Some histopathological alteration of the infected blue crab Portunus pelagicus with parasites (original) (raw)
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Prevalence of Parasitic Infestation in the Blue Crab Portunus Pelagicus, Damietta, Egypt
Journal of the Egyptian Society of Parasitology, 2020
The present study focused on parasites that infected the blue crab Portunus pelagicus. This crab is a very popular sea food for the inhabitants of the costal sea of Egypt. Samples were seasonally collected from Mediterranean Sea, Ras El Bar, Damietta, Egypt. The present study exhibited that 2 parasitic species (protozoa and larval nematode) infested the crab. The infestation rate varied according to the infected tissue of the host, seasons and sexes. Gills were found to be higher infected ( %) than gonads. Seasonal variation in the parasitic infection showed that the highest prevalence was during winter (37%) and summer (35%). Sex of the host crab also affected the infestation with the parasites. Male crabs were found to be higher infected (78%) than females (22%). So, the current study provides a contribution to our knowledge of the parasites that infesting one of the most important economic sea foods.
2014
The purpose of this paper is to present information about external abnormalities found in edible crabs Portunus pelagicus (Linnaeus, 1758) and P. sanguinolentus (Herbst, 1783), which were collected during January 2004 to December 2005 from the coastal waters of Karachi. A total of 3,025 specimens were collected out of which 1,968 were P. pelagicus and 1,057 were P. sanguinolentus. Out of 1,968 P. pelagicus, only 14 crabs (or 0.71%) displayed abnormalities either in carapace, chelipeds, swimming leg, or abdomen. In case of P. sanguinolentus, only 3 specimens out of 1,057 (or 0.28 %) were found abnormal morphologically. These abnormalities were associated with carapace and abdomen only.
Emerging Diseases and Epizootics in Crabs Under Cultivation
Frontiers in Marine Science
While most crab production for human consumption worldwide comes from capture fisheries, there is increasing production of selected species using aquaculture-based methods. This is both for the purpose of stock replacement and direct yield for human consumption. Disease has limited the ability to produce larval crabs in commercial hatcheries and this together with suitable feeds, are major hurdles in the sustainable development of cultivation methods. Juvenile and adult crabs are also subject to a range of diseases that can cause severe economic loss. Emerging pathogens/parasites are of major importance to crab aquaculture as they can cause high levels of mortality and are difficult to control. Diseases caused by viruses and bacteria receive considerable attention but the dinoflagellate parasites,Hematodiniumspp., also warrant concern because of their wide host range and lack of control methods to limit their spread. This concise review examines the emerging diseases in several crab...
Journal of Invertebrate Pathology, 2015
The prevalence of disease in edible crabs (Cancer pagurus) was assessed at two sites in South West Wales; one estuarine (Pembroke Ferry) and another facing open water (Freshwater East). Diseases included pink crab disease caused by Hematodinium sp., an infection of the antennal gland caused by Paramikrocytos canceri and an idiopathic inflammatory condition of the connective tissue surrounding the anterior ganglionic masses. This latter condition was only found in crabs from Pembroke Ferry. There was a significantly higher prevalence of pink crab disease at Freshwater East than Pembroke Ferry, although both sites had similar levels of infection by P. canceri.
Diseases of Aquatic Organisms, 2007
Lethargic crab disease (LCD) has caused extensive epizootic mortality of the mangrove land crab Ucides cordatus (Linnaeus 1763) (Brachyura: Ocypodidae) along the Brazilian coast. Direct culture of tissue samples from sick crabs and subsequent isolation and purification identified the causative agent as an Exophiala species of fungus. The histopathology of crabs with variable signs of LCD indicates that the most affected tissues are the epidermis, connective tissue, heart, hepatopancreas, nervous system, and gills. Gonads, somatic muscles, and digestive system are less affected by the fungus. The observed pathology is compatible with the clinical signs of LCD. Necrosis, tissue degeneration, and congestion of hemal sinuses and vessels are present in heavily infected organs. Nerve fibers may be compressed by accumulations of yeast-like cells. In heavy infections the tissue of gill lamellae is destroyed with subsequent dilation or compression. Cellular immune responses include hemocytic infiltration, agglutination and encapsulation, and phagocytosis. Phagocytosis of yeast-like cells is abundant in the connective tissue associated with the exoskeleton. These results indicate that LCD is the result of a systemic phaeohyphomycosis caused by a species of Exophiala. The present study also suggests that dispersal of the fungus within the crab occurs through the hemal system.
Journal of Applied Sciences and Environmental Management, 2017
Callinectes pallidus is an economically important species of crab which inhabits both inshore and estuaries often susceptible to contamination from anthropogenic sources. The present study examined histopathology of the tissues of Callinectes pallidus from two coastal areas in Lagos, Nigeria, as a possible measure of degree of susceptibility to environmental stress.Tissues (hepatopancreas, gill, ovary, intestine and flesh) of samples of 30 crabs from each coastal site were processed for histological examination using standard method. The histopathological results in this study showed no structural alteration in gills, intestine and flesh in crabs from both sites, but there was a great structural degeneration and lesion in the hepatopancreas and ovaries of C. pallidus from Agbara (site 2). The environmental stressors identified in Agbara based on documented literatures includes Brewery effluents-that contains high carbohydrate, nitrogen and washing reagents; high concentration of heavy metals such as Cu, Zn and Fe and pharmaceutical effluents. The present study thereby revealed that hepatopancreas and ovaries of C.pallidus from Agbara (site 2) are more susceptible to these environmental stressors. Thus, it could be concluded that C.pallidus from site 2 are more susceptible to environmental stress than those from site 1.The present study also provide a fundamental information on the well being of C.pallidus from the two sites. Therefore, efforts should be intensified to avert future deleterious effect of the environmental stressors on the studied species in Agbara water body. ©JASEM
Journal of Parasitology, 2009
Leeches exhibit a marked scope of diversity, including different kinds of symbiosis. The aim of the present study was to demonstrate through biochemical and histological analysis that a species of piscicolid leech, Myzobdella platensis, is a true parasite of blue crabs, feeding on their hemolymph and using them as a site for cocoon deposition. In a total of 48 blue crabs collected on October 2007 at 3 sites of the São Vicente Estuary, 12 specimens were infested with leeches. Callinectes bocourti (n ϭ 7) was the most infested species with leeches and cocoons; it was chosen for biochemical and histological assays. The immunoblotting assays showed a positive reaction of the proteins in the intestinal samples of leeches collected from crabs using antihemocyanin polyclonal antibody of Ampullaria canaliculata. In addition, leech intestinal samples were recognized by antihemolymph polyclonal antibody of nonparasitized blue crabs. Histological sections of leech gut showed hemocytes and a granular matrix similar to those found in crab blood vessels. Collectively, this evidence strongly suggests a parasitic interaction between the leech M. platensis and the blue crab C. bocourti, in which the former utilizes the latter as a site for cocoon deposition and possibly for dispersal similar to that proposed for Myzobdella lugubris in Callinectes sapidus in North America.
Diseases of Aquatic Organisms, 1999
The prevalence and severity of shell disease in the edible crab Cancer pagurus (L.) was investigated in animals collected from Langland Bay, Gower, South Wales, UK, at monthly intervals from 1997 to 1998. Shell disease is the progressive degradation of exoskeletal chitin accompanied by melanisation of the affected region. Over 50% of the crabs sampled had 1 or more black-spot lesions. The proportion of exoskeleton affected increased with the size of the crab. Male crabs showed significantly higher levels of the disease than females, a higher prevalence of black-spot lesions (63% in males, 40% in females) and a higher mean percentage of body covered by lesions (1 % in males, 0.2% in females). This difference between the sexes corresponded to an increase in ventral surface and chela infection in males. For both sexes, the dorsal carapace was the area most affected by the disease. Dorsal carapace regional breakdown revealed the areas most commonly affected were located to the posterior of the crab. Lesion location patterns suggested that sand abrasion injuries during back-burrowing behaviour of C. pagurus lead to the formation of shell disease lesions. Seasonal trends in shell disease were seen to be dependent on the onshore migration patterns of the different size classes and sexes over the sampling period.
Journal of Invertebrate Pathology
Sacculina carcini is a common parasite of the European shore crab, Carcinus maenas. Following successful penetration of the host, numerous rootlets are formed that permeate through the hosts' tissues. Ultimately, these form an externa that houses the developing nauplii larvae of the parasite. Most studies have quantified levels of infection by counting the presence of reproductive externae and their breakdown structures, called scars. However, the diagnosis of the disease based only on external features may lead to underreporting the prevalence of the parasite. In the current study, we examined the presence and severity of S. carcini in C. maenas (n = 221) in the Prince of Wales Dock, South Wales, U.K. using a range of diagnostic approaches to give an accurate representation of temporal dynamics of infection. Parasitized crabs were found with a mean prevalence of 24% as determined by histological examination of the hepatopancreas. However, the prevalence of S. carcini based on the presence of externae and scars was only 6.3% and 1.8%, respectively. Overall, parasitism was associated with smaller crabs, crabs later in the moulting cycle that were orange in colour (as opposed to green or yellow), and those with a higher number of bacteria in the haemolymph. Interestingly, only 7.5% of infected crabs showed evidence of distinct host (cellular) response to the presence of rootlets in the hepatopancreas.
The blue crab Callinectes sapidus is an invasive alien species in the Mediterranean Sea. In native habitats, it suffers mortalities determined by different pathogens, including viruses, dinoflagellates, and bacteria. In invaded habitats, scant information is available on the occurrence of parasites in blue crabs, and no comparisons have been made with native brachyuran species. Here, a preliminary screening of the hemolymph of C. sapidus hemolymph as well as of three indigenous crabs (Eriphia verrucosa, Carcinus aestuarii and Pachygrapsus marmoratus), captured in the Acquatina Lagoon (Salento Peninsula, SE Italy), evidenced the presence of unidentified protozoans in more than 70% of the analyzed specimens, with a low number of suspected infections due to dinoflagellates of the genus Hematodinium. In C. sapidus, the occurrence of parasites was accompanied by a decrease of hemocyte functionality, interfering with the role of the cells in innate immunity (i.e. phagocytosis or DOPA production). More studies are necessary in order to verify the impact of this alien brachyuran on invaded ecosystems as mediated by the spread of its parasites and other pathogens.