. Most of the offspring derived from individuals collected in 2016 had 1 : 1 sex ratios in subsequent generations. Contrastingly, all-female or female-biased broods appeared frequently from crossings of these female offspring with males derived from a laboratory line founded by individuals collected in 2011. These results suggest near-fixation of a nuclear suppressor against male killing in 2016 and reject the notion that a non-male-killing Spiroplasma variant has spread in the population. Consistently, no significant difference was detected in mitochondrial haplotype variation between 2011 and 2016. These findings, and earlier findings in the butterfly Hypolimnas bolina in Samoa, suggest that these quick events of male recovery occur more commonly than is generally appreciated.

Infestation by Octolasmis species (Lepadiformes, Poecilasmatidae) of the marine crab Lupocycloporus gracilimanus (Decapoda, Portunidae) from India

Crustaceana ◽  
2021 ◽  
Vol 94 (11-12) ◽  
pp. 1293-1312
Author(s):  
Gyanaranjan Dash ◽  
Swatipriyanka Sen ◽  
Jose Josileen
Keyword(s):  
Sex Ratio ◽  
Carapace Width ◽  
Adaptive Strategy ◽  
Fertilization Success ◽  
Strong Positive Correlation ◽  
Nearest Neighbour ◽  
Mean Intensity ◽  
Spatial Preference ◽  
Portunid Crab ◽  
Dwarf Males

Abstract The portunid crab Lupocycloporus gracilimanus from Digha, Bay of Bengal, India was investigated for an infestation by the lepadomorph cirriped Octolasmis spp. About 93% of the epibionts examined were found attached to the surface of the carapace, abdomen and legs, and these were identified as Octolasmis warwicki (EOW). Only 7% of the epibionts were attached to the branchial lamellae, and these were identified as Octolasmis angulata (EOA). Twenty-seven O. warwicki were also found to have conspecific dwarf males (CDM) attached to the scutum: probably an adaptive strategy to maximize the total insemination. Both the epibionts and the CDM showed spatial preference for the posterior mesobranchial region of the carapace. Most of the CDM (27%) were seen as a single attachment on the epibiont. The distance between the epibiont and its nearest neighbour (DNN) was found to be strongly and negatively correlated (, ) with the number of epibionts, indicating its preference to stay in an intermediate-sized group rather than remain solitary, which probably would have facilitated the evolution of dwarf males (CDMs). A higher percentage of epibionts were observed to have attached CDMs when the DNN increased, and above the 25 mm DNN, all epibionts were having CDM attachments, which is believed to be a strategy to maximize the fertilization success of CDMs by reducing sperm competition. A strong, positive correlation (, ) was observed between the carapace width of the host crab and the numbers of the infesting epibionts, proving that the larger crabs are more susceptible to the infestation compared to the smaller ones. The sex ratio of the host crab was 1 : 5.5 (Male : Female), nevertheless, only the females were infested by the epibionts. The percentage of the prevalence, relative abundance and mean intensity of EOW infestation were recorded as 46.15%, 182.05% and 394.44%, respectively. None of the crabs had serious external or internal infestations that seemed to hinder the activities of the animal. This is the first report of the infestation of these Octolasmis species on the portunid crab Lupocycloporus gracilimanus from India.

Parasitization of juvenile edible crabs (Cancer pagurus) by the dinoflagellate, Hematodinium sp.: pathobiology, seasonality and its potential effects on commercial fisheries

Parasitology ◽  
2014 ◽  
Vol 142 (3) ◽  
pp. 428-438 ◽  
Author(s):  
AMANDA L. SMITH ◽  
LUCY HIRSCHLE ◽  
CLAIRE L. VOGAN ◽  
ANDREW F. ROWLEY
Keyword(s):  
Histological Examination ◽  
Carapace Width ◽  
Seasonal Trend ◽  
Commercial Fisheries ◽  
Cancer Pagurus ◽  
Large Numbers ◽  
High Prevalence

SUMMARYThis study reports on the prevalence and severity of infections caused by the parasitic dinoflagellate, Hematodinium in juvenile edible crabs (Cancer pagurus) found in 2 intertidal survey sites (Mumbles Head and Oxwich Bay) in the Bristol Channel, UK. Crabs were assessed for the presence and severity of Hematodinium infections by the histological examination of infected tissues. Such infections were found to exhibit a seasonal trend in the 2 study areas with high numbers of animals (ca. 30%) infected in the spring to summer but with low severity. Conversely, in November only ca. 10% of crabs were infected but these animals had large numbers of parasites in their haemolymph and other tissues. At this time, the carapace and underlying tissues of infected crabs had the chalky, pinkish-orange appearance that is characteristic of this disease. Hematodinium-infected crabs ranged in size from 12 to 74 mm carapace width. Overall, it is concluded that the high prevalence of infection of juvenile crabs in this area may have implications for the sustainability of the edible crab fishery in the Bristol Channel.

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.

scholarly journals Life Cycle Observations on Amphilocus neapolitanus (Della Valle, 1853) (Crustacea, Amphipoda) Associated with Sargassum cymosum C. Agardh, 1820 in Ubatuba, (SP), Brazil

2002 ◽  
Vol 45 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Fosca Pedini Pereira Leite
Keyword(s):  
Life Cycle ◽  
Sex Ratio ◽  
Reproductive Biology ◽  
Egg Number ◽  
Sargassum Cymosum ◽  
Males And Females

Day and night densities, reproductive biology and life cycle of Amphilocus neapolitanus (Della Valle, 1853), associated with Sargassum cymosum C. Agardh, 1820, were studied during 13 months. The density of juveniles, males and females was higher in night samples than in day samples. Sex ratio was strongly favorable toward the females. Ovigerous females were present in similar densities in both the periods while the non-ovigerous females were predominant at night. The egg number was not correlated with the size of the females. Breeding occurred throughout the year.

scholarly journals SIZE COMPOSITION AND FECUNDITY OF THE ROCK CRAB GRAPSUS GRAPSUS (LINNAEUS, 1758) IN THE ISLANDS OF NAVACHISTE BAY, SINALOA, MEXICO

2020 ◽  
Vol 67 (1) ◽  
Author(s):  
Yecenia Gutierrez Rubio ◽  
Juan Francisco Arzola Gonzalez ◽  
Jorge Saul Ramirez Perez ◽  
Guillermo Rodriguez Dominguez ◽  
Raul Perez Gonzalez ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Carapace Width ◽  
Size Composition ◽  
Significant Difference ◽  
Average Fecundity ◽  
Rock Crab ◽  
Gravid Females

The present study analysed the size composition and fecundity of Grapsus grapsus (Linnaeus, 1758) in the intertidal regions of Guasayeye, La Ventana and San Lucas islands in Navachiste Bay, Sinaloa, Mexico. Samples were collected from November 2017 to October 2018 with a bimonthly periodicity and sampling stations were established in each island. Crab samples were collected randomly at nocturnal low tide. Sex of the crabs was determined and carapace width (CW), length (L) and height (H) in mm, and their weight (W) in g were measured. Biometric correlations were performed. Fecundity was estimated in gravid females. The highest percentage of capture for females was 53.3% whereas for males was 46.7%; and the sex ratio was 1.15:1. The highest percentage was in San Lucas Island (41.4%) and the lowest in La Ventana (27.7%). Maximum CW (69.3 mm) and weight (137.5 g) were recorded in San Lucas. Island, while the lowest CW (9.3 mm) and weight (0.5 g) were recorded in Guasayeye Island. No significant difference in size (CW and W) were observed between sexes or between islands. The average fecundity for female was 9,245 eggs. A high biometric correlation was obtained (r2=0.98) between the morphometric variables and G. grapsus was found to have an isometric growth.

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).

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