70 resultados para Crab Lice


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of the present study was to determine the size at sexual maturity in the freshwater crab Dilocarcinus pagei Stimpson, 1861, from a population located in Mendonça, state of São Paulo, Brazil. The crabs were sampled monthly (July 2005 to June 2007), at Barra Mansa reservoir. The specimens were captured manually or in sieves passed through the aquatic vegetation. The crabs were captured and separated by sex based on morphology of the pleon and on the number of pleopods. The following dimensions were measured: carapace width (CW); carapace length (CL); propodus length (PL); and abdomen width (AW). The morphological analysis of the gonads was used to identify and categorize individuals according to their stage of development. The morphological maturity was estimated based on the analysis of relative growth based on the allometric equation y = ax b. The gonadal maturity was based on the morphology of the gonads by the method CW50 which indicates the size at which 50% of the individuals in the population showed gonads morphologically mature to reproduction. The biometric relationships that best demonstrated the different patterns of growth for the juvenile and adult stages were CW vs. PL for males and CW vs. AW for females (p<0.001). Based on these relationships, the estimated value to morphological sexual maturity was 21.5 mm (CW) in males and 19.7 mm (CW) in females. The determination of the size at sexual maturity and the adjustment of the data based on the logistic curve (CW50) resulted in a size of 38.2 mm for males and 39.4 mm for females (CW). Based on the data obtained for sexual maturity for D. pagei, we can estimate a minimum size for capture of 40 mm (CW). This minimum size allows at least half of the population to reproduce and retains the juveniles and a portion of the adults in the population.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ucides cordatus (Linnaeus, 1763) is a hypo-hyper-regulating mangrove crab possessing gills for respiratory and osmoregulatory processes, separated in anterior and posterior sections. They also have hepatopancreas, which is responsible for digestion and absorption of nutrients and detoxification of toxic metals. Each of these organs has specific cells that are important for in vitro studies in cell biology, ion and toxic metals transport. In order to study and characterize cells from gills and hepatopancreas, both were separated using a Sucrose Gradient (SG) from 10 to 40% and cells in each gradient were characterized using the vital mitochondrial dye DASPEI (2-(4-dimethylaminostyryl)-N- ethylpyridinium iodide) and Trichrome Mallory's stain. Both in 20 and 40% SG for gill cells and 30% SG for hepatopancreatic cells, a greater number of cells were colored with DASPEI, indicating a larger number of mitochondria in these cells. It is concluded that the gill cells present in 20% and 40% SG are Thin cells, responsible for respiratory processes and Ionocytes responsible for ion transport, respectively. For hepatopancreatic cells, the 30% SG is composed of Fibrillar cells that possess larger number of membrane ion and nutrient transporters. Moreover, the transport of toxic metal cadmium (Cd) by isolated hepatopancreatic cells was performed as a way of following cell physiological integrity after cell separation and to study differences in transport among the cells. All hepatopancreatic cells were able to transport Cd. These findings are the first step for further work on isolated cells of these important exchange epithelia of crabs, using a simple separation method and to further develop successful in vitro cell culture in crabs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A louse survey based on samples of cut hair collected from floors of barbershops and beauty parlors was conducted in Belo Horizonte, Minas Gerais State, Brazil, from October 1984 to April 1985, as an alternative way to determine the prevalence of pediculosis capitis in the population. Of 475 samples examined for nits, nymphs, or adults of Pediculus capitis, 140 were infested (29.5%). A total of 58 lice and 3.553 nits were found in 33.632.9 g of hair collected, giving a ratio of 0.10 nit/g. Almost 29% of the nits were viable and capable of being transmitted after hatching. There was significant difference among the infestation rates by socioeconomic levels, and samples from barbershops with male customers were the most infested. based upon the number of haircuts in each sample, we estimated that 5 or 6% of the population might be infested by this species.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study presents a list of 34 Anoplura type specimens deposited in the Werneck Collection of Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil. It includes 18 holotypes, 16 allotypes, 88 paratypes and 10 neotypes, distributed among the genera: Enderleinellus, Fahrenholzia, Haematopinus, Hoplopleura, Linognathus, Microthoracius, Pecaroecus, Polyplax and Pterophthirus. The types are related according to their respective data and literature.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

From November 1996 to March 2000, a total of 884 children between 0 and 15 years, from 11 institutions including day care centres, public urban and public rural schools in Uberlândia, State of Minas Gerais, central Brazil, were examined for head louse infestation. Children's sex, race, age and some hairs characteristics were shown to be associated to parasite infestation. A prevalence rate of 35% was found and the highest rates were observed in black, female children, with long, dark, wavy hairs. Hairs density and thickness did not seem to influence significantly the distribution of this pediculosis in Uberlândia's schoolchildren. Differences observed between the prevalence rates of head lice in children from the urban institutions suggest there is a greater epidemiological heterogeneity in this group when compared to the rural schoolchildren.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper presents a list of 131 Mallophaga type specimens deposited in the Werneck Collection of Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil. It includes 69 holotypes, 62 allotypes, 683 paratypes, 1 syntype and 2 neoparatypes, distributed among 6 families and 35 genera. The types are listed with their respective data and literature.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Although lethargic crab disease (LCD) is causing massive mortalities in populations of the mangrove crab Ucides cordatus of Northeastern Brazil, the identity of its etiological agent was hitherto unknown. In this study we provide robust evidence suggesting that LCD is caused by an anamorph Ascomycota (Fungi). We examined specimens of U. cordatus collected from stocks affected by LCD. Histological and TEM methods detected the presence of hyphae, conidia, and condiophores in several host tissues. Moreover, the abundance of fungal stages is negatively associated with crab health. Finally, DNA was isolated from the fungus and a region of its 18S ribosomal gene was sequenced. Phylogenetic analyses not only confirm the diagnosis of the LCD fungus in crab tissues as an ascomycete, but also suggest a close relationship with members of the subphylum Pezizomycotina.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The embryonic development of human lice was evaluated according to the changes in the morphology of the embryo observed through the transparent chorion. Based on ocular and appendage development, three stages of embryogenesis were established: early, medium, and late. Influence of temperature and relative humidity (RH) on the laboratory rearing of Pediculus humanus capitis eggs was assessed. The optimal ranges for temperature and RH were 27-31°C and 45-75%. The susceptibility of human louse eggs to insecticide spinosad (a macrocyclic lactone) was assessed by immersion method. The results showed similar susceptibility to spinosad in early, medium, and late stages of head lice eggs. In addition, this study showed similar susceptibility of head and body lice eggs to spinosad, an insecticide that has not been used as pediculicide in Argentina (lethal concentration 50: 0.01%).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pediculosis seems to have afflicted humans since the most ancient times and lice have been found in several ancient human remains. Examination of the head hair and pubic hair of the artificial mummy of Ferdinand II of Aragon (1467-1496), King of Naples, revealed a double infestation with two different species of lice, Pediculus capitis, the head louse, and Pthirus pubis, the pubic louse. The hair samples were also positive for the presence of mercury, probably applied as an anti-pediculosis therapy. This is the first time that these parasites have been found in the hair of a king, demonstrating that even members of the wealthy classes in the Renaissance were subject to louse infestation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this work was to compare the morphometry of hatchery-reared and wild-caught mangrove crab (Ucides cordatus) megalopae. Ten U. cordatus megalopae of each group (hatchery-reared and wild-caught) were individually analyzed using a stereoscopic microscope equipped with an ocular micrometer. Length, width, and height of all megalopae were measured, and the size of body appendices was determined. The results indicate that the hatchery-reared megalopae are more robust than the wild ones. Furthermore, some significant differences in the size of certain appendices can be cues of the kind of alterations that hatchery-reared individuals experience.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this study Ucides cordatus crab shells were utilized as Fe (II) sorbent as material of low cost and simple preparation. Values of pH of standard solution, biosorbent mass, particles size, contact time (t c) and initial concentration of the standard solution were optimized. The best conditions were pH = 2.00, t c = 840 min and Mc = 0.25 g. The kinetic pseudo first-order model displayed the best description of the adsorption process and the equilibrium study showed that the Langmuir model better describes the adsorption of the Fe (II). There is great affinity between the Fe (II) and the biosorbent.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Intersexuality is a reproductive pathology that has been described in wild animals in recent years. However, its occurrence and consequences remain obscure and therefore all aspects of this reproductive disorder deserve attention. The aim of this study is to report a case of intersexuality with probable absence of gonadal tissue in the crab-eating fox (Cerdocyon thous) native to Brazil. The animal has male external genitalia, but its prepuce and penis were both hypoplastic. Because of a clinical suspicion of bilateral cryptorchidism, a laparotomy was performed and the absence of prostate and gonads were revealed. The procedure also revealed vas deferentia, extending laterally from the each side of the bladder basis to the right and left abdominal wall muscles. The animal died one month later, and post mortem examination confirmed the absence of prostatic and gonadal tissues. Muscular structures similar to uterine horns and cervix were founded macroscopically and confirmed by optic microscopy. In addition, post mortem findings corroborate with penis hypoplasia, since penile bone presence was observed. The vasa deferentia had a normal tissue structure, although hypoplastic. In conclusion, the case of a crab-eating fox (Cerdocyon thous) reported here represents a proved intersexual animal with probable absence of gonadal tissue.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

One of the most limiting factors affecting the larval rearing of Ucides cordatus in the laboratory is a period of high mortality, which usually occurs late in the course of the larviculture during the metamorphosis from the zoeal to the megalopal phase. The objective of the present research was to analyze the post-embryonic development of U. cordatus on an individual basis and, in particular, to search for patterns linking disturbances in the molting process to the high larval death rates observed in massive larvicultures. A total of 50 larvae were individually reared from hatching to metamorphosis into the megalopal phase under controlled conditions, fed a combination of microalgae and rotifers. The survivorship rate was 70% until zoea V. The 35 surviving zoea V larvae followed two different pathways. Eleven underwent metamorphosis directly to megalopa, eighteen molted to zoea VI and six died as zoea V. In the last molting event, only two zoea VI larvae reached the megalopal stage, while the remaining sixteen died. In further observation under microscope, 13 of the dead zoea VI showed characteristics of the pre-molt stage and pereiopods disproportionably large in relation to the carapace. The observed pattern resembles the Molt Death Syndrome (MDS) described for other decapod species, in which larvae die in the late pre-molt phase of the molting cycle. We suggest that U. cordatus larvae develop disturbances in the molting process similar to the MDS described for other species and that these disturbances are related to a more complex pathway involving the emergence of larval stage zoea VI.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The importance of studies with hematological, serum biochemistry and urinary values of Crab-eating Fox (Cerdocyon thous) is based on the need for health care and maintenance of those populations. This paper has the objective to investigate hematological, serum biochemistry and urinary physiological parameters of the Crab-eating fox, comparing gender and age differences. Blood samples were collected in 2003 from 52 animals of different Zoos in São Paulo state, Brazil; 7mL of blood was used to obtain a complete blood cell count (CBC) and the profile of the serum biochemistry. Moreover, 5mL of urine were collected for analysis. There was no difference in values for male and female animals, as for the CBC and serum biochemistry. Some hematological and serum biochemical parameters were influenced by age, showing significant differences. Urinalysis results were just demonstrated in a descriptive form. The studied values were, RBC 4.35±0.73 x 10(6) /µL, WBC 7.72±3.66 x 10³ /µL (predominance of segmented neutrophils), platelets 227.06±111.58 x 10³ /µL, urea 43.06±14.28mg/dL and creatinine 1.03±0.24mg/dL. Hematological, serum biochemistry and urinary values obtained in this study can be used as physiological values of the captive Crab-eating Fox. It is possible to conclude that wild species need their own reference values, differentiating animals in captivity from free-ranging animals.