Anatomo-radiographic description of the axial skeleton of the crab-eating fox (Cerdocyon thous)

The aim of this study was to describe the axial skeleton of a wild Brazilian carnivorous, the crab-eating fox (Cerdocyon thous). Five specimens of crab-eating fox were previously unfrozen for radiographic exams and their bones went through dissection and chemical maceration. This animal presents seven cervical vertebrae, and from the third on, they become shorter and wider than the other ones e the spinous process was makeable from the fifth cervical vertebrae on. There are thirteen thoracic vertebrae and the spinous process of the lumbar vertebrae, which are seven, decreases from the fifth on. The sacrum is formed by two vertebrae and there are twenty or twenty one caudal vertebrae. It can be concluded that the crab-eating fox axial skeleton is similar to that of the domestic dog.

Mode B ultrasonography and abdominal Doppler in crab-eating-foxes ( Cerdocyon thous )

Abstract: Annually hundreds of crab-eating foxes (Cerdocyon thous) are referred to rehabilitation centers and zoos in Brazil. The ultrasonographic study of wildlife species is an important tool for a non-invasive and accurate anatomical description and provides important information for wildlife veterinary care. The aim of the present study was to determine the characteristics of the main abdominal organs as well as the vascular indexes of the abdominal aorta and renal arteries of crab-eating foxes (Cerdocyon thous) using mode B ultrasonography and Doppler ultrasonography, respectively. Ultrasonographic features of the main abdominal organs were described and slight differences were noticed between ultrasound imaging of abdominal organs of crab-eating foxes and other species. The bladder presented wall thickness of 12±0.01mm, with three defined layers. Both, the right and left kidneys presented corticomedullary ratio of 1:1 and similarly to the adrenals and the liver, they were homogeneous and hypoechoic compared to the spleen. The spleen was homogeneous and hyperechoic compared to the kidneys. The stomach presented 3 to 5 peristaltic movements per minute, wall thickness of 39±0.05mm and lumen and mucosa with hyperechoic and hypoechoic features, respectively. Small and large intestines presented 2 to 3 peristaltic movements per minute, wall thickness of 34±0.03mm and three defined layers with hyperechogenic (submucosa and serosa) and hypoechogenic (muscular) features. Ovaries of the female crab-eating fox were hypoechoic compared to the spleen and with heterogeneous parenchyma due to the presence of 2x2mm ovarian follicles. Prostates of the six males were regular and with a well defined boundary, with a homogeneous and hyperechoic parenchyma compared to the spleen. Vascular indexes of the abdominal aorta (PSV: 25.60±0.32cm/s; EDV: 6.96±1.68cm/s; PI: 1.15±0.07 e RI: 0.73±0.07) and right (PSV: 23.08±3.34cm/s; EDV: 9.33±2.36cm/s; PI: 1.01±0.65 e RI: 0.65±0.16) and left renal arteries (PSV: 23.74±3.94cm/s; EDV: 9.07±3.02cm/s; PI: 1.04±0.31 e RI: 0.64±0.10) were determined. Thus, conventional and Doppler ultrasonographic imaging provides basic information that can be used as reference for the species as well for other wild canids and it is a precise and non-invasive method that can be safely used to evaluate and diagnose abdominal injuries in these patients.

Fecal cortisol metabolites as indicators of stress in crab-eating-fox (Cerdocyoun thous) in captivity

Abstract: Blood samples collection is a common method in biological research using domestic animals. However, most blood sampling techniques are complicated and highly invasive and may therefore not be appropriate for wildlife animals in research concerning stress. Thus, a non-invasive method to measure steroid hormones is critically needed. The first goal of this study was to determine how glucocorticoids concentrations are impacted by translocation and reproductive activity in crab-eating-fox (Cerdocyoun thous) in captivity. The physiological relevance of fecal glucocorticoid metabolites was further validated by demonstrating: (1) The translocation of a male to a females enclosure resulted in a 3.5-fold increase compared to baseline concentrations, (2) changes in adrenocortical activity, as reflected in concentrations of fecal cortisol metabolites during reproduction, gestation and lactation in females foxes, indicating that social interactions resulted in large increases of fecal glucocorticoids metabolites during the reproductive season. From these findings we conclude that fecal samples can be used for the non-invasive assessment of adrenocortical status in crab-eating-fox.

Long-term habituation (LTH) in the crab Chasmagnathus: a model for behavioral and mechanistic studies of memory

A decade of studies on long-term habituation (LTH) in the crab Chasmagnathus is reviewed. Upon sudden presentation of a passing object overhead, the crab reacts with an escape response that habituates promptly and for at least five days. LTH proved to be an instance of associative memory and showed context, stimulus frequency and circadian phase specificity. A strong training protocol (STP) (³15 trials, intertrial interval (ITI) of 171 s) invariably yielded LTH, while a weak training protocol (WTP) (£10 trials, ITI = 171 s) invariably failed. STP was used with a presumably amnestic agent and WTP with a presumably hypermnestic agent. Remarkably, systemic administration of low doses was effective, which is likely to be due to the lack of an endothelial blood-brain barrier. LTH was blocked by inhibitors of protein and RNA synthesis, enhanced by protein kinase A (PKA) activators and reduced by PKA inhibitors, facilitated by angiotensin II and IV and disrupted by saralasin. The presence of angiotensins and related compounds in the crab brain was demonstrated. Diverse results suggest that LTH includes two components: an initial memory produced by spaced training and mainly expressed at an initial phase of testing, and a retraining memory produced by massed training and expressed at a later phase of testing (retraining). The initial memory would be associative, context specific and sensitive to cycloheximide, while the retraining memory would be nonassociative, context independent and insensitive to cycloheximide

Electron microscopy of glial cells of the central nervous system in the crab Ucides cordatus

Invertebrate glial cells show a variety of morphologies depending on species and location. They have been classified according to relatively general morphological or functional criteria and also to their location. The present study was carried out to characterize the organization of glial cells and their processes in the zona fasciculata and in the protocerebral tract of the crab Ucides cordatus. We performed routine and cytochemical procedures for electron microscopy analysis. Semithin sections were observed at the light microscope. The Thiéry procedure indicated the presence of carbohydrates, particularly glycogen, in tissue and in cells. To better visualize the axonal ensheathment at the ultrastructural level, we employed a method to enhance the unsaturated fatty acids present in membranes. Our results showed that there are at least two types of glial cells in these nervous structures, a light one and a dark one. Most of the dark cell processes have been mentioned in the literature as extracellular matrix, but since they presented an enveloping membrane, glycogen and mitochondria - intact and with different degrees of disruption - they were considered to be glial cells in the present study. We assume that they correspond to the perineurial cells on the basis of their location. The light cells must correspond to the periaxonal cells. Some characteristics of the axons such as their organization, ensheathment and subcellular structures are also described.

Binding sites and actions of Tx1, a neurotoxin from the venom of the spider Phoneutria nigriventer, in guinea pig ileum

Tx1, a neurotoxin isolated from the venom of the South American spider Phoneutria nigriventer, produces tail elevation, behavioral excitation and spastic paralysis of the hind limbs after intracerebroventricular injection in mice. Since Tx1 contracts isolated guinea pig ileum, we have investigated the effect of this toxin on acetylcholine release, as well as its binding to myenteric plexus-longitudinal muscle membranes from the guinea pig ileum. [125I]-Tx1 binds specifically and with high affinity (Kd = 0.36 ± 0.02 nM) to a single, non-interacting (nH = 1.1), low capacity (Bmax 1.1 pmol/mg protein) binding site. In competition experiments using several compounds (including ion channel ligands), only PhTx2 and PhTx3 competed with [125I]-Tx1 for specific binding sites (K0.5 apparent = 7.50 x 10-4 g/l and 1.85 x 10-5 g/l, respectively). PhTx2 and PhTx3, fractions from P. nigriventer venom, contain toxins acting on sodium and calcium channels, respectively. However, the neurotoxin PhTx2-6, one of the isoforms found in the PhTx2 pool, did not affect [125I]-Tx1 binding. Tx1 reduced the [3H]-ACh release evoked by the PhTx2 pool by 33%, but did not affect basal or KCl-induced [3H]-ACh release. Based on these results, as well as on the homology of Tx1 with toxins acting on calcium channels (w-Aga IA and IB) and its competition with [125I]-w-Cono GVIA in the central nervous system, we suggest that the target site for Tx1 may be calcium channels.

Acute and chronic effects of cadmium on blood homeostasis of an estuarine crab, Chasmagnathus granulata, and the modifying effect of salinity

Whole body oxygen consumption and some hemolymph parameters such as pH, partial pressure of gases, level of ions and lactate were measured in the estuarine crab Chasmagnathus granulata after both acute (96 h) and chronic (2 weeks) exposure to cadmium at concentrations ranging from 0.4 to 6.3 mg/l. In all instances, the crabs developed hemolymph acidosis, but no respiratory (increased PCO2) or lactate increases were evident. Hemolymph levels of sodium and calcium were always increased by cadmium exposure. The chronic toxicity of cadmium was enhanced at 12‰ salinity, even causing a significantly higher mortality in comparison with the higher salinity (30‰) used. A general metabolic arrest took place at 12‰ salinity in the crabs chronically exposed to cadmium, as indicated by decreases of oxygen consumption and PCO2, an increase of PO2, along with no changes in lactate levels. These imbalances were associated with severe necrosis and telangiectasia in the respiratory gills, probably leading to respiratory impairment and finally histotoxic hypoxia and death of the animals.

Extracellular matrix molecules as targets for brown spider venom toxins

Loxoscelism, the term used to describe lesions and clinical manifestations induced by brown spider's venom (Loxosceles genus), has attracted much attention over the last years. Brown spider bites have been reported to cause a local and acute inflammatory reaction that may evolve to dermonecrosis (a hallmark of envenomation) and hemorrhage at the bite site, besides systemic manifestations such as thrombocytopenia, disseminated intravascular coagulation, hemolysis, and renal failure. The molecular mechanisms by which Loxosceles venoms induce injury are currently under investigation. In this review, we focused on the latest reports describing the biological and physiopathological aspects of loxoscelism, with reference mainly to the proteases recently described as metalloproteases and serine proteases, as well as on the proteolytic effects triggered by L. intermedia venom upon extracellular matrix constituents such as fibronectin, fibrinogen, entactin and heparan sulfate proteoglycan, besides the disruptive activity of the venom on Engelbreth-Holm-Swarm basement membranes. Degradation of these extracellular matrix molecules and the observed disruption of basement membranes could be related to deleterious activities of the venom such as loss of vessel and glomerular integrity and spreading of the venom toxins to underlying tissues.

A clinico-epidemiological study of bites by spiders of the genus Phoneutria

From January, 1984 to December, 1996, 422 patients (ages 9 m-99 y, median 29 y) were admitted after being bitten by spiders which were brought and identified as Phoneutria spp. Most of the bites occurred at March and April months (29.2%), in the houses (54.5%), during the day (76.5%), and in the limbs (feet 40.9%, hands 34.3%). Upon hospital admission, most patients presented only local complaints, mainly pain (92.1%) and edema (33.1%) and were classified as presenting mild (89.8%), moderate (8.5%) and severe (0.5%) envenomation. Few patients (1.2%) did not present signs of envenomation. Severe accidents were only confirmed in two children (9 m, 3 y). Both developed acute pulmonary edema, and the older died 9 h after the accident. Patients more than 70 year-old had a significantly greater (p<0.05) frequency of moderate envenomations compared to the 10-70-year-old individuals. Proceedings to relief local pain were frequently performed (local anesthesia alone 32.0%, local anesthesia plus analgesics 20.6% and oral analgesics alone 25.1%). Only 2.3% of the patients (two cases classified as severe and eight as moderate, eight of them in children) were treated with i.v. antiarachnid antivenom. No antivenom early reaction was observed. In conclusion, accidents involving the genus Phoneutria are common in the region of Campinas, with the highest risk groups being children under 10 years of age and adults over 70 years of age. Cases of serious envenomation are rare (0.5%).

Paragonimosis in the Cajabamba and Condebamba districts, Cajamarca, Peru

Stool samples from 409 pre-school and school students, living in six villages of the Cajabamba and Condebamba districts, Cajamarca, Perú, were examined using wet preparations and Lumbreras' method, looking for Paragonimus eggs. Fecal and sputum samples from two children (0.5%) of 6 and 8 year-old showed eggs of Paragonimus. One hundred and twenty freshwater crabs, Hypolobocera chilensis eigenmanni, were collected from the Condebamba valley and 21 (17.5%) of them were infected with P. mexicanus (syn. P. peruvianus) metacercariae. Our results show the persistence of Paragonimus in human beings and in the main source of infection, the crabs.

Clinical and epidemiological features of definitive and presumed loxoscelism in São Paulo, Brazil

A retrospective study analysed 359 proven or presume cases of loxoscelism seen at the Hospital Vital Brazil, Instituto Butantan, São Paulo, Brazil, between 1985 and 1996. The spider was identified in 14%. The bites occurred predominantly in the urban areas (73%) between September and February. Patients > 14 years were commonest inflicted (92%) and 41% were bitten while getting dressed. Only 11% sought medical care within the first 12 hours post bite. Cutaneous loxoscelism was the commonest form presenting (96%); commonest manifestations were: pain (76%), erythema (72%), edema with enduration (66%), ecchymosis (39%). Skin necrosis occurred in 53% of patients, most frequently seen on trunk, tigh and upper arm, and when patients seek medical care more than 72 hours after bite. Local infection was detected in 12 patients (3%). Hemolysis was confirmed in 4 cases (1.1%). Generalised cutaneous rash, fever and headache were also observed in 48% of the total of patients. None of them had acute renal failure or died. Treatment usually involved antivenom administration (66%), being associated with corticosteroids (47%) or dapsone (30%). Presumptive diagnosis of loxoscelism may be established based on clinical and epidemiological findings. Further investigations are required to prove the value of antivenom and other treatment schedules.

Vibrio spp. and Salmonella spp., presence and susceptibility in crabs Ucides cordatus

The presence of Vibrio spp. and Salmonella spp. in crabs marketed at the Bezerra de Menezes Ave., Fortaleza, State of Ceará, Brazil, was assessed between February and May, 2003. The number of individuals sampled in each one of the fifteen weekly samplings ranged between four and eight. Seven strains of Salmonella, from four different samplings, were identified, being five of them identified as serotype S. Senftenberg and two as S. Poona. All strains of Salmonella were sensitive to the tested anti-microbial drugs, with the exception of tetracycline and nalidixic acid, for which an intermediary sensibility was found. The MPN's for Vibrio ranged between 110/g and 110,000/g. Of the forty five Vibrio strains isolated from the crab samples, only 10 were identified up to the species level: two V. alginolyticus and eight V. parahaemolyticus. Bacteria belonging to the Enterobacteriaceae and Pseudomonaceae families were also identified, namely Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pantoea agglomerans and Pseudomonas aeruginosa. The proper cooking of the animals is recommended in order to avoid problems for the consumers of this crustacean.

First record on Loxosceles laeta (Nicolet, 1849) (Araneae, Sicariidae) in the West Zone of São Paulo City, São Paulo, Brazil, and considerations regarding its geographic distribution

Loxosceles laeta spiders were captured in the West zone of São Paulo City, this being the first record of the specie in this area. Since loxoscelism is an important public health problem in the South region of Brazil, it is necessary to investigate the presence of this spider in São Paulo City.

New records of Fredius denticulatus (H. Milne-Edwards, 1853) and F. reflexifrons (Ortmann, 1897), and the eastern limits of the distribution of pseudothelphusid crabs (Crustacea: Decapoda) in Brazil

The occurence of Fredius reflexifrons (Ortmann, 1897), a pseudothelphusid crab widely distributed in the Amazon region and the Atlantic Guianas, is recorded from the state of Ceará, northeastern Brazil. Other records of this species and Fredius denticulatus (H. Milne-Edwards, 1853) from the Amazon region are also presented. A discussion is made on the eastern limits of the distribution of the family Pseudothelphusidae in Brazil.

Decapod crustaceans used as food by the Yanomami Indians of the Balawa-ú village, State of Amazonas, Brazil

The Yanomami are a group of South American Indians that live in the rainforest along the borderlands of Brazil and Venezuela. They depend on hunting, gardening and wild food for survival; crustaceans are a highly prized food item in their diet. Taxonomical and ethnozoological aspects of the Yanomami Indians of the Balawa-ú village, state of Amazonas, Brazil, related to the crustaceans are described. Information and specimens were obtained from August to December, 2003. Interviews were conducted with residents of the village and focused on questions about species exploited, indigenous names, modes of capture and use of the species. One shrimp species of the family Palaemonidae (Macrobrachium brasiliense) and two crab species of Trichodactylidae (Sylviocarcinus pictus, Valdivia serrata) as well as two of Pseudothelphusidae (Fredius fittkaui, F. platyacanthus) were recorded. The indigenous names applied to these species are: shuhu, for shrimp, oko and peimatherimi for each of the two pseudothelphusid crabs, and hesiki tôtôrema for both trichodactylid crabs.