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Blue crab diseases, parasites, and commensals are not well studied in the Gulf of Mexico, and their prevalence rates have only been sporadically determined. Commercial soft shell shedding facilities in Louisiana experience high mortality rates of pre-molt crabs, and some of these deaths may be attributable to diseases or parasites. During the active shedding season in 2013, we determined the prevalence of shell disease, Vibrio spp., Lagenophrys callinectes, and Hematodinium perezi at 4 commercial shedding facilities along the Louisiana coast. We also detected Ameson michaelis and reo-like virus infections. Shell disease was moderately prevalent at rates above 50% and varied by shedding facility, collection month, and crab size. Vibrio spp. bacteria were prevalent in the hemolymph of 37% of the pre-molt crabs. Lagenophrys callinectes was highly prevalent in the pre-molt crabs, but because it is a commensal species, it may not cause high mortality rates. Hematodinium perezi was absent in all pre-molt crabs. KEY WORDS: Shell disease · Vibrio · Lagenophrys · Reo-like virus · Callinectes sapidus · MoltingResale or republication not permitted without written consent of the publisher Dis Aquat Org 112: 207-217, 2015 lence of shell disease may be high at shedding facilities due to stress and crowding (Iversen & Beardsley 1976). Vibrio spp. (Vibrionales: Vibrionaceae) are the main chitinoclastic bacteria that cause shell disease (Shields & Overstreet 2007), and infections can cause morbidity and mortality of infected crabs (Bowser et al. 1981, Shields & Overstreet 2007. Vibrio spp. infections have been correlated with mortality rates of > 80% in North Carolina shedding facilities (Sizemore 1985).Both A. michaelis and RLV are hypothesized to cause mass mortalities in shedding facilities, possibly due to crowding and cannibalism, which facilitate transmission (Messick & Sindermann 1992, Bowers et al. 2010, 2011. A. michaelis causes muscle lysis in infected crabs (Messick & Sindermann 1992). Crabs infected with A. michaelis appear lethargic, and lysed muscle is chalky white (Messick & Sindermann 1992). RLV is an RNA virus that infects hemocytes, hemopoietic, and connective tissues, the nervous system, and gills (Shields & Overstreet 2007). Crabs infected with RLV develop tremors, are lethargic, and eventually become paralyzed (Johnson 1977, Shields & Overstreet 2007. RLV may be the predominant cause of crab deaths in shedding facilities from Delaware to Florida (Bowers et al. 2011).L. callinectes is an ectocommensalistic ciliate that is prevalent on pre-molt crab gills before it is shed during ecdysis. It is usually harmless to the infested crab. However, it can occasionally cause asphyxiation, especially when a crab is stressed by low dissolved oxygen or poor water quality (Couch & Martin 1982), both of which can occur at shedding facilities.A parasitic dinoflagellate that indirectly can harm the soft shell industry is Hematodinium perezi (Coccidiniales: Syndiniaceae). H. perezi causes morbidity and mortality ...

The purpose of this study was to investigate the presence of pathogenic bacteria, specifically Escherichia coli and Salmonella and Vibrio species, and their antimicrobial resistance in shrimp aquaculture facilities of Bagerhat (Bangladesh). Sediment samples were collected from both Penaeus monodon and Macrobrachium rosenbergii farms and shrimp samples from the Macrobrachium rosenbergii facility. The abovementioned bacteria were not found, but five Enterobacterales (Proteus penneri, Proteus alimentorum, Morganella morganii, Enterobacter hormaechei subsp. xiangfangensis and Plesiomonas shigelloides) were detected. This is the first documented case of Enterobacter hormaechei subsp. xiangfangensis in a shrimp farm. Nine antibiotics—ampicillin, gentamicin, chloramphenicol, oxytetracycline, nitrofurantoin, levofloxacin, ciprofloxacin, azithromycin, and co-trimoxazole—were selected for antibiotic resistance testing, and the majority (88.9%) had at least one isolate that was resistant. Across sources, 78.0% of isolates were resistant to at least one antimicrobial, and multidrug resistance was also detected in 29.3% of all isolates. Despite the low number of samples analyzed, nine in total, the results of this experiment emphasize that shrimp farms in Bagerhat may have a problem with antimicrobial-resistant bacteria. This could have negative impacts on shrimp quality and consumers’ health.